Merge pull request #20108 from benpicco/drivers/dose-uart_ondemand_tx

drivers/periph/uart: add periph_uart_tx_ondemand feature
RIOT-OS · Dec 14, 2023 · 208790a · 208790a
2 parents 75c27f8 + 9cde80e
commit 208790a
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Showing 8 changed files with 53 additions and 2 deletions.
diff --git a/cpu/sam0_common/Kconfig b/cpu/sam0_common/Kconfig
@@ -30,6 +30,7 @@ config CPU_COMMON_SAM0
     select HAS_PERIPH_UART_NONBLOCKING
     select HAS_PERIPH_UART_RECONFIGURE
     select HAS_PERIPH_UART_RXSTART_IRQ
+    select HAS_PERIPH_UART_TX_ONDEMAND
     select HAS_PERIPH_WDT
     select HAS_PERIPH_WDT_CB
     select HAS_PERIPH_WDT_WARNING_PERIOD

diff --git a/cpu/sam0_common/Makefile.features b/cpu/sam0_common/Makefile.features
@@ -29,6 +29,7 @@ FEATURES_PROVIDED += periph_uart_modecfg
 FEATURES_PROVIDED += periph_uart_nonblocking
 FEATURES_PROVIDED += periph_uart_reconfigure
 FEATURES_PROVIDED += periph_uart_rxstart_irq
+FEATURES_PROVIDED += periph_uart_tx_ondemand
 FEATURES_PROVIDED += periph_wdt periph_wdt_cb periph_wdt_warning_period
 
 FEATURES_CONFLICT += periph_rtc:periph_rtt

diff --git a/cpu/sam0_common/include/periph_cpu_common.h b/cpu/sam0_common/include/periph_cpu_common.h
@@ -188,6 +188,7 @@ typedef enum {
     UART_FLAG_NONE            = 0x0,    /**< No flags set */
     UART_FLAG_RUN_STANDBY     = 0x1,    /**< run SERCOM in standby mode */
     UART_FLAG_WAKEUP          = 0x2,    /**< wake from sleep on receive */
+    UART_FLAG_TX_ONDEMAND     = 0x4,    /**< Only enable TX pin on demand */
 } uart_flag_t;
 
 #ifndef DOXYGEN

diff --git a/cpu/sam0_common/periph/uart.c b/cpu/sam0_common/periph/uart.c
@@ -129,6 +129,22 @@ static void _set_baud(uart_t uart, uint32_t baudrate, uint32_t f_src)
 #endif
 }
 
+void uart_enable_tx(uart_t uart)
+{
+    /* configure RX pin */
+    if (uart_config[uart].tx_pin != GPIO_UNDEF) {
+        gpio_init_mux(uart_config[uart].tx_pin, uart_config[uart].mux);
+    }
+}
+
+void uart_disable_tx(uart_t uart)
+{
+    /* configure RX pin */
+    if (uart_config[uart].tx_pin != GPIO_UNDEF) {
+        gpio_init_mux(uart_config[uart].tx_pin, GPIO_MUX_A);
+    }
+}
+
 static void _configure_pins(uart_t uart)
 {
     /* configure RX pin */
@@ -138,7 +154,8 @@ static void _configure_pins(uart_t uart)
     }
 
     /* configure TX pin */
-    if (uart_config[uart].tx_pin != GPIO_UNDEF) {
+    if (uart_config[uart].tx_pin != GPIO_UNDEF &&
+        !(uart_config[uart].flags & UART_FLAG_TX_ONDEMAND)) {
         gpio_set(uart_config[uart].tx_pin);
         gpio_init(uart_config[uart].tx_pin, GPIO_OUT);
         gpio_init_mux(uart_config[uart].tx_pin, uart_config[uart].mux);

diff --git a/drivers/dose/dose.c b/drivers/dose/dose.c
@@ -317,9 +317,10 @@ static void state(dose_t *ctx, dose_signal_t signal)
                 signal = state_transit_send(ctx, signal);
                 ctx->state = DOSE_STATE_SEND;
                 break;
-
             default:
                 DEBUG("dose state(): unexpected state transition (STATE=0x%02x SIGNAL=0x%02x)\n", ctx->state, signal);
+                /* fall-through */
+            case DOSE_STATE_RECV + DOSE_SIGNAL_SEND:
                 signal = DOSE_SIGNAL_NONE;
         }
     } while (signal != DOSE_SIGNAL_NONE);
@@ -503,6 +504,9 @@ static int send_data_octet(dose_t *ctx, uint8_t c)
 
 static inline void _send_start(dose_t *ctx)
 {
+#ifdef MODULE_PERIPH_UART_TX_ONDEMAND
+    uart_enable_tx(ctx->uart);
+#endif
 #ifdef MODULE_PERIPH_UART_COLLISION
     uart_collision_detect_enable(ctx->uart);
 #else
@@ -512,6 +516,9 @@ static inline void _send_start(dose_t *ctx)
 
 static inline void _send_done(dose_t *ctx, bool collision)
 {
+#ifdef MODULE_PERIPH_UART_TX_ONDEMAND
+    uart_disable_tx(ctx->uart);
+#endif
 #ifdef MODULE_PERIPH_UART_COLLISION
     uart_collision_detect_disable(ctx->uart);
     if (collision) {

diff --git a/drivers/include/periph/uart.h b/drivers/include/periph/uart.h
@@ -406,6 +406,24 @@ void uart_poweron(uart_t uart);
  */
 void uart_poweroff(uart_t uart);
 
+/**
+ * @brief Enable the TX line one the given UART
+ *
+ * @note requires the `periph_uart_tx_ondemand` feature
+ *
+ * @param[in] uart          the UART device start TX on
+ */
+void uart_enable_tx(uart_t uart);
+
+/**
+ * @brief Disable the TX line one the given UART
+ *
+ * @note requires the `periph_uart_tx_ondemand` feature
+ *
+ * @param[in] uart          the UART device to stop TX on
+ */
+void uart_disable_tx(uart_t uart);
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/drivers/soft_uart/include/soft_uart_params.h b/drivers/soft_uart/include/soft_uart_params.h
@@ -19,6 +19,7 @@
 #ifndef SOFT_UART_PARAMS_H
 #define SOFT_UART_PARAMS_H
 
+#include "board.h"
 #include "soft_uart.h"
 #include "macros/units.h"
 #include "kernel_defines.h"

diff --git a/kconfigs/Kconfig.features b/kconfigs/Kconfig.features
@@ -597,6 +597,11 @@ config HAS_PERIPH_UART_MODECFG
     help
         Indicates that the UART peripheral allows mode configuration.
 
+config HAS_PERIPH_UART_TX_ONDEMAND
+    bool
+    help
+        Indicates that the UART peripheral can enable the TX line on demmand.
+
 config HAS_PERIPH_UART_NONBLOCKING
     bool
     help