WIP RP2040 I2C workaround code

5 files changed, 45 insertions, 54 deletions

diff --git a/main/config.def.h b/main/config.def.h
index 0dae608..b3be5ed 100644
--- a/main/config.def.h
+++ b/main/config.def.h
@@ -72,13 +72,21 @@
  * \name I2C configuration
  * \{
  */
-#ifndef CFG_SDA_PIN
-//! I2C SDA pin
-#define CFG_SDA_PIN 16
+#ifndef CFG_SDA0_PIN
+//! I2C 0 SDA pin
+#define CFG_SDA0_PIN 16
 #endif
-#ifndef CFG_SCL_PIN
-//! I2C SCL pin
-#define CFG_SCL_PIN 17
+#ifndef CFG_SCL0_PIN
+//! I2C 0 SCL pin
+#define CFG_SCL0_PIN 17
+#endif
+#ifndef CFG_SDA1_PIN
+//! I2C 1 SDA pin
+#define CFG_SDA1_PIN 18
+#endif
+#ifndef CFG_SCL1_PIN
+//! I2C 1 SCL pin
+#define CFG_SCL1_PIN 19
 #endif
 /// \}
 
diff --git a/main/i2c.c b/main/i2c.c
index 2503560..0f23a13 100644
--- a/main/i2c.c
+++ b/main/i2c.c
@@ -16,6 +16,18 @@
 i2c_addr_t modules[CFG_PB_MOD_MAX];
 size_t modules_size = 0;
 
+static void bus_scan() {
+	pb_buf_t buf = pb_send_magic_req();
+
+	// check for all 7-bit addresses
+	uint16_t addr_max = 1 << 7;
+	for (uint16_t addr = 0x00; addr < addr_max; addr++) {
+		pb_i2c_send(addr, (uint8_t *) buf.data, buf.size);
+	}
+
+	pb_buf_free(&buf);
+}
+
 static void state_exchange() {
 	for (size_t i = 0; i < modules_size; i++) {
 		pb_buf_t buf = pb_send_state_req();
@@ -28,10 +40,6 @@ void bus_task() {
 	// do a scan of the bus
 	bus_scan();
 
-	// FIXME: this should be removed (see handover: RP2040 I2C limitations)
-	// wait for 5 seconds until all handshake responses are received
-	pb_mod_blocking_delay_ms(5e3);
-
 	while(1) {
 		// send my state to all puzzle modules
 		state_exchange();
diff --git a/main/init.c b/main/init.c
index 6d29d19..d85c94d 100644
--- a/main/init.c
+++ b/main/init.c
@@ -29,11 +29,15 @@ static void init_wifi() {
 }
 
 static void init_i2c() {
-	gpio_set_function(CFG_SDA_PIN, GPIO_FUNC_I2C);
-	gpio_set_function(CFG_SCL_PIN, GPIO_FUNC_I2C);
+	gpio_set_function(CFG_SDA0_PIN, GPIO_FUNC_I2C);
+	gpio_set_function(CFG_SCL0_PIN, GPIO_FUNC_I2C);
+	gpio_set_function(CFG_SDA1_PIN, GPIO_FUNC_I2C);
+	gpio_set_function(CFG_SCL1_PIN, GPIO_FUNC_I2C);
 
-	gpio_pull_up(CFG_SDA_PIN);
-	gpio_pull_up(CFG_SCL_PIN);
+	gpio_pull_up(CFG_SDA0_PIN);
+	gpio_pull_up(CFG_SCL0_PIN);
+	gpio_pull_up(CFG_SDA1_PIN);
+	gpio_pull_up(CFG_SCL1_PIN);
 
 	pb_setup();
 }
diff --git a/main/pbdrv.c b/main/pbdrv.c
index 0624897..6a89253 100644
--- a/main/pbdrv.c
+++ b/main/pbdrv.c
@@ -14,7 +14,9 @@
 #include <stdio.h>
 #include <timers.h>
 
