change the return type of i2c_write_byte

README.md

@@ -61,7 +61,7 @@ Use [Canokey-STM32](https://github.com/canokeys/canokey-stm32) as an example.
   * `uint8_t i2c_read_ack(void);`
   * `void i2c_send_ack(void);`
   * `void i2c_send_nack(void);`
-  * `void i2c_write_byte(uint8_t data);`
+  * `bool i2c_write_byte(uint8_t data);`
   * `uint8_t i2c_read_byte(void);`
 
 2. You should also provide a `random32` and a optional `random_buffer` function in `rand.h`.

include/device.h

@@ -75,7 +75,7 @@ void scl_delay(void);
 uint8_t i2c_read_ack(void);
 void i2c_send_ack(void);
 void i2c_send_nack(void);
-void i2c_write_byte(uint8_t data);
+bool i2c_write_byte(uint8_t data);
 uint8_t i2c_read_byte(void);
 #endif
 
@@ -115,17 +115,15 @@ void stop_blinking(void);
 uint8_t device_is_blinking(void);
 bool device_allow_kbd_touch(void);
 void fm11_init(void);
-uint8_t fm_read_reg(uint16_t reg);
-void fm_read_regs(uint16_t reg, uint8_t *buf, uint8_t len);
-void fm_write_reg(uint16_t reg, uint8_t val);
-void fm_write_regs(uint16_t reg, const uint8_t *buf, uint8_t len);
-void fm_read_eeprom(uint16_t addr, uint8_t *buf, uint8_t len);
-void fm_write_eeprom(uint16_t addr, const uint8_t *buf, uint8_t len);
-void fm_read_fifo(uint8_t *buf, uint8_t len);
-void fm_write_fifo(uint8_t *buf, uint8_t len);
+bool fm_read_regs(uint16_t reg, uint8_t *buf, uint8_t len);
+bool fm_write_regs(uint16_t reg, const uint8_t *buf, uint8_t len);
+bool fm_read_eeprom(uint16_t addr, uint8_t *buf, uint8_t len);
+bool fm_write_eeprom(uint16_t addr, const uint8_t *buf, uint8_t len);
+bool fm_read_fifo(uint8_t *buf, uint8_t len);
+bool fm_write_fifo(uint8_t *buf, uint8_t len);
 #if NFC_CHIP == NFC_CHIP_FM11NT
-void fm11nt_read(uint16_t addr, uint8_t *buf, uint8_t len);
-void fm11nt_write(uint16_t addr, const uint8_t *buf, uint8_t len);
+bool fm11nt_read(uint16_t addr, uint8_t *buf, uint8_t len);
+bool fm11nt_write(uint16_t addr, const uint8_t *buf, uint8_t len);
 uint8_t fm_crc8(const uint8_t *data, const uint8_t data_length);
 #endif
 

interfaces/NFC/fm.c

@@ -2,79 +2,58 @@
 #include "device.h"
 #include <stdint.h>
 
+#define I2C_WRITE_WITH_CHECK(data)           \
+  do {                                       \
+    if (!i2c_write_byte(data)) return false; \
+  } while (0)
+
 static void device_delay_us(int us) {
   for (int i = 0; i < us * 10; ++i)
     asm volatile("nop");
 }
 
-uint8_t fm_read_reg(uint16_t reg) {
-  uint8_t val;
-#if NFC_CHIP == NFC_CHIP_FM11NC
-  fm_csn_low();
-  uint8_t addr = reg;
-  addr |= 0x20;
-  spi_transmit(&addr, 1);
-  spi_receive(&val, 1);
-  fm_csn_high();
-#elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_read(reg, &val, 1);
-#else
-  val = 0;
-#endif
-  return val;
-}
-
-void fm_read_regs(uint16_t reg, uint8_t *buf, uint8_t len) {
+bool fm_read_regs(uint16_t reg, uint8_t *buf, uint8_t len) {
 #if NFC_CHIP == NFC_CHIP_FM11NC
   fm_csn_low();
   uint8_t addr = reg;
   addr |= 0x20;
   spi_transmit(&addr, 1);
   spi_receive(buf, len);
   fm_csn_high();
+  return true;
 #elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_read(reg, buf, len);
+  return fm11nt_read(reg, buf, len);
 #endif
 }
 
