arch/arm/src/imxrt/imxrt_usdhc.c: Initial commit of the i.MXRT SDHC driver. This driver is partially functional, working in PIO mode. DMA support and additional testing are needed.

arch/arm/src/imxrt/Kconfig

@@ -272,6 +272,13 @@ config IMXRT_SNVS_HPRTC
 	bool "HP RTC"
 	default n
 
+config IMXRT_USDHC
+	bool "USDHC"
+	default n
+	select ARCH_HAVE_SDIO
+	---help---
+		Support SD host controller
+
 endmenu # i.MX RT Peripheral Selection
 
 menuconfig IMXRT_GPIO_IRQ
@@ -508,6 +515,26 @@ config IMXRT_SRAM_HEAPOFFSET
 endmenu  # i.MX6 Primary RAM
 endmenu # Memory Configuration
 
+menu "USDHC Configuration"
+	depends on IMXRT_USDHC
+
+config IMXRT_USDHC_DMA
+	bool "Support DMA data transfers"
+	default y
+	select SDIO_DMA
+	---help---
+		Support DMA data transfers.
+		Enable SD card DMA data transfers.  This is marginally optional.
+		For most usages, SD accesses will cause data overruns if used without
+		DMA.
+
+config IMXRT_USDHC_WIDTH_D1_ONLY
+	bool "Use D1 only"
+	default n
+	---help---
+		Select 1-bit transfer mode.  Default: 4-bit transfer mode.
+endmenu # USDHC Configuration
+
 menu "eDMA Configuration"
 	depends on IMXRT_EDMA
 

arch/arm/src/imxrt/Make.defs

@@ -120,6 +120,10 @@ ifeq ($(CONFIG_IMXRT_EDMA),y)
 CHIP_CSRCS += imxrt_edma.c
 endif
 
+ifdef CONFIG_IMXRT_USDHC
+CHIP_CSRCS += imxrt_usdhc.c
+endif
+
 ifeq ($(CONFIG_IMXRT_SNVS_LPSRTC),y)
 CHIP_CSRCS += imxrt_lpsrtc.c
 CHIP_CSRCS += imxrt_hprtc.c

arch/arm/src/imxrt/imxrt_clockconfig.c

@@ -228,5 +228,21 @@ void imxrt_clockconfig(void)
   putreg32(reg, IMXRT_CCM_CBCMR);
 #endif
 
+#ifdef CONFIG_IMXRT_USDHC
+  /* Set USDHC1 & 2 to generate clocks from PPL2 PFD2 (396 MHz) */
+
+  reg  = getreg32(IMXRT_CCM_CSCMR1);
+  reg &= CCM_CSCMR1_USDHC1_CLK_SEL | CCM_CSCMR1_USDHC2_CLK_SEL;
+  reg |= CCM_CSCMR1_USDHC1_CLK_SEL_PLL2_PFD0 | CCM_CSCMR1_USDHC2_CLK_SEL_PLL2_PFD0;
+  putreg32(reg, IMXRT_CCM_CSCMR1);
+
+  /* Now divide down clocks by 2 ( --> 198 MHz) */
+
+  reg  = getreg32(IMXRT_CCM_CSCDR1);
+  reg &= CCM_CSCDR1_USDHC1_PODF_MASK | CCM_CSCDR1_USDHC2_PODF_MASK;
+  reg |= CCM_CSCDR1_USDHC1_PODF(1) | CCM_CSCDR1_USDHC2_PODF(1);
+  putreg32(reg, IMXRT_CCM_CSCDR1);
+#endif
+
 #endif
 }

arch/arm/src/imxrt/imxrt_usdhc.h

@@ -0,0 +1,70 @@
+/****************************************************************************
+ * arch/arm/src/imxrt/imxrt_usdhc.h
+ *
+ *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
+ *   Author: Ivan Ucherdzhiev <ivanucherdjiev@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_IMXRT_IMX_USDHC_H
+#define __ARCH_ARM_SRC_IMXRT_IMX_USDHC_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/sdio.h>
+#include <nuttx/mmcsd.h>
+
+#include "chip.h"
+#include "chip/imxrt_usdhc.h"
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: imxrt_usdhc_initialize
+ *
+ * Description:
+ *   Initialize USDHC for operation.
+ *
+ * Input Parameters:
+ *   slotno - Not used.
+ *
+ * Returned Value:
+ *   A reference to an USDIO interface structure.  NULL is returned on failures.
+ *
+ ****************************************************************************/
+
+FAR struct sdio_dev_s *imxrt_usdhc_initialize(int slotno);
+
+#endif /*__ARCH_ARM_SRC_IMXRT_IMX_USDHC_H */

configs/imxrt1050-evk/include/board.h

@@ -161,6 +161,39 @@
 
 #define BUTTON_SW8_BIT    (1 << BUTTON_SW8)
 
