[U-Boot] [PATCH] MMC: MSHCI: Add MSHCI driver

Jaehoon Chung jh80.chung at samsung.com
Tue May 29 13:38:00 CEST 2012


Hi Rajeshwari,

i added Some comments.

On 05/25/2012 08:51 PM, Rajeshwari Shinde wrote:

> Add MSHCI driver support and resgister description for same.
> 
> Signed-off-by: Alim Akhtar <alim.akhtar at samsung.com>
> Signed-off-by: Terry Lambert <tlambert at chromium.org>
> Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>
> ---
>  arch/arm/include/asm/arch-exynos/mshc.h |  174 ++++++++++
>  drivers/mmc/Makefile                    |    1 +
>  drivers/mmc/exynos_mshc.c               |  553 +++++++++++++++++++++++++++++++
>  3 files changed, 728 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/include/asm/arch-exynos/mshc.h
>  create mode 100644 drivers/mmc/exynos_mshc.c
> 
> diff --git a/arch/arm/include/asm/arch-exynos/mshc.h b/arch/arm/include/asm/arch-exynos/mshc.h
> new file mode 100644
> index 0000000..7226619
> --- /dev/null
> +++ b/arch/arm/include/asm/arch-exynos/mshc.h
> @@ -0,0 +1,174 @@
> +/*
> + * (C) Copyright 2012 SAMSUNG Electronics
> + * Abhilash Kesavan <a.kesavan at samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + *
> + */
> +#ifndef __ASM_ARCH_COMMON_MSHC_H
> +#define __ASM_ARCH_COMMON_MSHC_H
> +
> +#include <asm/arch/pinmux.h>
> +#ifndef __ASSEMBLY__
> +struct mshci_host {
> +	struct exynos_mshci	*reg;		/* Mapped address */
> +	unsigned int		clock;		/* Current clock in MHz */
> +	enum periph_id	peripheral;
> +};
> +
> +struct exynos_mshci {
> +	unsigned int	ctrl;
> +	unsigned int	pwren;
> +	unsigned int	clkdiv;
> +	unsigned int	clksrc;
> +	unsigned int	clkena;
> +	unsigned int	tmout;
> +	unsigned int	ctype;
> +	unsigned int	blksiz;
> +	unsigned int	bytcnt;
> +	unsigned int	intmask;
> +	unsigned int	cmdarg;
> +	unsigned int	cmd;
> +	unsigned int	resp0;
> +	unsigned int	resp1;
> +	unsigned int	resp2;
> +	unsigned int	resp3;
> +	unsigned int	mintsts;
> +	unsigned int	rintsts;
> +	unsigned int	status;
> +	unsigned int	fifoth;
> +	unsigned int	cdetect;
> +	unsigned int	wrtprt;
> +	unsigned int	gpio;
> +	unsigned int	tcbcnt;
> +	unsigned int	tbbcnt;
> +	unsigned int	debnce;
> +	unsigned int	usrid;
> +	unsigned int	verid;
> +	unsigned int	hcon;
> +	unsigned int	uhs_reg;
> +	unsigned int	rst_n;
> +	unsigned char	reserved1[4];
> +	unsigned int	bmod;
> +	unsigned int	pldmnd;
> +	unsigned int	dbaddr;
> +	unsigned int	idsts;
> +	unsigned int	idinten;
> +	unsigned int	dscaddr;
> +	unsigned int	bufaddr;
> +	unsigned int	clksel;
> +	unsigned char	reserved2[460];
> +	unsigned int	cardthrctl;
> +};

I think good that register offset is refer to sdhci.h.

