From 613c25e7b5d4129d64327f83c00ad1463b606b01 Mon Sep 17 00:00:00 2001 From: Teppei Kamijou Date: Wed, 12 Dec 2012 15:38:08 +0100 Subject: [PATCH] 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: Teppei Kamijou Signed-off-by: Shinya Kuribayashi Signed-off-by: Guennadi Liakhovetski Signed-off-by: Chris Ball --- drivers/mmc/host/sh_mmcif.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c index c7984bad8efc..6d4328dce320 100644 --- a/drivers/mmc/host/sh_mmcif.c +++ b/drivers/mmc/host/sh_mmcif.c @@ -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; } -- 2.30.2