mmc: meson: add MMC driver for Meson GX (S905)

This driver implements MMC support on Meson GX (S905) based systems.
It's based on Carlo Caione's work, changes:
- BLK support added
- general refactoring

Signed-off-by: Carlo Caione <carlo@caione.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Vagrant Cascadian <vagrant@debian.org>

1 files changed, 291 insertions, 0 deletions

diff --git a/drivers/mmc/meson_gx_mmc.c b/drivers/mmc/meson_gx_mmc.c
new file mode 100644
index 0000000000..8e28ab70f5
--- /dev/null
+++ b/drivers/mmc/meson_gx_mmc.c
@@ -0,0 +1,291 @@
+/*
+ * (C) Copyright 2016 Carlo Caione <carlo@caione.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <malloc.h>
+#include <mmc.h>
+#include <asm/io.h>
+#include <asm/arch/sd_emmc.h>
+#include <dm/device.h>
+#include <linux/log2.h>
+
+static inline void *get_regbase(const struct mmc *mmc)
+{
+	struct meson_mmc_platdata *pdata = mmc->priv;
+
+	return pdata->regbase;
+}
+
+static inline uint32_t meson_read(struct mmc *mmc, int offset)
+{
+	return readl(get_regbase(mmc) + offset);
+}
+
+static inline void meson_write(struct mmc *mmc, uint32_t val, int offset)
+{
+	writel(val, get_regbase(mmc) + offset);
+}
+
+static void meson_mmc_config_clock(struct mmc *mmc)
+{
+	uint32_t meson_mmc_clk = 0;
+	unsigned int clk, clk_src, clk_div;
+
+	/* 1GHz / CLK_MAX_DIV = 15,9 MHz */
+	if (mmc->clock > 16000000) {
+		clk = SD_EMMC_CLKSRC_DIV2;
+		clk_src = CLK_SRC_DIV2;
+	} else {
+		clk = SD_EMMC_CLKSRC_24M;
+		clk_src = CLK_SRC_24M;
+	}
+	clk_div = DIV_ROUND_UP(clk, mmc->clock);
+
+	/* 180 phase core clock */
+	meson_mmc_clk |= CLK_CO_PHASE_180;
+
+	/* 180 phase tx clock */
+	meson_mmc_clk |= CLK_TX_PHASE_000;
+
+	/* clock settings */
+	meson_mmc_clk |= clk_src;
+	meson_mmc_clk |= clk_div;
+
+	meson_write(mmc, meson_mmc_clk, MESON_SD_EMMC_CLOCK);
+}
+
+static int meson_dm_mmc_set_ios(struct udevice *dev)
+{
+	struct mmc *mmc = mmc_get_mmc_dev(dev);
+	uint32_t meson_mmc_cfg;
+
+	meson_mmc_config_clock(mmc);
+
+	meson_mmc_cfg = meson_read(mmc, MESON_SD_EMMC_CFG);
+
+	meson_mmc_cfg &= ~CFG_BUS_WIDTH_MASK;
+	if (mmc->bus_width == 1)
+		meson_mmc_cfg |= CFG_BUS_WIDTH_1;
+	else if (mmc->bus_width == 4)
+		meson_mmc_cfg |= CFG_BUS_WIDTH_4;
+	else if (mmc->bus_width == 8)
+		meson_mmc_cfg |= CFG_BUS_WIDTH_8;
+	else
+		return -EINVAL;
+
+	/* 512 bytes block length */
+	meson_mmc_cfg &= ~CFG_BL_LEN_MASK;
+	meson_mmc_cfg |= CFG_BL_LEN_512;
+
+	/* Response timeout 256 clk */
+	meson_mmc_cfg &= ~CFG_RESP_TIMEOUT_MASK;
+	meson_mmc_cfg |= CFG_RESP_TIMEOUT_256;
+
+	/* Command-command gap 16 clk */
+	meson_mmc_cfg &= ~CFG_RC_CC_MASK;
+	meson_mmc_cfg |= CFG_RC_CC_16;
+