> +
> +/*
> + * Struct idma
> + * Holds the descriptor list
> + */
> +struct mshci_idmac {
> +	u32	des0;
> +	u32	des1;
> +	u32	des2;
> +	u32	des3;
> +};
> +
> +/*  Control Register  Register */
> +#define CTRL_RESET	(0x1 << 0)
> +#define FIFO_RESET	(0x1 << 1)
> +#define DMA_RESET	(0x1 << 2)
> +#define DMA_ENABLE	(0x1 << 5)
> +#define SEND_AS_CCSD	(0x1 << 10)
> +#define ENABLE_IDMAC    (0x1 << 25)
> +
> +/*  Power Enable Register */
> +#define POWER_ENABLE	(0x1 << 0)
> +
> +/*  Clock Enable Register */
> +#define CLK_ENABLE	(0x1 << 0)
> +#define CLK_DISABLE	(0x0 << 0)
> +
> +/* Timeout Register */
> +#define TMOUT_MAX	0xffffffff
> +
> +/*  Card Type Register */
> +#define PORT0_CARD_WIDTH1	0
> +#define PORT0_CARD_WIDTH4	(0x1 << 0)
> +#define PORT0_CARD_WIDTH8	(0x1 << 16)
> +
> +/*  Interrupt Mask Register */
> +#define INTMSK_ALL	0xffffffff
> +#define INTMSK_RE	(0x1 << 1)
> +#define INTMSK_CDONE	(0x1 << 2)
> +#define INTMSK_DTO	(0x1 << 3)
> +#define INTMSK_DCRC	(0x1 << 7)
> +#define INTMSK_RTO	(0x1 << 8)
> +#define INTMSK_DRTO	(0x1 << 9)
> +#define INTMSK_HTO	(0x1 << 10)
> +#define INTMSK_FRUN	(0x1 << 11)
> +#define INTMSK_HLE	(0x1 << 12)
> +#define INTMSK_SBE	(0x1 << 13)
> +#define INTMSK_ACD	(0x1 << 14)
> +#define INTMSK_EBE	(0x1 << 15)
> +
> +/* Command Register */
> +#define CMD_RESP_EXP_BIT	(0x1 << 6)
> +#define CMD_RESP_LENGTH_BIT	(0x1 << 7)
> +#define CMD_CHECK_CRC_BIT	(0x1 << 8)
> +#define CMD_DATA_EXP_BIT	(0x1 << 9)
> +#define CMD_RW_BIT		(0x1 << 10)
> +#define CMD_SENT_AUTO_STOP_BIT	(0x1 << 12)
> +#define CMD_WAIT_PRV_DAT_BIT	(0x1 << 13)
> +#define CMD_SEND_CLK_ONLY	(0x1 << 21)
> +#define CMD_USE_HOLD_REG	(0x1 << 29)
> +#define CMD_STRT_BIT		(0x1 << 31)
> +#define CMD_ONLY_CLK		(CMD_STRT_BIT | CMD_SEND_CLK_ONLY | \
> +				CMD_WAIT_PRV_DAT_BIT)
> +
> +/*  Raw Interrupt Register */
> +#define DATA_ERR	(INTMSK_EBE | INTMSK_SBE | INTMSK_HLE |	\
> +			INTMSK_FRUN | INTMSK_EBE | INTMSK_DCRC)
> +#define DATA_TOUT	(INTMSK_HTO | INTMSK_DRTO)
> +
> +/*  Status Register */
> +#define DATA_BUSY	(0x1 << 9)
> +
> +/*  FIFO Threshold Watermark Register */
> +#define TX_WMARK	(0xFFF << 0)
> +#define RX_WMARK	(0xFFF << 16)
> +#define MSIZE_MASK	(0x7 << 28)
> +
> +/* DW DMA Mutiple Transaction Size */
> +#define MSIZE_8		(2 << 28)
> +
> +/*  Bus Mode Register */
> +#define BMOD_IDMAC_RESET	(0x1 << 0)
> +#define BMOD_IDMAC_FB		(0x1 << 1)
> +#define BMOD_IDMAC_ENABLE	(0x1 << 7)
> +
> +/* IDMAC bits */
> +#define MSHCI_IDMAC_OWN		(0x1 << 31)
> +#define MSHCI_IDMAC_CH		(0x1 << 4)
> +#define MSHCI_IDMAC_FS		(0x1 << 3)
> +#define MSHCI_IDMAC_LD		(0x1 << 2)
> +
> +#define MAX_MSHCI_CLOCK		52000000 /* Max limit is 52MHz */

Is Max clock 52MHz?

