From a7aacf4994895551649de799fb7d45241219083e Mon Sep 17 00:00:00 2001
From: SamulKyull <SamulKyull@SamulKyull.xyz>
Date: Mon, 15 Apr 2024 23:26:06 +0800
Subject: [PATCH] add fbtft module for spi display

---
 bsp/Kconfig                     |    3 +
 bsp/Makefile                    |    3 +-
 bsp/drivers/Makefile            |    1 -
 bsp/modules/Kconfig             |    4 +
 bsp/modules/Makefile            |    4 +
 bsp/modules/fbtft/Kconfig       |   21 +
 bsp/modules/fbtft/Makefile      |    7 +
 bsp/modules/fbtft/README        |   32 +
 bsp/modules/fbtft/TODO          |    3 +
 bsp/modules/fbtft/fb_st7789v.c  |  336 ++++++++
 bsp/modules/fbtft/fbtft-bus.c   |  243 ++++++
 bsp/modules/fbtft/fbtft-core.c  | 1361 +++++++++++++++++++++++++++++++
 bsp/modules/fbtft/fbtft-io.c    |  236 ++++++
 bsp/modules/fbtft/fbtft-sysfs.c |  220 +++++
 bsp/modules/fbtft/fbtft.h       |  423 ++++++++++
 bsp/modules/fbtft/internal.h    |   13 +
 16 files changed, 2908 insertions(+), 2 deletions(-)
 create mode 100644 bsp/modules/Kconfig
 create mode 100644 bsp/modules/Makefile
 create mode 100644 bsp/modules/fbtft/Kconfig
 create mode 100644 bsp/modules/fbtft/Makefile
 create mode 100644 bsp/modules/fbtft/README
 create mode 100644 bsp/modules/fbtft/TODO
 create mode 100644 bsp/modules/fbtft/fb_st7789v.c
 create mode 100644 bsp/modules/fbtft/fbtft-bus.c
 create mode 100644 bsp/modules/fbtft/fbtft-core.c
 create mode 100644 bsp/modules/fbtft/fbtft-io.c
 create mode 100644 bsp/modules/fbtft/fbtft-sysfs.c
 create mode 100644 bsp/modules/fbtft/fbtft.h
 create mode 100644 bsp/modules/fbtft/internal.h

diff --git a/bsp/Kconfig b/bsp/Kconfig
index 2facbe3af9..2b9635973d 100644
--- a/bsp/Kconfig
+++ b/bsp/Kconfig
@@ -6,4 +6,7 @@ source "bsp/platform/Kconfig"
 source "bsp/platform/Kconfig.debug"
 source "bsp/drivers/Kconfig"
 
+# Avaota SBC Modules
+source "bsp/modules/Kconfig"
+
 endmenu
diff --git a/bsp/Makefile b/bsp/Makefile
index 1b9abd0048..f0d2169c43 100644
--- a/bsp/Makefile
+++ b/bsp/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 
-obj-y += drivers/
\ No newline at end of file
+obj-y += drivers/
+obj-y += modules/
\ No newline at end of file
diff --git a/bsp/drivers/Makefile b/bsp/drivers/Makefile
index 6909f8746a..f7b242eade 100644
--- a/bsp/drivers/Makefile
+++ b/bsp/drivers/Makefile
@@ -108,4 +108,3 @@ obj-y += fs/
 
 #awlink
 obj-y += awlink/
-
diff --git a/bsp/modules/Kconfig b/bsp/modules/Kconfig
new file mode 100644
index 0000000000..9fe99faf7f
--- /dev/null
+++ b/bsp/modules/Kconfig
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# spi tft
+source "bsp/modules/fbtft/Kconfig"
\ No newline at end of file
diff --git a/bsp/modules/Makefile b/bsp/modules/Makefile
new file mode 100644
index 0000000000..f0241ec4da
--- /dev/null
+++ b/bsp/modules/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# spi tft
+obj-y += fbtft/
\ No newline at end of file
diff --git a/bsp/modules/fbtft/Kconfig b/bsp/modules/fbtft/Kconfig
new file mode 100644
index 0000000000..c63523bc5c
--- /dev/null
+++ b/bsp/modules/fbtft/Kconfig
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0
+menuconfig AVA_FB_TFT
+	tristate "Support for onboard SPI TFT LCD display modules"
+	depends on FB && SPI
+	depends on GPIOLIB || COMPILE_TEST
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select FB_SYS_FOPS
+	select FB_DEFERRED_IO
+	select FB_BACKLIGHT
+
+config AVA_FB_TFT_ST7789V
+	tristate "FB driver for the ST7789V LCD Controller"
+	depends on AVA_FB_TFT
+	help
+	  This enables generic framebuffer support for the Sitronix ST7789V
+	  display controller. The controller is intended for small color
+	  displays with a resolution of up to 320x240 pixels.
+
+	  Say Y if you have such a display that utilizes this controller.
diff --git a/bsp/modules/fbtft/Makefile b/bsp/modules/fbtft/Makefile
new file mode 100644
index 0000000000..13ebbc54b8
--- /dev/null
+++ b/bsp/modules/fbtft/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+# Core module
+obj-$(CONFIG_AVA_FB_TFT)             += fbtft.o
+fbtft-y                          += fbtft-core.o fbtft-sysfs.o fbtft-bus.o fbtft-io.o
+
+# drivers
+obj-$(CONFIG_AVA_FB_TFT_ST7789V)     += fb_st7789v.o
diff --git a/bsp/modules/fbtft/README b/bsp/modules/fbtft/README
new file mode 100644
index 0000000000..ba4c74c92e
--- /dev/null
+++ b/bsp/modules/fbtft/README
@@ -0,0 +1,32 @@
+  FBTFT
+=========
+
+Linux Framebuffer drivers for small TFT LCD display modules.
+The module 'fbtft' makes writing drivers for some of these displays very easy.
+
+Development is done on a Raspberry Pi running the Raspbian "wheezy" distribution.
+
+INSTALLATION
+  Download kernel sources
+
+  From Linux 3.15
+    cd drivers/video/fbdev/fbtft
+    git clone https://github.com/notro/fbtft.git
+
+    Add to drivers/video/fbdev/Kconfig:   source "drivers/video/fbdev/fbtft/Kconfig"
+    Add to drivers/video/fbdev/Makefile:  obj-y += fbtft/
+
+  Before Linux 3.15
+    cd drivers/video
+    git clone https://github.com/notro/fbtft.git
+
+    Add to drivers/video/Kconfig:   source "drivers/video/fbtft/Kconfig"
+    Add to drivers/video/Makefile:  obj-y += fbtft/
+
+  Enable driver(s) in menuconfig and build the kernel
+
+
+See wiki for more information: https://github.com/notro/fbtft/wiki
+
+
+Source: https://github.com/notro/fbtft/
diff --git a/bsp/modules/fbtft/TODO b/bsp/modules/fbtft/TODO
new file mode 100644
index 0000000000..e72a08bf22
--- /dev/null
+++ b/bsp/modules/fbtft/TODO
@@ -0,0 +1,3 @@
+* convert all these over to drm_simple_display_pipe and submit for inclusion
+  into the DRM subsystem under drivers/gpu/drm - fbdev doesn't take any new
+  drivers anymore.
diff --git a/bsp/modules/fbtft/fb_st7789v.c b/bsp/modules/fbtft/fb_st7789v.c
new file mode 100644
index 0000000000..1e7a704bd2
--- /dev/null
+++ b/bsp/modules/fbtft/fb_st7789v.c
@@ -0,0 +1,336 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * FB driver for the ST7789V LCD Controller
+ *
+ * Copyright (C) 2015 Dennis Menschel
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/module.h>
+
+#include <video/mipi_display.h>
+
+#include "fbtft.h"
+
+#define DRVNAME "fb_st7789v"
+
+#define DEFAULT_GAMMA \
+    "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25\n" \
+    "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25"
+
+#define HSD20_IPS_GAMMA \
+    "D0 05 0A 09 08 05 2E 44 45 0F 17 16 2B 33\n" \
+    "D0 05 0A 09 08 05 2E 43 45 0F 16 16 2B 33"
+
+#define HSD20_IPS 1
+
+/**
+ * enum st7789v_command - ST7789V display controller commands
+ *
+ * @PORCTRL: porch setting
+ * @GCTRL: gate control
+ * @VCOMS: VCOM setting
+ * @VDVVRHEN: VDV and VRH command enable
+ * @VRHS: VRH set
+ * @VDVS: VDV set
+ * @VCMOFSET: VCOM offset set
+ * @PWCTRL1: power control 1
+ * @PVGAMCTRL: positive voltage gamma control
+ * @NVGAMCTRL: negative voltage gamma control
+ *
+ * The command names are the same as those found in the datasheet to ease
+ * looking up their semantics and usage.
+ *
+ * Note that the ST7789V display controller offers quite a few more commands
+ * which have been omitted from this list as they are not used at the moment.
+ * Furthermore, commands that are compliant with the MIPI DCS have been left
+ * out as well to avoid duplicate entries.
+ */
+enum st7789v_command {
+    PORCTRL = 0xB2,
+    GCTRL = 0xB7,
+    VCOMS = 0xBB,
+    VDVVRHEN = 0xC2,
+    VRHS = 0xC3,
+    VDVS = 0xC4,
+    VCMOFSET = 0xC5,
+    PWCTRL1 = 0xD0,
+    PVGAMCTRL = 0xE0,
+    NVGAMCTRL = 0xE1,
+};
+
+#define MADCTL_BGR BIT(3) /* bitmask for RGB/BGR order */
+#define MADCTL_MV BIT(5) /* bitmask for page/column order */
+#define MADCTL_MX BIT(6) /* bitmask for column address order */
+#define MADCTL_MY BIT(7) /* bitmask for page address order */
+
+/* 60Hz for 16.6ms, configured as 2*16.6ms */
+#define PANEL_TE_TIMEOUT_MS  33
+
+static struct completion panel_te; /* completion for panel TE line */
+static int irq_te; /* Linux IRQ for LCD TE line */
+
+static irqreturn_t panel_te_handler(int irq, void *data)
+{
+    complete(&panel_te);
+    return IRQ_HANDLED;
+}
+
+/**
+ * init_display() - initialize the display controller
+ *
+ * @par: FBTFT parameter object
+ *
+ * Most of the commands in this init function set their parameters to the
+ * same default values which are already in place after the display has been
+ * powered up. (The main exception to this rule is the pixel format which
+ * would default to 18 instead of 16 bit per pixel.)
+ * Nonetheless, this sequence can be used as a template for concrete
+ * displays which usually need some adjustments.
+ *
+ * Return: 0 on success, < 0 if error occurred.
+ */
+static int init_display(struct fbtft_par *par)
+{
+    par->fbtftops.reset(par);
+    mdelay(50);
+    write_reg(par, PORCTRL, 0x0C, 0x0C, 0x00, 0x33, 0x33);
+    write_reg(par, GCTRL, 0x35);
+    write_reg(par, VCOMS, 0x19);
+    write_reg(par, VDVVRHEN, 0x01);
+    write_reg(par, VRHS, 0x12);
+    write_reg(par, VDVS, 0x20);
+    write_reg(par, VCMOFSET, 0x0F);
+    write_reg(par, PWCTRL1, 0xA4, 0xA1);
+    write_reg(par, PVGAMCTRL, 0xD0, 0x04, 0x0D, 0x11, 0x13, 0x2B, 0x3F, 0x54, 0x4C, 0x18, 0x0D, 0x0B, 0x1F, 0x23);
+    write_reg(par, NVGAMCTRL, 0xD0, 0x04, 0x0C, 0x11, 0x13, 0x2C, 0x3F, 0x44, 0x51, 0x2F, 0x1F, 0x1F, 0x20, 0x23);
+    write_reg(par, 0x21);
+    write_reg(par, 0x11);
+    mdelay(50);
+    write_reg(par, 0x29);
+    mdelay(200);
+    return 0;
+}
+
+
+/*
+ * write_vmem() - write data to display.
+ * @par: FBTFT parameter object.
+ * @offset: offset from screen_buffer.
+ * @len: the length of data to be writte.
+ *
+ * Return: 0 on success, or a negative error code otherwise.
+ */
+static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
+{
+    struct device *dev = par->info->device;
+    int ret;
+
+    if (irq_te) {
+        enable_irq(irq_te);
+        reinit_completion(&panel_te);
+        ret = wait_for_completion_timeout(&panel_te,
+                          msecs_to_jiffies(PANEL_TE_TIMEOUT_MS));
+        if (ret == 0)
+            dev_err(dev, "wait panel TE timeout\n");
+
+        disable_irq(irq_te);
+    }
+
+    switch (par->pdata->display.buswidth) {
+    case 8:
+        ret = fbtft_write_vmem16_bus8(par, offset, len);
+        break;
+    case 9:
+        ret = fbtft_write_vmem16_bus9(par, offset, len);
+        break;
+    case 16:
+        ret = fbtft_write_vmem16_bus16(par, offset, len);
+        break;
+    default:
+        dev_err(dev, "Unsupported buswidth %d\n",
+            par->pdata->display.buswidth);
+        ret = 0;
+        break;
+    }
+
+    return ret;
+}
+
+/**
+ * set_var() - apply LCD properties like rotation and BGR mode
+ *
+ * @par: FBTFT parameter object
+ *
+ * Return: 0 on success, < 0 if error occurred.
