esp32/sdcard: Add support for SDMMC power control with internal LDO.

A board can #define MICROPY_HW_SDMMC_LDO_CHAN_ID in mpconfigboard.h
for an internal LDO to control power to the SDMMC GPIO pins. This
is needed to use SDIO 3.0, because the IO level has to switch between
3.3V and 1.8V.

Signed-off-by: Dryw Wade <dryw.wade@sparkfun.com>

Author: sfe-SparkFro

ports/esp32/machine_sdcard.c

@@ -35,6 +35,9 @@
 
 #if SOC_SDMMC_HOST_SUPPORTED
 #include "driver/sdmmc_host.h"
+#if SOC_SDMMC_IO_POWER_EXTERNAL && defined(MICROPY_HW_SDMMC_LDO_CHAN_ID)
+#include "sd_pwr_ctrl_by_on_chip_ldo.h"
+#endif
 #endif
 #include "driver/sdspi_host.h"
 #include "sdmmc_cmd.h"
@@ -310,6 +313,14 @@ static mp_obj_t machine_sdcard_make_new(const mp_obj_type_t *type, size_t n_args
         self->host = _temp_host;
     }
     #endif
+    #if SOC_SDMMC_IO_POWER_EXTERNAL && defined(MICROPY_HW_SDMMC_LDO_CHAN_ID)
+    sd_pwr_ctrl_ldo_config_t ldo_config = {
+        .ldo_chan_id = MICROPY_HW_SDMMC_LDO_CHAN_ID,
+    };
+    sd_pwr_ctrl_handle_t pwr_ctrl_handle = NULL;
+    check_esp_err(sd_pwr_ctrl_new_on_chip_ldo(&ldo_config, &pwr_ctrl_handle));
+    self->host.pwr_ctrl_handle = pwr_ctrl_handle;
+    #endif
 
     DEBUG_printf("  Calling host.init()");
 
@@ -431,6 +442,11 @@ static mp_obj_t sd_deinit(mp_obj_t self_in) {
             // SD card used a (dedicated) SPI bus, so free that SPI bus.
             spi_bus_free(self->host.slot);
         }
+        #if SOC_SDMMC_IO_POWER_EXTERNAL && defined(MICROPY_HW_SDMMC_LDO_CHAN_ID)
+        if (self->host.pwr_ctrl_handle) {
+            check_esp_err(sd_pwr_ctrl_del_on_chip_ldo(self->host.pwr_ctrl_handle));
+        }
+        #endif
         self->flags &= ~SDCARD_CARD_FLAGS_HOST_INIT_DONE;
     }