--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Amit Singh Tomar <amittomer25@gmail.com>
+ *
+ * Driver for SD/MMC controller present on Actions Semi S700/S900 SoC, based
+ * on Linux Driver "drivers/mmc/host/owl-mmc.c".
+ *
+ * Though, there is a bit (BSEL, BUS or DMA Special Channel Selection) that
+ * controls the data transfer from SDx_DAT register either using CPU AHB Bus
+ * or DMA channel, but seems like, it only works correctly using external DMA
+ * channel, and those special bits used in this driver is picked from vendor
+ * source exclusively for MMC/SD.
+ */
+#include <common.h>
+#include <clk.h>
+#include <cpu_func.h>
+#include <dm.h>
+#include <errno.h>
+#include <log.h>
+#include <mmc.h>
+#include <asm/io.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/iopoll.h>
+
+/*
+ * SDC registers
+ */
+#define OWL_REG_SD_EN 0x0000
+#define OWL_REG_SD_CTL 0x0004
+#define OWL_REG_SD_STATE 0x0008
+#define OWL_REG_SD_CMD 0x000c
+#define OWL_REG_SD_ARG 0x0010
+#define OWL_REG_SD_RSPBUF0 0x0014
+#define OWL_REG_SD_RSPBUF1 0x0018
+#define OWL_REG_SD_RSPBUF2 0x001c
+#define OWL_REG_SD_RSPBUF3 0x0020
+#define OWL_REG_SD_RSPBUF4 0x0024
+#define OWL_REG_SD_DAT 0x0028
+#define OWL_REG_SD_BLK_SIZE 0x002c
+#define OWL_REG_SD_BLK_NUM 0x0030
+#define OWL_REG_SD_BUF_SIZE 0x0034
+
+/* SD_EN Bits */
+#define OWL_SD_EN_RANE BIT(31)
+#define OWL_SD_EN_RESE BIT(10)
+#define OWL_SD_ENABLE BIT(7)
+#define OWL_SD_EN_BSEL BIT(6)
+#define OWL_SD_EN_DATAWID(x) (((x) & 0x3) << 0)
+#define OWL_SD_EN_DATAWID_MASK 0x03
+
+/* SD_CTL Bits */
+#define OWL_SD_CTL_TOUTEN BIT(31)
+#define OWL_SD_CTL_DELAY_MSK GENMASK(23, 16)
+#define OWL_SD_CTL_RDELAY(x) (((x) & 0xf) << 20)
+#define OWL_SD_CTL_WDELAY(x) (((x) & 0xf) << 16)
+#define OWL_SD_CTL_TS BIT(7)
+#define OWL_SD_CTL_LBE BIT(6)
+#define OWL_SD_CTL_TM(x) (((x) & 0xf) << 0)
+
+#define OWL_SD_DELAY_LOW_CLK 0x0f
+#define OWL_SD_DELAY_MID_CLK 0x0a
+#define OWL_SD_RDELAY_HIGH 0x08
+#define OWL_SD_WDELAY_HIGH 0x09
+
+/* SD_STATE Bits */
+#define OWL_SD_STATE_DAT0S BIT(7)
+#define OWL_SD_STATE_CLNR BIT(4)
+#define OWL_SD_STATE_CRC7ER BIT(0)
+
+#define OWL_MMC_OCR (MMC_VDD_32_33 | MMC_VDD_33_34 | \
+ MMC_VDD_165_195)
+
+#define DATA_TRANSFER_TIMEOUT 3000000
+#define DMA_TRANSFER_TIMEOUT 5000000
+
+/*
+ * Simple DMA transfer operations defines for MMC/SD card
+ */
+#define SD_DMA_CHANNEL(base, channel) ((base) + 0x100 + 0x100 * (channel))
+
+#define DMA_MODE 0x0000
+#define DMA_SOURCE 0x0004
+#define DMA_DESTINATION 0x0008
+#define DMA_FRAME_LEN 0x000C
+#define DMA_FRAME_CNT 0x0010
+#define DMA_START 0x0024
+
+/* DMAx_MODE */
+#define DMA_MODE_ST(x) (((x) & 0x3) << 8)
+#define DMA_MODE_ST_DEV DMA_MODE_ST(0)
+#define DMA_MODE_DT(x) (((x) & 0x3) << 10)
+#define DMA_MODE_DT_DCU DMA_MODE_DT(2)