+ */
+static int set_var(struct fbtft_par *par)
+{
+    u8 madctl_par = 0;
+
+    if (par->bgr)
+        madctl_par |= MADCTL_BGR;
+    switch (par->info->var.rotate) {
+    case 0:
+        break;
+    case 90:
+        madctl_par |= (MADCTL_MV | MADCTL_MY);
+        break;
+    case 180:
+        madctl_par |= (MADCTL_MX | MADCTL_MY);
+        break;
+    case 270:
+        madctl_par |= (MADCTL_MV | MADCTL_MX);
+        break;
+    default:
+        return -EINVAL;
+    }
+    write_reg(par, MIPI_DCS_SET_ADDRESS_MODE, madctl_par);
+    return 0;
+}
+
+/**
+ * set_gamma() - set gamma curves
+ *
+ * @par: FBTFT parameter object
+ * @curves: gamma curves
+ *
+ * Before the gamma curves are applied, they are preprocessed with a bitmask
+ * to ensure syntactically correct input for the display controller.
+ * This implies that the curves input parameter might be changed by this
+ * function and that illegal gamma values are auto-corrected and not
+ * reported as errors.
+ *
+ * Return: 0 on success, < 0 if error occurred.
+ */
+static int set_gamma(struct fbtft_par *par, u32 *curves)
+{
+    int i;
+    int j;
+    int c; /* curve index offset */
+
+    /*
+     * Bitmasks for gamma curve command parameters.
+     * The masks are the same for both positive and negative voltage
+     * gamma curves.
+     */
+    static const u8 gamma_par_mask[] = {
+        0xFF, /* V63[3:0], V0[3:0]*/
+        0x3F, /* V1[5:0] */
+        0x3F, /* V2[5:0] */
+        0x1F, /* V4[4:0] */
+        0x1F, /* V6[4:0] */
+        0x3F, /* J0[1:0], V13[3:0] */
+        0x7F, /* V20[6:0] */
+        0x77, /* V36[2:0], V27[2:0] */
+        0x7F, /* V43[6:0] */
+        0x3F, /* J1[1:0], V50[3:0] */
+        0x1F, /* V57[4:0] */
+        0x1F, /* V59[4:0] */
+        0x3F, /* V61[5:0] */
+        0x3F, /* V62[5:0] */
+    };
+
+    for (i = 0; i < par->gamma.num_curves; i++) {
+        c = i * par->gamma.num_values;
+        for (j = 0; j < par->gamma.num_values; j++)
+            curves[c + j] &= gamma_par_mask[j];
+        write_reg(par, PVGAMCTRL + i,
+              curves[c + 0],  curves[c + 1],  curves[c + 2],
+              curves[c + 3],  curves[c + 4],  curves[c + 5],
+              curves[c + 6],  curves[c + 7],  curves[c + 8],
+              curves[c + 9],  curves[c + 10], curves[c + 11],
+              curves[c + 12], curves[c + 13]);
+    }
+    return 0;
+}
+
+/**
+ * blank() - blank the display
+ *
+ * @par: FBTFT parameter object
+ * @on: whether to enable or disable blanking the display
+ *
+ * Return: 0 on success, < 0 if error occurred.
+ */
+static int blank(struct fbtft_par *par, bool on)
+{
+    if (on)
+        write_reg(par, MIPI_DCS_SET_DISPLAY_OFF);
+    else
+        write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
+    return 0;
+}
+
+static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
+{
+	switch(par->info->var.rotate)
+	{
+		case   0: xs += 52; xe += 52; ys += 40; ye += 40;
+				 break;
+		case  90: xs += 40; xe += 40; ys +=52 ; ye += 52;
+				 break;
+		case 180: xs += 52; xe += 52; ys +=40 ; ye += 40;
+				 break;
+		case 270: xs += 40; xe += 40; ys +=52 ; ye += 52;
+				 break;
+		default :
+				 break;
+	}
+
+	write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
+		  (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);
+
+	write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
+		  (ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);
+
+	write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
+}
+
+static void reset(struct fbtft_par *par)
+{
+    if (!par->gpio.reset)
+        return;
+    gpiod_set_value_cansleep(par->gpio.reset, 1);
+    msleep(10);
+    gpiod_set_value_cansleep(par->gpio.reset, 0);
+    msleep(200);
+    gpiod_set_value_cansleep(par->gpio.reset, 1);
+    msleep(10);
+    gpiod_set_value_cansleep(par->gpio.cs, 1);  /* Activate chip */
+}
+
+static struct fbtft_display display = {
+    .regwidth = 8,
+    .width = 135,
+    .height = 240,
+    .gamma_num = 2,
+    .gamma_len = 14,
+    .gamma = HSD20_IPS_GAMMA,
+    .fbtftops = {
+        .init_display = init_display,
+        .set_addr_win = set_addr_win,
+        .write_vmem = write_vmem,
+        .set_var = set_var,
+        .set_gamma = set_gamma,
+        .blank = blank,
+        .reset = reset,
+    },
+};
+
+FBTFT_REGISTER_DRIVER(DRVNAME, "sitronix,st7789v", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("platform:" DRVNAME);
+MODULE_ALIAS("spi:st7789v");
+MODULE_ALIAS("platform:st7789v");
+
+MODULE_DESCRIPTION("FB driver for the ST7789V LCD Controller");
+MODULE_AUTHOR("Dennis Menschel");
+MODULE_LICENSE("GPL");
diff --git a/bsp/modules/fbtft/fbtft-bus.c b/bsp/modules/fbtft/fbtft-bus.c
new file mode 100644
index 0000000000..3d422bc116
--- /dev/null
+++ b/bsp/modules/fbtft/fbtft-bus.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+#include "fbtft.h"
+
+/*****************************************************************************
+ *
+ *   void (*write_reg)(struct fbtft_par *par, int len, ...);
+ *
+ *****************************************************************************/
+
+#define define_fbtft_write_reg(func, buffer_type, data_type, modifier)        \
+void func(struct fbtft_par *par, int len, ...)                                \
+{                                                                             \
+	va_list args;                                                         \
+	int i, ret;                                                           \
+	int offset = 0;                                                       \
+	buffer_type *buf = (buffer_type *)par->buf;                           \
+									      \
+	if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {                    \
+		va_start(args, len);                                          \
+		for (i = 0; i < len; i++) {                                   \
+			buf[i] = modifier((data_type)va_arg(args,             \
+							    unsigned int));   \
+		}                                                             \
+		va_end(args);                                                 \
+		fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,                  \
+				  par->info->device, buffer_type, buf, len,   \
+				  "%s: ", __func__);                          \
+	}                                                                     \
+									      \
+	va_start(args, len);                                                  \
+									      \
+	if (par->startbyte) {                                                 \
+		*(u8 *)par->buf = par->startbyte;                             \
+		buf = (buffer_type *)(par->buf + 1);                          \
+		offset = 1;                                                   \
+	}                                                                     \
+									      \
+	*buf = modifier((data_type)va_arg(args, unsigned int));               \
+	ret = fbtft_write_buf_dc(par, par->buf, sizeof(data_type) + offset,   \
+				 0);                                          \
+	if (ret < 0)							      \
+		goto out;						      \
+	len--;                                                                \
+									      \
+	if (par->startbyte)                                                   \
+		*(u8 *)par->buf = par->startbyte | 0x2;                       \
+									      \
+	if (len) {                                                            \
+		i = len;                                                      \
+		while (i--)						      \
+			*buf++ = modifier((data_type)va_arg(args,             \
+							    unsigned int));   \
+		fbtft_write_buf_dc(par, par->buf,			      \
+				   len * (sizeof(data_type) + offset), 1);    \
+	}                                                                     \
+out:									      \
+	va_end(args);                                                         \
+}                                                                             \
+EXPORT_SYMBOL(func);
+
+define_fbtft_write_reg(fbtft_write_reg8_bus8, u8, u8, )
+define_fbtft_write_reg(fbtft_write_reg16_bus8, __be16, u16, cpu_to_be16)
+define_fbtft_write_reg(fbtft_write_reg16_bus16, u16, u16, )
+
+void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...)
+{
+	va_list args;
+	int i, ret;
+	int pad = 0;
+	u16 *buf = (u16 *)par->buf;
+
+	if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
+		va_start(args, len);
+		for (i = 0; i < len; i++)
+			*(((u8 *)buf) + i) = (u8)va_arg(args, unsigned int);
+		va_end(args);
+		fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
+				  par->info->device, u8, buf, len, "%s: ",
+				  __func__);
+	}
+	if (len <= 0)
+		return;
+
+	if (par->spi && (par->spi->bits_per_word == 8)) {
+		/* we're emulating 9-bit, pad start of buffer with no-ops
+		 * (assuming here that zero is a no-op)
+		 */
+		pad = (len % 4) ? 4 - (len % 4) : 0;
+		for (i = 0; i < pad; i++)
+			*buf++ = 0x000;
+	}
+
+	va_start(args, len);
+	*buf++ = (u8)va_arg(args, unsigned int);
+	i = len - 1;
+	while (i--) {
+		*buf = (u8)va_arg(args, unsigned int);
+		*buf++ |= 0x100; /* dc=1 */
+	}
+	va_end(args);
+	ret = par->fbtftops.write(par, par->buf, (len + pad) * sizeof(u16));
+	if (ret < 0) {
+		dev_err(par->info->device,
+			"write() failed and returned %d\n", ret);
+		return;
+	}
+}
+EXPORT_SYMBOL(fbtft_write_reg8_bus9);
+
+/*****************************************************************************
+ *
+ *   int (*write_vmem)(struct fbtft_par *par);
+ *
+ *****************************************************************************/
+
+/* 16 bit pixel over 8-bit databus */
+int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u16 *vmem16;
+	__be16 *txbuf16 = par->txbuf.buf;
+	size_t remain;
+	size_t to_copy;
+	size_t tx_array_size;
+	int i;
+	int ret = 0;
+	size_t startbyte_size = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+		      __func__, offset, len);
+
+	remain = len / 2;
+	vmem16 = (u16 *)(par->info->screen_buffer + offset);
+
+	gpiod_set_value(par->gpio.dc, 1);
+
+	/* non buffered write */
+	if (!par->txbuf.buf)
+		return par->fbtftops.write(par, vmem16, len);
+
+	/* buffered write */
+	tx_array_size = par->txbuf.len / 2;
+
+	if (par->startbyte) {
+		txbuf16 = par->txbuf.buf + 1;
+		tx_array_size -= 2;
+		*(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
+		startbyte_size = 1;
+	}
+
+	while (remain) {
+		to_copy = min(tx_array_size, remain);
+		dev_dbg(par->info->device, "to_copy=%zu, remain=%zu\n",
+			to_copy, remain - to_copy);
+
+		for (i = 0; i < to_copy; i++)
+			txbuf16[i] = cpu_to_be16(vmem16[i]);
+
+		vmem16 = vmem16 + to_copy;
+		ret = par->fbtftops.write(par, par->txbuf.buf,
+						startbyte_size + to_copy * 2);
+		if (ret < 0)
+			return ret;
+		remain -= to_copy;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
+
+/* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
+int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u8 *vmem8;
+	u16 *txbuf16 = par->txbuf.buf;
+	size_t remain;
+	size_t to_copy;
+	size_t tx_array_size;
+	int i;
+	int ret = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+		      __func__, offset, len);
+
+	if (!par->txbuf.buf) {
+		dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
+		return -1;
+	}
+
+	remain = len;
+	vmem8 = par->info->screen_buffer + offset;
+
+	tx_array_size = par->txbuf.len / 2;
+
+	while (remain) {
+		to_copy = min(tx_array_size, remain);
+		dev_dbg(par->info->device, "to_copy=%zu, remain=%zu\n",
+			to_copy, remain - to_copy);
+
+#ifdef __LITTLE_ENDIAN
+		for (i = 0; i < to_copy; i += 2) {
+			txbuf16[i]     = 0x0100 | vmem8[i + 1];
+			txbuf16[i + 1] = 0x0100 | vmem8[i];
+		}
+#else
+		for (i = 0; i < to_copy; i++)
+			txbuf16[i]   = 0x0100 | vmem8[i];
+#endif
+		vmem8 = vmem8 + to_copy;
+		ret = par->fbtftops.write(par, par->txbuf.buf, to_copy * 2);
+		if (ret < 0)
+			return ret;
+		remain -= to_copy;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
+
+int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+	dev_err(par->info->device, "%s: function not implemented\n", __func__);
+	return -1;
+}
+EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
+
+/* 16 bit pixel over 16-bit databus */
+int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u16 *vmem16;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+		      __func__, offset, len);
+
+	vmem16 = (u16 *)(par->info->screen_buffer + offset);
+
+	/* no need for buffered write with 16-bit bus */
+	return fbtft_write_buf_dc(par, vmem16, len, 1);
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus16);
diff --git a/bsp/modules/fbtft/fbtft-core.c b/bsp/modules/fbtft/fbtft-core.c
new file mode 100644
index 0000000000..d69be37e26
--- /dev/null
+++ b/bsp/modules/fbtft/fbtft-core.c
@@ -0,0 +1,1361 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2013 Noralf Tronnes
+ *
+ * This driver is inspired by:
+ *   st7735fb.c, Copyright (C) 2011, Matt Porter
+ *   broadsheetfb.c, Copyright (C) 2008, Jaya Kumar
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/fb.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/backlight.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/spinlock.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+#include <video/mipi_display.h>
+
+#include "fbtft.h"
+#include "internal.h"
+
+static unsigned long debug;
+module_param(debug, ulong, 0000);
+MODULE_PARM_DESC(debug, "override device debug level");
+
+int fbtft_write_buf_dc(struct fbtft_par *par, void *buf, size_t len, int dc)
+{
+	int ret;
+
+	gpiod_set_value(par->gpio.dc, dc);
+
+	ret = par->fbtftops.write(par, buf, len);
+	if (ret < 0)
+		dev_err(par->info->device,
+			"write() failed and returned %d\n", ret);
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_write_buf_dc);
+
+void fbtft_dbg_hex(const struct device *dev, int groupsize,
+		   void *buf, size_t len, const char *fmt, ...)
