mmc: openpiton: add piton_mmc driver

This commit adds support to piton_mmc driver for OpenPiton-riscv64
This driver has many things set as preconfigured because the hardware
automatically configures most of the settings during startup.

Signed-off-by: Tianrui Wei <tianrui-wei@outlook.com>
Signed-off-by: Jonathan Balkind <jbalkind@ucsb.edu>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

drivers/mmc/Kconfig

@@ -727,6 +727,15 @@ config MMC_SUNXI_HAS_MODE_SWITCH
 	bool
 	depends on MMC_SUNXI
 
+config MMC_PITON
+	bool "MMC support for OpenPiton SoC"
+	depends on DM_MMC && BLK
+	help
+	  This selects support for the SD host controller on OpenPiton SoC.
+	  Note that this SD controller directly exposes the contents of the
+	  SD card as memory mapped, so there is no manual configuration
+	  required
+
 config GENERIC_ATMEL_MCI
 	bool "Atmel Multimedia Card Interface support"
 	depends on DM_MMC && BLK && ARCH_AT91

drivers/mmc/Makefile

@@ -72,6 +72,7 @@ obj-$(CONFIG_MMC_SDHCI_XENON)		+= xenon_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_ZYNQ)		+= zynq_sdhci.o
 
 obj-$(CONFIG_MMC_SUNXI)			+= sunxi_mmc.o
+obj-$(CONFIG_MMC_PITON)			+= piton_mmc.o
 obj-$(CONFIG_MMC_UNIPHIER)		+= tmio-common.o uniphier-sd.o
 obj-$(CONFIG_RENESAS_SDHI)		+= tmio-common.o renesas-sdhi.o
 obj-$(CONFIG_MMC_BCM2835)		+= bcm2835_sdhost.o