+#define DMA_MODE_SAM(x) (((x) & 0x3) << 16)
+#define DMA_MODE_SAM_CONST DMA_MODE_SAM(0)
+#define DMA_MODE_DAM(x) (((x) & 0x3) << 18)
+#define DMA_MODE_DAM_INC DMA_MODE_DAM(1)
+
+#define DMA_ENABLE 0x1
+
+struct owl_mmc_plat {
+ struct mmc_config cfg;
+ struct mmc mmc;
+};
+
+struct owl_mmc_priv {
+ void *reg_base;
+ void *dma_channel;
+ struct clk clk;
+ unsigned int clock; /* Current clock */
+ unsigned int dma_drq; /* Trigger Source */
+};
+
+static void owl_dma_config(struct owl_mmc_priv *priv, unsigned int src,
+ unsigned int dst, unsigned int len)
+{
+ unsigned int mode = priv->dma_drq;
+
+ /* Set Source and Destination adderess mode */
+ mode |= (DMA_MODE_ST_DEV | DMA_MODE_SAM_CONST | DMA_MODE_DT_DCU |
+ DMA_MODE_DAM_INC);
+
+ writel(mode, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_MODE);
+ writel(src, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_SOURCE);
+ writel(dst, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_DESTINATION);
+ writel(len, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_FRAME_LEN);
+ writel(0x1, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_FRAME_CNT);
+}
+
+static void owl_mmc_prepare_data(struct owl_mmc_priv *priv,
+ struct mmc_data *data)
+{
+ unsigned int total;
+ u32 buf = 0;
+
+ setbits_le32(priv->reg_base + OWL_REG_SD_EN, OWL_SD_EN_BSEL);
+
+ writel(data->blocks, priv->reg_base + OWL_REG_SD_BLK_NUM);
+ writel(data->blocksize, priv->reg_base + OWL_REG_SD_BLK_SIZE);
+ total = data->blocksize * data->blocks;
+
+ if (total < 512)
+ writel(total, priv->reg_base + OWL_REG_SD_BUF_SIZE);
+ else
+ writel(512, priv->reg_base + OWL_REG_SD_BUF_SIZE);
+
+ /* DMA STOP */
+ writel(0x0, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);
+
+ if (data) {
+ if (data->flags == MMC_DATA_READ) {
+ buf = (ulong) (data->dest);
+ owl_dma_config(priv, (ulong) priv->reg_base +
+ OWL_REG_SD_DAT, buf, total);
+ invalidate_dcache_range(buf, buf + total);
+ } else {
+ buf = (ulong) (data->src);
+ owl_dma_config(priv, buf, (ulong) priv->reg_base +
+ OWL_REG_SD_DAT, total);
+ flush_dcache_range(buf, buf + total);
+ }
+ /* DMA START */
+ writel(0x1, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);
+ }
+}
+
+static int owl_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
+ struct mmc_data *data)
+{
+ struct owl_mmc_priv *priv = dev_get_priv(dev);
+ unsigned int cmd_rsp_mask, mode, reg;
+ int ret;
+
+ setbits_le32(priv->reg_base + OWL_REG_SD_EN, OWL_SD_ENABLE);
+
+ /* setup response */
+ mode = 0;
+ if (cmd->resp_type != MMC_RSP_NONE)
+ cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
+ if (cmd->resp_type == MMC_RSP_R1) {
+ if (data) {
+ if (data->flags == MMC_DATA_READ)
+ mode |= OWL_SD_CTL_TM(4);
+ else
+ mode |= OWL_SD_CTL_TM(5);
+ } else
+ mode |= OWL_SD_CTL_TM(1);
