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mmc: sh_mmcif: Add support for eMMC Dual Data Rate

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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: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Teppei Kamijou 2012-12-12 15:38:08 +01:00 committed by Chris Ball
parent 2cd5b3e061
commit 555061f987
1 changed files with 14 additions and 0 deletions
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14
drivers/mmc/host/sh_mmcif.c
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@ -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;
}