> +#define MIN_MSHCI_CLOCK		400000 /* Lower limit is 400KHz */
> +#define COMMAND_TIMEOUT		10000
> +#define TIMEOUT_MS		100
> +
> +int exynos_mshci_init(enum periph_id periph_id, int bus_width);
> +
> +#endif
> +#endif

#endif /* .... */

> diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
> index c245352..84e2d6a 100644
> --- a/drivers/mmc/Makefile
> +++ b/drivers/mmc/Makefile
> @@ -27,6 +27,7 @@ LIB	:= $(obj)libmmc.o
>  
>  COBJS-$(CONFIG_BFIN_SDH) += bfin_sdh.o
>  COBJS-$(CONFIG_DAVINCI_MMC) += davinci_mmc.o
> +COBJS-$(CONFIG_EXYNOS_MSHCI) += exynos_mshc.o
>  COBJS-$(CONFIG_FSL_ESDHC) += fsl_esdhc.o
>  COBJS-$(CONFIG_FTSDC010) += ftsdc010_esdhc.o
>  COBJS-$(CONFIG_GENERIC_MMC) += mmc.o
> diff --git a/drivers/mmc/exynos_mshc.c b/drivers/mmc/exynos_mshc.c
> new file mode 100644
> index 0000000..eb133c0
> --- /dev/null
> +++ b/drivers/mmc/exynos_mshc.c
> @@ -0,0 +1,553 @@
> +/*
> + * (C) Copyright 2012 Samsung Electronics Co. Ltd
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <mmc.h>
> +#include <asm/arch/clk.h>
> +#include <asm/arch/cpu.h>
> +#include <asm/arch/mshc.h>
> +#include <asm/arch/pinmux.h>
> +
> +/* support 4 mmc hosts */
> +enum {
> +	MAX_MMC_HOSTS	= 4
> +};
> +
> +static struct mmc mshci_dev[MAX_MMC_HOSTS];
> +static struct mshci_host mshci_host[MAX_MMC_HOSTS];
> +static int num_devs;
> +
> +/* Struct to hold mshci register and bus width */
> +struct mshci_config {
> +	struct exynos_mshci *reg; /* registers address in physical memory */
> +	int bus_width; /* bus width */
> +	int removable; /* removable device? */
> +	enum periph_id periph_id; /* Peripheral ID for this peripheral */
> +};
> +
> +/**
> + * Set bits of MSHCI host control register.
> + *
> + * @param host	MSHCI host
> + * @param bits	bits to be set
> + * @return 0 on success, -1 on failure
> + */
> +static int mshci_setbits(struct mshci_host *host, unsigned int bits)
> +{
> +	ulong start;
> +
> +	setbits_le32(&host->reg->ctrl, bits);
> +
> +	start = get_timer(0);
> +	while (readl(&host->reg->ctrl) & bits) {
> +		if (get_timer(start) > TIMEOUT_MS) {
> +			debug("Set bits failed\n");
> +			return -1;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * Reset MSHCI host control register.
> + *
> + * @param host	MSHCI host
> + * @return 0 on success, -1 on failure
> + */
> +static int mshci_reset_all(struct mshci_host *host)
> +{
> +	ulong start;
> +
> +	/*
> +	* Before we reset ciu check the DATA0 line.  If it is low and
> +	* we resets the ciu then we might see some errors.
> +	*/
> +	start = get_timer(0);
> +	while (readl(&host->reg->status) & DATA_BUSY) {
> +		if (get_timer(start) > TIMEOUT_MS) {
> +			debug("Controller did not release"
> +				"data0 before ciu reset\n");
> +			return -1;
> +		}
> +	}
> +
> +	if (mshci_setbits(host, CTRL_RESET)) {
> +		debug("Fail to reset card.\n");
> +		return -1;
> +	}
> +	if (mshci_setbits(host, FIFO_RESET)) {
> +		debug("Fail to reset fifo.\n");
> +		return -1;
> +	}
> +	if (mshci_setbits(host, DMA_RESET)) {
> +		debug("Fail to reset dma.\n");
> +		return -1;
> +	}