+ } else if (cmd->resp_type == MMC_RSP_R2) {
+ mode = OWL_SD_CTL_TM(2);
+ } else if (cmd->resp_type == MMC_RSP_R1b) {
+ mode = OWL_SD_CTL_TM(3);
+ } else if (cmd->resp_type == MMC_RSP_R3) {
+ cmd_rsp_mask = OWL_SD_STATE_CLNR;
+ mode = OWL_SD_CTL_TM(1);
+ }
+
+ mode |= (readl(priv->reg_base + OWL_REG_SD_CTL) & (0xff << 16));
+
+ /* setup command */
+ writel(cmd->cmdidx, priv->reg_base + OWL_REG_SD_CMD);
+ writel(cmd->cmdarg, priv->reg_base + OWL_REG_SD_ARG);
+
+ /* Set LBE to send clk at the end of last read block */
+ if (data)
+ mode |= (OWL_SD_CTL_TS | OWL_SD_CTL_LBE | 0xE4000000);
+ else
+ mode |= OWL_SD_CTL_TS;
+
+ if (data)
+ owl_mmc_prepare_data(priv, data);
+
+ /* Start transfer */
+ writel(mode, priv->reg_base + OWL_REG_SD_CTL);
+
+ ret = readl_poll_timeout(priv->reg_base + OWL_REG_SD_CTL, reg,
+ !(reg & OWL_SD_CTL_TS), DATA_TRANSFER_TIMEOUT);
+
+ if (ret == -ETIMEDOUT) {
+ debug("error: transferred data timeout\n");
+ return ret;
+ }
+
+ reg = readl(priv->reg_base + OWL_REG_SD_STATE) & cmd_rsp_mask;
+ if (cmd->resp_type & MMC_RSP_PRESENT) {
+ if (reg & OWL_SD_STATE_CLNR) {
+ printf("Error CMD_NO_RSP\n");
+ return -1;
+ }
+
+ if (reg & OWL_SD_STATE_CRC7ER) {
+ printf("Error CMD_RSP_CRC\n");
+ return -1;
+ }
+
+ if (cmd->resp_type & MMC_RSP_136) {
+ cmd->response[3] = readl(priv->reg_base + OWL_REG_SD_RSPBUF0);
+ cmd->response[2] = readl(priv->reg_base + OWL_REG_SD_RSPBUF1);
+ cmd->response[1] = readl(priv->reg_base + OWL_REG_SD_RSPBUF2);
+ cmd->response[0] = readl(priv->reg_base + OWL_REG_SD_RSPBUF3);
+ } else {
+ u32 rsp[2];
+
+ rsp[0] = readl(priv->reg_base + OWL_REG_SD_RSPBUF0);
+ rsp[1] = readl(priv->reg_base + OWL_REG_SD_RSPBUF1);
+ cmd->response[0] = rsp[1] << 24 | rsp[0] >> 8;
+ cmd->response[1] = rsp[1] >> 8;
+ }
+ }
+
+ if (data) {
+ ret = readl_poll_timeout(SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START,
+ reg, !(reg & DMA_ENABLE), DMA_TRANSFER_TIMEOUT);
+
+ if (ret == -ETIMEDOUT) {
+ debug("error: DMA transfer timeout\n");
+ return ret;
+ }
+
+ /* DMA STOP */
+ writel(0x0, SD_DMA_CHANNEL(priv->dma_channel, 0) + DMA_START);
+ /* Transmission STOP */
+ while (readl(priv->reg_base + OWL_REG_SD_CTL) & OWL_SD_CTL_TS)
+ clrbits_le32(priv->reg_base + OWL_REG_SD_CTL,
+ OWL_SD_CTL_TS);
+ }
+
+ return 0;
+}
+
+static int owl_mmc_clk_set(struct owl_mmc_priv *priv, int rate)
+{
+ u32 reg, wdelay, rdelay;
+
+ reg = readl(priv->reg_base + OWL_REG_SD_CTL);
+ reg &= ~OWL_SD_CTL_DELAY_MSK;
+
+ /* Set RDELAY and WDELAY based on the clock */
+ if (rate <= 1000000)
+ rdelay = wdelay = OWL_SD_DELAY_LOW_CLK;
+ else if ((rate > 1000000) && (rate <= 26000000))
+ rdelay = wdelay = OWL_SD_DELAY_MID_CLK;
+ else if ((rate > 26000000) && (rate <= 52000000)) {
+ rdelay = OWL_SD_RDELAY_HIGH;
+ wdelay = OWL_SD_WDELAY_HIGH;