+{
+	va_list args;
+	static char textbuf[512];
+	char *text = textbuf;
+	size_t text_len;
+
+	va_start(args, fmt);
+	text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
+	va_end(args);
+
+	hex_dump_to_buffer(buf, len, 32, groupsize, text + text_len,
+			   512 - text_len, false);
+
+	if (len > 32)
+		dev_info(dev, "%s ...\n", text);
+	else
+		dev_info(dev, "%s\n", text);
+}
+EXPORT_SYMBOL(fbtft_dbg_hex);
+
+static int fbtft_request_one_gpio(struct fbtft_par *par,
+                  const char *name, int index,
+                  struct gpio_desc **gpiop)
+{
+    struct device *dev = par->info->device;
+    struct device_node *node = dev->of_node;
+    int gpio, flags, ret = 0;
+    enum of_gpio_flags of_flags;
+
+    if (of_find_property(node, name, NULL)) {
+        gpio = of_get_named_gpio_flags(node, name, index, &of_flags);
+        if (gpio == -ENOENT)
+            return 0;
+        if (gpio == -EPROBE_DEFER)
+            return gpio;
+        if (gpio < 0) {
+            dev_err(dev,
+                "failed to get '%s' from DT\n", name);
+            return gpio;
+        }
+        flags = (of_flags & OF_GPIO_ACTIVE_LOW) ? GPIOF_OUT_INIT_LOW :
+                            GPIOF_OUT_INIT_HIGH;
+        ret = devm_gpio_request_one(dev, gpio, flags,
+                        dev->driver->name);
+        if (ret) {
+            dev_err(dev,
+                "gpio_request_one('%s'=%d) failed with %d\n",
+                name, gpio, ret);
+            return ret;
+        }
+
+        *gpiop = gpio_to_desc(gpio);
+        fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' = GPIO%d\n",
+                            __func__, name, gpio);
+    }
+
+    return ret;
+}
+
+
+static int fbtft_request_gpios(struct fbtft_par *par)
+{
+	int i;
+	int ret;
+
+	ret = fbtft_request_one_gpio(par, "reset", 0, &par->gpio.reset);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "dc", 0, &par->gpio.dc);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "rd", 0, &par->gpio.rd);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "wr", 0, &par->gpio.wr);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "cs", 0, &par->gpio.cs);
+	if (ret)
+		return ret;
+	ret = fbtft_request_one_gpio(par, "latch", 0, &par->gpio.latch);
+	if (ret)
+		return ret;
+	for (i = 0; i < 16; i++) {
+		ret = fbtft_request_one_gpio(par, "db", i,
+					     &par->gpio.db[i]);
+		if (ret)
+			return ret;
+		ret = fbtft_request_one_gpio(par, "led", i,
+					     &par->gpio.led[i]);
+		if (ret)
+			return ret;
+		ret = fbtft_request_one_gpio(par, "aux", i,
+					     &par->gpio.aux[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int fbtft_backlight_update_status(struct backlight_device *bd)
+{
+	struct fbtft_par *par = bl_get_data(bd);
+	bool polarity = par->polarity;
+
+	fbtft_par_dbg(DEBUG_BACKLIGHT, par,
+		      "%s: polarity=%d, power=%d, fb_blank=%d\n",
+		      __func__, polarity, bd->props.power, bd->props.fb_blank);
+
+	if ((bd->props.power == FB_BLANK_UNBLANK) &&
+	    (bd->props.fb_blank == FB_BLANK_UNBLANK))
+		gpiod_set_value(par->gpio.led[0], polarity);
+	else
+		gpiod_set_value(par->gpio.led[0], !polarity);
+
+	return 0;
+}
+
+static int fbtft_backlight_get_brightness(struct backlight_device *bd)
+{
+	return bd->props.brightness;
+}
+
+void fbtft_unregister_backlight(struct fbtft_par *par)
+{
+	if (par->info->bl_dev) {
+		par->info->bl_dev->props.power = FB_BLANK_POWERDOWN;
+		backlight_update_status(par->info->bl_dev);
+		backlight_device_unregister(par->info->bl_dev);
+		par->info->bl_dev = NULL;
+	}
+}
+EXPORT_SYMBOL(fbtft_unregister_backlight);
+
+static const struct backlight_ops fbtft_bl_ops = {
+	.get_brightness	= fbtft_backlight_get_brightness,
+	.update_status	= fbtft_backlight_update_status,
+};
+
+void fbtft_register_backlight(struct fbtft_par *par)
+{
+	struct backlight_device *bd;
+	struct backlight_properties bl_props = { 0, };
+
+	if (!par->gpio.led[0]) {
+		fbtft_par_dbg(DEBUG_BACKLIGHT, par,
+			      "%s(): led pin not set, exiting.\n", __func__);
+		return;
+	}
+
+	bl_props.type = BACKLIGHT_RAW;
+	/* Assume backlight is off, get polarity from current state of pin */
+	bl_props.power = FB_BLANK_POWERDOWN;
+	if (!gpiod_get_value(par->gpio.led[0]))
+		par->polarity = true;
+
+	bd = backlight_device_register(dev_driver_string(par->info->device),
+				       par->info->device, par,
+				       &fbtft_bl_ops, &bl_props);
+	if (IS_ERR(bd)) {
+		dev_err(par->info->device,
+			"cannot register backlight device (%ld)\n",
+			PTR_ERR(bd));
+		return;
+	}
+	par->info->bl_dev = bd;
+
+	if (!par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
+}
+EXPORT_SYMBOL(fbtft_register_backlight);
+
+static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
+			       int ye)
+{
+	write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
+		  (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);
+
+	write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
+		  (ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);
+
+	write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
+}
+
+static void fbtft_reset(struct fbtft_par *par)
+{
+	if (!par->gpio.reset)
+		return;
+
+	fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);
+
+	gpiod_set_value_cansleep(par->gpio.reset, 1);
+	usleep_range(20, 40);
+	gpiod_set_value_cansleep(par->gpio.reset, 0);
+	msleep(120);
+
+	gpiod_set_value_cansleep(par->gpio.cs, 1);  /* Activate chip */
+}
+
+static void fbtft_update_display(struct fbtft_par *par, unsigned int start_line,
+				 unsigned int end_line)
+{
+	size_t offset, len;
+	ktime_t ts_start, ts_end;
+	long fps, throughput;
+	bool timeit = false;
+	int ret = 0;
+
+	if (unlikely(par->debug & (DEBUG_TIME_FIRST_UPDATE |
+			DEBUG_TIME_EACH_UPDATE))) {
+		if ((par->debug & DEBUG_TIME_EACH_UPDATE) ||
+		    ((par->debug & DEBUG_TIME_FIRST_UPDATE) &&
+		    !par->first_update_done)) {
+			ts_start = ktime_get();
+			timeit = true;
+		}
+	}
+
+	/* Sanity checks */
+	if (start_line > end_line) {
+		dev_warn(par->info->device,
+			 "%s: start_line=%u is larger than end_line=%u. Shouldn't happen, will do full display update\n",
+			 __func__, start_line, end_line);
+		start_line = 0;
+		end_line = par->info->var.yres - 1;
+	}
+	if (start_line > par->info->var.yres - 1 ||
+	    end_line > par->info->var.yres - 1) {
+		dev_warn(par->info->device,
+			 "%s: start_line=%u or end_line=%u is larger than max=%d. Shouldn't happen, will do full display update\n",
+			 __func__, start_line,
+			 end_line, par->info->var.yres - 1);
+		start_line = 0;
+		end_line = par->info->var.yres - 1;
+	}
+
+	fbtft_par_dbg(DEBUG_UPDATE_DISPLAY, par, "%s(start_line=%u, end_line=%u)\n",
+		      __func__, start_line, end_line);
+
+	if (par->fbtftops.set_addr_win)
+		par->fbtftops.set_addr_win(par, 0, start_line,
+				par->info->var.xres - 1, end_line);
+
+	offset = start_line * par->info->fix.line_length;
+	len = (end_line - start_line + 1) * par->info->fix.line_length;
+	ret = par->fbtftops.write_vmem(par, offset, len);
+	if (ret < 0)
+		dev_err(par->info->device,
+			"%s: write_vmem failed to update display buffer\n",
+			__func__);
+
+	if (unlikely(timeit)) {
+		ts_end = ktime_get();
+		if (!ktime_to_ns(par->update_time))
+			par->update_time = ts_start;
+
+		fps = ktime_us_delta(ts_start, par->update_time);
+		par->update_time = ts_start;
+		fps = fps ? 1000000 / fps : 0;
+
+		throughput = ktime_us_delta(ts_end, ts_start);
+		throughput = throughput ? (len * 1000) / throughput : 0;
+		throughput = throughput * 1000 / 1024;
+
+		dev_info(par->info->device,
+			 "Display update: %ld kB/s, fps=%ld\n",
+			 throughput, fps);
+		par->first_update_done = true;
+	}
+}
+
+static void fbtft_mkdirty(struct fb_info *info, int y, int height)
+{
+	struct fbtft_par *par = info->par;
+	struct fb_deferred_io *fbdefio = info->fbdefio;
+
+	/* special case, needed ? */
+	if (y == -1) {
+		y = 0;
+		height = info->var.yres;
+	}
+
+	/* Mark display lines/area as dirty */
+	spin_lock(&par->dirty_lock);
+	if (y < par->dirty_lines_start)
+		par->dirty_lines_start = y;
+	if (y + height - 1 > par->dirty_lines_end)
+		par->dirty_lines_end = y + height - 1;
+	spin_unlock(&par->dirty_lock);
+
+	/* Schedule deferred_io to update display (no-op if already on queue)*/
+	schedule_delayed_work(&info->deferred_work, fbdefio->delay);
+}
+
+static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagereflist)
+{
+	struct fbtft_par *par = info->par;
+	unsigned int dirty_lines_start, dirty_lines_end;
+	struct fb_deferred_io_pageref *pageref;
+	unsigned long index;
+	unsigned int y_low = 0, y_high = 0;
+	int count = 0;
+
+	spin_lock(&par->dirty_lock);
+	dirty_lines_start = par->dirty_lines_start;
+	dirty_lines_end = par->dirty_lines_end;
+	/* set display line markers as clean */
+	par->dirty_lines_start = par->info->var.yres - 1;
+	par->dirty_lines_end = 0;
+	spin_unlock(&par->dirty_lock);
+
+	/* Mark display lines as dirty */
+	list_for_each_entry(pageref, pagereflist, list) {
+		struct page *page = pageref->page;
+		count++;
+		index = page->index << PAGE_SHIFT;
+		y_low = index / info->fix.line_length;
+		y_high = (index + PAGE_SIZE - 1) / info->fix.line_length;
+		dev_dbg(info->device,
+			"page->index=%lu y_low=%d y_high=%d\n",
+			page->index, y_low, y_high);
+		if (y_high > info->var.yres - 1)
+			y_high = info->var.yres - 1;
+		if (y_low < dirty_lines_start)
+			dirty_lines_start = y_low;
+		if (y_high > dirty_lines_end)
+			dirty_lines_end = y_high;
+	}
+
+	par->fbtftops.update_display(info->par,
+					dirty_lines_start, dirty_lines_end);
+}
+
+static void fbtft_fb_fillrect(struct fb_info *info,
+			      const struct fb_fillrect *rect)
+{
+	struct fbtft_par *par = info->par;
+
+	dev_dbg(info->dev,
+		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
+		__func__, rect->dx, rect->dy, rect->width, rect->height);
+	sys_fillrect(info, rect);
+
+	par->fbtftops.mkdirty(info, rect->dy, rect->height);
+}
+
+static void fbtft_fb_copyarea(struct fb_info *info,
+			      const struct fb_copyarea *area)
+{
+	struct fbtft_par *par = info->par;
+
+	dev_dbg(info->dev,
+		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
+		__func__,  area->dx, area->dy, area->width, area->height);
+	sys_copyarea(info, area);
+
+	par->fbtftops.mkdirty(info, area->dy, area->height);
+}
+
+static void fbtft_fb_imageblit(struct fb_info *info,
+			       const struct fb_image *image)
+{
+	struct fbtft_par *par = info->par;