I want to use the error number..That's helpful for debugging. not return -1;
And Why do you reset each bit?
If (mshci_setbits(host, CTRL_RESET | FIFO_RESET | DMA_RESET))
is this problem?

> +
> +	return 0;
> +}
> +
> +static void mshci_set_mdma_desc(u8 *desc_vir, u8 *desc_phy,
> +		unsigned int des0, unsigned int des1, unsigned int des2)
> +{
> +	struct mshci_idmac *desc = (struct mshci_idmac *)desc_vir;
> +
> +	desc->des0 = des0;
> +	desc->des1 = des1;
> +	desc->des2 = des2;
> +	desc->des3 = (unsigned int)desc_phy + sizeof(struct mshci_idmac);
> +}
> +
> +static int mshci_prepare_data(struct mshci_host *host, struct mmc_data *data)
> +{
> +	unsigned int i;
> +	unsigned int data_cnt;
> +	unsigned int des_flag;
> +	unsigned int blksz;
> +	static struct mshci_idmac idmac_desc[0x10000];
> +	struct mshci_idmac *pdesc_dmac;
> +
> +	if (mshci_setbits(host, FIFO_RESET)) {
> +		debug("Fail to reset FIFO\n");
> +		return -1;
> +	}
> +
> +	pdesc_dmac = idmac_desc;
> +	blksz = data->blocksize;
> +	data_cnt = data->blocks;
> +
> +	for  (i = 0;; i++) {
> +		des_flag = (MSHCI_IDMAC_OWN | MSHCI_IDMAC_CH);
> +		des_flag |= (i == 0) ? MSHCI_IDMAC_FS : 0;
> +		if (data_cnt <= 8) {
> +			des_flag |= MSHCI_IDMAC_LD;
> +			mshci_set_mdma_desc((u8 *)pdesc_dmac,
> +			(u8 *)virt_to_phys(pdesc_dmac),
> +			des_flag, blksz * data_cnt,
> +			(unsigned int)(virt_to_phys(data->dest)) +
> +			(unsigned int)(i * 0x1000));
> +			break;
> +		}
> +		/* max transfer size is 4KB per descriptor */
> +		mshci_set_mdma_desc((u8 *)pdesc_dmac,
> +			(u8 *)virt_to_phys(pdesc_dmac),
> +			des_flag, blksz * 8,
> +			virt_to_phys(data->dest) +
> +			(unsigned int)(i * 0x1000));
> +
> +		data_cnt -= 8;
> +		pdesc_dmac++;
> +	}
> +
> +	writel((unsigned int)virt_to_phys(idmac_desc), &host->reg->dbaddr);
> +
> +	/* enable the Internal DMA Controller */
> +	setbits_le32(&host->reg->ctrl, ENABLE_IDMAC | DMA_ENABLE);
> +	setbits_le32(&host->reg->bmod, BMOD_IDMAC_ENABLE | BMOD_IDMAC_FB);
> +
> +	writel(data->blocksize, &host->reg->blksiz);
> +	writel(data->blocksize * data->blocks, &host->reg->bytcnt);
> +
> +	return 0;
> +}
> +
> +static int mshci_set_transfer_mode(struct mshci_host *host,
> +	struct mmc_data *data)
> +{
> +	int mode = CMD_DATA_EXP_BIT;
> +
> +	if (data->blocks > 1)
> +		mode |= CMD_SENT_AUTO_STOP_BIT;
> +	if (data->flags & MMC_DATA_WRITE)
> +		mode |= CMD_RW_BIT;
> +
> +	return mode;
> +}
> +
> +/*
> + * Sends a command out on the bus.
> + *
> + * @param mmc	mmc device
