[U-Boot] [PATCH v2 1/1] mmc: Add MMC support for stm32h7 Socs

Patrice CHOTARD patrice.chotard at st.com
Wed Jul 19 12:20:25 UTC 2017


Hi Jaehoon

On 07/19/2017 12:11 PM, Jaehoon Chung wrote:
> Hi,
> 
> On 07/19/2017 04:27 PM, patrice.chotard at st.com wrote:
>> From: Patrice Chotard <patrice.chotard at st.com>
>>
>> This patch adds SD/MMC support for STM32H7 SoCs.
>>
>> Here is an extraction of SDMMC main features, embedded in
>> STM32H7 SoCs.
>> The SD/MMC block include the following:
>>   _ Full compliance with MultiMediaCard System Specification
>>     Version 4.51. Card support for three different databus modes:
>>     1-bit (default), 4-bit and 8-bit.
>>   _ Full compatibility with previous versions of MultiMediaCards
>>     (backward compatibility).
>>   _ Full compliance with SD memory card specifications version 4.1.
>>     (SDR104 SDMMC_CK speed limited to maximum allowed IO speed,
>>      SPI mode and UHS-II mode not supported).
>>   _ Full compliance with SDIO card specification version 4.0.
>>     Card support for two different databus modes: 1-bit (default)
>>     and 4-bit. (SDR104 SDMMC_CK speed limited to maximum allowed IO
>>     speed, SPI mode and UHS-II mode not supported).
>>   _ Data transfer up to 208 Mbyte/s for the 8 bit mode.
>>     (depending maximum allowed IO speed).
>>   _ Data and command output enable signals to control external
>>     bidirectional drivers.
>>
>> The current version of the SDMMC supports only one SD/SDIO/MMC card
>> at any one time and a stack of MMC Version 4.51 or previous.
>>
>> Signed-off-by: Christophe Kerello <christophe.kerello at st.com>
>> Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
>> ---
>>
>> v2: _ add .get_cd() callback support
>>
>>   drivers/mmc/Kconfig        |   8 +
>>   drivers/mmc/Makefile       |   1 +
>>   drivers/mmc/stm32_sdmmc2.c | 619 +++++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 628 insertions(+)
>>   create mode 100644 drivers/mmc/stm32_sdmmc2.c
>>
>> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
>> index 82b8d75..f2e4c26 100644
>> --- a/drivers/mmc/Kconfig
>> +++ b/drivers/mmc/Kconfig
>> @@ -377,6 +377,14 @@ config GENERIC_ATMEL_MCI
>>   	  the SD Memory Card Specification V2.0, the SDIO V2.0 specification
>>   	  and CE-ATA V1.1.
>>   
>> +config STM32_SDMMC2
> 
> Why add the SDMMC2? not SDMMC?
> Is there a special reason?