+	meson_write(mmc, meson_mmc_cfg, MESON_SD_EMMC_CFG);
+
+	return 0;
+}
+
+static void meson_mmc_setup_cmd(struct mmc *mmc, struct mmc_data *data,
+				struct mmc_cmd *cmd)
+{
+	uint32_t meson_mmc_cmd = 0, cfg;
+
+	meson_mmc_cmd |= cmd->cmdidx << CMD_CFG_CMD_INDEX_SHIFT;
+
+	if (cmd->resp_type & MMC_RSP_PRESENT) {
+		if (cmd->resp_type & MMC_RSP_136)
+			meson_mmc_cmd |= CMD_CFG_RESP_128;
+
+		if (cmd->resp_type & MMC_RSP_BUSY)
+			meson_mmc_cmd |= CMD_CFG_R1B;
+
+		if (!(cmd->resp_type & MMC_RSP_CRC))
+			meson_mmc_cmd |= CMD_CFG_RESP_NOCRC;
+	} else {
+		meson_mmc_cmd |= CMD_CFG_NO_RESP;
+	}
+
+	if (data) {
+		cfg = meson_read(mmc, MESON_SD_EMMC_CFG);
+		cfg &= ~CFG_BL_LEN_MASK;
+		cfg |= ilog2(data->blocksize) << CFG_BL_LEN_SHIFT;
+		meson_write(mmc, cfg, MESON_SD_EMMC_CFG);
+
+		if (data->flags == MMC_DATA_WRITE)
+			meson_mmc_cmd |= CMD_CFG_DATA_WR;
+
+		meson_mmc_cmd |= CMD_CFG_DATA_IO | CMD_CFG_BLOCK_MODE |
+				 data->blocks;
+	}
+
+	meson_mmc_cmd |= CMD_CFG_TIMEOUT_4S | CMD_CFG_OWNER |
+			 CMD_CFG_END_OF_CHAIN;
+
+	meson_write(mmc, meson_mmc_cmd, MESON_SD_EMMC_CMD_CFG);
+}
+
+static void meson_mmc_setup_addr(struct mmc *mmc, struct mmc_data *data)
+{
+	struct meson_mmc_platdata *pdata = mmc->priv;
+	unsigned int data_size;
+	uint32_t data_addr = 0;
+
+	if (data) {
+		data_size = data->blocks * data->blocksize;
+
+		if (data->flags == MMC_DATA_READ) {
+			data_addr = (ulong) data->dest;
+			invalidate_dcache_range(data_addr,
+						data_addr + data_size);
+		} else {
+			pdata->w_buf = calloc(data_size, sizeof(char));
+			data_addr = (ulong) pdata->w_buf;
+			memcpy(pdata->w_buf, data->src, data_size);
+			flush_dcache_range(data_addr, data_addr + data_size);
+		}
+	}
+
+	meson_write(mmc, data_addr, MESON_SD_EMMC_CMD_DAT);
+}
+
+static void meson_mmc_read_response(struct mmc *mmc, struct mmc_cmd *cmd)
+{
+	if (cmd->resp_type & MMC_RSP_136) {
+		cmd->response[0] = meson_read(mmc, MESON_SD_EMMC_CMD_RSP3);
+		cmd->response[1] = meson_read(mmc, MESON_SD_EMMC_CMD_RSP2);
+		cmd->response[2] = meson_read(mmc, MESON_SD_EMMC_CMD_RSP1);
+		cmd->response[3] = meson_read(mmc, MESON_SD_EMMC_CMD_RSP);
+	} else {
+		cmd->response[0] = meson_read(mmc, MESON_SD_EMMC_CMD_RSP);
+	}
+}
+
+static int meson_dm_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
+				 struct mmc_data *data)
+{
+	struct mmc *mmc = mmc_get_mmc_dev(dev);
+	struct meson_mmc_platdata *pdata = mmc->priv;
+	uint32_t status;
+	ulong start;
+	int ret = 0;
+
+	/* max block size supported by chip is 512 byte */
+	if (data && data->blocksize > 512)
+		return -EINVAL;
+
+	meson_mmc_setup_cmd(mmc, data, cmd);
+	meson_mmc_setup_addr(mmc, data);
+