> + * @param cmd	mmc_cmd to be sent on bus
> + * @param data	mmc data to be sent (optional)
> + *
> + * @return	return 0 if ok, else -1
> + */
> +static int exynos_mshci_send_command(struct mmc *mmc, struct mmc_cmd *cmd,
> +		struct mmc_data *data)
> +{
> +	struct mshci_host *host = mmc->priv;
> +
> +	int flags = 0, i;
> +	unsigned int mask;
> +	ulong start;
> +
> +	/*
> +	* We shouldn't wait for data inihibit for stop commands, even
> +	* though they might use busy signaling
> +	*/
> +	start = get_timer(0);
> +	while (readl(&host->reg->status) & DATA_BUSY) {
> +		if (get_timer(start) > COMMAND_TIMEOUT) {
> +			debug("timeout on data busy\n");
> +			return -1;
> +		}
> +	}
> +
> +	if (readl(&host->reg->rintsts)) {
> +		if ((readl(&host->reg->rintsts) &
> +				(INTMSK_CDONE | INTMSK_ACD)) == 0)
> +			debug("there are pending interrupts 0x%x\n",
> +				readl(&host->reg->rintsts));
> +	}
> +	/* It clears all pending interrupts before sending a command*/
> +	writel(INTMSK_ALL, &host->reg->rintsts);
> +
> +	if (data) {
> +		if (mshci_prepare_data(host, data)) {
> +			debug("fail to prepare data\n");
> +			return -1;
> +		}
> +	}
> +
> +	writel(cmd->cmdarg, &host->reg->cmdarg);
> +
> +	if (data)
> +		flags = mshci_set_transfer_mode(host, data);
> +
> +	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
> +		/* this is out of SD spec */
> +		return -1;
> +
> +	if (cmd->resp_type & MMC_RSP_PRESENT) {
> +		flags |= CMD_RESP_EXP_BIT;
> +		if (cmd->resp_type & MMC_RSP_136)
> +			flags |= CMD_RESP_LENGTH_BIT;
> +	}
> +
> +	if (cmd->resp_type & MMC_RSP_CRC)
> +		flags |= CMD_CHECK_CRC_BIT;
> +	flags |= (cmd->cmdidx | CMD_STRT_BIT | CMD_USE_HOLD_REG |
> +			CMD_WAIT_PRV_DAT_BIT);
> +
> +	mask = readl(&host->reg->cmd);
> +	if (mask & CMD_STRT_BIT)
> +		debug("cmd busy, current cmd: %d", cmd->cmdidx);
> +
> +	writel(flags, &host->reg->cmd);
> +	/* wait for command complete by busy waiting. */
> +	for (i = 0; i < COMMAND_TIMEOUT; i++) {
> +		mask = readl(&host->reg->rintsts);
> +		if (mask & INTMSK_CDONE) {
> +			if (!data)
> +				writel(mask, &host->reg->rintsts);
> +			break;
> +		}
> +	}
> +	/* timeout for command complete. */
> +	if (COMMAND_TIMEOUT == i) {
> +		debug("timeout waiting for status update\n");
> +		return TIMEOUT;
> +	}
> +
> +	if (mask & INTMSK_RTO) {
> +		if (((cmd->cmdidx == 8 || cmd->cmdidx == 41 ||
> +			cmd->cmdidx == 55)) == 0) {
> +			debug("response timeout error: 0x%x cmd: %d\n",
> +				mask, cmd->cmdidx);
> +		}

cmdidx 8, 41, 55 is not readable. Use macro.