-#define PB_I2C i2c0
+#define PB_I2C_S i2c0
+#define PB_I2C_M i2c1
+
 #define BUF_SIZE 256
 #define MSGS_MAX 4
 
@@ -32,6 +34,8 @@ static void async_pb_i2c_recv(void * _msg, uint32_t _) {
 }
 
 static void msg_complete(i2c_msg_buf_t * msg) {
+	return pb_i2c_recv(msg->data, msg->size);
+
 	// defer pb_i2c_recv call to FreeRTOS scheduler as pb_i2c_recv takes
 	// too long to return from an ISR
 	xTimerPendFunctionCallFromISR(async_pb_i2c_recv, msg, 0, NULL);
@@ -48,7 +52,7 @@ static void recv_event(i2c_inst_t *i2c, i2c_slave_event_t event) {
 	switch (event) {
 		case I2C_SLAVE_RECEIVE: {
 			if (msg->size == BUF_SIZE) return;
-			msg->data[msg->size++] = i2c_read_byte_raw(PB_I2C);
+			msg->data[msg->size++] = i2c_read_byte_raw(PB_I2C_S);
 			break;
 		}
 		case I2C_SLAVE_FINISH: {
@@ -60,33 +64,15 @@ static void recv_event(i2c_inst_t *i2c, i2c_slave_event_t event) {
 }
 
 void pb_setup() {
-	i2c_init(PB_I2C, PB_CLOCK_SPEED_HZ);
-	i2c_slave_init(PB_I2C, PB_MOD_ADDR, &recv_event);
+	i2c_init(PB_I2C_S, PB_CLOCK_SPEED_HZ);
+	i2c_init(PB_I2C_M, PB_CLOCK_SPEED_HZ);
+
+	i2c_slave_init(PB_I2C_S, PB_MOD_ADDR, &recv_event);
 }
 
 __weak void pb_i2c_send(i2c_addr_t addr, const uint8_t * buf, size_t sz) {
-	i2c_set_slave_mode(PB_I2C, false, PB_MOD_ADDR);
-
 	// false to write stop condition to i2c bus
-	i2c_write_timeout_us(PB_I2C, addr, buf, sz, false, PB_TIMEOUT_US);
-
-	i2c_set_slave_mode(PB_I2C, true, PB_MOD_ADDR);
-}
-
-void bus_scan() {
-	i2c_set_slave_mode(PB_I2C, false, PB_MOD_ADDR);
-
-	pb_buf_t buf = pb_send_magic_req();
-
-	// check for all 7-bit addresses
-	uint16_t addr_max = 1 << 7;
-	for (uint16_t addr = 0x00; addr < addr_max; addr++) {
-		i2c_write_timeout_us(PB_I2C, addr, (uint8_t *) buf.data, buf.size, false, PB_TIMEOUT_US);
-	}
-
-	pb_buf_free(&buf);
-
-	i2c_set_slave_mode(PB_I2C, true, PB_MOD_ADDR);
+	i2c_write_timeout_us(PB_I2C_M, addr, buf, sz, false, PB_TIMEOUT_US);
 }
 
 void pb_mod_blocking_delay_ms(unsigned long ms) {
diff --git a/main/pbdrv.h b/main/pbdrv.h
index 9496aa9..89a4870 100644
--- a/main/pbdrv.h
+++ b/main/pbdrv.h
@@ -41,21 +41,6 @@ void pb_setup();
  */
 void pb_i2c_send(i2c_addr_t addr, const uint8_t * buf, size_t sz);
 
-/**
- * \brief Scan the bus for I2C slaves, and send handshake messages to ACK-ing
- * slaves.
- *
- * \note As a result of the RP2040 hardware limitations, this function is also
- * implemented in this file, even though it does not belong to the puzzle bus
- * driver.
- *
- * \warning In order to not miss any handshake responses, the bus should remain
- * busy during the entire scan. The \c nostop parameter of the \c
- * i2c_write_timeout_us() function from the pico-sdk does not seem to keep the
- * bus busy.
- */
-void bus_scan();
-
 /// \}
 
 #ifdef __cplusplus