[PATCH v2 5/6] mmc: actions: add MMC driver for Actions OWL S700

Jaehoon Chung jh80.chung at samsung.com
Wed Dec 23 05:25:26 CET 2020


On 12/23/20 11:22 AM, Amit Tomer wrote:
> On Wed, Dec 23, 2020 at 5:57 AM André Przywara <andre.przywara at arm.com> wrote:
>>
>> On 19/12/2020 14:51, Amit Singh Tomar wrote:
>>> From: Amit Singh Tomar <amittomer25 at gmail.com>
>>>
>>> This commit adds support for MMC controllers found on Actions OWL
>>> S700 SoC platform.
>>>
>>> Signed-off-by: Amit Singh Tomar <amittomer25 at gmail.com>
>>> ---
>>> 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 | 399 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 407 insertions(+)
>>>  create mode 100644 drivers/mmc/owl_mmc.c
>>>
>>> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
>>> index 14d7913..61f9c67 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 SoC.
>>
>> And S900 as well?
>>
>>> +
>>>  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..5c48307
>>> --- /dev/null
>>> +++ b/drivers/mmc/owl_mmc.c
>>> @@ -0,0 +1,399 @@
>>> +// 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 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
>>
>> w/s? Here and elsewhere. I would use tabs everywhere instead.
>>
>>> +
>>> +/* 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 * (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)
>>> +
>>> +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 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);
>>> +
>>> +     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);
>>> +     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 */
>>> +     switch (cmd->resp_type) {
>>> +     case MMC_RSP_NONE:
>>> +             break;
>>> +     case 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);
>>> +             }
>>> +             cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
>>> +             break;
>>> +     case MMC_RSP_R1b:
>>> +             mode = OWL_SD_CTL_TM(3);
>>> +             cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
>>> +             break;
>>> +     case MMC_RSP_R2:
>>> +             mode = OWL_SD_CTL_TM(2);
>>> +             cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
>>> +             break;
>>> +     case MMC_RSP_R3:
>>> +             mode = OWL_SD_CTL_TM(1);
>>> +             cmd_rsp_mask = OWL_SD_STATE_CLNR;
>>> +             break;
>>> +     default:
>>> +             debug("Unknown MMC command\n");
>>
>> "Unsupported MMC response type"
>> And I wonder if you should define MMC_RSP_R7 as well.
>>
>>> +             return -EINVAL;
>>> +     }
>>> +
>>> +     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;
>>> +     }
>>> +
>>> +     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);
>>> +     }
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static void owl_mmc_clk_set(struct owl_mmc_priv *priv, int rate)
>>> +{
>>> +     u32 reg;
>>> +
>>> +     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) {
>>> +             writel(reg | OWL_SD_CTL_RDELAY(OWL_SD_DELAY_LOW_CLK) |
>>> +                     OWL_SD_CTL_WDELAY(OWL_SD_DELAY_LOW_CLK),
>>> +                     priv->reg_base + OWL_REG_SD_CTL);
>>> +     } else if ((rate > 1000000) && (rate <= 26000000)) {
>>> +             writel(reg | OWL_SD_CTL_RDELAY(OWL_SD_DELAY_MID_CLK) |
>>> +                     OWL_SD_CTL_WDELAY(OWL_SD_DELAY_MID_CLK),
>>> +                     priv->reg_base + OWL_REG_SD_CTL);
>>> +     } else if ((rate > 26000000) && (rate <= 52000000)) {
>>> +             writel(reg | OWL_SD_CTL_RDELAY(OWL_SD_RDELAY_HIGH) |
>>> +                     OWL_SD_CTL_WDELAY(OWL_SD_WDELAY_HIGH),
>>> +                     priv->reg_base + OWL_REG_SD_CTL);
>>
>> Can you please have a variable "delay", and set just that to
>> OWL_SD_DELAY_{LOW,MID,HIGH}_CLK, respectively? And then have one
>> writel() call instead?
> 
> But for HIGH Clock, delay values for read and write are different
> unlike LOW and MID.

I had already mentioned about making more readable than now.

if (rate <= 1000000) {
	rdelay = wdelay = OWL_SD_DELAY_LOW_CLK;
} else if ( ...) {
	rdelay = wdelay = OWL_SD_DELAY_MID_CLK;
} else if (....) {
	rdelay = OWL_SD_RDELAY_HIGH;
	wdelay = OWL_SD_WDELAY_HIGH;
}

writel(reg | OWL_SD_CTRL_RDELAY(rdelay) | OWL_SD_CTL_WDELAY(wdelay)...);

There are many approach to make readable..but Amit mentioned it's using same code in Linux kernel driver.

Well, i don't know what's good or not..But i don't understand that "kernel drier is using" is a reason of one.
While last few years, i couldn't check u-boot mailing..So I don't know that it's u-boot policy or not.
If it's u-boot policy, i will also rework kernel driver to change.


Best Regards,
Jaehoon Chung

> 
> Thanks
> -Amit
> 



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