+
+	dev_dbg(info->dev,
+		"%s: dx=%d, dy=%d, width=%d, height=%d\n",
+		__func__,  image->dx, image->dy, image->width, image->height);
+	sys_imageblit(info, image);
+
+	par->fbtftops.mkdirty(info, image->dy, image->height);
+}
+
+static ssize_t fbtft_fb_write(struct fb_info *info, const char __user *buf,
+			      size_t count, loff_t *ppos)
+{
+	struct fbtft_par *par = info->par;
+	ssize_t res;
+
+	dev_dbg(info->dev,
+		"%s: count=%zd, ppos=%llu\n", __func__,  count, *ppos);
+	res = fb_sys_write(info, buf, count, ppos);
+
+	/* TODO: only mark changed area update all for now */
+	par->fbtftops.mkdirty(info, -1, 0);
+
+	return res;
+}
+
+/* from pxafb.c */
+static unsigned int chan_to_field(unsigned int chan, struct fb_bitfield *bf)
+{
+	chan &= 0xffff;
+	chan >>= 16 - bf->length;
+	return chan << bf->offset;
+}
+
+static int fbtft_fb_setcolreg(unsigned int regno, unsigned int red,
+			      unsigned int green, unsigned int blue,
+			      unsigned int transp, struct fb_info *info)
+{
+	unsigned int val;
+	int ret = 1;
+
+	dev_dbg(info->dev,
+		"%s(regno=%u, red=0x%X, green=0x%X, blue=0x%X, trans=0x%X)\n",
+		__func__, regno, red, green, blue, transp);
+
+	switch (info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+		if (regno < 16) {
+			u32 *pal = info->pseudo_palette;
+
+			val  = chan_to_field(red,   &info->var.red);
+			val |= chan_to_field(green, &info->var.green);
+			val |= chan_to_field(blue,  &info->var.blue);
+
+			pal[regno] = val;
+			ret = 0;
+		}
+		break;
+	}
+	return ret;
+}
+
+static int fbtft_fb_blank(int blank, struct fb_info *info)
+{
+	struct fbtft_par *par = info->par;
+	int ret = -EINVAL;
+
+	dev_dbg(info->dev, "%s(blank=%d)\n",
+		__func__, blank);
+
+	if (!par->fbtftops.blank)
+		return ret;
+
+	switch (blank) {
+	case FB_BLANK_POWERDOWN:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_NORMAL:
+		ret = par->fbtftops.blank(par, true);
+		break;
+	case FB_BLANK_UNBLANK:
+		ret = par->fbtftops.blank(par, false);
+		break;
+	}
+	return ret;
+}
+
+static void fbtft_merge_fbtftops(struct fbtft_ops *dst, struct fbtft_ops *src)
+{
+	if (src->write)
+		dst->write = src->write;
+	if (src->read)
+		dst->read = src->read;
+	if (src->write_vmem)
+		dst->write_vmem = src->write_vmem;
+	if (src->write_register)
+		dst->write_register = src->write_register;
+	if (src->set_addr_win)
+		dst->set_addr_win = src->set_addr_win;
+	if (src->reset)
+		dst->reset = src->reset;
+	if (src->mkdirty)
+		dst->mkdirty = src->mkdirty;
+	if (src->update_display)
+		dst->update_display = src->update_display;
+	if (src->init_display)
+		dst->init_display = src->init_display;
+	if (src->blank)
+		dst->blank = src->blank;
+	if (src->request_gpios_match)
+		dst->request_gpios_match = src->request_gpios_match;
+	if (src->request_gpios)
+		dst->request_gpios = src->request_gpios;
+	if (src->verify_gpios)
+		dst->verify_gpios = src->verify_gpios;
+	if (src->register_backlight)
+		dst->register_backlight = src->register_backlight;
+	if (src->unregister_backlight)
+		dst->unregister_backlight = src->unregister_backlight;
+	if (src->set_var)
+		dst->set_var = src->set_var;
+	if (src->set_gamma)
+		dst->set_gamma = src->set_gamma;
+}
+
+/**
+ * fbtft_framebuffer_alloc - creates a new frame buffer info structure
+ *
+ * @display: pointer to structure describing the display
+ * @dev: pointer to the device for this fb, this can be NULL
+ * @pdata: platform data for the display in use
+ *
+ * Creates a new frame buffer info structure.
+ *
+ * Also creates and populates the following structures:
+ *   info->fbops
+ *   info->fbdefio
+ *   info->pseudo_palette
+ *   par->fbtftops
+ *   par->txbuf
+ *
+ * Returns the new structure, or NULL if an error occurred.
+ *
+ */
+struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
+					struct device *dev,
+					struct fbtft_platform_data *pdata)
+{
+	struct fb_info *info;
+	struct fbtft_par *par;
+	struct fb_ops *fbops = NULL;
+	struct fb_deferred_io *fbdefio = NULL;
+	u8 *vmem = NULL;
+	void *txbuf = NULL;
+	void *buf = NULL;
+	unsigned int width;
+	unsigned int height;
+	int txbuflen = display->txbuflen;
+	unsigned int bpp = display->bpp;
+	unsigned int fps = display->fps;
+	int vmem_size;
+	const s16 *init_sequence = display->init_sequence;
+	char *gamma = display->gamma;
+	u32 *gamma_curves = NULL;
+
+	/* sanity check */
+	if (display->gamma_num * display->gamma_len >
+			FBTFT_GAMMA_MAX_VALUES_TOTAL) {
+		dev_err(dev, "FBTFT_GAMMA_MAX_VALUES_TOTAL=%d is exceeded\n",
+			FBTFT_GAMMA_MAX_VALUES_TOTAL);
+		return NULL;
+	}
+
+	/* defaults */
+	if (!fps)
+		fps = 20;
+	if (!bpp)
+		bpp = 16;
+
+	if (!pdata) {
+		dev_err(dev, "platform data is missing\n");
+		return NULL;
+	}
+
+	/* override driver values? */
+	if (pdata->fps)
+		fps = pdata->fps;
+	if (pdata->txbuflen)
+		txbuflen = pdata->txbuflen;
+	if (pdata->display.init_sequence)
+		init_sequence = pdata->display.init_sequence;
+	if (pdata->gamma)
+		gamma = pdata->gamma;
+	if (pdata->display.debug)
+		display->debug = pdata->display.debug;
+	if (pdata->display.backlight)
+		display->backlight = pdata->display.backlight;
+	if (pdata->display.width)
+		display->width = pdata->display.width;
+	if (pdata->display.height)
+		display->height = pdata->display.height;
+	if (pdata->display.buswidth)
+		display->buswidth = pdata->display.buswidth;
+	if (pdata->display.regwidth)
+		display->regwidth = pdata->display.regwidth;
+
+	display->debug |= debug;
+	fbtft_expand_debug_value(&display->debug);
+
+	switch (pdata->rotate) {
+	case 90:
+	case 270:
+		width =  display->height;
+		height = display->width;
+		break;
+	default:
+		width =  display->width;
+		height = display->height;
+	}
+
+	vmem_size = display->width * display->height * bpp / 8;
+	vmem = vzalloc(vmem_size);
+	if (!vmem)
+		goto alloc_fail;
+
+	fbops = devm_kzalloc(dev, sizeof(struct fb_ops), GFP_KERNEL);
+	if (!fbops)
+		goto alloc_fail;
+
+	fbdefio = devm_kzalloc(dev, sizeof(struct fb_deferred_io), GFP_KERNEL);
+	if (!fbdefio)
+		goto alloc_fail;
+
+	buf = devm_kzalloc(dev, 128, GFP_KERNEL);
+	if (!buf)
+		goto alloc_fail;
+
+	if (display->gamma_num && display->gamma_len) {
+		gamma_curves = devm_kcalloc(dev,
+					    display->gamma_num *
+					    display->gamma_len,
+					    sizeof(gamma_curves[0]),
+					    GFP_KERNEL);
+		if (!gamma_curves)
+			goto alloc_fail;
+	}
+
+	info = framebuffer_alloc(sizeof(struct fbtft_par), dev);
+	if (!info)
+		goto alloc_fail;
+
+	info->screen_buffer = vmem;
+	info->fbops = fbops;
+	info->fbdefio = fbdefio;
+
+	fbops->owner        =      dev->driver->owner;
+	fbops->fb_read      =      fb_sys_read;
+	fbops->fb_write     =      fbtft_fb_write;
+	fbops->fb_fillrect  =      fbtft_fb_fillrect;
+	fbops->fb_copyarea  =      fbtft_fb_copyarea;
+	fbops->fb_imageblit =      fbtft_fb_imageblit;
+	fbops->fb_setcolreg =      fbtft_fb_setcolreg;
+	fbops->fb_blank     =      fbtft_fb_blank;
+
+	fbdefio->delay =            HZ / fps;
+	fbdefio->sort_pagereflist = true;
+	fbdefio->deferred_io =      fbtft_deferred_io;
+
+	snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
+	info->fix.type =           FB_TYPE_PACKED_PIXELS;
+	info->fix.visual =         FB_VISUAL_TRUECOLOR;
+	info->fix.xpanstep =	   0;
+	info->fix.ypanstep =	   0;
+	info->fix.ywrapstep =	   0;
+	info->fix.line_length =    width * bpp / 8;
+	info->fix.accel =          FB_ACCEL_NONE;
+	info->fix.smem_len =       vmem_size;
+	fb_deferred_io_init(info);
+
+	info->var.rotate =         pdata->rotate;
+	info->var.xres =           width;
+	info->var.yres =           height;
+	info->var.xres_virtual =   info->var.xres;
+	info->var.yres_virtual =   info->var.yres;
+	info->var.bits_per_pixel = bpp;
+	info->var.nonstd =         1;
+
+	/* RGB565 */
+	info->var.red.offset =     11;
+	info->var.red.length =     5;
+	info->var.green.offset =   5;
+	info->var.green.length =   6;
+	info->var.blue.offset =    0;
+	info->var.blue.length =    5;
+	info->var.transp.offset =  0;
+	info->var.transp.length =  0;
+
+	info->flags =              FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
+
+	par = info->par;
+	par->info = info;
+	par->pdata = pdata;
+	par->debug = display->debug;
+	par->buf = buf;
+	spin_lock_init(&par->dirty_lock);
+	par->bgr = pdata->bgr;
+	par->startbyte = pdata->startbyte;
+	par->init_sequence = init_sequence;
+	par->gamma.curves = gamma_curves;
+	par->gamma.num_curves = display->gamma_num;
+	par->gamma.num_values = display->gamma_len;
+	mutex_init(&par->gamma.lock);
+	info->pseudo_palette = par->pseudo_palette;
+
+	if (par->gamma.curves && gamma) {
+		if (fbtft_gamma_parse_str(par, par->gamma.curves, gamma,
+					  strlen(gamma)))
+			goto release_framebuf;
+	}
+
+	/* Transmit buffer */
+	if (txbuflen == -1)
+		txbuflen = vmem_size + 2; /* add in case startbyte is used */
+	if (txbuflen >= vmem_size + 2)
+		txbuflen = 0;
+
+#ifdef __LITTLE_ENDIAN
+	if ((!txbuflen) && (bpp > 8))
+		txbuflen = PAGE_SIZE; /* need buffer for byteswapping */
+#endif
+
+	if (txbuflen > 0) {
+		txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
+		if (!txbuf)
+			goto release_framebuf;
+		par->txbuf.buf = txbuf;
+		par->txbuf.len = txbuflen;
+	}
+
+	/* default fbtft operations */
+	par->fbtftops.write = fbtft_write_spi;
+	par->fbtftops.read = fbtft_read_spi;
+	par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
+	par->fbtftops.write_register = fbtft_write_reg8_bus8;
+	par->fbtftops.set_addr_win = fbtft_set_addr_win;
+	par->fbtftops.reset = fbtft_reset;
+	par->fbtftops.mkdirty = fbtft_mkdirty;
+	par->fbtftops.update_display = fbtft_update_display;
+	if (display->backlight)
+		par->fbtftops.register_backlight = fbtft_register_backlight;
+
+	/* use driver provided functions */
+	fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
+
+	return info;
+
+release_framebuf:
+	framebuffer_release(info);
+
+alloc_fail:
+	vfree(vmem);
+
+	return NULL;
+}
+EXPORT_SYMBOL(fbtft_framebuffer_alloc);
+
+/**
+ * fbtft_framebuffer_release - frees up all memory used by the framebuffer
+ *
+ * @info: frame buffer info structure
+ *
+ */
+void fbtft_framebuffer_release(struct fb_info *info)
+{
+	fb_deferred_io_cleanup(info);
+	vfree(info->screen_buffer);
+	framebuffer_release(info);
+}
+EXPORT_SYMBOL(fbtft_framebuffer_release);
+
+/**
+ *	fbtft_register_framebuffer - registers a tft frame buffer device
+ *	@fb_info: frame buffer info structure
+ *
+ *  Sets SPI driverdata if needed
+ *  Requests needed gpios.