It's simply the IP name

> 
>> +	bool "STMicroelectronics STM32H7 SD/MMC Host Controller support"
>> +	depends on DM_MMC && OF_CONTROL && DM_MMC_OPS
>> +	help
>> +	  This selects support for the SD/MMC controller on STM32H7 SoCs.
>> +	  If you have a board based on such a SoC and with a SD/MMC slot,
>> +	  say Y or M here.
>> +
>>   endif
>>   
>>   config TEGRA124_MMC_DISABLE_EXT_LOOPBACK
>> diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
>> index 2d781c3..2584663 100644
>> --- a/drivers/mmc/Makefile
>> +++ b/drivers/mmc/Makefile
>> @@ -43,6 +43,7 @@ obj-$(CONFIG_SUPPORT_EMMC_RPMB) += rpmb.o
>>   obj-$(CONFIG_MMC_SANDBOX)		+= sandbox_mmc.o
>>   obj-$(CONFIG_SH_MMCIF) += sh_mmcif.o
>>   obj-$(CONFIG_SH_SDHI) += sh_sdhi.o
>> +obj-$(CONFIG_STM32_SDMMC2) += stm32_sdmmc2.o
>>   
>>   # SDHCI
>>   obj-$(CONFIG_MMC_SDHCI)			+= sdhci.o
>> diff --git a/drivers/mmc/stm32_sdmmc2.c b/drivers/mmc/stm32_sdmmc2.c
>> new file mode 100644
>> index 0000000..84f96e5
>> --- /dev/null
>> +++ b/drivers/mmc/stm32_sdmmc2.c
>> @@ -0,0 +1,619 @@
>> +/*
>> + *  Copyright (c) 2017 STMicrelectronics
>> + *
>> + * SPDX-License-Identifier:	GPL-2.0
>> + */
>> +
>> +#include <common.h>
>> +#include <clk.h>
>> +#include <dm.h>
>> +#include <fdtdec.h>
>> +#include <libfdt.h>
>> +#include <mmc.h>
>> +#include <reset.h>
>> +#include <asm/io.h>
>> +#include <asm/gpio.h>
>> +
>> +struct stm32_sdmmc2 {
>> +	u32 power;		/* SDMMC power control             [0x00] */
>> +	u32 clkcr;		/* SDMMC clock control             [0x04] */
>> +	u32 arg;		/* SDMMC argument                  [0x08] */
>> +	u32 cmd;		/* SDMMC command                   [0x0C] */
>> +	u32 respcmd;		/* SDMMC command response          [0x10] */
>> +	u32 resp1;		/* SDMMC response 1                [0x14] */
>> +	u32 resp2;		/* SDMMC response 2                [0x18] */
>> +	u32 resp3;		/* SDMMC response 3                [0x1C] */
>> +	u32 resp4;		/* SDMMC response 4                [0x20] */
>> +	u32 dtimer;		/* SDMMC data timer                [0x24] */
>> +	u32 dlen;		/* SDMMC data length               [0x28] */
>> +	u32 dctrl;		/* SDMMC data control              [0x2C] */
>> +	u32 dcount;		/* SDMMC data counter              [0x30] */
>> +	u32 sta;		/* SDMMC status                    [0x34] */
>> +	u32 icr;		/* SDMMC interrupt clear           [0x38] */
>> +	u32 mask;		/* SDMMC mask                      [0x3C] */
>> +	u32 acktime;		/* SDMMC Acknowledgment timer      [0x40] */
>> +	u32 reserved0[3];	/* Reserved, 0x44 - 0x4C - 0x4C           */
>> +	u32 idmactrl;		/* SDMMC DMA control               [0x50] */
>> +	u32 idmabsize;		/* SDMMC DMA buffer size           [0x54] */
>> +	u32 idmabase0;		/* SDMMC DMA buffer 0 base address [0x58] */
>> +	u32 idmabase1;		/* SDMMC DMA buffer 1 base address [0x5C] */
>> +	u32 reserved1[8];	/* Reserved, 0x4C-0x7C                    */
>> +	u32 fifo;		/* SDMMC data FIFO                 [0x80] */
>> +};
> 
> This is for register offset, right?

yes

> 
> I want to use the defined value..likes "#define SDMMC_POWER_CONTROL 0x00"
> (It's my preference.)
> I'm not sure but i have remembered that was difficult to debug.

But on http://www.denx.de/wiki/U-Boot/CodingStyle, it's recommended to 
use structures for I/O access, see "Use structures for I/O access " chapter.


