[PATCH v3 5/6] mmc: actions: add MMC driver for Actions OWL S700/S900
André Przywara
andre.przywara at arm.com
Mon Jan 18 12:15:24 CET 2021
On 16/01/2021 18:32, Amit Singh Tomar wrote:
> From: Amit Singh Tomar <amittomer25 at gmail.com>
Hi,
> This commit adds support for MMC controllers found on Actions OWL
> SoC platform(S700/S900).
>
> Signed-off-by: Amit Singh Tomar <amittomer25 at gmail.com>
> ---
> Changes since v2:
> * Progammed read/write delays as suggested by
> Jaehoon, its more readable now.
> * Updated commit message and source file to reflect
> it supports S900 as well.
> * Updated SD_DMA_CHANNEL macro to include channel offset.
> * Checked the command response Error based on SDC STATU register
> bits.
> * Replaced switch/case with if/else to correlate with MMC_RSP_Rx bitmask
> values, as suggested by Andre.
> * Introduced clk_disable based on mmc->clk_disable flag.
> * Guarded the clk_set_rate under if statment to avoid reprogramming the
> rate.
> * Fetched the DRQ number from using args.args[0].
> Changes since previous version
> * Corrected block count to 512.
> * Changed the command timeout value to 30ms.
> * Used readl_poll_timeout.
> * Read DMA parameters from DT instead of hardcoding it.
> * Reduced number of arguments passed to own_dma_cofig.
> * Removed debug leftover.
> * Used mmc_of_parse().
> ---
> drivers/mmc/Kconfig | 7 +
> drivers/mmc/Makefile | 1 +
> drivers/mmc/owl_mmc.c | 401 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 409 insertions(+)
> create mode 100644 drivers/mmc/owl_mmc.c
>
> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
> index 14d7913..3478a4e 100644
> --- a/drivers/mmc/Kconfig
> +++ b/drivers/mmc/Kconfig
> @@ -289,6 +289,13 @@ config MMC_MXC
>
> If unsure, say N.
>
> +config MMC_OWL
> + bool "Actions OWL Multimedia Card Interface support"
> + depends on ARCH_OWL && DM_MMC && BLK
> + help
> + This selects the OWL SD/MMC host controller found on board
> + based on Actions S700/S900 SoC.
> +
> config MMC_MXS
> bool "Freescale MXS Multimedia Card Interface support"
> depends on MX23 || MX28 || MX6 || MX7
> diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
> index 1c849cb..f270f6c 100644
> --- a/drivers/mmc/Makefile
> +++ b/drivers/mmc/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_MMC_OMAP_HS) += omap_hsmmc.o
> obj-$(CONFIG_MMC_MXC) += mxcmmc.o
> obj-$(CONFIG_MMC_MXS) += mxsmmc.o
> obj-$(CONFIG_MMC_OCTEONTX) += octeontx_hsmmc.o
> +obj-$(CONFIG_MMC_OWL) += owl_mmc.o
> obj-$(CONFIG_MMC_PCI) += pci_mmc.o
> obj-$(CONFIG_PXA_MMC_GENERIC) += pxa_mmc_gen.o
> obj-$(CONFIG_$(SPL_TPL_)SUPPORT_EMMC_RPMB) += rpmb.o
> diff --git a/drivers/mmc/owl_mmc.c b/drivers/mmc/owl_mmc.c
> new file mode 100644
> index 0000000..de52583
> --- /dev/null
> +++ b/drivers/mmc/owl_mmc.c
> @@ -0,0 +1,401 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2020 Amit Singh Tomar <amittomer25 at 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 30000
> +
> +/*
> + * 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 */
There are still spaces in the below section.
> +#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)
> +
> +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 */
address
> + 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 reg, total;
> + u32 buf = 0;
> +
> + reg = readl(priv->reg_base + OWL_REG_SD_EN);
> + reg |= OWL_SD_EN_BSEL;
> + writel(reg, priv->reg_base + OWL_REG_SD_EN);
Can't you use setbits_le32() here? The same to all the other occasions
where you just set or clear some constant bits in a register.
> +
> + 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 (data->blocksize < 512)
> + writel(total, priv->reg_base + OWL_REG_SD_BUF_SIZE);
Is that correct? I would think you either check for total being smaller
than 512, or you write data->blocksize into the register.
> + 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;
> +
> + reg = readl(priv->reg_base + OWL_REG_SD_EN);
> + reg |= OWL_SD_ENABLE;
> + writel(reg, priv->reg_base + OWL_REG_SD_EN);
> +
> + /* setup response */
> + if (cmd->resp_type == MMC_RSP_NONE)
> + mode = OWL_SD_CTL_TM(0);
So this whole mode handling here looks dodgy. Below you mix "assignments
to mode" with "ORing in values", without actually ever initialising mode
explicitly. I wonder why the compiler doesn't warn about this, I can see
paths were you OR into an uninitialised value.
Also, the above two lines are actually: if (resp_type == 0) mode = 0;
So I would suggest:
mode = 0;
if (cmd->resp_type != MMC_RSP_NONE)
cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
if (md->resp_type == MMC_RSP_R1) {
.... (always assign to "mode")
(I haven't checked yet whether the actual combinations are correct.)
> + else {
> + 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);
> + if (cmd->resp_type & MMC_RSP_PRESENT) {
> + if (cmd_rsp_mask & reg) {
Can't you mask the bits in reg, then save the outer if?
> + 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) {
> + /* 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);
Should there be a timeout here?
> + }
> +
> + return 0;
> +}
> +
> +static void 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");
Shouldn't this be more fatal? You still continue to set the register
below. Why not make this function return an int, and check for an error
in the caller?
Cheers,
Andre
> +
> + writel(reg | OWL_SD_CTL_RDELAY(rdelay) | OWL_SD_CTL_WDELAY(wdelay),
> + priv->reg_base + OWL_REG_SD_CTL);
> +}
> +
> +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_platdata(dev);
> + struct mmc *mmc = &plat->mmc;
> + u32 reg, ret;
> +
> + if (mmc->clock != priv->clock) {
> + priv->clock = mmc->clock;
> + owl_mmc_clk_set(priv, mmc->clock);
> +
> + 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_platdata(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_platdata(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,
> + .platdata_auto_alloc_size = sizeof(struct owl_mmc_plat),
> + .priv_auto_alloc_size = sizeof(struct owl_mmc_priv),
> +};
>
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