+ *  Initializes display
+ *  Updates display.
+ *	Registers a frame buffer device @fb_info.
+ *
+ *	Returns negative errno on error, or zero for success.
+ *
+ */
+int fbtft_register_framebuffer(struct fb_info *fb_info)
+{
+	int ret;
+	char text1[50] = "";
+	char text2[50] = "";
+	struct fbtft_par *par = fb_info->par;
+	struct spi_device *spi = par->spi;
+
+	/* sanity checks */
+	if (!par->fbtftops.init_display) {
+		dev_err(fb_info->device, "missing fbtftops.init_display()\n");
+		return -EINVAL;
+	}
+
+	if (spi)
+		spi_set_drvdata(spi, fb_info);
+	if (par->pdev)
+		platform_set_drvdata(par->pdev, fb_info);
+
+	ret = par->fbtftops.request_gpios(par);
+	if (ret < 0)
+		goto reg_fail;
+
+	if (par->fbtftops.verify_gpios) {
+		ret = par->fbtftops.verify_gpios(par);
+		if (ret < 0)
+			goto reg_fail;
+	}
+
+	ret = par->fbtftops.init_display(par);
+	if (ret < 0)
+		goto reg_fail;
+	if (par->fbtftops.set_var) {
+		ret = par->fbtftops.set_var(par);
+		if (ret < 0)
+			goto reg_fail;
+	}
+
+	/* update the entire display */
+	par->fbtftops.update_display(par, 0, par->info->var.yres - 1);
+
+	if (par->fbtftops.set_gamma && par->gamma.curves) {
+		ret = par->fbtftops.set_gamma(par, par->gamma.curves);
+		if (ret)
+			goto reg_fail;
+	}
+
+	if (par->fbtftops.register_backlight)
+		par->fbtftops.register_backlight(par);
+
+	ret = register_framebuffer(fb_info);
+	if (ret < 0)
+		goto reg_fail;
+
+	fbtft_sysfs_init(par);
+
+	if (par->txbuf.buf && par->txbuf.len >= 1024)
+		sprintf(text1, ", %zu KiB buffer memory", par->txbuf.len >> 10);
+	if (spi)
+		sprintf(text2, ", spi%d.%d at %d MHz", spi->master->bus_num,
+			spi->chip_select, spi->max_speed_hz / 1000000);
+	dev_info(fb_info->dev,
+		 "%s frame buffer, %dx%d, %d KiB video memory%s, fps=%lu%s\n",
+		 fb_info->fix.id, fb_info->var.xres, fb_info->var.yres,
+		 fb_info->fix.smem_len >> 10, text1,
+		 HZ / fb_info->fbdefio->delay, text2);
+
+	/* Turn on backlight if available */
+	if (fb_info->bl_dev) {
+		fb_info->bl_dev->props.power = FB_BLANK_UNBLANK;
+		fb_info->bl_dev->ops->update_status(fb_info->bl_dev);
+	}
+
+	return 0;
+
+reg_fail:
+	if (par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight(par);
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_register_framebuffer);
+
+/**
+ *	fbtft_unregister_framebuffer - releases a tft frame buffer device
+ *	@fb_info: frame buffer info structure
+ *
+ *  Frees SPI driverdata if needed
+ *  Frees gpios.
+ *	Unregisters frame buffer device.
+ *
+ */
+int fbtft_unregister_framebuffer(struct fb_info *fb_info)
+{
+	struct fbtft_par *par = fb_info->par;
+
+	if (par->fbtftops.unregister_backlight)
+		par->fbtftops.unregister_backlight(par);
+	fbtft_sysfs_exit(par);
+	unregister_framebuffer(fb_info);
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_unregister_framebuffer);
+
+/**
+ * fbtft_init_display_from_property() - Device Tree init_display() function
+ * @par: Driver data
+ *
+ * Return: 0 if successful, negative if error
+ */
+static int fbtft_init_display_from_property(struct fbtft_par *par)
+{
+	struct device *dev = par->info->device;
+	int buf[64], count, index, i, j, ret;
+	u32 *values;
+	u32 val;
+
+	count = device_property_count_u32(dev, "init");
+	if (count < 0)
+		return count;
+	if (count == 0)
+		return -EINVAL;
+
+	values = kmalloc_array(count + 1, sizeof(*values), GFP_KERNEL);
+	if (!values)
+		return -ENOMEM;
+
+	ret = device_property_read_u32_array(dev, "init", values, count);
+	if (ret)
+		goto out_free;
+
+	par->fbtftops.reset(par);
+
+	index = -1;
+	val = values[++index];
+
+	while (index < count) {
+		if (val & FBTFT_OF_INIT_CMD) {
+			val &= 0xFFFF;
+			i = 0;
+			while ((index < count) && !(val & 0xFFFF0000)) {
+				if (i > 63) {
+					dev_err(dev,
+						"%s: Maximum register values exceeded\n",
+						__func__);
+					ret = -EINVAL;
+					goto out_free;
+				}
+				buf[i++] = val;
+				val = values[++index];
+			}
+			/* make debug message */
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				      "init: write_register:\n");
+			for (j = 0; j < i; j++)
+				fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+					      "buf[%d] = %02X\n", j, buf[j]);
+
+			par->fbtftops.write_register(par, i,
+				buf[0], buf[1], buf[2], buf[3],
+				buf[4], buf[5], buf[6], buf[7],
+				buf[8], buf[9], buf[10], buf[11],
+				buf[12], buf[13], buf[14], buf[15],
+				buf[16], buf[17], buf[18], buf[19],
+				buf[20], buf[21], buf[22], buf[23],
+				buf[24], buf[25], buf[26], buf[27],
+				buf[28], buf[29], buf[30], buf[31],
+				buf[32], buf[33], buf[34], buf[35],
+				buf[36], buf[37], buf[38], buf[39],
+				buf[40], buf[41], buf[42], buf[43],
+				buf[44], buf[45], buf[46], buf[47],
+				buf[48], buf[49], buf[50], buf[51],
+				buf[52], buf[53], buf[54], buf[55],
+				buf[56], buf[57], buf[58], buf[59],
+				buf[60], buf[61], buf[62], buf[63]);
+		} else if (val & FBTFT_OF_INIT_DELAY) {
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				      "init: msleep(%u)\n", val & 0xFFFF);
+			msleep(val & 0xFFFF);
+			val = values[++index];
+		} else {
+			dev_err(dev, "illegal init value 0x%X\n", val);
+			ret = -EINVAL;
+			goto out_free;
+		}
+	}
+
+out_free:
+	kfree(values);
+	return ret;
+}
+
+/**
+ * fbtft_init_display() - Generic init_display() function
+ * @par: Driver data
+ *
+ * Uses par->init_sequence to do the initialization
+ *
+ * Return: 0 if successful, negative if error
+ */
+int fbtft_init_display(struct fbtft_par *par)
+{
+	int buf[64];
+	int i;
+	int j;
+
+	/* sanity check */
+	if (!par->init_sequence) {
+		dev_err(par->info->device,
+			"error: init_sequence is not set\n");
+		return -EINVAL;
+	}
+
+	/* make sure stop marker exists */
+	for (i = 0; i < FBTFT_MAX_INIT_SEQUENCE; i++) {
+		if (par->init_sequence[i] == -3)
+			break;
+	}
+
+	if (i == FBTFT_MAX_INIT_SEQUENCE) {
+		dev_err(par->info->device,
+			"missing stop marker at end of init sequence\n");
+		return -EINVAL;
+	}
+
+	par->fbtftops.reset(par);
+
+	i = 0;
+	while (i < FBTFT_MAX_INIT_SEQUENCE) {
+		if (par->init_sequence[i] == -3) {
+			/* done */
+			return 0;
+		}
+		if (par->init_sequence[i] >= 0) {
+			dev_err(par->info->device,
+				"missing delimiter at position %d\n", i);
+			return -EINVAL;
+		}
+		if (par->init_sequence[i + 1] < 0) {
+			dev_err(par->info->device,
+				"missing value after delimiter %d at position %d\n",
+				par->init_sequence[i], i);
+			return -EINVAL;
+		}
+		switch (par->init_sequence[i]) {
+		case -1:
+			i++;
+
+			/* make debug message */
+			for (j = 0; par->init_sequence[i + 1 + j] >= 0; j++);
+
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				      "init: write(0x%02X) %*ph\n",
+				      par->init_sequence[i], j,
+				      &par->init_sequence[i + 1]);
+
+			/* Write */
+			j = 0;
+			while (par->init_sequence[i] >= 0) {
+				if (j > 63) {
+					dev_err(par->info->device,
+						"%s: Maximum register values exceeded\n",
+						__func__);
+					return -EINVAL;
+				}
+				buf[j++] = par->init_sequence[i++];
+			}
+			par->fbtftops.write_register(par, j,
+				buf[0], buf[1], buf[2], buf[3],
+				buf[4], buf[5], buf[6], buf[7],
+				buf[8], buf[9], buf[10], buf[11],
+				buf[12], buf[13], buf[14], buf[15],
+				buf[16], buf[17], buf[18], buf[19],
+				buf[20], buf[21], buf[22], buf[23],
+				buf[24], buf[25], buf[26], buf[27],
+				buf[28], buf[29], buf[30], buf[31],
+				buf[32], buf[33], buf[34], buf[35],
+				buf[36], buf[37], buf[38], buf[39],
+				buf[40], buf[41], buf[42], buf[43],
+				buf[44], buf[45], buf[46], buf[47],
+				buf[48], buf[49], buf[50], buf[51],
+				buf[52], buf[53], buf[54], buf[55],
+				buf[56], buf[57], buf[58], buf[59],
+				buf[60], buf[61], buf[62], buf[63]);
+			break;
+		case -2:
+			i++;
+			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+				      "init: mdelay(%d)\n",
+				      par->init_sequence[i]);
+			mdelay(par->init_sequence[i++]);
+			break;
+		default:
+			dev_err(par->info->device,
+				"unknown delimiter %d at position %d\n",
+				par->init_sequence[i], i);
+			return -EINVAL;
+		}
+	}
+
+	dev_err(par->info->device,
+		"%s: something is wrong. Shouldn't get here.\n", __func__);
+	return -EINVAL;
+}
+EXPORT_SYMBOL(fbtft_init_display);
+
+/**
+ * fbtft_verify_gpios() - Generic verify_gpios() function
+ * @par: Driver data
+ *
+ * Uses @spi, @pdev and @buswidth to determine which GPIOs is needed
+ *
+ * Return: 0 if successful, negative if error
+ */
+static int fbtft_verify_gpios(struct fbtft_par *par)
+{
+	struct fbtft_platform_data *pdata = par->pdata;
+	int i;
+
+	fbtft_par_dbg(DEBUG_VERIFY_GPIOS, par, "%s()\n", __func__);
+
+	if (pdata->display.buswidth != 9 &&  par->startbyte == 0 &&
+	    !par->gpio.dc) {
+		dev_err(par->info->device,
+			"Missing info about 'dc' gpio. Aborting.\n");
+		return -EINVAL;
+	}
+
+	if (!par->pdev)
+		return 0;
+
+	if (!par->gpio.wr) {
+		dev_err(par->info->device, "Missing 'wr' gpio. Aborting.\n");
+		return -EINVAL;
+	}
+	for (i = 0; i < pdata->display.buswidth; i++) {
+		if (!par->gpio.db[i]) {
+			dev_err(par->info->device,
+				"Missing 'db%02d' gpio. Aborting.\n", i);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/* returns 0 if the property is not present */
+static u32 fbtft_property_value(struct device *dev, const char *propname)
+{
+	int ret;
+	u32 val = 0;
+
+	ret = device_property_read_u32(dev, propname, &val);
+	if (ret == 0)
+		dev_info(dev, "%s: %s = %u\n", __func__, propname, val);
+
+	return val;
+}
+
+static struct fbtft_platform_data *fbtft_properties_read(struct device *dev)
+{
+	struct fbtft_platform_data *pdata;
+
+	if (!dev_fwnode(dev)) {
+		dev_err(dev, "Missing platform data or properties\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	pdata->display.width = fbtft_property_value(dev, "width");
+	pdata->display.height = fbtft_property_value(dev, "height");
+	pdata->display.regwidth = fbtft_property_value(dev, "regwidth");
+	pdata->display.buswidth = fbtft_property_value(dev, "buswidth");
+	pdata->display.backlight = fbtft_property_value(dev, "backlight");
+	pdata->display.bpp = fbtft_property_value(dev, "bpp");
+	pdata->display.debug = fbtft_property_value(dev, "debug");
+	pdata->rotate = fbtft_property_value(dev, "rotate");
+	pdata->bgr = device_property_read_bool(dev, "bgr");
+	pdata->fps = fbtft_property_value(dev, "fps");
+	pdata->txbuflen = fbtft_property_value(dev, "txbuflen");