> 
>> +
>> +struct stm32_sdmmc2_host {
>> +	struct stm32_sdmmc2 *base;
>> +	struct mmc_config cfg;
>> +	struct clk clk;
>> +	struct reset_ctl reset_ctl;
>> +	struct gpio_desc cd_gpio;
>> +	u32 clk_reg_add;
>> +	u32 pwr_reg_add;
>> +};
>> +
>> +struct stm32_sdmmc2_ctx {
>> +	u32 cache_start;
>> +	u32 cache_end;
>> +	u32 data_length;
>> +	bool dpsm_abort;
>> +};
>> +
>> +/* SDMMC_POWER register */
>> +#define SDMMC_POWER_PWRCTRL		GENMASK(1, 0)
>> +#define SDMMC_POWER_VSWITCH		BIT(2)
>> +#define SDMMC_POWER_VSWITCHEN		BIT(3)
>> +#define SDMMC_POWER_DIRPOL		BIT(4)
>> +
>> +/* SDMMC_CLKCR register */
>> +#define SDMMC_CLKCR_CLKDIV		GENMASK(9, 0)
>> +#define SDMMC_CLKCR_CLKDIV_MAX		SDMMC_CLKCR_CLKDIV
>> +#define SDMMC_CLKCR_PWRSAV		BIT(12)
>> +#define SDMMC_CLKCR_WIDBUS_4		BIT(14)
>> +#define SDMMC_CLKCR_WIDBUS_8		BIT(15)
>> +#define SDMMC_CLKCR_NEGEDGE		BIT(16)
>> +#define SDMMC_CLKCR_HWFC_EN		BIT(17)
>> +#define SDMMC_CLKCR_DDR			BIT(18)
>> +#define SDMMC_CLKCR_BUSSPEED		BIT(19)
>> +#define SDMMC_CLKCR_SELCLKRX		GENMASK(21, 20)
>> +
>> +/* SDMMC_CMD register */
>> +#define SDMMC_CMD_CMDINDEX		GENMASK(5, 0)
>> +#define SDMMC_CMD_CMDTRANS		BIT(6)
>> +#define SDMMC_CMD_CMDSTOP		BIT(7)
>> +#define SDMMC_CMD_WAITRESP		GENMASK(9, 8)
>> +#define SDMMC_CMD_WAITRESP_0		BIT(8)
>> +#define SDMMC_CMD_WAITRESP_1		BIT(9)
>> +#define SDMMC_CMD_WAITINT		BIT(10)
>> +#define SDMMC_CMD_WAITPEND		BIT(11)
>> +#define SDMMC_CMD_CPSMEN		BIT(12)
>> +#define SDMMC_CMD_DTHOLD		BIT(13)
>> +#define SDMMC_CMD_BOOTMODE		BIT(14)
>> +#define SDMMC_CMD_BOOTEN		BIT(15)
>> +#define SDMMC_CMD_CMDSUSPEND		BIT(16)
>> +
>> +/* SDMMC_DCTRL register */
>> +#define SDMMC_DCTRL_DTEN		BIT(0)
>> +#define SDMMC_DCTRL_DTDIR		BIT(1)
>> +#define SDMMC_DCTRL_DTMODE		GENMASK(3, 2)
>> +#define SDMMC_DCTRL_DBLOCKSIZE		GENMASK(7, 4)
>> +#define SDMMC_DCTRL_DBLOCKSIZE_SHIFT	4
>> +#define SDMMC_DCTRL_RWSTART		BIT(8)
>> +#define SDMMC_DCTRL_RWSTOP		BIT(9)
>> +#define SDMMC_DCTRL_RWMOD		BIT(10)
>> +#define SDMMC_DCTRL_SDMMCEN		BIT(11)
>> +#define SDMMC_DCTRL_BOOTACKEN		BIT(12)
>> +#define SDMMC_DCTRL_FIFORST		BIT(13)
>> +
>> +/* SDMMC_STA register */
>> +#define SDMMC_STA_CCRCFAIL		BIT(0)
>> +#define SDMMC_STA_DCRCFAIL		BIT(1)
>> +#define SDMMC_STA_CTIMEOUT		BIT(2)
>> +#define SDMMC_STA_DTIMEOUT		BIT(3)
>> +#define SDMMC_STA_TXUNDERR		BIT(4)
>> +#define SDMMC_STA_RXOVERR		BIT(5)
>> +#define SDMMC_STA_CMDREND		BIT(6)
>> +#define SDMMC_STA_CMDSENT		BIT(7)
>> +#define SDMMC_STA_DATAEND		BIT(8)
>> +#define SDMMC_STA_DHOLD			BIT(9)
>> +#define SDMMC_STA_DBCKEND		BIT(10)
>> +#define SDMMC_STA_DABORT		BIT(11)
>> +#define SDMMC_STA_DPSMACT		BIT(12)
>> +#define SDMMC_STA_CPSMACT		BIT(13)
>> +#define SDMMC_STA_TXFIFOHE		BIT(14)
>> +#define SDMMC_STA_RXFIFOHF		BIT(15)
>> +#define SDMMC_STA_TXFIFOF		BIT(16)
>> +#define SDMMC_STA_RXFIFOF		BIT(17)
>> +#define SDMMC_STA_TXFIFOE		BIT(18)
>> +#define SDMMC_STA_RXFIFOE		BIT(19)
>> +#define SDMMC_STA_BUSYD0		BIT(20)
>> +#define SDMMC_STA_BUSYD0END		BIT(21)
>> +#define SDMMC_STA_SDMMCIT		BIT(22)
>> +#define SDMMC_STA_ACKFAIL		BIT(23)
>> +#define SDMMC_STA_ACKTIMEOUT		BIT(24)
>> +#define SDMMC_STA_VSWEND		BIT(25)
>> +#define SDMMC_STA_CKSTOP		BIT(26)
>> +#define SDMMC_STA_IDMATE		BIT(27)
