drivers/dose: make use of periph_uart_rx_start feature

drivers/dose/Makefile.dep

@@ -1,5 +1,6 @@
 FEATURES_REQUIRED += periph_gpio_irq
 FEATURES_REQUIRED += periph_uart
+FEATURES_OPTIONAL += periph_uart_rxstart_irq
 
 USEMODULE += eui_provider
 USEMODULE += iolist

drivers/dose/dose.c

@@ -60,6 +60,42 @@ static uint16_t crc16_update(uint16_t crc, uint8_t octet)
     return crc;
 }
 
+static void _init_sense(dose_t *ctx, const dose_params_t *params)
+{
+#ifdef MODULE_PERIPH_UART_RXSTART_IRQ
+    (void)params;
+    uart_rxstart_irq_configure(ctx->uart, _isr_gpio, ctx);
+#else
+    ctx->sense_pin = params->sense_pin;
+    if (gpio_is_valid(ctx->sense_pin)) {
+        gpio_init_int(ctx->sense_pin, GPIO_IN, GPIO_FALLING, _isr_gpio, ctx);
+        gpio_irq_disable(ctx->sense_pin);
+    }
+#endif
+}
+
+static inline void _enable_sense(dose_t *ctx)
+{
+#ifdef MODULE_PERIPH_UART_RXSTART_IRQ
+    uart_rxstart_irq_enable(ctx->uart);
+#else
+    if (gpio_is_valid(ctx->sense_pin)) {
+        gpio_irq_enable(ctx->sense_pin);
+    }
+#endif
+}
+
+static inline void _disable_sense(dose_t *ctx)
+{
+#ifdef MODULE_PERIPH_UART_RXSTART_IRQ
+    uart_rxstart_irq_disable(ctx->uart);
+#else
+    if (gpio_is_valid(ctx->sense_pin)) {
+        gpio_irq_disable(ctx->sense_pin);
+    }
+#endif
+}
+
 static dose_signal_t state_transit_blocked(dose_t *ctx, dose_signal_t signal)
 {
     uint32_t backoff;
@@ -73,10 +109,8 @@ static dose_signal_t state_transit_blocked(dose_t *ctx, dose_signal_t signal)
         netdev_trigger_event_isr((netdev_t *) ctx);
     }
 
-    if (gpio_is_valid(ctx->sense_pin)) {
+    /* Enable interrupt for start bit sensing */
-        /* Enable GPIO interrupt for start bit sensing */
+    _enable_sense(ctx);
-        gpio_irq_enable(ctx->sense_pin);
-    }
 
     /* The timeout will bring us back into IDLE state by a random time.
      * If we entered this state from RECV state, the random time lays
@@ -107,10 +141,10 @@ static dose_signal_t state_transit_recv(dose_t *ctx, dose_signal_t signal)
 {
     dose_signal_t rc = DOSE_SIGNAL_NONE;
 
-    if (ctx->state != DOSE_STATE_RECV && gpio_is_valid(ctx->sense_pin)) {
+    if (ctx->state != DOSE_STATE_RECV) {
         /* We freshly entered this state. Thus, no start bit sensing is required
-         * anymore. Disable GPIO IRQs during the transmission. */
+         * anymore. Disable RX Start IRQs during the transmission. */
-        gpio_irq_disable(ctx->sense_pin);
+        _disable_sense(ctx);
     }
 
     if (signal == DOSE_SIGNAL_UART) {
@@ -149,9 +183,9 @@ static dose_signal_t state_transit_send(dose_t *ctx, dose_signal_t signal)
 {
     (void) signal;
 
-    if (ctx->state != DOSE_STATE_SEND && gpio_is_valid(ctx->sense_pin)) {
+    if (ctx->state != DOSE_STATE_SEND) {
-        /* Disable GPIO IRQs during the transmission. */
+        /* Disable RX Start IRQs during the transmission. */
-        gpio_irq_disable(ctx->sense_pin);
+        _disable_sense(ctx);
     }
 
     /* Don't trace any END octets ... the timeout or the END signal
@@ -550,11 +584,7 @@ void dose_setup(dose_t *ctx, const dose_params_t *params, uint8_t index)
     ctx->uart = params->uart;
     uart_init(ctx->uart, params->baudrate, _isr_uart, (void *) ctx);
 
-    ctx->sense_pin = params->sense_pin;
+    _init_sense(ctx, params);
-    if (gpio_is_valid(ctx->sense_pin)) {
-        gpio_init_int(ctx->sense_pin, GPIO_IN, GPIO_FALLING, _isr_gpio, (void *) ctx);
-        gpio_irq_disable(ctx->sense_pin);
-    }
 
     netdev_register(&ctx->netdev, NETDEV_DOSE, index);
 

drivers/dose/include/dose_params.h

@@ -40,10 +40,15 @@ extern "C" {
 #endif
 
 #ifndef DOSE_PARAMS
+#ifdef MODULE_PERIPH_UART_RXSTART_IRQ
+#define DOSE_PARAMS             { .uart = DOSE_PARAM_UART,         \
+                                  .baudrate = DOSE_PARAM_BAUDRATE }
+#else
 #define DOSE_PARAMS             { .uart = DOSE_PARAM_UART,         \
                                   .baudrate = DOSE_PARAM_BAUDRATE, \
                                   .sense_pin = DOSE_PARAM_SENSE_PIN }
 #endif
+#endif
 /**@}*/
 
 /**

drivers/include/dose.h

@@ -31,7 +31,8 @@
  * you could use an IC such as the SN65HVD233.)
  *
  * Basically, UART TX and RX are connected to respective pins of the
- * transceiver. In addition, the RX pin can also be connected to the sense GPIO.
+ * transceiver. In addition, the RX pin can also be connected to the sense GPIO
+ * if the UART does not implement the `periph_uart_rxstart_irq` feature.
  * In this case, the bus allocation can be detected more precisely and
  * collisions are less likely.
  *
@@ -157,7 +158,9 @@ typedef struct {
     size_t recv_buf_ptr;                    /**< Index of the next empty octet of the recveive buffer */
     uart_t uart;                            /**< UART device to use */
     uint8_t uart_octet;                     /**< Last received octet */
+#if !defined(MODULE_PERIPH_UART_RXSTART_IRQ) || DOXYGEN
     gpio_t sense_pin;                       /**< GPIO to sense for start bits on the UART's rx line */
+#endif
     xtimer_t timeout;                       /**< Timeout timer ensuring always to get back to IDLE state */
     uint32_t timeout_base;                  /**< Base timeout in us */
 } dose_t;
@@ -167,7 +170,9 @@ typedef struct {
  */
 typedef struct {
     uart_t uart;                            /**< UART device to use */
+#if !defined(MODULE_PERIPH_UART_RXSTART_IRQ) || DOXYGEN
     gpio_t sense_pin;                       /**< GPIO to sense for start bits on the UART's rx line */
+#endif
     uint32_t baudrate;                      /**< Baudrate to UART device */
 } dose_params_t;