+	pdata->startbyte = fbtft_property_value(dev, "startbyte");
+	device_property_read_string(dev, "gamma", (const char **)&pdata->gamma);
+
+	if (device_property_present(dev, "led-gpios"))
+		pdata->display.backlight = 1;
+	if (device_property_present(dev, "init"))
+		pdata->display.fbtftops.init_display =
+			fbtft_init_display_from_property;
+
+	pdata->display.fbtftops.request_gpios = fbtft_request_gpios;
+
+	return pdata;
+}
+
+/**
+ * fbtft_probe_common() - Generic device probe() helper function
+ * @display: Display properties
+ * @sdev: SPI device
+ * @pdev: Platform device
+ *
+ * Allocates, initializes and registers a framebuffer
+ *
+ * Either @sdev or @pdev should be NULL
+ *
+ * Return: 0 if successful, negative if error
+ */
+int fbtft_probe_common(struct fbtft_display *display,
+		       struct spi_device *sdev,
+		       struct platform_device *pdev)
+{
+	struct device *dev;
+	struct fb_info *info;
+	struct fbtft_par *par;
+	struct fbtft_platform_data *pdata;
+	int ret;
+
+	if (sdev)
+		dev = &sdev->dev;
+	else
+		dev = &pdev->dev;
+
+	if (unlikely(display->debug & DEBUG_DRIVER_INIT_FUNCTIONS))
+		dev_info(dev, "%s()\n", __func__);
+
+	pdata = dev->platform_data;
+	if (!pdata) {
+		pdata = fbtft_properties_read(dev);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+	}
+
+	info = fbtft_framebuffer_alloc(display, dev, pdata);
+	if (!info)
+		return -ENOMEM;
+
+	par = info->par;
+	par->spi = sdev;
+	par->pdev = pdev;
+
+	if (display->buswidth == 0) {
+		dev_err(dev, "buswidth is not set\n");
+		return -EINVAL;
+	}
+
+	/* write register functions */
+	if (display->regwidth == 8 && display->buswidth == 8)
+		par->fbtftops.write_register = fbtft_write_reg8_bus8;
+	else if (display->regwidth == 8 && display->buswidth == 9 && par->spi)
+		par->fbtftops.write_register = fbtft_write_reg8_bus9;
+	else if (display->regwidth == 16 && display->buswidth == 8)
+		par->fbtftops.write_register = fbtft_write_reg16_bus8;
+	else if (display->regwidth == 16 && display->buswidth == 16)
+		par->fbtftops.write_register = fbtft_write_reg16_bus16;
+	else
+		dev_warn(dev,
+			 "no default functions for regwidth=%d and buswidth=%d\n",
+			 display->regwidth, display->buswidth);
+
+	/* write_vmem() functions */
+	if (display->buswidth == 8)
+		par->fbtftops.write_vmem = fbtft_write_vmem16_bus8;
+	else if (display->buswidth == 9)
+		par->fbtftops.write_vmem = fbtft_write_vmem16_bus9;
+	else if (display->buswidth == 16)
+		par->fbtftops.write_vmem = fbtft_write_vmem16_bus16;
+
+	/* GPIO write() functions */
+	if (par->pdev) {
+		if (display->buswidth == 8)
+			par->fbtftops.write = fbtft_write_gpio8_wr;
+		else if (display->buswidth == 16)
+			par->fbtftops.write = fbtft_write_gpio16_wr;
+	}
+
+	/* 9-bit SPI setup */
+	if (par->spi && display->buswidth == 9) {
+		if (par->spi->master->bits_per_word_mask & SPI_BPW_MASK(9)) {
+			par->spi->bits_per_word = 9;
+		} else {
+			dev_warn(&par->spi->dev,
+				 "9-bit SPI not available, emulating using 8-bit.\n");
+			/* allocate buffer with room for dc bits */
+			par->extra = devm_kzalloc(par->info->device,
+						  par->txbuf.len +
+						  (par->txbuf.len / 8) + 8,
+						  GFP_KERNEL);
+			if (!par->extra) {
+				ret = -ENOMEM;
+				goto out_release;
+			}
+			par->fbtftops.write = fbtft_write_spi_emulate_9;
+		}
+	}
+
+	if (!par->fbtftops.verify_gpios)
+		par->fbtftops.verify_gpios = fbtft_verify_gpios;
+
+	/* make sure we still use the driver provided functions */
+	fbtft_merge_fbtftops(&par->fbtftops, &display->fbtftops);
+
+	/* use init_sequence if provided */
+	if (par->init_sequence)
+		par->fbtftops.init_display = fbtft_init_display;
+
+	/* use platform_data provided functions above all */
+	fbtft_merge_fbtftops(&par->fbtftops, &pdata->display.fbtftops);
+
+	ret = fbtft_register_framebuffer(info);
+	if (ret < 0)
+		goto out_release;
+
+	return 0;
+
+out_release:
+	fbtft_framebuffer_release(info);
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_probe_common);
+
+/**
+ * fbtft_remove_common() - Generic device remove() helper function
+ * @dev: Device
+ * @info: Framebuffer
+ *
+ * Unregisters and releases the framebuffer
+ *
+ * Return: 0 if successful, negative if error
+ */
+int fbtft_remove_common(struct device *dev, struct fb_info *info)
+{
+	struct fbtft_par *par;
+
+	if (!info)
+		return -EINVAL;
+	par = info->par;
+	if (par)
+		fbtft_par_dbg(DEBUG_DRIVER_INIT_FUNCTIONS, par,
+			      "%s()\n", __func__);
+	fbtft_unregister_framebuffer(info);
+	fbtft_framebuffer_release(info);
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_remove_common);
+
+MODULE_LICENSE("GPL");
diff --git a/bsp/modules/fbtft/fbtft-io.c b/bsp/modules/fbtft/fbtft-io.c
new file mode 100644
index 0000000000..de1904a443
--- /dev/null
+++ b/bsp/modules/fbtft/fbtft-io.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+#include "fbtft.h"
+
+int fbtft_write_spi(struct fbtft_par *par, void *buf, size_t len)
+{
+	struct spi_transfer t = {
+		.tx_buf = buf,
+		.len = len,
+	};
+	struct spi_message m;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+			  "%s(len=%zu): ", __func__, len);
+
+	if (!par->spi) {
+		dev_err(par->info->device,
+			"%s: par->spi is unexpectedly NULL\n", __func__);
+		return -1;
+	}
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+	return spi_sync(par->spi, &m);
+}
+EXPORT_SYMBOL(fbtft_write_spi);
+
+/**
+ * fbtft_write_spi_emulate_9() - write SPI emulating 9-bit
+ * @par: Driver data
+ * @buf: Buffer to write
+ * @len: Length of buffer (must be divisible by 8)
+ *
+ * When 9-bit SPI is not available, this function can be used to emulate that.
+ * par->extra must hold a transformation buffer used for transfer.
+ */
+int fbtft_write_spi_emulate_9(struct fbtft_par *par, void *buf, size_t len)
+{
+	u16 *src = buf;
+	u8 *dst = par->extra;
+	size_t size = len / 2;
+	size_t added = 0;
+	int bits, i, j;
+	u64 val, dc, tmp;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+			  "%s(len=%zu): ", __func__, len);
+
+	if (!par->extra) {
+		dev_err(par->info->device, "%s: error: par->extra is NULL\n",
+			__func__);
+		return -EINVAL;
+	}
+	if ((len % 8) != 0) {
+		dev_err(par->info->device,
+			"error: len=%zu must be divisible by 8\n", len);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < size; i += 8) {
+		tmp = 0;
+		bits = 63;
+		for (j = 0; j < 7; j++) {
+			dc = (*src & 0x0100) ? 1 : 0;
+			val = *src & 0x00FF;
+			tmp |= dc << bits;
+			bits -= 8;
+			tmp |= val << bits--;
+			src++;
+		}
+		tmp |= ((*src & 0x0100) ? 1 : 0);
+		*(__be64 *)dst = cpu_to_be64(tmp);
+		dst += 8;
+		*dst++ = (u8)(*src++ & 0x00FF);
+		added++;
+	}
+
+	return spi_write(par->spi, par->extra, size + added);
+}
+EXPORT_SYMBOL(fbtft_write_spi_emulate_9);
+
+int fbtft_read_spi(struct fbtft_par *par, void *buf, size_t len)
+{
+	int ret;
+	u8 txbuf[32] = { 0, };
+	struct spi_transfer	t = {
+			.speed_hz = 2000000,
+			.rx_buf		= buf,
+			.len		= len,
+		};
+	struct spi_message	m;
+
+	if (!par->spi) {
+		dev_err(par->info->device,
+			"%s: par->spi is unexpectedly NULL\n", __func__);
+		return -ENODEV;
+	}
+
+	if (par->startbyte) {
+		if (len > 32) {
+			dev_err(par->info->device,
+				"len=%zu can't be larger than 32 when using 'startbyte'\n",
+				len);
+			return -EINVAL;
+		}
+		txbuf[0] = par->startbyte | 0x3;
+		t.tx_buf = txbuf;
+		fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8,
+				  txbuf, len, "%s(len=%zu) txbuf => ",
+				  __func__, len);
+	}
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+	ret = spi_sync(par->spi, &m);
+	fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8, buf, len,
+			  "%s(len=%zu) buf <= ", __func__, len);
+
+	return ret;
+}
+EXPORT_SYMBOL(fbtft_read_spi);
+
+/*
+ * Optimized use of gpiolib is twice as fast as no optimization
+ * only one driver can use the optimized version at a time
+ */
+int fbtft_write_gpio8_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+	u8 data;
+	int i;
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+	static u8 prev_data;
+#endif
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+			  "%s(len=%zu): ", __func__, len);
+
+	while (len--) {
+		data = *(u8 *)buf;
+
+		/* Start writing by pulling down /WR */
+		gpiod_set_value(par->gpio.wr, 1);
+
+		/* Set data */
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		if (data == prev_data) {
+			gpiod_set_value(par->gpio.wr, 1); /* used as delay */
+		} else {
+			for (i = 0; i < 8; i++) {
+				if ((data & 1) != (prev_data & 1))
+					gpiod_set_value(par->gpio.db[i],
+							data & 1);
+				data >>= 1;
+				prev_data >>= 1;
+			}
+		}
+#else
+		for (i = 0; i < 8; i++) {
+			gpiod_set_value(par->gpio.db[i], data & 1);
+			data >>= 1;
+		}
+#endif
+
+		/* Pullup /WR */
+		gpiod_set_value(par->gpio.wr, 0);
+
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		prev_data = *(u8 *)buf;
+#endif
+		buf++;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio8_wr);
+
+int fbtft_write_gpio16_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+	u16 data;
+	int i;
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+	static u16 prev_data;
+#endif
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+			  "%s(len=%zu): ", __func__, len);
+
+	while (len) {
+		data = *(u16 *)buf;
+
+		/* Start writing by pulling down /WR */
+		gpiod_set_value(par->gpio.wr, 1);
+
+		/* Set data */
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		if (data == prev_data) {
+			gpiod_set_value(par->gpio.wr, 1); /* used as delay */
+		} else {
+			for (i = 0; i < 16; i++) {
+				if ((data & 1) != (prev_data & 1))
+					gpiod_set_value(par->gpio.db[i],
+							data & 1);
+				data >>= 1;
+				prev_data >>= 1;
+			}
+		}
+#else
+		for (i = 0; i < 16; i++) {
+			gpiod_set_value(par->gpio.db[i], data & 1);
+			data >>= 1;
+		}
+#endif
+
+		/* Pullup /WR */
+		gpiod_set_value(par->gpio.wr, 0);
+
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+		prev_data = *(u16 *)buf;
+#endif
+		buf += 2;
+		len -= 2;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr);
+
+int fbtft_write_gpio16_wr_latched(struct fbtft_par *par, void *buf, size_t len)
+{
+	dev_err(par->info->device, "%s: function not implemented\n", __func__);
+	return -1;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr_latched);
diff --git a/bsp/modules/fbtft/fbtft-sysfs.c b/bsp/modules/fbtft/fbtft-sysfs.c
new file mode 100644
index 0000000000..39e8d28066
--- /dev/null