>> +#define SDMMC_STA_IDMABTC		BIT(28)
>> +
>> +/* SDMMC_ICR register */
>> +#define SDMMC_ICR_CCRCFAILC		BIT(0)
>> +#define SDMMC_ICR_DCRCFAILC		BIT(1)
>> +#define SDMMC_ICR_CTIMEOUTC		BIT(2)
>> +#define SDMMC_ICR_DTIMEOUTC		BIT(3)
>> +#define SDMMC_ICR_TXUNDERRC		BIT(4)
>> +#define SDMMC_ICR_RXOVERRC		BIT(5)
>> +#define SDMMC_ICR_CMDRENDC		BIT(6)
>> +#define SDMMC_ICR_CMDSENTC		BIT(7)
>> +#define SDMMC_ICR_DATAENDC		BIT(8)
>> +#define SDMMC_ICR_DHOLDC		BIT(9)
>> +#define SDMMC_ICR_DBCKENDC		BIT(10)
>> +#define SDMMC_ICR_DABORTC		BIT(11)
>> +#define SDMMC_ICR_BUSYD0ENDC		BIT(21)
>> +#define SDMMC_ICR_SDMMCITC		BIT(22)
>> +#define SDMMC_ICR_ACKFAILC		BIT(23)
>> +#define SDMMC_ICR_ACKTIMEOUTC		BIT(24)
>> +#define SDMMC_ICR_VSWENDC		BIT(25)
>> +#define SDMMC_ICR_CKSTOPC		BIT(26)
>> +#define SDMMC_ICR_IDMATEC		BIT(27)
>> +#define SDMMC_ICR_IDMABTCC		BIT(28)
>> +#define SDMMC_ICR_STATIC_FLAGS		((GENMASK(28, 21)) | (GENMASK(11, 0)))
>> +
>> +/* SDMMC_MASK register */
>> +#define SDMMC_MASK_CCRCFAILIE		BIT(0)
>> +#define SDMMC_MASK_DCRCFAILIE		BIT(1)
>> +#define SDMMC_MASK_CTIMEOUTIE		BIT(2)
>> +#define SDMMC_MASK_DTIMEOUTIE		BIT(3)
>> +#define SDMMC_MASK_TXUNDERRIE		BIT(4)
>> +#define SDMMC_MASK_RXOVERRIE		BIT(5)
>> +#define SDMMC_MASK_CMDRENDIE		BIT(6)
>> +#define SDMMC_MASK_CMDSENTIE		BIT(7)
>> +#define SDMMC_MASK_DATAENDIE		BIT(8)
>> +#define SDMMC_MASK_DHOLDIE		BIT(9)
>> +#define SDMMC_MASK_DBCKENDIE		BIT(10)
>> +#define SDMMC_MASK_DABORTIE		BIT(11)
>> +#define SDMMC_MASK_TXFIFOHEIE		BIT(14)
>> +#define SDMMC_MASK_RXFIFOHFIE		BIT(15)
>> +#define SDMMC_MASK_RXFIFOFIE		BIT(17)
>> +#define SDMMC_MASK_TXFIFOEIE		BIT(18)
>> +#define SDMMC_MASK_BUSYD0ENDIE		BIT(21)
>> +#define SDMMC_MASK_SDMMCITIE		BIT(22)
>> +#define SDMMC_MASK_ACKFAILIE		BIT(23)
>> +#define SDMMC_MASK_ACKTIMEOUTIE		BIT(24)
>> +#define SDMMC_MASK_VSWENDIE		BIT(25)
>> +#define SDMMC_MASK_CKSTOPIE		BIT(26)
>> +#define SDMMC_MASK_IDMABTCIE		BIT(28)
>> +
>> +/* SDMMC_IDMACTRL register */
>> +#define SDMMC_IDMACTRL_IDMAEN		BIT(0)
>> +
>> +#define SDMMC_CMD_TIMEOUT		0xFFFFFFFF
>> +
>> +DECLARE_GLOBAL_DATA_PTR;
>> +
>> +static void stm32_sdmmc2_start_data(struct mmc *mmc, struct mmc_data *data,
>> +				    struct stm32_sdmmc2_ctx *ctx)
>> +{
>> +	struct stm32_sdmmc2_host *host = mmc->priv;
>> +	struct stm32_sdmmc2 *sdmmc_handler = host->base;
>> +	u32 data_ctrl, idmabase0;
>> +
>> +	/* Configure the SDMMC DPSM (Data Path State Machine) */
>> +	data_ctrl = (__ilog2(data->blocksize) <<
>> +		     SDMMC_DCTRL_DBLOCKSIZE_SHIFT) &
>> +		    SDMMC_DCTRL_DBLOCKSIZE;
>> +
>> +	if (data->flags & MMC_DATA_READ) {
>> +		data_ctrl |= SDMMC_DCTRL_DTDIR;
>> +		idmabase0 = (u32)data->dest;
>> +	} else {
>> +		idmabase0 = (u32)data->src;
>> +	}
>> +
>> +	/* Set the SDMMC Data TimeOut value */
>> +	writel(SDMMC_CMD_TIMEOUT, &sdmmc_handler->dtimer);
>> +
>> +	/* Set the SDMMC DataLength value */
>> +	writel(ctx->data_length, &sdmmc_handler->dlen);
>> +
>> +	/* Write to SDMMC DCTRL */
>> +	writel(data_ctrl, &sdmmc_handler->dctrl);
>> +
>> +	/* Cache align */
>> +	ctx->cache_start = rounddown(idmabase0, ARCH_DMA_MINALIGN);
>> +	ctx->cache_end = roundup(idmabase0 + ctx->data_length,
>> +				  ARCH_DMA_MINALIGN);
>> +
>> +	/*
