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Implement logical address allocation for playback addresses.
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With an array of the playback addresses, ping each one in order to
discover which is free.

Whilst here, implement the CEC version reply (and reply with 1.3a).
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@gkoh
gkoh committed Jul 21, 2024
1 parent 0cb1cda commit e0160c0
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Showing 3 changed files with 101 additions and 38 deletions.
3 changes: 0 additions & 3 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -185,9 +185,6 @@ This project uses:
* research says this is 'just' i2c, needs further investigation and
testing
* EDID is 5V, Pico GPIO _might_ be 5V tolerant, may need level shifter
* logical address is hardcoded to 4 (Player 1)
* make it a CMake variable ala physical address
* perform a CEC ping and choose a non-occupied logical address
* more blinken LEDs
* most Pico boards appear to have an RGB LED, use it
* perhaps:
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8 changes: 5 additions & 3 deletions include/hdmi-cec.h
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Original file line number Diff line number Diff line change
Expand Up @@ -30,9 +30,10 @@ typedef enum {
HDMI_FRAME_STATE_EOM_HIGH = 5,
HDMI_FRAME_STATE_ACK_LOW = 6,
HDMI_FRAME_STATE_ACK_HIGH = 7,
HDMI_FRAME_STATE_ACK_END = 8,
HDMI_FRAME_STATE_END = 9,
HDMI_FRAME_STATE_ABORT = 10
HDMI_FRAME_STATE_ACK_WAIT = 8,
HDMI_FRAME_STATE_ACK_END = 9,
HDMI_FRAME_STATE_END = 10,
HDMI_FRAME_STATE_ABORT = 11
} hdmi_frame_state_t;

typedef struct {
Expand All @@ -42,6 +43,7 @@ typedef struct {
uint64_t start;
bool first;
bool eom;
bool ack;
uint8_t address;
hdmi_frame_state_t state;
} hdmi_frame_t;
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128 changes: 96 additions & 32 deletions src/hdmi-cec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -52,9 +52,18 @@ const command_t keymap[256] = {[0x00] = {"User Control Select", HID_KEY_ENTER},
[0x46] = {"User Control Pause", HID_KEY_SPACE},
[0x48] = {"User Control Rewind", HID_KEY_R},
[0x49] = {"User Control Fast Forward", HID_KEY_F}};

#define DEFAULT_TYPE 0x04 // HDMI Playback 1

// HDMI Playback logical addresses
#define NUM_ADDRESS 4
static const uint8_t address[NUM_ADDRESS] = {0x04, 0x08, 0x0b, 0x0f};

/* The HDMI address for this device. Respond to CEC sent to this address. */
#define ADDRESS 0x04
#define TYPE 0x04 // HDMI Playback 1
static uint8_t l_address = address[0];

/* Construct the frame address header. */
#define HEADER0(iaddr, daddr) ((iaddr << 4) | daddr)

TaskHandle_t xCECTask;

Expand Down Expand Up @@ -261,34 +270,55 @@ static int64_t hdmi_tx_callback(alarm_id_t alarm, void *user_data) {
frame->state = HDMI_FRAME_STATE_DATA_LOW;
return time_next(frame->start, 2400);
} else {
frame->state = HDMI_FRAME_STATE_END;
frame->state = HDMI_FRAME_STATE_ACK_WAIT;
// middle of safe sample period (0.85ms, 1.25ms)
return time_next(frame->start, (850 + 1250) / 2);
}
// need to handle follower sending ack
// fall through
case HDMI_FRAME_STATE_ACK_WAIT:
// handle follower sending ack
if (gpio_get(CEC_PIN) == false) {
frame->ack = true;
}
frame->state = HDMI_FRAME_STATE_END;
return time_next(frame->start, 2400);
case HDMI_FRAME_STATE_END:
default:
xTaskNotifyIndexedFromISR(xCECTask, NOTIFY_TX, 0, eNoAction, NULL);
return 0;
}
}

static void hdmi_tx_frame(uint8_t *data, uint8_t len) {
// wait 13 bit times before sending
vTaskDelay(pdMS_TO_TICKS(13 * 2.4));
static bool hdmi_tx_frame(uint8_t *data, uint8_t len) {
unsigned char i = 0;

// wait 13 bit times of idle before sending
while (i < 13) {
vTaskDelay(pdMS_TO_TICKS(2.4));
if (gpio_get(CEC_PIN)) {
i++;
} else {
// reset
i = 0;
}
}

hdmi_message_t message = {data, len};
hdmi_frame_t frame = {
.message = &message, .bit = 7, .byte = 0, .start = 0, .state = HDMI_FRAME_STATE_START_LOW};
hdmi_frame_t frame = {.message = &message,
.bit = 7,
.byte = 0,
.start = 0,
.ack = false,
.state = HDMI_FRAME_STATE_START_LOW};
add_alarm_at(from_us_since_boot(time_us_64()), hdmi_tx_callback, &frame, true);
ulTaskNotifyTakeIndexed(NOTIFY_TX, pdTRUE, portMAX_DELAY);
printf("high water mark = %lu\n", uxTaskGetStackHighWaterMark(xCECTask));
return frame.ack;
}

