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 <[email protected]> --- v2: Dropped QUIRK in favour of writeb callback drivers/mmc/host/Kconfig | 1 + drivers/mmc/host/sdhci_am654.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index 28fcd8f580a1..6379fba8b122 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -993,6 +993,7 @@ 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, }; -- 2.19.2