>> +	 * Flush data cache before DMA start (clean and invalidate)
>> +	 * Clean also needed for read
>> +	 * Avoid issue on buffer not cached-aligned
>> +	 */
>> +	flush_dcache_range(ctx->cache_start, ctx->cache_end);
>> +
>> +	/* Enable internal DMA */
>> +	writel(idmabase0, &sdmmc_handler->idmabase0);
>> +	writel(SDMMC_IDMACTRL_IDMAEN, &sdmmc_handler->idmactrl);
>> +}
>> +
>> +static void stm32_sdmmc2_start_cmd(struct mmc *mmc, struct mmc_cmd *cmd, u32 c)
>> +{
>> +	struct stm32_sdmmc2_host *host = mmc->priv;
>> +	struct stm32_sdmmc2 *sdmmc_handler = host->base;
>> +
>> +	if (readl(&sdmmc_handler->arg) & SDMMC_CMD_CPSMEN)
>> +		writel(0, &sdmmc_handler->arg);
>> +
>> +	c |= cmd->cmdidx | SDMMC_CMD_CPSMEN;
>> +	if (cmd->resp_type & MMC_RSP_PRESENT) {
>> +		if (cmd->resp_type & MMC_RSP_136)
>> +			c |= SDMMC_CMD_WAITRESP;
>> +		else if (cmd->resp_type & MMC_RSP_CRC)
>> +			c |= SDMMC_CMD_WAITRESP_0;
>> +		else
>> +			c |= SDMMC_CMD_WAITRESP_1;
>> +	}
>> +
>> +	/* Clear flags */
>> +	writel(SDMMC_ICR_STATIC_FLAGS, &sdmmc_handler->icr);
>> +
>> +	/* Set SDMMC argument value */
>> +	writel(cmd->cmdarg, &sdmmc_handler->arg);
>> +
>> +	/* Set SDMMC command parameters */
>> +	writel(c, &sdmmc_handler->cmd);
>> +}
>> +
>> +static int stm32_sdmmc2_end_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
>> +				struct stm32_sdmmc2_ctx *ctx)
>> +{
>> +	struct stm32_sdmmc2_host *host = mmc->priv;
>> +	struct stm32_sdmmc2 *sdmmc_handler = host->base;
>> +	u32 mask = SDMMC_STA_CTIMEOUT;
>> +	u32 status;
>> +
>> +	if (cmd->resp_type & MMC_RSP_PRESENT) {
>> +		mask |= SDMMC_STA_CMDREND;
>> +		if (cmd->resp_type & MMC_RSP_CRC)
>> +			mask |= SDMMC_STA_CCRCFAIL;
>> +	} else {
>> +		mask |= SDMMC_STA_CMDSENT;
>> +	}
>> +
>> +	/* Polling status register */
>> +	status = readl(&sdmmc_handler->sta);
>> +	while (!(status & mask))
>> +		status = readl(&sdmmc_handler->sta);
>> +
>> +	/* Check status */
>> +	if (status & SDMMC_STA_CTIMEOUT) {
>> +		debug("%s: error SDMMC_STA_CTIMEOUT (0x%x) for cmd %d\n",
>> +		      __func__, status, cmd->cmdidx);
>> +		ctx->dpsm_abort = true;
>> +		return -ETIMEDOUT;
>> +	}
>> +
>> +	if (status & SDMMC_STA_CCRCFAIL && cmd->resp_type & MMC_RSP_CRC) {
>> +		debug("%s: error SDMMC_STA_CCRCFAIL (0x%x) for cmd %d\n",
>> +		      __func__, status, cmd->cmdidx);
>> +		ctx->dpsm_abort = true;
>> +		return -EILSEQ;
>> +	}
>> +
>> +	if (status & SDMMC_STA_CMDREND && cmd->resp_type & MMC_RSP_PRESENT) {
>> +		cmd->response[0] = readl(&sdmmc_handler->resp1);
>> +		if (cmd->resp_type & MMC_RSP_136) {
>> +			cmd->response[1] = readl(&sdmmc_handler->resp2);
>> +			cmd->response[2] = readl(&sdmmc_handler->resp3);
>> +			cmd->response[3] = readl(&sdmmc_handler->resp4);
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int stm32_sdmmc2_end_data(struct mmc *mmc, struct mmc_cmd *cmd,
>> +				   struct mmc_data *data,
>> +				   struct stm32_sdmmc2_ctx *ctx)
>> +{
>> +	struct stm32_sdmmc2_host *host = mmc->priv;
>> +	struct stm32_sdmmc2 *sdmmc_handler = host->base;
>> +	u32 mask = SDMMC_STA_DCRCFAIL | SDMMC_STA_DTIMEOUT |
>> +		   SDMMC_STA_IDMATE | SDMMC_STA_DATAEND;
>> +	u32 status;
>> +
>> +	if (data->flags & MMC_DATA_READ)
>> +		mask |= SDMMC_STA_RXOVERR;
>> +	else
>> +		mask |= SDMMC_STA_TXUNDERR;