+	meson_write(mmc, cmd->cmdarg, MESON_SD_EMMC_CMD_ARG);
+
+	/* use 10s timeout */
+	start = get_timer(0);
+	do {
+		status = meson_read(mmc, MESON_SD_EMMC_STATUS);
+	} while(!(status & STATUS_END_OF_CHAIN) && get_timer(start) < 10000);
+
+	if (!(status & STATUS_END_OF_CHAIN))
+		ret = -ETIMEDOUT;
+	else if (status & STATUS_RESP_TIMEOUT)
+		ret = -ETIMEDOUT;
+	else if (status & STATUS_ERR_MASK)
+		ret = -EIO;
+
+	meson_mmc_read_response(mmc, cmd);
+
+	if (data && data->flags == MMC_DATA_WRITE)
+		free(pdata->w_buf);
+
+	/* reset status bits */
+	meson_write(mmc, STATUS_MASK, MESON_SD_EMMC_STATUS);
+
+	return ret;
+}
+
+static const struct dm_mmc_ops meson_dm_mmc_ops = {
+	.send_cmd = meson_dm_mmc_send_cmd,
+	.set_ios = meson_dm_mmc_set_ios,
+};
+
+static int meson_mmc_ofdata_to_platdata(struct udevice *dev)
+{
+	struct meson_mmc_platdata *pdata = dev_get_platdata(dev);
+	fdt_addr_t addr;
+
+	addr = dev_get_addr(dev);
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	pdata->regbase = (void *)addr;
+
+	return 0;
+}
+
+static int meson_mmc_probe(struct udevice *dev)
+{
+	struct meson_mmc_platdata *pdata = dev_get_platdata(dev);
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct mmc *mmc = &pdata->mmc;
+	struct mmc_config *cfg = &pdata->cfg;
+	uint32_t val;
+
+	cfg->voltages = MMC_VDD_33_34 | MMC_VDD_32_33 |
+			MMC_VDD_31_32 | MMC_VDD_165_195;
+	cfg->host_caps = MMC_MODE_8BIT | MMC_MODE_4BIT |
+			MMC_MODE_HS_52MHz | MMC_MODE_HS;
+	cfg->f_min = DIV_ROUND_UP(SD_EMMC_CLKSRC_24M, CLK_MAX_DIV);
+	cfg->f_max = 100000000; /* 100 MHz */
+	cfg->b_max = 256; /* max 256 blocks */
+	cfg->name = dev->name;
+
+	mmc->priv = pdata;
+	upriv->mmc = mmc;
+
+	mmc_set_clock(mmc, cfg->f_min);
+
+	/* reset all status bits */
+	meson_write(mmc, STATUS_MASK, MESON_SD_EMMC_STATUS);
+
+	/* disable interrupts */
+	meson_write(mmc, 0, MESON_SD_EMMC_IRQ_EN);
+
+	/* enable auto clock mode */
+	val = meson_read(mmc, MESON_SD_EMMC_CFG);
+	val &= ~CFG_SDCLK_ALWAYS_ON;
+	val |= CFG_AUTO_CLK;
+	meson_write(mmc, val, MESON_SD_EMMC_CFG);
+
+	return 0;
+}
+
+int meson_mmc_bind(struct udevice *dev)
+{
+	struct meson_mmc_platdata *pdata = dev_get_platdata(dev);
+
+	return mmc_bind(dev, &pdata->mmc, &pdata->cfg);
+}
+
+static const struct udevice_id meson_mmc_match[] = {
+	{ .compatible = "amlogic,meson-gx-mmc" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(meson_mmc) = {
+	.name = "meson_gx_mmc",
+	.id = UCLASS_MMC,
+	.of_match = meson_mmc_match,
+	.ops = &meson_dm_mmc_ops,
+	.probe = meson_mmc_probe,
+	.bind = meson_mmc_bind,
+	.ofdata_to_platdata = meson_mmc_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct meson_mmc_platdata),
+};