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mmc: sdhci_am654: Clear HISPD_ENA in some lower speed modes

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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: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Faiz Abbas 2019-04-01 18:28:04 +05:30 committed by Ulf Hansson
parent 3b407b4f3a
commit e374e87538
2 changed files with 23 additions and 0 deletions
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1
drivers/mmc/host/Kconfig
View File

@ -994,6 +994,7 @@ config MMC_SDHCI_OMAP
config MMC_SDHCI_AM654 config MMC_SDHCI_AM654
tristate "Support for the SDHCI Controller in TI's AM654 SOCs" tristate "Support for the SDHCI Controller in TI's AM654 SOCs"
depends on MMC_SDHCI_PLTFM && OF depends on MMC_SDHCI_PLTFM && OF
select MMC_SDHCI_IO_ACCESSORS
help help
This selects the Secure Digital Host Controller Interface (SDHCI) This selects the Secure Digital Host Controller Interface (SDHCI)
support present in TI's AM654 SOCs. The controller supports support present in TI's AM654 SOCs. The controller supports

22
drivers/mmc/host/sdhci_am654.c
View File

@ -158,6 +158,27 @@ static void sdhci_am654_set_power(struct sdhci_host *host, unsigned char mode,
sdhci_set_power_noreg(host, mode, vdd); 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 = { static struct sdhci_ops sdhci_am654_ops = {
.get_max_clock = sdhci_pltfm_clk_get_max_clock, .get_max_clock = sdhci_pltfm_clk_get_max_clock,
.get_timeout_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_bus_width = sdhci_set_bus_width,
.set_power = sdhci_am654_set_power, .set_power = sdhci_am654_set_power,
.set_clock = sdhci_am654_set_clock, .set_clock = sdhci_am654_set_clock,
.write_b = sdhci_am654_write_b,
.reset = sdhci_reset, .reset = sdhci_reset,
}; };