>> +
>> +	status = readl(&sdmmc_handler->sta);
>> +	while (!(status & mask))
>> +		status = readl(&sdmmc_handler->sta);
>> +
>> +	/*
>> +	 * Need invalidate the dcache again to avoid any
>> +	 * cache-refill during the DMA operations (pre-fetching)
>> +	 */
>> +	if (data->flags & MMC_DATA_READ)
>> +		invalidate_dcache_range(ctx->cache_start, ctx->cache_end);
>> +
>> +	if (status & SDMMC_STA_DCRCFAIL) {
>> +		debug("%s: error SDMMC_STA_DCRCFAIL (0x%x) for cmd %d\n",
>> +		      __func__, status, cmd->cmdidx);
>> +		if (readl(&sdmmc_handler->dcount))
>> +			ctx->dpsm_abort = true;
>> +		return -EILSEQ;
>> +	}
>> +
>> +	if (status & SDMMC_STA_DTIMEOUT) {
>> +		debug("%s: error SDMMC_STA_DTIMEOUT (0x%x) for cmd %d\n",
>> +		      __func__, status, cmd->cmdidx);
>> +		ctx->dpsm_abort = true;
>> +		return -ETIMEDOUT;
>> +	}
>> +
>> +	if (status & SDMMC_STA_TXUNDERR) {
>> +		debug("%s: error SDMMC_STA_TXUNDERR (0x%x) for cmd %d\n",
>> +		      __func__, status, cmd->cmdidx);
>> +		ctx->dpsm_abort = true;
>> +		return -EIO;
>> +	}
>> +
>> +	if (status & SDMMC_STA_RXOVERR) {
>> +		debug("%s: error SDMMC_STA_RXOVERR (0x%x) for cmd %d\n",
>> +		      __func__, status, cmd->cmdidx);
>> +		ctx->dpsm_abort = true;
>> +		return -EIO;
>> +	}
>> +
>> +	if (status & SDMMC_STA_IDMATE) {
>> +		debug("%s: error SDMMC_STA_IDMATE (0x%x) for cmd %d\n",
>> +		      __func__, status, cmd->cmdidx);
>> +		ctx->dpsm_abort = true;
>> +		return -EIO;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int stm32_sdmmc2_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
>> +				 struct mmc_data *data)
>> +{
>> +	struct mmc *mmc = mmc_get_mmc_dev(dev);
>> +	struct stm32_sdmmc2_host *host = mmc->priv;
>> +	struct stm32_sdmmc2 *sdmmc_handler = host->base;
>> +	struct stm32_sdmmc2_ctx ctx;
>> +	u32 cmdat = data ? SDMMC_CMD_CMDTRANS : 0;
>> +	int ret, retry = 3;
>> +
>> +retry_cmd:
>> +	ctx.data_length = 0;
>> +	ctx.dpsm_abort = false;
>> +
>> +	if (data) {
>> +		ctx.data_length = data->blocks * data->blocksize;
>> +		stm32_sdmmc2_start_data(mmc, data, &ctx);
>> +	}
>> +
>> +	stm32_sdmmc2_start_cmd(mmc, cmd, cmdat);
>> +
>> +	debug("%s: send cmd %d data: 0x%x @ 0x%x\n",
>> +	      __func__, cmd->cmdidx,
>> +	      data ? ctx.data_length : 0, (unsigned int)data);
>> +
>> +	ret = stm32_sdmmc2_end_cmd(mmc, cmd, &ctx);
>> +
>> +	if (data && !ret)
>> +		ret = stm32_sdmmc2_end_data(mmc, cmd, data, &ctx);
>> +
>> +	/* Clear flags */
>> +	writel(SDMMC_ICR_STATIC_FLAGS, &sdmmc_handler->icr);
>> +	if (data)
>> +		writel(0x0, &sdmmc_handler->idmactrl);
>> +
>> +	/*
>> +	 * To stop Data Path State Machine, a stop_transmission command
>> +	 * shall be send on cmd or data errors.
>> +	 */
>> +	if (ctx.dpsm_abort && (cmd->cmdidx != MMC_CMD_STOP_TRANSMISSION)) {
>> +		struct mmc_cmd stop_cmd;
>> +
>> +		stop_cmd.cmdidx = MMC_CMD_STOP_TRANSMISSION;
>> +		stop_cmd.cmdarg = 0;
>> +		stop_cmd.resp_type = MMC_RSP_R1b;
>> +
>> +		debug("%s: send STOP command to abort dpsm treatments\n",
>> +		      __func__);
>> +
>> +		stm32_sdmmc2_start_cmd(mmc, &stop_cmd, SDMMC_CMD_CMDSTOP);
>> +		stm32_sdmmc2_end_cmd(mmc, &stop_cmd, &ctx);
>> +
>> +		writel(SDMMC_ICR_STATIC_FLAGS, &sdmmc_handler->icr);
>> +	}
>> +
