feat: Add the ability for ESP ports to not initialize peripherals

This adds the ability of the ESP serial and SPI ports to not initialize
the peripheral. This enables using the peripherals for multiple devices
or multiple uses for one device (e.g. flashing and monitoring).

The boolean flag added to config structures will be false by default
so no changes are required for existing code.

Author: DNedic

port/esp32_port.c

@@ -41,6 +41,7 @@ static int64_t s_time_end;
 static int32_t s_uart_port;
 static int32_t s_reset_trigger_pin;
 static int32_t s_gpio0_trigger_pin;
+static bool s_peripheral_needs_deinit;
 
 esp_loader_error_t loader_port_esp32_init(const loader_esp32_config_t *config)
 {
@@ -49,30 +50,34 @@ esp_loader_error_t loader_port_esp32_init(const loader_esp32_config_t *config)
     s_gpio0_trigger_pin = config->gpio0_trigger_pin;
 
     // Initialize UART
-    uart_config_t uart_config = {
-        .baud_rate = config->baud_rate,
-        .data_bits = UART_DATA_8_BITS,
-        .parity    = UART_PARITY_DISABLE,
-        .stop_bits = UART_STOP_BITS_1,
-        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
+    if (!config->dont_initialize_peripheral) {
+        uart_config_t uart_config = {
+            .baud_rate = config->baud_rate,
+            .data_bits = UART_DATA_8_BITS,
+            .parity    = UART_PARITY_DISABLE,
+            .stop_bits = UART_STOP_BITS_1,
+            .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
 #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 0, 0)
-        .source_clk = UART_SCLK_DEFAULT,
+            .source_clk = UART_SCLK_DEFAULT,
 #endif
-    };
-
-    int rx_buffer_size = config->rx_buffer_size ? config->rx_buffer_size : 400;
-    int tx_buffer_size = config->tx_buffer_size ? config->tx_buffer_size : 400;
-    QueueHandle_t *uart_queue = config->uart_queue ? config->uart_queue : NULL;
-    int queue_size = config->queue_size ? config->queue_size : 0;
-
-    if ( uart_param_config(s_uart_port, &uart_config) != ESP_OK ) {
-        return ESP_LOADER_ERROR_FAIL;
-    }
-    if ( uart_set_pin(s_uart_port, config->uart_tx_pin, config->uart_rx_pin, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE) != ESP_OK ) {
-        return ESP_LOADER_ERROR_FAIL;
-    }
-    if ( uart_driver_install(s_uart_port, rx_buffer_size, tx_buffer_size, queue_size, uart_queue, 0) != ESP_OK ) {
-        return ESP_LOADER_ERROR_FAIL;
+        };
+
+        int rx_buffer_size = config->rx_buffer_size ? config->rx_buffer_size : 400;
+        int tx_buffer_size = config->tx_buffer_size ? config->tx_buffer_size : 400;
+        QueueHandle_t *uart_queue = config->uart_queue ? config->uart_queue : NULL;
+        int queue_size = config->queue_size ? config->queue_size : 0;
+
+        if ( uart_param_config(s_uart_port, &uart_config) != ESP_OK ) {
+            return ESP_LOADER_ERROR_FAIL;
+        }
+        if ( uart_set_pin(s_uart_port, config->uart_tx_pin, config->uart_rx_pin, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE) != ESP_OK ) {
+            return ESP_LOADER_ERROR_FAIL;
+        }
+        if ( uart_driver_install(s_uart_port, rx_buffer_size, tx_buffer_size, queue_size, uart_queue, 0) != ESP_OK ) {
+            return ESP_LOADER_ERROR_FAIL;
+        }
+
+        s_peripheral_needs_deinit = true;
     }
 
     // Initialize boot pin selection pins
@@ -89,7 +94,9 @@ esp_loader_error_t loader_port_esp32_init(const loader_esp32_config_t *config)
 
 void loader_port_esp32_deinit(void)
 {
-    uart_driver_delete(s_uart_port);
+    if (s_peripheral_needs_deinit) {
+        uart_driver_delete(s_uart_port);
+    }
 }
 
 

port/esp32_port.h

@@ -35,6 +35,9 @@ typedef struct {
     uint32_t queue_size;        /*!< Set to zero for default UART queue size */
     QueueHandle_t *uart_queue;  /*!< Set to NULL, if UART queue handle is not
                                    necessary. Otherwise, it will be assigned here */
+    bool dont_initialize_peripheral; /* Use if the peripheral has already been initialized,
+                                        useful when using the peripheral for multiple
+                                        purposes (e.g. monitoring) */
 } loader_esp32_config_t;
 
 /**

port/esp32_spi_port.c

@@ -70,6 +70,7 @@ static uint32_t s_strap_bit1_pin;
 static uint32_t s_strap_bit2_pin;
 static uint32_t s_strap_bit3_pin;
 static uint32_t s_spi_cs_pin;
+static bool s_bus_needs_deinit;
 
 esp_loader_error_t loader_port_esp32_spi_init(const loader_esp32_spi_config_t *config)
 {
@@ -83,15 +84,19 @@ esp_loader_error_t loader_port_esp32_spi_init(const loader_esp32_spi_config_t *c
     s_spi_cs_pin = config->spi_cs_pin;
 
     /* Configure and initialize the SPI bus*/
-    s_spi_config.mosi_io_num = config->spi_mosi_pin;
-    s_spi_config.miso_io_num = config->spi_miso_pin;
-    s_spi_config.sclk_io_num = config->spi_clk_pin;
-    s_spi_config.quadwp_io_num = config->spi_quadwp_pin;
-    s_spi_config.quadhd_io_num = config->spi_quadhd_pin;
-    s_spi_config.max_transfer_sz = 4096 * 4;
-
-    if (spi_bus_initialize(s_spi_bus, &s_spi_config, DMA_CHAN) != ESP_OK) {
-        return ESP_LOADER_ERROR_FAIL;
+    if (!config->dont_initialize_bus) {
+        s_spi_config.mosi_io_num = config->spi_mosi_pin;
+        s_spi_config.miso_io_num = config->spi_miso_pin;
+        s_spi_config.sclk_io_num = config->spi_clk_pin;
+        s_spi_config.quadwp_io_num = config->spi_quadwp_pin;
+        s_spi_config.quadhd_io_num = config->spi_quadhd_pin;
+        s_spi_config.max_transfer_sz = 4096 * 4;
+
+        if (spi_bus_initialize(s_spi_bus, &s_spi_config, DMA_CHAN) != ESP_OK) {
+            return ESP_LOADER_ERROR_FAIL;
+        }
+
+        s_bus_needs_deinit = true;
     }
 
     /* Configure and add the device */
@@ -125,7 +130,9 @@ void loader_port_esp32_spi_deinit(void)
     gpio_reset_pin(s_reset_trigger_pin);
     gpio_reset_pin(s_spi_cs_pin);
     spi_bus_remove_device(s_device_h);
-    spi_bus_free(s_spi_bus);
+    if (s_bus_needs_deinit) {
+        spi_bus_free(s_spi_bus);
+    }
 }
 
 

port/esp32_spi_port.h

@@ -36,6 +36,8 @@ typedef struct {
     uint32_t strap_bit1_pin;
     uint32_t strap_bit2_pin;
     uint32_t strap_bit3_pin;
+    bool dont_initialize_bus; /* Use if the bus has already been initialized,
+                                 useful when sharing the bus with other devices. */
 } loader_esp32_spi_config_t;
 
 /**