[PATCH 4.10 42/81] mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection

Greg Kroah-Hartman
2017-04-06T09:01:40Z

From: Ludovic Desroches <ludovic.desroches@microchip.com>

commit d0918764c17b94c30bbb2619929b1719ff52707a upstream.

The controller has different timings for MMC_TIMING_UHS_DDR50 and
MMC_TIMING_MMC_DDR52. Configuring the controller with SDHCI_CTRL_UHS_DDR50,
when MMC_TIMING_MMC_DDR52 timings are requested, is not correct and can
lead to unexpected behavior.

Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Fixes: bb5f8ea4d514 ("mmc: sdhci-of-at91: introduce driver for the Atmel SDMMC")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mmc/host/sdhci-of-at91.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -29,6 +29,8 @@

#include "sdhci-pltfm.h"

+#define SDMMC_MC1R 0x204
+#define SDMMC_MC1R_DDR BIT(3)
#define SDMMC_CACR 0x230
#define SDMMC_CACR_CAPWREN BIT(0)
#define SDMMC_CACR_KEY (0x46 << 8)
@@ -103,11 +105,18 @@ static void sdhci_at91_set_power(struct
sdhci_set_power_noreg(host, mode, vdd);
}

+void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)
+{
+ if (timing == MMC_TIMING_MMC_DDR52)
+ sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
+ sdhci_set_uhs_signaling(host, timing);
+}
+
static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
.set_clock = sdhci_at91_set_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_reset,
- .set_uhs_signaling = sdhci_set_uhs_signaling,
+ .set_uhs_signaling = sdhci_at91_set_uhs_signaling,
.set_power = sdhci_at91_set_power,
};