+++ b/bsp/modules/fbtft/fbtft-sysfs.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "fbtft.h"
+#include "internal.h"
+
+static int get_next_ulong(char **str_p, unsigned long *val, char *sep, int base)
+{
+	char *p_val;
+
+	if (!str_p || !(*str_p))
+		return -EINVAL;
+
+	p_val = strsep(str_p, sep);
+
+	if (!p_val)
+		return -EINVAL;
+
+	return kstrtoul(p_val, base, val);
+}
+
+int fbtft_gamma_parse_str(struct fbtft_par *par, u32 *curves,
+			  const char *str, int size)
+{
+	char *str_p, *curve_p = NULL;
+	char *tmp;
+	unsigned long val = 0;
+	int ret = 0;
+	int curve_counter, value_counter;
+	int _count;
+
+	fbtft_par_dbg(DEBUG_SYSFS, par, "%s() str=\n", __func__);
+
+	if (!str || !curves)
+		return -EINVAL;
+
+	fbtft_par_dbg(DEBUG_SYSFS, par, "%s\n", str);
+
+	tmp = kmemdup(str, size + 1, GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	/* replace optional separators */
+	str_p = tmp;
+	while (*str_p) {
+		if (*str_p == ',')
+			*str_p = ' ';
+		if (*str_p == ';')
+			*str_p = '\n';
+		str_p++;
+	}
+
+	str_p = strim(tmp);
+
+	curve_counter = 0;
+	while (str_p) {
+		if (curve_counter == par->gamma.num_curves) {
+			dev_err(par->info->device, "Gamma: Too many curves\n");
+			ret = -EINVAL;
+			goto out;
+		}
+		curve_p = strsep(&str_p, "\n");
+		value_counter = 0;
+		while (curve_p) {
+			if (value_counter == par->gamma.num_values) {
+				dev_err(par->info->device,
+					"Gamma: Too many values\n");
+				ret = -EINVAL;
+				goto out;
+			}
+			ret = get_next_ulong(&curve_p, &val, " ", 16);
+			if (ret)
+				goto out;
+
+			_count = curve_counter * par->gamma.num_values +
+				 value_counter;
+			curves[_count] = val;
+			value_counter++;
+		}
+		if (value_counter != par->gamma.num_values) {
+			dev_err(par->info->device, "Gamma: Too few values\n");
+			ret = -EINVAL;
+			goto out;
+		}
+		curve_counter++;
+	}
+	if (curve_counter != par->gamma.num_curves) {
+		dev_err(par->info->device, "Gamma: Too few curves\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+out:
+	kfree(tmp);
+	return ret;
+}
+
+static ssize_t
+sprintf_gamma(struct fbtft_par *par, u32 *curves, char *buf)
+{
+	ssize_t len = 0;
+	unsigned int i, j;
+
+	mutex_lock(&par->gamma.lock);
+	for (i = 0; i < par->gamma.num_curves; i++) {
+		for (j = 0; j < par->gamma.num_values; j++)
+			len += scnprintf(&buf[len], PAGE_SIZE,
+			     "%04x ", curves[i * par->gamma.num_values + j]);
+		buf[len - 1] = '\n';
+	}
+	mutex_unlock(&par->gamma.lock);
+
+	return len;
+}
+
+static ssize_t store_gamma_curve(struct device *device,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+	u32 tmp_curves[FBTFT_GAMMA_MAX_VALUES_TOTAL];
+	int ret;
+
+	ret = fbtft_gamma_parse_str(par, tmp_curves, buf, count);
+	if (ret)
+		return ret;
+
+	ret = par->fbtftops.set_gamma(par, tmp_curves);
+	if (ret)
+		return ret;
+
+	mutex_lock(&par->gamma.lock);
+	memcpy(par->gamma.curves, tmp_curves,
+	       par->gamma.num_curves * par->gamma.num_values *
+	       sizeof(tmp_curves[0]));
+	mutex_unlock(&par->gamma.lock);
+
+	return count;
+}
+
+static ssize_t show_gamma_curve(struct device *device,
+				struct device_attribute *attr, char *buf)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+
+	return sprintf_gamma(par, par->gamma.curves, buf);
+}
+
+static struct device_attribute gamma_device_attrs[] = {
+	__ATTR(gamma, 0660, show_gamma_curve, store_gamma_curve),
+};
+
+void fbtft_expand_debug_value(unsigned long *debug)
+{
+	switch (*debug & 0x7) {
+	case 1:
+		*debug |= DEBUG_LEVEL_1;
+		break;
+	case 2:
+		*debug |= DEBUG_LEVEL_2;
+		break;
+	case 3:
+		*debug |= DEBUG_LEVEL_3;
+		break;
+	case 4:
+		*debug |= DEBUG_LEVEL_4;
+		break;
+	case 5:
+		*debug |= DEBUG_LEVEL_5;
+		break;
+	case 6:
+		*debug |= DEBUG_LEVEL_6;
+		break;
+	case 7:
+		*debug = 0xFFFFFFFF;
+		break;
+	}
+}
+
+static ssize_t store_debug(struct device *device,
+			   struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &par->debug);
+	if (ret)
+		return ret;
+	fbtft_expand_debug_value(&par->debug);
+
+	return count;
+}
+
+static ssize_t show_debug(struct device *device,
+			  struct device_attribute *attr, char *buf)
+{
+	struct fb_info *fb_info = dev_get_drvdata(device);
+	struct fbtft_par *par = fb_info->par;
+
+	return sysfs_emit(buf, "%lu\n", par->debug);
+}
+
+static struct device_attribute debug_device_attr =
+	__ATTR(debug, 0660, show_debug, store_debug);
+
+void fbtft_sysfs_init(struct fbtft_par *par)
+{
+	device_create_file(par->info->dev, &debug_device_attr);
+	if (par->gamma.curves && par->fbtftops.set_gamma)
+		device_create_file(par->info->dev, &gamma_device_attrs[0]);
+}
+
+void fbtft_sysfs_exit(struct fbtft_par *par)
+{
+	device_remove_file(par->info->dev, &debug_device_attr);
+	if (par->gamma.curves && par->fbtftops.set_gamma)
+		device_remove_file(par->info->dev, &gamma_device_attrs[0]);
+}
diff --git a/bsp/modules/fbtft/fbtft.h b/bsp/modules/fbtft/fbtft.h
new file mode 100644
index 0000000000..06afaa9d50
--- /dev/null
+++ b/bsp/modules/fbtft/fbtft.h
@@ -0,0 +1,423 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Copyright (C) 2013 Noralf Tronnes */
+
+#ifndef __LINUX_FBTFT_H
+#define __LINUX_FBTFT_H
+
+#include <linux/fb.h>
+#include <linux/spinlock.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_device.h>
+
+#define FBTFT_ONBOARD_BACKLIGHT 2
+
+#define FBTFT_GPIO_NO_MATCH		0xFFFF
+#define FBTFT_GPIO_NAME_SIZE	32
+#define FBTFT_MAX_INIT_SEQUENCE      512
+#define FBTFT_GAMMA_MAX_VALUES_TOTAL 128
+
+#define FBTFT_OF_INIT_CMD	BIT(24)
+#define FBTFT_OF_INIT_DELAY	BIT(25)
+
+/**
+ * struct fbtft_gpio - Structure that holds one pinname to gpio mapping
+ * @name: pinname (reset, dc, etc.)
+ * @gpio: GPIO number
+ *
+ */
+struct fbtft_gpio {
+	char name[FBTFT_GPIO_NAME_SIZE];
+	struct gpio_desc *gpio;
+};
+
+struct fbtft_par;
+
+/**
+ * struct fbtft_ops - FBTFT operations structure
+ * @write: Writes to interface bus
+ * @read: Reads from interface bus
+ * @write_vmem: Writes video memory to display
+ * @write_reg: Writes to controller register
+ * @set_addr_win: Set the GRAM update window
+ * @reset: Reset the LCD controller
+ * @mkdirty: Marks display lines for update
+ * @update_display: Updates the display
+ * @init_display: Initializes the display
+ * @blank: Blank the display (optional)
+ * @request_gpios_match: Do pinname to gpio matching
+ * @request_gpios: Request gpios from the kernel
+ * @free_gpios: Free previously requested gpios
+ * @verify_gpios: Verify that necessary gpios is present (optional)
+ * @register_backlight: Used to register backlight device (optional)
+ * @unregister_backlight: Unregister backlight device (optional)
+ * @set_var: Configure LCD with values from variables like @rotate and @bgr
+ *           (optional)
+ * @set_gamma: Set Gamma curve (optional)
+ *
+ * Most of these operations have default functions assigned to them in
+ *     fbtft_framebuffer_alloc()
+ */
+struct fbtft_ops {
+	int (*write)(struct fbtft_par *par, void *buf, size_t len);
+	int (*read)(struct fbtft_par *par, void *buf, size_t len);
+	int (*write_vmem)(struct fbtft_par *par, size_t offset, size_t len);
+	void (*write_register)(struct fbtft_par *par, int len, ...);
+
+	void (*set_addr_win)(struct fbtft_par *par,
+			     int xs, int ys, int xe, int ye);
+	void (*reset)(struct fbtft_par *par);
+	void (*mkdirty)(struct fb_info *info, int from, int to);
+	void (*update_display)(struct fbtft_par *par,
+			       unsigned int start_line, unsigned int end_line);
+	int (*init_display)(struct fbtft_par *par);
+	int (*blank)(struct fbtft_par *par, bool on);
+
+	unsigned long (*request_gpios_match)(struct fbtft_par *par,
+					     const struct fbtft_gpio *gpio);
+	int (*request_gpios)(struct fbtft_par *par);
+	int (*verify_gpios)(struct fbtft_par *par);
+
+	void (*register_backlight)(struct fbtft_par *par);
+	void (*unregister_backlight)(struct fbtft_par *par);
+
+	int (*set_var)(struct fbtft_par *par);
+	int (*set_gamma)(struct fbtft_par *par, u32 *curves);
+};
+
+/**
+ * struct fbtft_display - Describes the display properties
+ * @width: Width of display in pixels
+ * @height: Height of display in pixels
+ * @regwidth: LCD Controller Register width in bits
+ * @buswidth: Display interface bus width in bits
+ * @backlight: Backlight type.
+ * @fbtftops: FBTFT operations provided by driver or device (platform_data)
+ * @bpp: Bits per pixel
+ * @fps: Frames per second
+ * @txbuflen: Size of transmit buffer
+ * @init_sequence: Pointer to LCD initialization array
+ * @gamma: String representation of Gamma curve(s)
+ * @gamma_num: Number of Gamma curves
+ * @gamma_len: Number of values per Gamma curve
+ * @debug: Initial debug value
+ *
+ * This structure is not stored by FBTFT except for init_sequence.
+ */
+struct fbtft_display {
+	unsigned int width;
+	unsigned int height;
+	unsigned int regwidth;
+	unsigned int buswidth;
+	unsigned int backlight;
+	struct fbtft_ops fbtftops;
+	unsigned int bpp;
+	unsigned int fps;
+	int txbuflen;
+	const s16 *init_sequence;
+	char *gamma;
+	int gamma_num;
+	int gamma_len;
+	unsigned long debug;
+};
+
+/**
+ * struct fbtft_platform_data - Passes display specific data to the driver
+ * @display: Display properties
+ * @gpios: Pointer to an array of pinname to gpio mappings
+ * @rotate: Display rotation angle
+ * @bgr: LCD Controller BGR bit
+ * @fps: Frames per second (this will go away, use @fps in @fbtft_display)
+ * @txbuflen: Size of transmit buffer
+ * @startbyte: When set, enables use of Startbyte in transfers
+ * @gamma: String representation of Gamma curve(s)
+ * @extra: A way to pass extra info
+ */
+struct fbtft_platform_data {
+	struct fbtft_display display;
+	unsigned int rotate;
+	bool bgr;
+	unsigned int fps;
+	int txbuflen;
+	u8 startbyte;
+	char *gamma;
+	void *extra;
+};
+
+/**
+ * struct fbtft_par - Main FBTFT data structure
+ *
+ * This structure holds all relevant data to operate the display
+ *
+ * See sourcefile for documentation since nested structs is not
+ * supported by kernel-doc.
+ *
+ */
+/* @spi: Set if it is a SPI device
+ * @pdev: Set if it is a platform device
+ * @info: Pointer to framebuffer fb_info structure
+ * @pdata: Pointer to platform data
+ * @ssbuf: Not used
+ * @pseudo_palette: Used by fb_set_colreg()
+ * @txbuf.buf: Transmit buffer
+ * @txbuf.len: Transmit buffer length
+ * @buf: Small buffer used when writing init data over SPI
+ * @startbyte: Used by some controllers when in SPI mode.