>> +	if ((ret != -ETIMEDOUT) && (ret != 0) && retry) {
>> +		printf("%s: cmd %d failed, retrying ...\n",
>> +		       __func__, cmd->cmdidx);
>> +		retry--;
>> +		goto retry_cmd;
>> +	}
>> +
>> +	debug("%s: end for CMD %d, ret = %d\n", __func__, cmd->cmdidx, ret);
>> +
>> +	return ret;
>> +}
>> +
>> +static void stm32_sdmmc2_pwron(struct stm32_sdmmc2_host *host)
>> +{
>> +	struct stm32_sdmmc2 *sdmmc_handler = host->base;
>> +
>> +	/* Reset */
>> +	reset_assert(&host->reset_ctl);
>> +	udelay(2);
>> +	reset_deassert(&host->reset_ctl);
>> +
>> +	udelay(1000);
>> +
>> +	/* Set Power State to ON */
>> +	writel(SDMMC_POWER_PWRCTRL | host->pwr_reg_add, &sdmmc_handler->power);
>> +
>> +	/*
>> +	 * 1ms: required power up waiting time before starting the
>> +	 * SD initialization sequence
>> +	 */
>> +	udelay(1000);
>> +}
>> +
>> +#define IS_RISING_EDGE(reg) (reg & SDMMC_CLKCR_NEGEDGE ? 0 : 1)
>> +static int stm32_sdmmc2_set_ios(struct udevice *dev)
>> +{
>> +	struct mmc *mmc = mmc_get_mmc_dev(dev);
>> +	struct stm32_sdmmc2_host *host = mmc->priv;
>> +	struct stm32_sdmmc2 *sdmmc_handler = host->base;
>> +	struct mmc_config *cfg = &host->cfg;
>> +	u32 desired = mmc->clock;
>> +	u32 sys_clock = clk_get_rate(&host->clk);
>> +	u32 clk = 0;
>> +
>> +	debug("%s: bus_with = %d, clock = %d\n", __func__,
>> +	      mmc->bus_width, mmc->clock);
>> +
>> +	if ((mmc->bus_width == 1) && (desired == cfg->f_min))
>> +		stm32_sdmmc2_pwron(host);
>> +
>> +	/*
>> +	 * clk_div = 0 => command and data generated on SDMMCCLK falling edge
>> +	 * clk_div > 0 and NEGEDGE = 0 => command and data generated on
>> +	 * SDMMCCLK rising edge
>> +	 * clk_div > 0 and NEGEDGE = 1 => command and data generated on
>> +	 * SDMMCCLK falling edge
>> +	 */
>> +	if (desired && ((sys_clock > desired) ||
>> +			IS_RISING_EDGE(host->clk_reg_add))) {
>> +		clk = DIV_ROUND_UP(sys_clock, 2 * desired);
>> +		if (clk > SDMMC_CLKCR_CLKDIV_MAX)
>> +			clk = SDMMC_CLKCR_CLKDIV_MAX;
>> +	}
>> +
>> +	if (mmc->bus_width == 4)
>> +		clk |= SDMMC_CLKCR_WIDBUS_4;
>> +	if (mmc->bus_width == 8)
>> +		clk |= SDMMC_CLKCR_WIDBUS_8;
>> +
>> +	writel(clk | host->clk_reg_add, &sdmmc_handler->clkcr);
>> +
>> +	return 0;
>> +}
>> +
>> +static int stm32_sdmmc2_getcd(struct udevice *dev)
>> +{
>> +	struct stm32_sdmmc2_host *host = dev_get_priv(dev);
>> +
>> +	debug("stm32_sdmmc2_getcd called\n");
>> +
>> +	if (dm_gpio_is_valid(&host->cd_gpio))
>> +		return dm_gpio_get_value(&host->cd_gpio);
>> +
>> +	return 1;
>> +}
>> +
>> +static const struct dm_mmc_ops stm32_sdmmc2_ops = {
>> +	.send_cmd = stm32_sdmmc2_send_cmd,
>> +	.set_ios = stm32_sdmmc2_set_ios,
>> +	.get_cd = stm32_sdmmc2_getcd,
>> +};
>> +
>> +static int stm32_sdmmc2_probe(struct udevice *dev)
>> +{
>> +	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
>> +	struct stm32_sdmmc2_host *host = dev_get_priv(dev);
>> +	struct mmc_config *cfg = &host->cfg;
>> +	struct mmc *mmc;
>> +	fdt_addr_t addr;
>> +	int ret;
>> +
>> +	addr = devfdt_get_addr(dev);
>> +	if (addr == FDT_ADDR_T_NONE)
>> +		return -EINVAL;
>> +
>> +	host->base = (struct stm32_sdmmc2 *)addr;
>> +
>> +	if (dev_read_bool(dev, "st,negedge"))
>> +		host->clk_reg_add |= SDMMC_CLKCR_NEGEDGE;
> 
> why did "or" with host->clk_reg_add?

