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Commit 555061f9 authored by Teppei Kamijou's avatar Teppei Kamijou Committed by Chris Ball
Browse files

mmc: sh_mmcif: Add support for eMMC Dual Data Rate 



Some MMCIF implementations support the Dual Data Rate. With this patch,
platforms can set the MMC_CAP_UHS_DDR50 capability flag in MMCIF platform
data. This will let the MMC core to actually use the DDR mode.

Signed-off-by: default avatarTeppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: default avatarShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 2cd5b3e0

drivers/mmc/host/sh_mmcif.c

+14 −0
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ 
#define CMD_SET_TBIT		(1 << 7) /* 1: tran mission bit "Low" */

#define CMD_SET_OPDM		(1 << 6) /* 1: open/drain */

#define CMD_SET_CCSH		(1 << 5)

#define CMD_SET_DARS		(1 << 2) /* Dual Data Rate */

#define CMD_SET_DATW_1		((0 << 1) | (0 << 0)) /* 1bit */

#define CMD_SET_DATW_4		((0 << 1) | (1 << 0)) /* 4bit */

#define CMD_SET_DATW_8		((1 << 1) | (0 << 0)) /* 8bit */
@@ -216,6 +217,7 @@ struct sh_mmcif_host { 
	struct clk *hclk;

	unsigned int clk;

	int bus_width;

	unsigned char timing;

	bool sd_error;

	bool dying;

	long timeout;
@@ -781,6 +783,17 @@ static u32 sh_mmcif_set_cmd(struct sh_mmcif_host *host, 
			dev_err(&host->pd->dev, "Unsupported bus width.\n");

			break;

		}

		switch (host->timing) {

		case MMC_TIMING_UHS_DDR50:

			/*

			 * MMC core will only set this timing, if the host

			 * advertises the MMC_CAP_UHS_DDR50 capability. MMCIF

			 * implementations with this capability, e.g. sh73a0,

			 * will have to set it in their platform data.

			 */

			tmp |= CMD_SET_DARS;

			break;

		}

	}

	/* DWEN */

	if (opc == MMC_WRITE_BLOCK || opc == MMC_WRITE_MULTIPLE_BLOCK)
@@ -1002,6 +1015,7 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) 
		sh_mmcif_clock_control(host, ios->clock);

	}



	host->timing = ios->timing;

	host->bus_width = ios->bus_width;

	host->state = STATE_IDLE;

}