> +			return TIMEOUT;
> +	} else if (mask & INTMSK_RE) {
> +		debug("response error: 0x%x cmd: %d\n", mask, cmd->cmdidx);
> +		return -1;
> +	}
> +	if (cmd->resp_type & MMC_RSP_PRESENT) {
> +		if (cmd->resp_type & MMC_RSP_136) {
> +			/* CRC is stripped so we need to do some shifting. */
> +				cmd->response[0] = readl(&host->reg->resp3);
> +				cmd->response[1] = readl(&host->reg->resp2);
> +				cmd->response[2] = readl(&host->reg->resp1);
> +				cmd->response[3] = readl(&host->reg->resp0);
> +		} else {
> +			cmd->response[0] = readl(&host->reg->resp0);
> +			debug("\tcmd->response[0]: 0x%08x\n", cmd->response[0]);
> +		}
> +	}
> +
> +	if (data) {
> +		while (!(mask & (DATA_ERR | DATA_TOUT | INTMSK_DTO)))
> +			mask = readl(&host->reg->rintsts);

If !(mask & (DATA_ERR) | DATA_TOUT | INTMSK_DTO) is always true,
this point should be infinite loop. i think good that prevent it with timeout.

> +		writel(mask, &host->reg->rintsts);
> +		if (mask & (DATA_ERR | DATA_TOUT)) {
> +			debug("error during transfer: 0x%x\n", mask);
> +			/* make sure disable IDMAC and IDMAC_Interrupts */
> +			writel((readl(&host->reg->ctrl) &
> +			~(DMA_ENABLE | ENABLE_IDMAC)), &host->reg->ctrl);
> +			/* mask all interrupt source of IDMAC */
> +			writel(0, &host->reg->idinten);
> +			return -1;
> +		} else if (mask & INTMSK_DTO) {
> +			debug("mshci dma interrupt end\n");
> +		} else {
> +			debug("unexpected condition 0x%x\n", mask);
> +		}
> +		/* make sure disable IDMAC and IDMAC_Interrupts */
> +		writel((readl(&host->reg->ctrl) & ~(DMA_ENABLE | ENABLE_IDMAC)),
> +				&host->reg->ctrl);
> +		/* mask all interrupt source of IDMAC */
> +		writel(0, &host->reg->idinten);
> +	}
> +
> +	udelay(100);

why use udelay(100)?

> +
> +	return 0;
> +}
> +
> +/*
> + * ON/OFF host controller clock
> + *
> + * @param host		pointer to mshci_host
> + * @param val		to enable/disable clock
> + */
> +static void mshci_clock_onoff(struct mshci_host *host, int val)
> +{
> +
> +	if (val) {
> +		writel(CLK_ENABLE, &host->reg->clkena);
> +		writel(0, &host->reg->cmd);
> +		writel(CMD_ONLY_CLK, &host->reg->cmd);
> +	} else {
> +		writel(CLK_DISABLE, &host->reg->clkena);
> +		writel(0, &host->reg->cmd);
> +		writel(CMD_ONLY_CLK, &host->reg->cmd);
> +	}
> +}

If (val)
	writel(CLK_ENABLE, ...);
else
	writel(CLK_DISABLE, ...);

writel(0, &host->reg->cmd);
writel(CMD_ONLY_CLK, &host->reg->cmd); 

> +
> +/*
> + * change host controller clock
> + *
> + * @param host		pointer to mshci_host
> + * @param clock		request clock
> + *
> + */

Remove unnecessary 

> +static void mshci_change_clock(struct mshci_host *host, uint clock)
> +{
> +	int div;
> +	u32 sclk_mshc;
> +
> +	if (clock == host->clock)
> +		return;
> +
> +	/* If Input clock is higher than maximum mshc clock */
> +	if (clock > MAX_MSHCI_CLOCK) {
> +		debug("Input clock is too high\n");
> +		clock = MAX_MSHCI_CLOCK;
> +	}
> +
> +	/* disable the clock before changing it */
> +	mshci_clock_onoff(host, CLK_DISABLE);
> +
> +	/* get the clock division */
> +	if (host->peripheral == PERIPH_ID_SDMMC4)
> +		sclk_mshc = get_mshci_clk_div(host->peripheral) / 2;
> +	else
> +		sclk_mshc = get_mshci_clk_div(host->peripheral) / 4;
> +
> +	/* CLKDIV */
> +	for (div = 1 ; div <= 0xff; div++) {

What means 0xff? more readable..