Ok i think i understood your remark, the clk_reg_add name is confusing.

clk_reg_add is a mask that will be applied during stm32_sdmmc2_set_ios()
in the clock control register (clkcr).

I will rename this field from clk_reg_add to clk_reg_msk

> 
>> +	if (dev_read_bool(dev, "st,dirpol"))
>> +		host->pwr_reg_add |= SDMMC_POWER_DIRPOL;
> 
> ditto

ok, same reason than for clk_reg_add, it will be renamed pwr_reg_msk

> 
>> +
>> +	ret = clk_get_by_index(dev, 0, &host->clk);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = clk_enable(&host->clk);
>> +	if (ret)
>> +		goto clk_free;
>> +
>> +	ret = reset_get_by_index(dev, 0, &host->reset_ctl);
>> +	if (ret)
>> +		goto clk_disable;
>> +
>> +	gpio_request_by_name(dev, "cd-gpios", 0, &host->cd_gpio,
>> +			     GPIOD_IS_IN);
>> +
>> +	cfg->f_min = 400000;
>> +	cfg->f_max = dev_read_u32_default(dev, "max-frequency", 52000000);
>> +	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
>> +	cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;
>> +	cfg->name = "STM32 SD/MMCv2";
>> +
>> +	cfg->host_caps = 0;
>> +	if (cfg->f_max > 25000000)
>> +		cfg->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
>> +
>> +	switch (dev_read_u32_default(dev, "bus-width", 1)) {
>> +	case 8:
>> +		cfg->host_caps |= MMC_MODE_8BIT;
>> +	case 4:
>> +		cfg->host_caps |= MMC_MODE_4BIT;
>> +		break;
>> +	case 1:
>> +		break;
>> +	default:
>> +		printf("%s: invalid \"bus-width\" property\n", __func__);
>> +		ret = -ENOENT;
>> +		goto reset_free;
> 
> Maybe default value can be 1..

Default value is already set to 1 in case the property "bus-width" is 
not present in DT.

The "default" case is just a protection in case of "bus-width" property 
is set with other values than 1, 4 or 8.

> 
>> +	}
>> +
>> +	mmc = mmc_create(cfg, host);
>> +	if (!mmc) {
>> +		ret = -ENOMEM;
>> +		goto reset_free;
>> +	}
>> +
>> +	mmc->block_dev.removable = !dev_read_bool(dev, "non-removable");
>> +	mmc->dev = dev;
>> +	upriv->mmc = mmc;
>> +
>> +	return 0;
>> +
>> +reset_free:
>> +	reset_free(&host->reset_ctl);
>> +clk_disable:
>> +	clk_disable(&host->clk);
>> +clk_free:
>> +	clk_free(&host->clk);
>> +
>> +	return ret;
>> +}
>> +
>> +static const struct udevice_id stm32_sdmmc2_ids[] = {
>> +	{ .compatible = "st,stm32-sdmmc2" },
>> +	{ }
>> +};
>> +
>> +U_BOOT_DRIVER(stm32_sdmmc2) = {
>> +	.name = "stm32_sdmmc2",
>> +	.id = UCLASS_MMC,
>> +	.of_match = stm32_sdmmc2_ids,
>> +	.ops = &stm32_sdmmc2_ops,
>> +	.probe = stm32_sdmmc2_probe,
>> +	.priv_auto_alloc_size = sizeof(struct stm32_sdmmc2_host),
>> +};
>>
> 


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