static void send_frame(uint8_t pldcnt, uint8_t *pld) {
// gpio_put(PICO_DEFAULT_LED_PIN, true);
// disable GPIO ISR for sending
static bool send_frame(uint8_t pldcnt, uint8_t *pld) {
// disable GPIO ISR for sending
gpio_set_irq_enabled(CEC_PIN, GPIO_IRQ_EDGE_RISE | GPIO_IRQ_EDGE_FALL, false);
hdmi_tx_frame(pld, pldcnt);
printf("high water mark = %lu\n", uxTaskGetStackHighWaterMark(xCECTask));
// gpio_put(PICO_DEFAULT_LED_PIN, false);
return hdmi_tx_frame(pld, pldcnt);
}

static void device_vendor_id(uint8_t initiator, uint8_t destination, uint32_t vendor_id) {
Expand Down Expand Up @@ -361,6 +391,35 @@ static void report_physical_address(uint8_t initiator,
printf("\n<-- %02x:84 [Report Physical Address]", pld[0]);
}

static void report_cec_version(uint8_t initiator, uint8_t destination) {
// 0x04 = 1.3a
uint8_t pld[3] = {HEADER0(initiator, destination), 0x9e, 0x04};
send_frame(3, pld);
printf("\n<-- %02x: 9e [CEC Version]", pld[0]);
}

static bool ping(uint8_t destination) {
uint8_t pld[1] = {HEADER0(destination, destination)};

bool ack = send_frame(1, pld);
printf("ack = %d\n", ack);
return ack;
}

static uint8_t allocate_logical_address(void) {
uint8_t a;
for (unsigned int i = 0; i < NUM_ADDRESS; i++) {
a = address[i];
printf("Attempting to allocate logical address 0x%02x\n", a);
if (!ping(a)) {
break;
}
}

printf("Allocated logical address 0x%02x\n", a);
return a;
}

void cec_task(void *data) {
QueueHandle_t *q = (QueueHandle_t *)data;

Expand All @@ -372,13 +431,15 @@ void cec_task(void *data) {
irq_set_enabled(IO_IRQ_BANK0, true);
gpio_set_irq_enabled(CEC_PIN, GPIO_IRQ_EDGE_RISE | GPIO_IRQ_EDGE_FALL, false);

l_address = allocate_logical_address();

while (true) {
uint8_t pld[16] = {0x0};
uint8_t pldcnt, pldcntrcvd;
uint8_t initiator, destination;
uint8_t key = HID_KEY_NONE;

pldcnt = recv_frame(pld, ADDRESS);
pldcnt = recv_frame(pld, l_address);
printf("pldcnt = %u\n", pldcnt);
pldcntrcvd = pldcnt;
initiator = (pld[0] & 0xf0) >> 4;
Expand All @@ -398,21 +459,21 @@ void cec_task(void *data) {
break;
case 0x70:
printf("[System Audio Mode Request]");
if (destination == ADDRESS)
set_system_audio_mode(ADDRESS, 0x0f, 1);
if (destination == l_address)
set_system_audio_mode(l_address, 0x0f, 1);
break;
case 0x71:
printf("[Give Audio Status]");
if (destination == ADDRESS)
report_audio_status(ADDRESS, initiator, 0x32); // volume 50%, mute off
if (destination == l_address)
report_audio_status(l_address, initiator, 0x32); // volume 50%, mute off
break;
case 0x72:
printf("[Set System Audio Mode]");
break;
case 0x7d:
printf("[Give System Audio Mode Status]");
if (destination == ADDRESS)
system_audio_mode_status(ADDRESS, initiator, 1);
if (destination == l_address)
system_audio_mode_status(l_address, initiator, 1);
break;
case 0x7e:
printf("[System Audio Mode Status]");
Expand All @@ -432,16 +493,16 @@ void cec_task(void *data) {
break;
case 0x8c:
printf("[Give Device Vendor ID]");
if (destination == ADDRESS)
device_vendor_id(ADDRESS, 0x0f, 0x0010FA);
if (destination == l_address)
device_vendor_id(l_address, 0x0f, 0x0010FA);
break;
case 0x8e:
printf("[Menu Status]");
break;
case 0x8f:
printf("[Give Device Power Status]");
if (destination == ADDRESS)
report_power_status(ADDRESS, initiator, 0x00);
if (destination == l_address)
report_power_status(l_address, initiator, 0x00);
/* Hack for Google Chromecast to force it sending V+/V- if no CEC TV is present */
if (destination == 0)
report_power_status(0, initiator, 0x00);
Expand All @@ -460,19 +521,22 @@ void cec_task(void *data) {
break;
case 0x9f:
printf("[Get CEC Version]");
if (destination == l_address) {
report_cec_version(l_address, initiator);
}
break;
case 0x46:
printf("[Give OSD Name]");
if (destination == ADDRESS)
set_osd_name(ADDRESS, initiator);
if (destination == l_address)
set_osd_name(l_address, initiator);
break;
case 0x47:
printf("[Set OSD Name]");
break;
case 0x83:
printf("[Give Physical Address]");
if (destination == ADDRESS)
report_physical_address(ADDRESS, 0x0f, CEC_PHYS_ADDR, TYPE);
if (destination == l_address)
report_physical_address(l_address, 0x0f, CEC_PHYS_ADDR, DEFAULT_TYPE);
break;
case 0x44:
gpio_put(PICO_DEFAULT_LED_PIN, true);
Expand Down Expand Up @@ -511,7 +575,7 @@ void cec_task(void *data) {
} else {
// single byte polling message
printf("[Polling Message]: 0x%01x -> 0x%01x\n", initiator, destination);
// report_physical_address(ADDRESS, 0x0f, 0x1000, TYPE);
// report_physical_address(l_address, 0x0f, 0x1000, DEFAULT_TYPE);
}
}
}

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