> +		if ((sclk_mshc / (2 * div)) <= clock) {
> +			writel(div, &host->reg->clkdiv);
> +			break;
> +		}
> +	}
> +
> +	writel(0, &host->reg->cmd);
> +	writel(CMD_ONLY_CLK, &host->reg->cmd);
> +
> +	writel(readl(&host->reg->cmd) & (~CMD_SEND_CLK_ONLY),
> +					&host->reg->cmd);
> +
> +	mshci_clock_onoff(host, CLK_ENABLE);
> +	host->clock = clock;
> +}
> +
> +/*
> + * Set ios for host controller clock
> + *
> + * This sets the card bus width and clksel
> + */
> +static void exynos_mshci_set_ios(struct mmc *mmc)
> +{
> +	struct mshci_host *host = mmc->priv;
> +
> +	debug("bus_width: %x, clock: %d\n", mmc->bus_width, mmc->clock);
> +
> +	if (mmc->clock > 0)
> +		mshci_change_clock(host, mmc->clock);
> +
> +	if (mmc->bus_width == 8)
> +		writel(PORT0_CARD_WIDTH8, &host->reg->ctype);
> +	else if (mmc->bus_width == 4)
> +		writel(PORT0_CARD_WIDTH4, &host->reg->ctype);
> +	else
> +		writel(PORT0_CARD_WIDTH1, &host->reg->ctype);
> +
> +	if (host->peripheral == PERIPH_ID_SDMMC0)
> +		writel(0x03030001, &host->reg->clksel);
> +	if (host->peripheral == PERIPH_ID_SDMMC2)
> +		writel(0x03020001, &host->reg->clksel);
> +	if (host->peripheral == PERIPH_ID_SDMMC4)
> +		writel(0x00020001, &host->reg->clksel);

What means 0x3030001 or 03020001...anybody didn't know what mean is that value.

> +}
> +
> +/*
> + * Fifo init for host controller
> + */
> +static void mshci_fifo_init(struct mshci_host *host)
> +{
> +	int fifo_val, fifo_depth, fifo_threshold;
> +
> +	fifo_val = readl(&host->reg->fifoth);
> +
> +	fifo_depth = 0x80;
> +	fifo_threshold = fifo_depth / 2;

Fifo depth is not always 0x80.