-void fm_write_reg(uint16_t reg, uint8_t val) {
-#if NFC_CHIP == NFC_CHIP_FM11NC
-  fm_csn_low();
-  uint8_t addr = reg;
-  spi_transmit(&addr, 1);
-  spi_transmit(&val, 1);
-  fm_csn_high();
-#elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_write(reg, &val, 1);
-#endif
-}
-
-void fm_write_regs(uint16_t reg, const uint8_t *buf, uint8_t len) {
+bool fm_write_regs(uint16_t reg, const uint8_t *buf, uint8_t len) {
 #if NFC_CHIP == NFC_CHIP_FM11NC
   fm_csn_low();
   uint8_t addr = reg;
   spi_transmit(&addr, 1);
   spi_transmit(buf, len);
   fm_csn_high();
+  return true;
 #elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_write(reg, buf, len);
+  return fm11nt_write(reg, buf, len);
 #endif
 }
 
-void fm_read_eeprom(uint16_t addr, uint8_t *buf, uint8_t len) {
+bool fm_read_eeprom(uint16_t addr, uint8_t *buf, uint8_t len) {
 #if NFC_CHIP == NFC_CHIP_FM11NC
   fm_csn_low();
   device_delay_us(100);
   uint8_t data[2] = {0x60 | (addr >> 8), addr & 0xFF};
   spi_transmit(data, 2);
   spi_receive(buf, len);
   fm_csn_high();
+  return true;
 #elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_read(addr, buf, len);
+  return fm11nt_read(addr, buf, len);
 #endif
 }
 
-void fm_write_eeprom(uint16_t addr, const uint8_t *buf, uint8_t len) {
+bool fm_write_eeprom(uint16_t addr, const uint8_t *buf, uint8_t len) {
 #if NFC_CHIP == NFC_CHIP_FM11NC
   fm_csn_low();
   device_delay_us(100);
@@ -90,33 +69,37 @@ void fm_write_eeprom(uint16_t addr, const uint8_t *buf, uint8_t len) {
   spi_transmit(data, 2);
   spi_transmit(buf, len);
   fm_csn_high();
+  return true;
 #elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_write(addr, buf, len);
+  const bool ret = fm11nt_write(addr, buf, len);
   device_delay(10);
+  return ret;
 #endif
 }
 
-void fm_read_fifo(uint8_t *buf, uint8_t len) {
+bool fm_read_fifo(uint8_t *buf, uint8_t len) {
 #if NFC_CHIP == NFC_CHIP_FM11NC
   fm_csn_low();
   uint8_t addr = 0xA0;
   spi_transmit(&addr, 1);
   spi_receive(buf, len);
   fm_csn_high();
+  return true;
 #elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_read(FM_REG_FIFO_ACCESS, buf, len);
+  return fm11nt_read(FM_REG_FIFO_ACCESS, buf, len);
 #endif
 }
 
-void fm_write_fifo(uint8_t *buf, uint8_t len) {
+bool fm_write_fifo(uint8_t *buf, uint8_t len) {
 #if NFC_CHIP == NFC_CHIP_FM11NC
   fm_csn_low();
   uint8_t addr = 0x80;
   spi_transmit(&addr, 1);
   spi_transmit(buf, len);
   fm_csn_high();
+  return true;
 #elif NFC_CHIP == NFC_CHIP_FM11NT
-  fm11nt_write(FM_REG_FIFO_ACCESS, buf, len);
+  return fm11nt_write(FM_REG_FIFO_ACCESS, buf, len);
 #endif
 }
 
@@ -144,7 +127,8 @@ void fm11_init(void) {
   fm_write_eeprom(FM_EEPROM_ATS, ats, sizeof(ats));
   fm_write_eeprom(FM_EEPROM_ATQA, atqa_sak, sizeof(atqa_sak));
   fm_read_eeprom(FM_EEPROM_SN, crc_buffer, 9);
-  DBG_MSG("SN: "); PRINT_HEX(crc_buffer, 9);
+  DBG_MSG("SN: ");
+  PRINT_HEX(crc_buffer, 9);
   memcpy(crc_buffer + 9, atqa_sak, sizeof(atqa_sak));
   const uint8_t crc8 = fm_crc8(crc_buffer, sizeof(crc_buffer));
   fm_write_eeprom(FM_EEPROM_CRC8, &crc8, 1);
@@ -156,19 +140,19 @@ void fm11_init(void) {
 
 #define I2C_ADDR 0x57
 
-void fm11nt_read(uint16_t addr, uint8_t *buf, uint8_t len) {
+bool fm11nt_read(uint16_t addr, uint8_t *buf, uint8_t len) {
   uint8_t slave_id = (I2C_ADDR << 1) | 0;
   i2c_start();
-  i2c_write_byte(slave_id);
+  I2C_WRITE_WITH_CHECK(slave_id);
 