drivers/mmc/piton_mmc.c

@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2009 SAMSUNG Electronics
+ * Minkyu Kang <mk7.kang@samsung.com>
+ * Jaehoon Chung <jh80.chung@samsung.com>
+ * Portions Copyright 2011-2019 NVIDIA Corporation
+ * Portions Copyright 2021 Tianrui Wei
+ * This file is adapted from tegra_mmc.c
+ * Tianrui Wei <tianrui-wei@outlook.com>
+ */
+
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <common.h>
+#include <div64.h>
+#include <dm.h>
+#include <errno.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/sizes.h>
+#include <log.h>
+#include <mmc.h>
+
+
+#define PITON_MMC_DUMMY_F_MAX 20000000
+#define PITON_MMC_DUMMY_F_MIN 10000000
+#define PITON_MMC_DUMMY_CAPACITY SZ_4G << 3
+#define PITON_MMC_DUMMY_B_MAX SZ_4G
+
+struct piton_mmc_plat {
+	struct mmc_config cfg;
+	struct mmc mmc;
+};
+
+struct piton_mmc_priv {
+	void __iomem *base_addr;
+};
+
+static int piton_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
+							  struct mmc_data *data)
+{
+	if (!data)
+		return 0;
+
+	struct piton_mmc_priv *priv = dev_get_priv(dev);
+	u32 *buff, *start_addr, *write_src;
+	size_t byte_cnt, start_block;
+
+	buff = (u32 *)data->dest;
+	write_src = (u32 *)data->src;
+	start_block = cmd->cmdarg;
+	start_addr = priv->base_addr + start_block;
+
+	/* if there is a read */
+	for (byte_cnt = data->blocks * data->blocksize; byte_cnt;
+				 byte_cnt -= sizeof(u32)) {
+		if (data->flags & MMC_DATA_READ) {
+			*buff++ = readl(start_addr++);
+		}
+		else if (data->flags & MMC_DATA_WRITE) {
+			writel(*write_src++,start_addr++);
+		}
+	}
+	return 0;
+}
+
+static int piton_mmc_ofdata_to_platdata(struct udevice *dev)
+{
+	struct piton_mmc_priv *priv = dev_get_priv(dev);
+	struct piton_mmc_plat *plat = dev_get_plat(dev);
+	struct mmc_config *cfg;
+	struct mmc *mmc;
+	struct blk_desc *bdesc;
+
+	priv->base_addr = (void *)dev_read_addr(dev);
+	cfg = &plat->cfg;
+	cfg->name = "PITON MMC";
+	cfg->host_caps = MMC_MODE_8BIT;
+	cfg->f_max = PITON_MMC_DUMMY_F_MAX;
+	cfg->f_min = PITON_MMC_DUMMY_F_MIN;
+	cfg->voltages = MMC_VDD_21_22;
+
+	mmc = &plat->mmc;
+	mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
+	mmc->capacity_user = PITON_MMC_DUMMY_CAPACITY;
+	mmc->capacity_user *= mmc->read_bl_len;
+	mmc->capacity_boot = 0;
+	mmc->capacity_rpmb = 0;
+	for (int i = 0; i < 4; i++)
+		mmc->capacity_gp[i] = 0;
+	mmc->capacity = PITON_MMC_DUMMY_CAPACITY;
+	mmc->has_init = 1;
+
+	bdesc = mmc_get_blk_desc(mmc);
+	bdesc->lun = 0;
+	bdesc->hwpart = 0;
+	bdesc->type = 0;
+	bdesc->blksz = mmc->read_bl_len;
+	bdesc->log2blksz = LOG2(bdesc->blksz);
+	bdesc->lba = lldiv(mmc->capacity, mmc->read_bl_len);
+
+	return 0;
+}
+
+static int piton_mmc_getcd(struct udevice *dev)
+{
+	return 1;
+}
+
+static const struct dm_mmc_ops piton_mmc_ops = {
+	.send_cmd = piton_mmc_send_cmd,
+	.get_cd = piton_mmc_getcd,
+};
+
+static int piton_mmc_probe(struct udevice *dev)
+{
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct piton_mmc_plat *plat = dev_get_plat(dev);
+	struct mmc_config *cfg = &plat->cfg;
+
+	cfg->name = dev->name;
+	upriv->mmc = &plat->mmc;
+	upriv->mmc->has_init = 1;
+	upriv->mmc->capacity = PITON_MMC_DUMMY_CAPACITY;
+	upriv->mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
+	return 0;
+}
+
+static int piton_mmc_bind(struct udevice *dev)
+{
+	struct piton_mmc_plat *plat = dev_get_plat(dev);
+	struct mmc_config *cfg = &plat->cfg;
+
+	cfg->name = dev->name;
+	cfg->host_caps = MMC_MODE_HS_52MHz | MMC_MODE_HS | MMC_MODE_8BIT;
+	cfg->voltages = MMC_VDD_165_195 | MMC_VDD_32_33 | MMC_VDD_33_34;
+	cfg->f_min = PITON_MMC_DUMMY_F_MIN;
+	cfg->f_max = PITON_MMC_DUMMY_F_MAX;
+	cfg->b_max = MMC_MAX_BLOCK_LEN;
+
+	return mmc_bind(dev, &plat->mmc, cfg);
+}
+
+static const struct udevice_id piton_mmc_ids[] = {
+	{.compatible = "openpiton,piton-mmc"},
+	{/* sentinel */}
+};
+
+U_BOOT_DRIVER(piton_mmc_drv) = {
+	.name = "piton_mmc",
+	.id = UCLASS_MMC,
+	.of_match = piton_mmc_ids,
+	.of_to_plat = piton_mmc_ofdata_to_platdata,
+	.bind = piton_mmc_bind,
+	.probe = piton_mmc_probe,
+	.ops = &piton_mmc_ops,
+	.plat_auto = sizeof(struct piton_mmc_plat),
+	.priv_auto = sizeof(struct piton_mmc_priv),
+};