> +
> +	fifo_val &= ~(RX_WMARK | TX_WMARK | MSIZE_MASK);
> +	fifo_val |= (fifo_threshold | (fifo_threshold << 16) | MSIZE_8);
> +	writel(fifo_val, &host->reg->fifoth);
> +}
> +
> +
> +static void mshci_init(struct mshci_host *host)
> +{
> +	/* power on the card */
> +	writel(POWER_ENABLE, &host->reg->pwren);
> +
> +	mshci_reset_all(host);
> +	mshci_fifo_init(host);
> +
> +	/* clear all pending interrupts */
> +	writel(INTMSK_ALL, &host->reg->rintsts);
> +
> +	/* interrupts are not used, disable all */
> +	writel(0, &host->reg->intmask);
> +}
> +
> +static int exynos_mshci_initialize(struct mmc *mmc)
> +{
> +	struct mshci_host *host = (struct mshci_host *)mmc->priv;
> +	unsigned int ier;
> +
> +	mshci_init(host);
> +
> +	/* enumerate at 400KHz */
> +	mshci_change_clock(host, MIN_MSHCI_CLOCK);
> +
> +	/* set auto stop command */
> +	ier = readl(&host->reg->ctrl);
> +	ier |= SEND_AS_CCSD;
> +	writel(ier, &host->reg->ctrl);
> +
> +	/* set 1bit card mode */
> +	writel(PORT0_CARD_WIDTH1, &host->reg->ctype);
> +
> +	writel(0xfffff, &host->reg->debnce);
> +
> +	/* set bus mode register for IDMAC */
> +	writel(BMOD_IDMAC_RESET, &host->reg->bmod);
> +
> +	writel(0x0, &host->reg->idinten);
> +
> +	/* set the max timeout for data and response */
> +	writel(TMOUT_MAX, &host->reg->tmout);
> +
> +	return 0;
> +}
> +
> +static int mshci_initialize(struct mshci_config *config)
> +{
> +	struct mshci_host *mmc_host;
> +	struct mmc *mmc;
> +
> +	if (num_devs == MAX_MMC_HOSTS) {
> +		debug("%s: Too many hosts\n", __func__);
> +		return -1;
> +	}
> +
> +	/* set the clock for mshci controller */
> +	if (set_mshci_clk_div(config->periph_id)) {
> +		debug("clock_set_mshci failed\n");
> +		return -1;
> +	}
> +
> +	mmc = &mshci_dev[num_devs];
> +	mmc_host = &mshci_host[num_devs];
> +
> +	sprintf(mmc->name, "EXYNOS MSHCI%d", num_devs);
> +	num_devs++;
> +
> +	mmc->priv = mmc_host;
> +	mmc->send_cmd = exynos_mshci_send_command;
> +	mmc->set_ios = exynos_mshci_set_ios;
> +	mmc->init = exynos_mshci_initialize;
> +
> +	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
> +	mmc->host_caps = MMC_MODE_HS_52MHz | MMC_MODE_HS | MMC_MODE_HC;
> +
> +	if (config->bus_width == 8)
> +		mmc->host_caps |= MMC_MODE_8BIT;
> +	else
> +		mmc->host_caps |= MMC_MODE_4BIT;
> +
> +	mmc->f_min = MIN_MSHCI_CLOCK;
> +	mmc->f_max = MAX_MSHCI_CLOCK;
> +
> +	exynos_pinmux_config(config->periph_id,
> +			config->bus_width == 8 ? PINMUX_FLAG_8BIT_MODE : 0);
> +
> +	mmc_host->clock = 0;
> +	mmc_host->reg =  config->reg;
> +	mmc_host->peripheral =  config->periph_id;
> +	mmc->b_max = 1;
> +	mmc_register(mmc);
> +	mmc->block_dev.removable = config->removable;
> +	debug("exynos_mshci: periph_id=%d, width=%d, reg=%p\n",
> +	      config->periph_id, config->bus_width, config->reg);
> +
> +	return 0;
> +}
> +
> +int exynos_mshci_init(enum periph_id periph_id, int bus_width)
> +{
> +	struct mshci_config config;
> +	int ret = 0;
> +	config.bus_width = bus_width;
> +	config.reg = (struct exynos_mshci *)samsung_get_base_mshci();
> +	config.periph_id = periph_id;
> +	config.removable = 1;
> +	if (mshci_initialize(&config)) {
> +		debug("%s: Failed to init MSHCI\n", __func__);
> +		ret = -1;
> +	}
> +	return ret;
> +}


Generally, you didn't use return -1...if you used them, we can't debug what is problem.
And mshci is not exynos specific feature. It's DesignWare Cores Mobile Storage host contoller.
It should be common driver. if you want to use this IP for exynos,
then you must seperate to mshci.c and exynos-mshci.c.

IDMAC is used by default?

And i want to change the dwmmc.c instead of mshci.c. In kernel side, already used dwmmc.c.
It's confused.

Best Regards,
Jaehoon Chung



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