On 1/04/19 3:58 PM, Faiz Abbas wrote:
> 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_ab...@ti.com>
Acked-by: Adrian Hunter <adrian.hun...@intel.com>
> ---
>
> 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,
> };
>
>
