sdspi, vfs_fat: allow sharing SPI bus among devices, and mounting multiple SD cards

examples/storage/sd_card/main/sd_card_example_main.c

@@ -15,16 +15,21 @@
 #include "esp_vfs_fat.h"
 #include "driver/sdmmc_host.h"
 #include "driver/sdspi_host.h"
+#include "driver/spi_common.h"
 #include "sdmmc_cmd.h"
 
 static const char *TAG = "example";
 
+#define MOUNT_POINT "/sdcard"
+
 // This example can use SDMMC and SPI peripherals to communicate with SD card.
 // By default, SDMMC peripheral is used.
 // To enable SPI mode, uncomment the following line:
 
 // #define USE_SPI_MODE
 
+#define SPI_DMA_CHAN    1
+
 // When testing SD and SPI modes, keep in mind that once the card has been
 // initialized in SPI mode, it can not be reinitialized in SD mode without
 // toggling power to the card.
@@ -41,8 +46,23 @@ static const char *TAG = "example";
 
 void app_main(void)
 {
+    esp_err_t ret;
+    // Options for mounting the filesystem.
+    // If format_if_mount_failed is set to true, SD card will be partitioned and
+    // formatted in case when mounting fails.
+    esp_vfs_fat_sdmmc_mount_config_t mount_config = {
+        .format_if_mount_failed = false,
+        .max_files = 5,
+        .allocation_unit_size = 16 * 1024
+    };
+    sdmmc_card_t* card;
+    const char mount_point[] = MOUNT_POINT;
     ESP_LOGI(TAG, "Initializing SD card");
 
+    // Use settings defined above to initialize SD card and mount FAT filesystem.
+    // Note: esp_vfs_fat_sdmmc/sdspi_mount is all-in-one convenience functions.
+    // Please check its source code and implement error recovery when developing
+    // production applications.
 #ifndef USE_SPI_MODE
     ESP_LOGI(TAG, "Using SDMMC peripheral");
     sdmmc_host_t host = SDMMC_HOST_DEFAULT();
@@ -63,35 +83,33 @@ void app_main(void)
     gpio_set_pull_mode(12, GPIO_PULLUP_ONLY);   // D2, needed in 4-line mode only
     gpio_set_pull_mode(13, GPIO_PULLUP_ONLY);   // D3, needed in 4- and 1-line modes
 
+    ret = esp_vfs_fat_sdmmc_mount(mount_point, &host, &slot_config, &mount_config, &card);
 #else
     ESP_LOGI(TAG, "Using SPI peripheral");
 
     sdmmc_host_t host = SDSPI_HOST_DEFAULT();
-    sdspi_slot_config_t slot_config = SDSPI_SLOT_CONFIG_DEFAULT();
-    slot_config.gpio_miso = PIN_NUM_MISO;
-    slot_config.gpio_mosi = PIN_NUM_MOSI;
-    slot_config.gpio_sck  = PIN_NUM_CLK;
-    slot_config.gpio_cs   = PIN_NUM_CS;
+    spi_bus_config_t bus_cfg = {
+        .mosi_io_num = PIN_NUM_MOSI,
+        .miso_io_num = PIN_NUM_MISO,
+        .sclk_io_num = PIN_NUM_CLK,
+        .quadwp_io_num = -1,
+        .quadhd_io_num = -1,
+        .max_transfer_sz = 4000,
+    };
+    ret = spi_bus_initialize(host.slot, &bus_cfg, SPI_DMA_CHAN);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to initialize bus.");
+        return;
+    }
+
     // This initializes the slot without card detect (CD) and write protect (WP) signals.
     // Modify slot_config.gpio_cd and slot_config.gpio_wp if your board has these signals.
+    sdspi_device_config_t slot_config = SDSPI_DEVICE_CONFIG_DEFAULT();
+    slot_config.gpio_cs   = PIN_NUM_CS;
+
+    ret = esp_vfs_fat_sdspi_mount(mount_point, &host, &slot_config, &mount_config, &card);
 #endif //USE_SPI_MODE
 
-    // Options for mounting the filesystem.
-    // If format_if_mount_failed is set to true, SD card will be partitioned and
-    // formatted in case when mounting fails.
-    esp_vfs_fat_sdmmc_mount_config_t mount_config = {
-        .format_if_mount_failed = false,
-        .max_files = 5,
-        .allocation_unit_size = 16 * 1024
-    };
-
-    // Use settings defined above to initialize SD card and mount FAT filesystem.
-    // Note: esp_vfs_fat_sdmmc_mount is an all-in-one convenience function.
-    // Please check its source code and implement error recovery when developing
-    // production applications.
-    sdmmc_card_t* card;
-    esp_err_t ret = esp_vfs_fat_sdmmc_mount("/sdcard", &host, &slot_config, &mount_config, &card);
-
     if (ret != ESP_OK) {
         if (ret == ESP_FAIL) {
             ESP_LOGE(TAG, "Failed to mount filesystem. "
@@ -109,7 +127,7 @@ void app_main(void)
     // Use POSIX and C standard library functions to work with files.
     // First create a file.
     ESP_LOGI(TAG, "Opening file");
-    FILE* f = fopen("/sdcard/hello.txt", "w");
+    FILE* f = fopen(MOUNT_POINT"/hello.txt", "w");
     if (f == NULL) {
         ESP_LOGE(TAG, "Failed to open file for writing");
         return;
@@ -120,21 +138,21 @@ void app_main(void)
 
     // Check if destination file exists before renaming
     struct stat st;
-    if (stat("/sdcard/foo.txt", &st) == 0) {
+    if (stat(MOUNT_POINT"/foo.txt", &st) == 0) {
         // Delete it if it exists
-        unlink("/sdcard/foo.txt");
+        unlink(MOUNT_POINT"/foo.txt");
     }
 
     // Rename original file
     ESP_LOGI(TAG, "Renaming file");
-    if (rename("/sdcard/hello.txt", "/sdcard/foo.txt") != 0) {
+    if (rename(MOUNT_POINT"/hello.txt", MOUNT_POINT"/foo.txt") != 0) {
         ESP_LOGE(TAG, "Rename failed");
         return;
     }
 
     // Open renamed file for reading
     ESP_LOGI(TAG, "Reading file");
-    f = fopen("/sdcard/foo.txt", "r");
+    f = fopen(MOUNT_POINT"/foo.txt", "r");
     if (f == NULL) {
         ESP_LOGE(TAG, "Failed to open file for reading");
         return;
@@ -150,6 +168,10 @@ void app_main(void)
     ESP_LOGI(TAG, "Read from file: '%s'", line);
 
     // All done, unmount partition and disable SDMMC or SPI peripheral
-    esp_vfs_fat_sdmmc_unmount();
+    esp_vfs_fat_sdcard_unmount(mount_point, card);
     ESP_LOGI(TAG, "Card unmounted");
+#ifdef USE_SPI_MODE
+    //deinitialize the bus after all devices are removed
+    spi_bus_free(host.slot);
+#endif
 }