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Commit af51079e authored by Sascha Hauer's avatar Sascha Hauer Committed by Chris Ball
Browse files

mmc: sdhci-esdhc-imx: support 8bit mode 



The i.MX esdhc has a nonstandard bit layout for the SDHCI_HOST_CONTROL
register. To support 8bit bus width on i.MX populate the platform_bus_width
callback. This is tested on an i.MX25, but should according to the datasheets
work on the other i.MX using this hardware aswell. The i.MX6, while having
a SDHCI_SPEC_300 controller, still uses the same nonstandard register layout.

Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: default avatarShawn Guo <shawn.guo@linaro.org>
Tested-by: default avatarDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 7bc088d3

drivers/mmc/host/sdhci-esdhc-imx.c

+54 −2
Original line number Diff line number Diff line
@@ -40,6 +40,13 @@ 
/* Bits 3 and 6 are not SDHCI standard definitions */

#define  ESDHC_MIX_CTRL_SDHCI_MASK	0xb7



/*

 * Our interpretation of the SDHCI_HOST_CONTROL register

 */

#define ESDHC_CTRL_4BITBUS		(0x1 << 1)

#define ESDHC_CTRL_8BITBUS		(0x2 << 1)

#define ESDHC_CTRL_BUSWIDTH_MASK	(0x3 << 1)



/*

 * There is an INT DMA ERR mis-match between eSDHC and STD SDHC SPEC:

 * Bit25 is used in STD SPEC, and is reserved in fsl eSDHC design,
@@ -294,6 +301,7 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) 
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);

	struct pltfm_imx_data *imx_data = pltfm_host->priv;

	u32 new_val;

	u32 mask;



	switch (reg) {

	case SDHCI_POWER_CONTROL:
@@ -304,7 +312,7 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) 
		return;

	case SDHCI_HOST_CONTROL:

		/* FSL messed up here, so we need to manually compose it. */

		new_val = val & (SDHCI_CTRL_LED | SDHCI_CTRL_4BITBUS);

		new_val = val & SDHCI_CTRL_LED;

		/* ensure the endianness */

		new_val |= ESDHC_HOST_CONTROL_LE;

		/* bits 8&9 are reserved on mx25 */
@@ -313,7 +321,13 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) 
			new_val |= (val & SDHCI_CTRL_DMA_MASK) << 5;

		}



		esdhc_clrset_le(host, 0xffff, new_val, reg);

		/*

		 * Do not touch buswidth bits here. This is done in

		 * esdhc_pltfm_bus_width.

		 */

		mask = 0xffff & ~ESDHC_CTRL_BUSWIDTH_MASK;



		esdhc_clrset_le(host, mask, new_val, reg);

		return;

	}

	esdhc_clrset_le(host, 0xff, val, reg);
@@ -370,6 +384,28 @@ static unsigned int esdhc_pltfm_get_ro(struct sdhci_host *host) 
	return -ENOSYS;

}



static int esdhc_pltfm_bus_width(struct sdhci_host *host, int width)

{

	u32 ctrl;



	switch (width) {

	case MMC_BUS_WIDTH_8:

		ctrl = ESDHC_CTRL_8BITBUS;

		break;

	case MMC_BUS_WIDTH_4:

		ctrl = ESDHC_CTRL_4BITBUS;

		break;

	default:

		ctrl = 0;

		break;

	}



	esdhc_clrset_le(host, ESDHC_CTRL_BUSWIDTH_MASK, ctrl,

			SDHCI_HOST_CONTROL);



	return 0;

}



static struct sdhci_ops sdhci_esdhc_ops = {

	.read_l = esdhc_readl_le,

	.read_w = esdhc_readw_le,
@@ -380,6 +416,7 @@ static struct sdhci_ops sdhci_esdhc_ops = { 
	.get_max_clock = esdhc_pltfm_get_max_clock,

	.get_min_clock = esdhc_pltfm_get_min_clock,

	.get_ro = esdhc_pltfm_get_ro,

	.platform_bus_width = esdhc_pltfm_bus_width,

};



static struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
@@ -417,6 +454,8 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, 
	if (gpio_is_valid(boarddata->wp_gpio))

		boarddata->wp_type = ESDHC_WP_GPIO;



	of_property_read_u32(np, "bus-width", &boarddata->max_bus_width);



	return 0;

}

#else
@@ -548,6 +587,19 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev) 
		break;

	}



	switch (boarddata->max_bus_width) {

	case 8:

		host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA;

		break;

	case 4:

		host->mmc->caps |= MMC_CAP_4_BIT_DATA;

		break;

	case 1:

	default:

		host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA;

		break;

	}



	err = sdhci_add_host(host);

	if (err)

		goto disable_clk;

include/linux/platform_data/mmc-esdhc-imx.h

+1 −0
Original line number Diff line number Diff line
@@ -39,5 +39,6 @@ struct esdhc_platform_data { 
	unsigned int cd_gpio;

	enum wp_types wp_type;

	enum cd_types cd_type;

	int max_bus_width;

};

#endif /* __ASM_ARCH_IMX_ESDHC_H */