On Mon, 7 Sep 2015 16:48:38 +0530
Vaibhav Hiremath <vaibhav.hiremath@xxxxxxxxxx> wrote:
> Different bus clock may need different pin setting.
> For example, fast bus clock like 208Mhz need pin drive fast
> while slow bus clock prefer pin drive slow to guarantee
> signal quality.
>
> So this patch creates two states,
> - Default (slow/normal) pin state
> - And fast pin state for higher freq bus speed.
>
> And selection of pin state is done based on timing mode.
>
> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@xxxxxxxxxx>
> Signed-off-by: Kevin Liu <kliu5@xxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-pxav3.c | 45 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
> index c2b2b78..d933f75 100644
> --- a/drivers/mmc/host/sdhci-pxav3.c
> +++ b/drivers/mmc/host/sdhci-pxav3.c
> @@ -35,6 +35,7 @@
> #include <linux/pm.h>
> #include <linux/pm_runtime.h>
> #include <linux/mbus.h>
> +#include <linux/pinctrl/consumer.h>
>
> #include "sdhci.h"
> #include "sdhci-pltfm.h"
> @@ -92,6 +93,10 @@ struct sdhci_pxa {
> void __iomem *io_pwr_reg;
> void __iomem *io_pwr_lock_reg;
> struct sdhci_pxa_data *data;
> +
> + struct pinctrl *pinctrl;
> + struct pinctrl_state *pins_default;
> + struct pinctrl_state *pins_fast;
> };
>
> static struct sdhci_pxa_data pxav3_data_v1 = {
> @@ -298,6 +303,33 @@ static void pxav3_gen_init_74_clocks(struct sdhci_host *host, u8 power_mode)
> pxa->power_mode = power_mode;
> }
>
> +static int pxav3_select_pinstate(struct sdhci_host *host, unsigned int uhs)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_pxa *pxa = pltfm_host->priv;
> + struct pinctrl_state *pinctrl;
> +
> + if (IS_ERR(pxa->pinctrl) ||
> + IS_ERR(pxa->pins_default) ||
> + IS_ERR(pxa->pins_fast))
> + return -EINVAL;
> +
> + switch (uhs) {
> + case MMC_TIMING_UHS_SDR50:
> + case MMC_TIMING_UHS_SDR104:
> + case MMC_TIMING_MMC_HS200:
> + case MMC_TIMING_MMC_HS400:
Are you sure this IP can support HS400?
> + pinctrl = pxa->pins_fast;
> + break;
> + default:
> + /* back to default state for other legacy timing */
> + pinctrl = pxa->pins_default;
> + break;
> + }
> +
> + return pinctrl_select_state(pxa->pinctrl, pinctrl);
> +}
> +
> static void pxav3_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
> {
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -353,6 +385,8 @@ static void pxav3_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
> dev_dbg(mmc_dev(host->mmc),
> "%s uhs = %d, ctrl_2 = %04X\n",
> __func__, uhs, ctrl_2);
> +
> + pxav3_select_pinstate(host, uhs);
> }
>
> static void pxav3_voltage_switch(struct sdhci_host *host,
> @@ -416,7 +450,6 @@ static void pxav3_set_clock(struct sdhci_host *host, unsigned int clock)
> /* TX internal clock selection */
> pxav3_set_tx_clock(host);
> }
> -
> }
>
> static const struct sdhci_ops pxav3_sdhci_ops = {
> @@ -586,6 +619,16 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
> }
> }
>
> + pxa->pinctrl = devm_pinctrl_get(dev);
> + if (!IS_ERR(pxa->pinctrl)) {
> + pxa->pins_default = pinctrl_lookup_state(pxa->pinctrl, "default");
> + if (IS_ERR(pxa->pins_default))
> + dev_err(dev, "could not get default pinstate\n");
> + pxa->pins_fast = pinctrl_lookup_state(pxa->pinctrl, "fast");
> + if (IS_ERR(pxa->pins_fast))
> + dev_info(dev, "could not get fast pinstate\n");
> + }
> +
> pm_runtime_get_noresume(&pdev->dev);
> pm_runtime_set_active(&pdev->dev);
> pm_runtime_set_autosuspend_delay(&pdev->dev, PXAV3_RPM_DELAY_MS);
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