   // set reg/eeprom addr
-  i2c_write_byte(addr >> 8);
-  i2c_write_byte(addr & 0xFF);
+  I2C_WRITE_WITH_CHECK(addr >> 8);
+  I2C_WRITE_WITH_CHECK(addr & 0xFF);
 
   // switch to read mode
   slave_id |= 1;
   i2c_start();
-  i2c_write_byte(slave_id);
+  I2C_WRITE_WITH_CHECK(slave_id);
 
   // master transmit
   for (size_t k = 0; k < len; k++) {
@@ -186,23 +170,27 @@ void fm11nt_read(uint16_t addr, uint8_t *buf, uint8_t len) {
     // wait to receive next byte from slave
     scl_delay();
   }
+
+  return true;
 }
 
-void fm11nt_write(const uint16_t addr, const uint8_t *buf, const uint8_t len) {
+bool fm11nt_write(const uint16_t addr, const uint8_t *buf, const uint8_t len) {
   const uint8_t slave_id = (I2C_ADDR << 1) | 0;
   i2c_start();
-  i2c_write_byte(slave_id);
+  I2C_WRITE_WITH_CHECK(slave_id);
 
   // set reg/eeprom addr
-  i2c_write_byte(addr >> 8);
-  i2c_write_byte(addr & 0xFF);
+  I2C_WRITE_WITH_CHECK(addr >> 8);
+  I2C_WRITE_WITH_CHECK(addr & 0xFF);
 
   // master transmit
   for (size_t i = 0; i < len; i++) {
     // master write a byte to salve and check ACK signal
-    i2c_write_byte(buf[i]);
+    I2C_WRITE_WITH_CHECK(buf[i]);
   }
   i2c_stop();
+
+  return true;
 }
 
 uint8_t fm_crc8(const uint8_t *data, const uint8_t data_length) {
@@ -220,4 +208,4 @@ uint8_t fm_crc8(const uint8_t *data, const uint8_t data_length) {
   return crc8 & 0xff;
 }
 
-#endif
+#endif

interfaces/NFC/nfc.c

@@ -33,7 +33,7 @@ void nfc_init(void) {
   // NFC interface uses global_buffer w/o calling acquire_apdu_buffer(), because NFC mode is exclusive with USB mode
   apdu_cmd.data = global_buffer;
   apdu_resp.data = global_buffer;
-  fm_write_reg(FM_REG_FIFO_FLUSH, 0); // writing anything to this reg will flush FIFO buffer
+  fm_write_regs(FM_REG_FIFO_FLUSH, &block_number, 1); // writing anything to this reg will flush FIFO buffer
 }
 
 static void nfc_error_handler(int code __attribute__((unused))) {
@@ -46,8 +46,10 @@ static void nfc_error_handler(int code __attribute__((unused))) {
   state_spinlock = 0;
   next_state = TO_RECEIVE;
 #if NFC_CHIP == NFC_CHIP_FM11NT
-  fm_write_reg(FM_REG_RF_TXEN, 0x77); // set NFC to IDLE
-  fm_write_reg(FM_REG_RESET_SILENCE, 0x55); // reset
+  uint8_t data = 0x77; // set NFC to IDLE
+  fm_write_regs(FM_REG_RF_TXEN, &data, 1);
+  data = 0x55; // reset
+  fm_write_regs(FM_REG_RESET_SILENCE, &data, 1);
 #endif
 }
 
@@ -61,7 +63,8 @@ static void do_nfc_send_frame(uint8_t prologue, uint8_t *data, uint8_t len) {
   PRINT_HEX(tx_frame_buf, len + 1);
 
   fm_write_fifo(tx_frame_buf, len + 1);
-  fm_write_reg(FM_REG_RF_TXEN, 0x55);
+  const uint8_t val = 0x55;
+  fm_write_regs(FM_REG_RF_TXEN, &val, 1);
 }
 
 void nfc_send_frame(uint8_t prologue, uint8_t *data, uint8_t len) {
@@ -181,7 +184,7 @@ void nfc_handler(void) {
   }
 
   if (irq[0] & MAIN_IRQ_RX_DONE) {
-    rx_frame_size = fm_read_reg(FM_REG_FIFO_WORDCNT);
+    fm_read_regs(FM_REG_FIFO_WORDCNT, &rx_frame_size, 1);
     if (rx_frame_size > 32) {
       nfc_error_handler(-5);
       return;