+/* SDIO *****************************************************************************/
+
+/* Pin drive characteristics - drive strength in particular may need tuning for specific boards */
+
+#define PADCTL_USDHC1_DATAX (PADCTL_SRE|PADCTL_DSE_60OHM|PADCTL_HYS)
+#define PADCTL_USDHC1_CMD    PADCTL_USDHC1_DATAX
+#define PADCTL_USDHC1_CLK   (PADCTL_SRE|PADCTL_DSE_60OHM|PADCTL_SPEED_MAX)
+#define PADCTL_USDHC1_CD    (0)
+
+#define PIN_USDHC1_D0 GPIO_USDHC1_DATA0
+#define PIN_USDHC1_D1 GPIO_USDHC1_DATA1
+#define PIN_USDHC1_D2 GPIO_USDHC1_DATA2
+#define PIN_USDHC1_D3 GPIO_USDHC1_DATA3
+#define PIN_USDHC1_DCLK GPIO_USDHC1_CLK
+#define PIN_USDHC1_CMD GPIO_USDHC1_CMD
+#define PIN_USDHC1_CD GPIO_USDHC1_CD_2
+
+/* 386 KHz for initial inquiry stuff */
+
+#define BOARD_USDHC_IDMODE_PRESCALER    USDHC_SYSCTL_SDCLKFS_DIV256
+#define BOARD_USDHC_IDMODE_DIVISOR      USDHC_SYSCTL_DVS_DIV(2)
+
+/* 24.8MHz for other modes */
+
+#define BOARD_USDHC_MMCMODE_PRESCALER   USDHC_SYSCTL_SDCLKFS_DIV8
+#define BOARD_USDHC_MMCMODE_DIVISOR     USDHC_SYSCTL_DVS_DIV(1)
+
+#define BOARD_USDHC_SD1MODE_PRESCALER   USDHC_SYSCTL_SDCLKFS_DIV8
+#define BOARD_USDHC_SD1MODE_DIVISOR     USDHC_SYSCTL_DVS_DIV(1)
+
+#define BOARD_USDHC_SD4MODE_PRESCALER   USDHC_SYSCTL_SDCLKFS_DIV8
+#define BOARD_USDHC_SD4MODE_DIVISOR     USDHC_SYSCTL_DVS_DIV(1)
+
 /* PIO Disambiguation ***************************************************************/
 /* LPUARTs
  *

configs/imxrt1050-evk/src/imxrt_bringup.c

@@ -48,6 +48,10 @@
 #include <imxrt_lpi2c.h>
 #include <imxrt_lpspi.h>
 
+#ifdef CONFIG_IMXRT_USDHC
+#  include "imxrt_usdhc.h"
+#endif
+
 #include "imxrt1050-evk.h"
 
 #include <arch/board/board.h>  /* Must always be included last */
@@ -91,6 +95,37 @@ static void imxrt_i2c_register(int bus)
 }
 #endif
 
+#ifdef CONFIG_IMXRT_USDHC
+static int nsh_sdmmc_initialize(void)
+{
+  struct sdio_dev_s *sdmmc;
+  int ret = 0;
+
+  /* Get an instance of the SDIO interface */
+
+  sdmmc = imxrt_usdhc_initialize(0);
+  if (!sdmmc)
+    {
+      syslog(LOG_ERR, "ERROR: Failed to initialize SD/MMC\n");
+    }
+  else
+    {
+      /* Bind the SDIO interface to the MMC/SD driver */
+
+      ret = mmcsd_slotinitialize(0, sdmmc);
+      if (ret != OK)
+        {
+          syslog(LOG_ERR,
+                 "ERROR: Failed to bind SDIO to the MMC/SD driver: %d\n",
+                 ret);
+        }
+    }
+  return OK;
+  }
+#else
+#  define nsh_sdmmc_initialize() (OK)
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -126,6 +161,12 @@ int imxrt_bringup(void)
   imxrt_i2c_register(1);
 #endif
 
+#ifdef CONFIG_IMXRT_USDHC
+  /* Initialize SDHC-base MMC/SD card support */
+
+  nsh_sdmmc_initialize();
+#endif
+
 #ifdef CONFIG_MMCSD_SPI
   /* Initialize SPI-based MMC/SD card support */