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authorFaiz Abbas <faiz_abbas@ti.com>2019-04-01 18:28:04 +0530
committerUlf Hansson <ulf.hansson@linaro.org>2019-04-15 11:55:54 +0200
commite374e87538f4c7cd364bce6b9048ad5829ccc604 (patch)
treea0004296e8224632bf68fc376b527b05ff9f980f /drivers/mmc
parent3b407b4f3a9273467a6b3d6a640948a739794950 (diff)
downloadlinux-e374e87538f4c7cd364bce6b9048ad5829ccc604.tar.gz
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: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/Kconfig1
-rw-r--r--drivers/mmc/host/sdhci_am654.c22
2 files changed, 23 insertions, 0 deletions
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index de7a38dab2aa..9c01310a0d2e 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -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
diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index eea183e90f1b..a91c0b45c48d 100644
--- a/drivers/mmc/host/sdhci_am654.c
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -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,
 };