Commit e374e875 authored by Faiz Abbas's avatar Faiz Abbas Committed by Ulf Hansson
Browse files

mmc: sdhci_am654: Clear HISPD_ENA in some lower speed modes 

According to the AM654x Data Manual[1], the setup timing in lower speed
modes can only be met if the controller uses a falling edge data launch.

To ensure this, the HIGH_SPEED_ENA (HOST_CONTROL[2]) bit should be
cleared in default speed, SD high speed, MMC high speed, SDR12 and SDR25
speed modes.

Use the sdhci writeb callback to implement this condition.

[1] http://www.ti.com/lit/gpn/am6546

 Section 5.10.5.16.1

Signed-off-by: default avatarFaiz Abbas <faiz_abbas@ti.com>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 3b407b4f

drivers/mmc/host/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -994,6 +994,7 @@ config MMC_SDHCI_OMAP 
config MMC_SDHCI_AM654

	tristate "Support for the SDHCI Controller in TI's AM654 SOCs"

	depends on MMC_SDHCI_PLTFM && OF

	select MMC_SDHCI_IO_ACCESSORS

	help

	  This selects the Secure Digital Host Controller Interface (SDHCI)

	  support present in TI's AM654 SOCs. The controller supports

drivers/mmc/host/sdhci_am654.c

+22 −0
Original line number Diff line number Diff line
@@ -158,6 +158,27 @@ static void sdhci_am654_set_power(struct sdhci_host *host, unsigned char mode, 
	sdhci_set_power_noreg(host, mode, vdd);

}



static void sdhci_am654_write_b(struct sdhci_host *host, u8 val, int reg)

{

	unsigned char timing = host->mmc->ios.timing;



	if (reg == SDHCI_HOST_CONTROL) {

		switch (timing) {

		/*

		 * According to the data manual, HISPD bit

		 * should not be set in these speed modes.

		 */

		case MMC_TIMING_SD_HS:

		case MMC_TIMING_MMC_HS:

		case MMC_TIMING_UHS_SDR12:

		case MMC_TIMING_UHS_SDR25:

			val &= ~SDHCI_CTRL_HISPD;

		}

	}



	writeb(val, host->ioaddr + reg);

}



static struct sdhci_ops sdhci_am654_ops = {

	.get_max_clock = sdhci_pltfm_clk_get_max_clock,

	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
@@ -165,6 +186,7 @@ static struct sdhci_ops sdhci_am654_ops = { 
	.set_bus_width = sdhci_set_bus_width,

	.set_power = sdhci_am654_set_power,

	.set_clock = sdhci_am654_set_clock,

	.write_b = sdhci_am654_write_b,

	.reset = sdhci_reset,

};

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