From 3d02ebb4e8262b67433eadc80100155387c6f186 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@wilson.house>
Date: Thu, 1 Aug 2019 19:54:32 -0700
Subject: [PATCH] stm32/sdcard: Support configuring the SD/MMC bus width to 1
 or 4 bits.

Some SD/MMC breakout boards don't support 4-bit bus mode.  This adds a new
macro MICROPY_HW_SDMMC_BUS_WIDTH that allows each board to define the width
of the SD/MMC bus interface used on that board, defaulting to 4 bits.
---
 ports/stm32/mpconfigboard_common.h |  5 +++++
 ports/stm32/sdcard.c               | 16 ++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/ports/stm32/mpconfigboard_common.h b/ports/stm32/mpconfigboard_common.h
index 121b64d038..603215af4b 100644
--- a/ports/stm32/mpconfigboard_common.h
+++ b/ports/stm32/mpconfigboard_common.h
@@ -102,6 +102,11 @@
 #define MICROPY_HW_ENABLE_MMCARD (0)
 #endif
 
+// SD/MMC interface bus width (defaults to 4 bits)
+#ifndef MICROPY_HW_SDMMC_BUS_WIDTH
+#define MICROPY_HW_SDMMC_BUS_WIDTH (4)
+#endif
+
 // Whether to automatically mount (and boot from) the SD card if it's present
 #ifndef MICROPY_HW_SDCARD_MOUNT_AT_BOOT
 #define MICROPY_HW_SDCARD_MOUNT_AT_BOOT (MICROPY_HW_ENABLE_SDCARD)
diff --git a/ports/stm32/sdcard.c b/ports/stm32/sdcard.c
index 0cb09b8189..f54d67ea49 100644
--- a/ports/stm32/sdcard.c
+++ b/ports/stm32/sdcard.c
@@ -156,17 +156,21 @@ void sdcard_init(void) {
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC2_CK, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC2_CK);
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC2_CMD, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC2_CMD);
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC2_D0, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC2_D0);
+    #if MICROPY_HW_SDMMC_BUS_WIDTH == 4
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC2_D1, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC2_D1);
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC2_D2, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC2_D2);
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC2_D3, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC2_D3);
+    #endif
     #else
     // Default SDIO/SDMMC1 config
+    mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_CK, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_CK);
+    mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_CMD, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_CMD);
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_D0, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_D0);
+    #if MICROPY_HW_SDMMC_BUS_WIDTH == 4
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_D1, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_D1);
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_D2, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_D2);
     mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_D3, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_D3);
-    mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_CK, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_CK);
-    mp_hal_pin_config_alt_static(MICROPY_HW_SDMMC_CMD, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_SDMMC_CMD);
+    #endif
     #endif
 
     // configure the SD card detect pin
@@ -252,12 +256,14 @@ STATIC HAL_StatusTypeDef sdmmc_init_sd(void) {
         mp_hal_delay_ms(50);
     }
 
-    // configure the SD bus width for wide operation
+    #if MICROPY_HW_SDMMC_BUS_WIDTH == 4
+    // configure the SD bus width for 4-bit wide operation
     status = HAL_SD_ConfigWideBusOperation(&sdmmc_handle.sd, SDIO_BUS_WIDE_4B);
     if (status != HAL_OK) {
         HAL_SD_DeInit(&sdmmc_handle.sd);
         return status;
     }
+    #endif
 
     return HAL_OK;
 }
@@ -285,7 +291,8 @@ STATIC HAL_StatusTypeDef sdmmc_init_mmc(void) {
     // As this is an eMMC card, overwrite LogBlockNbr with actual value
     sdmmc_handle.mmc.MmcCard.LogBlockNbr = 7469056 + 2048;
 
-    // Configure the SDIO bus width for wide operation
+    #if MICROPY_HW_SDMMC_BUS_WIDTH == 4
+    // Configure the SDIO bus width for 4-bit wide operation
     #ifdef STM32F7
     sdmmc_handle.mmc.Init.ClockBypass = SDIO_CLOCK_BYPASS_ENABLE;
     #endif
@@ -294,6 +301,7 @@ STATIC HAL_StatusTypeDef sdmmc_init_mmc(void) {
         HAL_MMC_DeInit(&sdmmc_handle.mmc);
         return status;
     }
+    #endif
 
     return HAL_OK;
 }