+ } else {
+ debug("SD clock rate not supported\n");
+ return -EINVAL;
+ }
+
+ writel(reg | OWL_SD_CTL_RDELAY(rdelay) | OWL_SD_CTL_WDELAY(wdelay),
+ priv->reg_base + OWL_REG_SD_CTL);
+
+ return 0;
+}
+
+static int owl_mmc_set_ios(struct udevice *dev)
+{
+ struct owl_mmc_priv *priv = dev_get_priv(dev);
+ struct owl_mmc_plat *plat = dev_get_plat(dev);
+ struct mmc *mmc = &plat->mmc;
+ u32 reg, ret;
+
+ if (mmc->clock != priv->clock) {
+ priv->clock = mmc->clock;
+ ret = owl_mmc_clk_set(priv, mmc->clock);
+ if (IS_ERR_VALUE(ret))
+ return ret;
+
+ ret = clk_set_rate(&priv->clk, mmc->clock);
+ if (IS_ERR_VALUE(ret))
+ return ret;
+ }
+
+ if (mmc->clk_disable)
+ ret = clk_disable(&priv->clk);
+ else
+ ret = clk_enable(&priv->clk);
+ if (ret)
+ return ret;
+
+ /* Set the Bus width */
+ reg = readl(priv->reg_base + OWL_REG_SD_EN);
+ reg &= ~OWL_SD_EN_DATAWID_MASK;
+ if (mmc->bus_width == 8)
+ reg |= OWL_SD_EN_DATAWID(2);
+ else if (mmc->bus_width == 4)
+ reg |= OWL_SD_EN_DATAWID(1);
+
+ writel(reg, priv->reg_base + OWL_REG_SD_EN);
+
+ return 0;
+}
+
+static const struct dm_mmc_ops owl_mmc_ops = {
+ .send_cmd = owl_mmc_send_cmd,
+ .set_ios = owl_mmc_set_ios,
+};
+
+static int owl_mmc_probe(struct udevice *dev)
+{
+ struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+ struct owl_mmc_plat *plat = dev_get_plat(dev);
+ struct owl_mmc_priv *priv = dev_get_priv(dev);
+ struct mmc_config *cfg = &plat->cfg;
+ struct ofnode_phandle_args args;
+ int ret;
+ fdt_addr_t addr;
+
+ cfg->name = dev->name;
+ cfg->voltages = OWL_MMC_OCR;
+ cfg->f_min = 400000;
+ cfg->f_max = 52000000;
+ cfg->b_max = 512;
+ cfg->host_caps = MMC_MODE_HS | MMC_MODE_HS_52MHz;
+
+ ret = mmc_of_parse(dev, cfg);
+ if (ret)
+ return ret;
+
+ addr = dev_read_addr(dev);
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ priv->reg_base = (void *)addr;
+
+ ret = dev_read_phandle_with_args(dev, "dmas", "#dma-cells", 0, 0,
+ &args);
+ if (ret)
+ return ret;
+
+ priv->dma_channel = (void *)ofnode_get_addr(args.node);
+ priv->dma_drq = args.args[0];
+
+ ret = clk_get_by_index(dev, 0, &priv->clk);
+ if (ret) {
+ debug("clk_get_by_index() failed: %d\n", ret);
+ return ret;
+ }
+
+ upriv->mmc = &plat->mmc;
+
+ return 0;
+}
+
+static int owl_mmc_bind(struct udevice *dev)
+{
+ struct owl_mmc_plat *plat = dev_get_plat(dev);
+
+ return mmc_bind(dev, &plat->mmc, &plat->cfg);
+}
+
+static const struct udevice_id owl_mmc_ids[] = {
+ { .compatible = "actions,s700-mmc" },
+ { .compatible = "actions,owl-mmc" },
+ { }
+};
+
+U_BOOT_DRIVER(owl_mmc_drv) = {
+ .name = "owl_mmc",
+ .id = UCLASS_MMC,
+ .of_match = owl_mmc_ids,
+ .bind = owl_mmc_bind,
+ .probe = owl_mmc_probe,
+ .ops = &owl_mmc_ops,
+ .plat_auto = sizeof(struct owl_mmc_plat),
+ .priv_auto = sizeof(struct owl_mmc_priv),
+};