+ *             Format: 6 bit Device id + RS bit + RW bit
+ * @fbtftops: FBTFT operations provided by driver or device (platform_data)
+ * @dirty_lock: Protects dirty_lines_start and dirty_lines_end
+ * @dirty_lines_start: Where to begin updating display
+ * @dirty_lines_end: Where to end updating display
+ * @gpio.reset: GPIO used to reset display
+ * @gpio.dc: Data/Command signal, also known as RS
+ * @gpio.rd: Read latching signal
+ * @gpio.wr: Write latching signal
+ * @gpio.latch: Bus latch signal, eg. 16->8 bit bus latch
+ * @gpio.cs: LCD Chip Select with parallel interface bus
+ * @gpio.db[16]: Parallel databus
+ * @gpio.led[16]: Led control signals
+ * @gpio.aux[16]: Auxiliary signals, not used by core
+ * @init_sequence: Pointer to LCD initialization array
+ * @gamma.lock: Mutex for Gamma curve locking
+ * @gamma.curves: Pointer to Gamma curve array
+ * @gamma.num_values: Number of values per Gamma curve
+ * @gamma.num_curves: Number of Gamma curves
+ * @debug: Pointer to debug value
+ * @current_debug:
+ * @first_update_done: Used to only time the first display update
+ * @update_time: Used to calculate 'fps' in debug output
+ * @bgr: BGR mode/\n
+ * @extra: Extra info needed by driver
+ */
+struct fbtft_par {
+	struct spi_device *spi;
+	struct platform_device *pdev;
+	struct fb_info *info;
+	struct fbtft_platform_data *pdata;
+	u16 *ssbuf;
+	u32 pseudo_palette[16];
+	struct {
+		void *buf;
+		size_t len;
+	} txbuf;
+	u8 *buf;
+	u8 startbyte;
+	struct fbtft_ops fbtftops;
+	spinlock_t dirty_lock;
+	unsigned int dirty_lines_start;
+	unsigned int dirty_lines_end;
+	struct {
+		struct gpio_desc *reset;
+		struct gpio_desc *dc;
+		struct gpio_desc *rd;
+		struct gpio_desc *wr;
+		struct gpio_desc *latch;
+		struct gpio_desc *cs;
+		struct gpio_desc *db[16];
+		struct gpio_desc *led[16];
+		struct gpio_desc *aux[16];
+	} gpio;
+	const s16 *init_sequence;
+	struct {
+		struct mutex lock;
+		u32 *curves;
+		int num_values;
+		int num_curves;
+	} gamma;
+	unsigned long debug;
+	bool first_update_done;
+	ktime_t update_time;
+	bool bgr;
+	void *extra;
+	bool polarity;
+};
+
+#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__}) / sizeof(int))
+
+#define write_reg(par, ...)                                            \
+	((par)->fbtftops.write_register(par, NUMARGS(__VA_ARGS__), __VA_ARGS__))
+
+/* fbtft-core.c */
+int fbtft_write_buf_dc(struct fbtft_par *par, void *buf, size_t len, int dc);
+__printf(5, 6)
+void fbtft_dbg_hex(const struct device *dev, int groupsize,
+		   void *buf, size_t len, const char *fmt, ...);
+struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
+					struct device *dev,
+					struct fbtft_platform_data *pdata);
+void fbtft_framebuffer_release(struct fb_info *info);
+int fbtft_register_framebuffer(struct fb_info *fb_info);
+int fbtft_unregister_framebuffer(struct fb_info *fb_info);
+void fbtft_register_backlight(struct fbtft_par *par);
+void fbtft_unregister_backlight(struct fbtft_par *par);
+int fbtft_init_display(struct fbtft_par *par);
+int fbtft_probe_common(struct fbtft_display *display, struct spi_device *sdev,
+		       struct platform_device *pdev);
+int fbtft_remove_common(struct device *dev, struct fb_info *info);
+
+/* fbtft-io.c */
+int fbtft_write_spi(struct fbtft_par *par, void *buf, size_t len);
+int fbtft_write_spi_emulate_9(struct fbtft_par *par, void *buf, size_t len);
+int fbtft_read_spi(struct fbtft_par *par, void *buf, size_t len);
+int fbtft_write_gpio8_wr(struct fbtft_par *par, void *buf, size_t len);
+int fbtft_write_gpio16_wr(struct fbtft_par *par, void *buf, size_t len);
+int fbtft_write_gpio16_wr_latched(struct fbtft_par *par, void *buf, size_t len);
+
+/* fbtft-bus.c */
+int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len);
+int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len);
+int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len);
+int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len);
+void fbtft_write_reg8_bus8(struct fbtft_par *par, int len, ...);
+void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...);
+void fbtft_write_reg16_bus8(struct fbtft_par *par, int len, ...);
+void fbtft_write_reg16_bus16(struct fbtft_par *par, int len, ...);
+
+#define FBTFT_REGISTER_DRIVER(_name, _compatible, _display)                \
+									   \
+static int fbtft_driver_probe_spi(struct spi_device *spi)                  \
+{                                                                          \
+	return fbtft_probe_common(_display, spi, NULL);                    \
+}                                                                          \
+									   \
+static int fbtft_driver_remove_spi(struct spi_device *spi)                 \
+{                                                                          \
+	struct fb_info *info = spi_get_drvdata(spi);                       \
+									   \
+	return fbtft_remove_common(&spi->dev, info);                       \
+}                                                                          \
+									   \
+static int fbtft_driver_probe_pdev(struct platform_device *pdev)           \
+{                                                                          \
+	return fbtft_probe_common(_display, NULL, pdev);                   \
+}                                                                          \
+									   \
+static int fbtft_driver_remove_pdev(struct platform_device *pdev)          \
+{                                                                          \
+	struct fb_info *info = platform_get_drvdata(pdev);                 \
+									   \
+	return fbtft_remove_common(&pdev->dev, info);                      \
+}                                                                          \
+									   \
+static const struct of_device_id dt_ids[] = {                              \
+	{ .compatible = _compatible },                                     \
+	{},                                                                \
+};                                                                         \
+									   \
+MODULE_DEVICE_TABLE(of, dt_ids);                                           \
+									   \
+									   \
+static struct spi_driver fbtft_driver_spi_driver = {                       \
+	.driver = {                                                        \
+		.name   = _name,                                           \
+		.of_match_table = dt_ids,                                  \
+	},                                                                 \
+	.probe  = fbtft_driver_probe_spi,                                  \
+	.remove = fbtft_driver_remove_spi,                                 \
+};                                                                         \
+									   \
+static struct platform_driver fbtft_driver_platform_driver = {             \
+	.driver = {                                                        \
+		.name   = _name,                                           \
+		.owner  = THIS_MODULE,                                     \
+		.of_match_table = dt_ids,                                  \
+	},                                                                 \
+	.probe  = fbtft_driver_probe_pdev,                                 \
+	.remove = fbtft_driver_remove_pdev,                                \
+};                                                                         \
+									   \
+static int __init fbtft_driver_module_init(void)                           \
+{                                                                          \
+	int ret;                                                           \
+									   \
+	ret = spi_register_driver(&fbtft_driver_spi_driver);               \
+	if (ret < 0)                                                       \
+		return ret;                                                \
+	ret = platform_driver_register(&fbtft_driver_platform_driver);     \
+	if (ret < 0)                                                       \
+		spi_unregister_driver(&fbtft_driver_spi_driver);           \
+	return ret;                                                        \
+}                                                                          \
+									   \
+static void __exit fbtft_driver_module_exit(void)                          \
+{                                                                          \
+	spi_unregister_driver(&fbtft_driver_spi_driver);                   \
+	platform_driver_unregister(&fbtft_driver_platform_driver);         \
+}                                                                          \
+									   \
+module_init(fbtft_driver_module_init);                                     \
+module_exit(fbtft_driver_module_exit);
+
+/* Debug macros */
+
+/* shorthand debug levels */
+#define DEBUG_LEVEL_1	DEBUG_REQUEST_GPIOS
+#define DEBUG_LEVEL_2	(DEBUG_LEVEL_1 | DEBUG_DRIVER_INIT_FUNCTIONS        \
+				       | DEBUG_TIME_FIRST_UPDATE)
+#define DEBUG_LEVEL_3	(DEBUG_LEVEL_2 | DEBUG_RESET | DEBUG_INIT_DISPLAY   \
+				       | DEBUG_BLANK | DEBUG_REQUEST_GPIOS  \
+				       | DEBUG_FREE_GPIOS                   \
+				       | DEBUG_VERIFY_GPIOS                 \
+				       | DEBUG_BACKLIGHT | DEBUG_SYSFS)
+#define DEBUG_LEVEL_4	(DEBUG_LEVEL_2 | DEBUG_FB_READ | DEBUG_FB_WRITE     \
+				       | DEBUG_FB_FILLRECT                  \
+				       | DEBUG_FB_COPYAREA                  \
+				       | DEBUG_FB_IMAGEBLIT | DEBUG_FB_BLANK)
+#define DEBUG_LEVEL_5	(DEBUG_LEVEL_3 | DEBUG_UPDATE_DISPLAY)
+#define DEBUG_LEVEL_6	(DEBUG_LEVEL_4 | DEBUG_LEVEL_5)
+#define DEBUG_LEVEL_7	0xFFFFFFFF
+
+#define DEBUG_DRIVER_INIT_FUNCTIONS BIT(3)
+#define DEBUG_TIME_FIRST_UPDATE     BIT(4)
+#define DEBUG_TIME_EACH_UPDATE      BIT(5)
+#define DEBUG_DEFERRED_IO           BIT(6)
+#define DEBUG_FBTFT_INIT_FUNCTIONS  BIT(7)
+
+/* fbops */
+#define DEBUG_FB_READ               BIT(8)
+#define DEBUG_FB_WRITE              BIT(9)
+#define DEBUG_FB_FILLRECT           BIT(10)
+#define DEBUG_FB_COPYAREA           BIT(11)
+#define DEBUG_FB_IMAGEBLIT          BIT(12)
+#define DEBUG_FB_SETCOLREG          BIT(13)
+#define DEBUG_FB_BLANK              BIT(14)
+
+#define DEBUG_SYSFS                 BIT(16)
+
+/* fbtftops */
+#define DEBUG_BACKLIGHT             BIT(17)
+#define DEBUG_READ                  BIT(18)
+#define DEBUG_WRITE                 BIT(19)
+#define DEBUG_WRITE_VMEM            BIT(20)
+#define DEBUG_WRITE_REGISTER        BIT(21)
+#define DEBUG_SET_ADDR_WIN          BIT(22)
+#define DEBUG_RESET                 BIT(23)
+#define DEBUG_MKDIRTY               BIT(24)
+#define DEBUG_UPDATE_DISPLAY        BIT(25)
+#define DEBUG_INIT_DISPLAY          BIT(26)
+#define DEBUG_BLANK                 BIT(27)
+#define DEBUG_REQUEST_GPIOS         BIT(28)
+#define DEBUG_FREE_GPIOS            BIT(29)
+#define DEBUG_REQUEST_GPIOS_MATCH   BIT(30)
+#define DEBUG_VERIFY_GPIOS          BIT(31)
+
+#define fbtft_init_dbg(dev, format, arg...)                  \
+do {                                                         \
+	if (unlikely((dev)->platform_data &&                 \
+	    (((struct fbtft_platform_data *)(dev)->platform_data)->display.debug & DEBUG_DRIVER_INIT_FUNCTIONS))) \
+		dev_info(dev, format, ##arg);                \
+} while (0)
+
+#define fbtft_par_dbg(level, par, format, arg...)            \
+do {                                                         \
+	if (unlikely((par)->debug & (level)))                    \
+		dev_info((par)->info->device, format, ##arg);  \
+} while (0)
+
+#define fbtft_par_dbg_hex(level, par, dev, type, buf, num, format, arg...) \
+do {                                                                       \
+	if (unlikely((par)->debug & (level)))                                  \
+		fbtft_dbg_hex(dev, sizeof(type), buf,\
+			      (num) * sizeof(type), format, ##arg); \
+} while (0)
+
+#endif /* __LINUX_FBTFT_H */
diff --git a/bsp/modules/fbtft/internal.h b/bsp/modules/fbtft/internal.h
new file mode 100644
index 0000000000..ae2ff4a4a4
--- /dev/null
+++ b/bsp/modules/fbtft/internal.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Copyright (C) 2013 Noralf Tronnes */
+
+#ifndef __LINUX_FBTFT_INTERNAL_H
+#define __LINUX_FBTFT_INTERNAL_H
+
+void fbtft_sysfs_init(struct fbtft_par *par);
+void fbtft_sysfs_exit(struct fbtft_par *par);
+void fbtft_expand_debug_value(unsigned long *debug);
+int fbtft_gamma_parse_str(struct fbtft_par *par, u32 *curves,
+			  const char *str, int size);
+
+#endif /* __LINUX_FBTFT_INTERNAL_H */