dm: mmc: Add an MMC uclass

Add basic support for MMC, providing a uclass which can set up an MMC
device. This allows MMC drivers to move to using driver model.
Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/mmc/Kconfig

 menu "MMC Host controller Support"
 
+config DM_MMC
+	bool "Enable MMC controllers using Driver Model"
+	depends on DM
+	help
+	  This enables the MultiMediaCard (MMC) uclass which suports MMC and
+	  Secure Digital I/O (SDIO) cards. Both removable (SD, micro-SD, etc.)
+	  and non-removable (e.g. eMMC chip) devices are supported. These
+	  appear as block devices in U-Boot and can support filesystems such
+	  as EXT4 and FAT.
+
 config SH_SDHI
 	bool "SuperH/Renesas ARM SoCs on-chip SDHI host controller support"
 	depends on RMOBILE

drivers/mmc/Makefile

@@ -5,6 +5,8 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+obj-$(CONFIG_DM_MMC) += mmc-uclass.o
+
 obj-$(CONFIG_ARM_PL180_MMCI) += arm_pl180_mmci.o
 obj-$(CONFIG_BCM2835_SDHCI) += bcm2835_sdhci.o
 obj-$(CONFIG_BFIN_SDH) += bfin_sdh.o

drivers/mmc/mmc-uclass.c

+/*
+ * Copyright (C) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <mmc.h>
+#include <dm.h>
+#include <dm/lists.h>
+#include <dm/root.h>
+
+struct mmc *mmc_get_mmc_dev(struct udevice *dev)
+{
+	struct mmc_uclass_priv *upriv;
+
+	if (!device_active(dev))
+		return NULL;
+	upriv = dev_get_uclass_priv(dev);
+	return upriv->mmc;
+}
+
+U_BOOT_DRIVER(mmc) = {
+	.name	= "mmc",
+	.id	= UCLASS_MMC,
+};
+
+UCLASS_DRIVER(mmc) = {
+	.id		= UCLASS_MMC,
+	.name		= "mmc",
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+	.per_device_auto_alloc_size = sizeof(struct mmc_uclass_priv),
+};

drivers/mmc/mmc.c

@@ -1761,8 +1761,10 @@ int mmc_initialize(bd_t *bis)
 	INIT_LIST_HEAD (&mmc_devices);
 	cur_dev_num = 0;
 
+#ifndef CONFIG_DM_MMC
 	if (board_mmc_init(bis) < 0)
 		cpu_mmc_init(bis);
+#endif
 
 #ifndef CONFIG_SPL_BUILD
 	print_mmc_devices(',');

include/dm/uclass-id.h

@@ -36,6 +36,7 @@ enum uclass_id {
 	UCLASS_LED,		/* Light-emitting diode (LED) */
 	UCLASS_LPC,		/* x86 'low pin count' interface */
 	UCLASS_MASS_STORAGE,	/* Mass storage device */
+	UCLASS_MMC,		/* SD / MMC card or chip */
 	UCLASS_MOD_EXP,		/* RSA Mod Exp device */
 	UCLASS_PCH,		/* x86 platform controller hub */
 	UCLASS_PCI,		/* PCI bus */

include/mmc.h

@@ -266,6 +266,28 @@
 #define MMC_NUM_BOOT_PARTITION	2
 #define MMC_PART_RPMB           3       /* RPMB partition number */
 
+/* Driver model support */
+
+/**
+ * struct mmc_uclass_priv - Holds information about a device used by the uclass
+ */
+struct mmc_uclass_priv {
+	struct mmc *mmc;
+};
+
+/**
+ * mmc_get_mmc_dev() - get the MMC struct pointer for a device
+ *
+ * Provided that the device is already probed and ready for use, this value
+ * will be available.
+ *
+ * @dev:	Device
+ * @return associated mmc struct pointer if available, else NULL
+ */
+struct mmc *mmc_get_mmc_dev(struct udevice *dev);
+
+/* End of driver model support */
+
 struct mmc_cid {
 	unsigned long psn;
 	unsigned short oid;