Re: [PATCH] mmc: sdhci-msm: Add support for UHS cards

[Ulf Hansson]

On 24 June 2016 at 17:07, Georgi Djakov <georgi.djakov@xxxxxxxxxx> wrote:
> Enabling support for ultra high speed mode cards requires some
> voltage switching and interaction with the PMIC via a special
> power IRQ. Add support for this.
>
> Signed-off-by: Georgi Djakov <georgi.djakov@xxxxxxxxxx>

Thanks, applied for next!

Kind regards
Uffe

> ---
>  drivers/mmc/host/sdhci-msm.c |   66 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 66 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 0653fe730150..ac5700233e12 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -32,6 +32,21 @@
>  #define CORE_POWER             0x0
>  #define CORE_SW_RST            BIT(7)
>
> +#define CORE_PWRCTL_STATUS     0xdc
> +#define CORE_PWRCTL_MASK       0xe0
> +#define CORE_PWRCTL_CLEAR      0xe4
> +#define CORE_PWRCTL_CTL                0xe8
> +#define CORE_PWRCTL_BUS_OFF    BIT(0)
> +#define CORE_PWRCTL_BUS_ON     BIT(1)
> +#define CORE_PWRCTL_IO_LOW     BIT(2)
> +#define CORE_PWRCTL_IO_HIGH    BIT(3)
> +#define CORE_PWRCTL_BUS_SUCCESS BIT(0)
> +#define CORE_PWRCTL_IO_SUCCESS BIT(2)
> +#define REQ_BUS_OFF            BIT(0)
> +#define REQ_BUS_ON             BIT(1)
> +#define REQ_IO_LOW             BIT(2)
> +#define REQ_IO_HIGH            BIT(3)
> +#define INT_MASK               0xf
>  #define MAX_PHASES             16
>  #define CORE_DLL_LOCK          BIT(7)
>  #define CORE_DLL_EN            BIT(16)
> @@ -56,6 +71,7 @@
>  struct sdhci_msm_host {
>         struct platform_device *pdev;
>         void __iomem *core_mem; /* MSM SDCC mapped address */
> +       int pwr_irq;            /* power irq */
>         struct clk *clk;        /* main SD/MMC bus clock */
>         struct clk *pclk;       /* SDHC peripheral bus clock */
>         struct clk *bus_clk;    /* SDHC bus voter clock */
> @@ -410,6 +426,39 @@ retry:
>         return rc;
>  }
>
> +static void sdhci_msm_voltage_switch(struct sdhci_host *host)
> +{
> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +       u32 irq_status, irq_ack = 0;
> +
> +       irq_status = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
> +       irq_status &= INT_MASK;
> +
> +       writel_relaxed(irq_status, msm_host->core_mem + CORE_PWRCTL_CLEAR);
> +
> +       if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF))
> +               irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
> +       if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH))
> +               irq_ack |= CORE_PWRCTL_IO_SUCCESS;
> +
> +       /*
> +        * The driver has to acknowledge the interrupt, switch voltages and
> +        * report back if it succeded or not to this register. The voltage
> +        * switches are handled by the sdhci core, so just report success.
> +        */
> +       writel_relaxed(irq_ack, msm_host->core_mem + CORE_PWRCTL_CTL);
> +}
> +
> +static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
> +{
> +       struct sdhci_host *host = (struct sdhci_host *)data;
> +
> +       sdhci_msm_voltage_switch(host);
> +
> +       return IRQ_HANDLED;
> +}
> +
>  static const struct of_device_id sdhci_msm_dt_match[] = {
>         { .compatible = "qcom,sdhci-msm-v4" },
>         {},
> @@ -423,6 +472,7 @@ static const struct sdhci_ops sdhci_msm_ops = {
>         .set_clock = sdhci_set_clock,
>         .set_bus_width = sdhci_set_bus_width,
>         .set_uhs_signaling = sdhci_set_uhs_signaling,
> +       .voltage_switch = sdhci_msm_voltage_switch,
>  };
>
>  static const struct sdhci_pltfm_data sdhci_msm_pdata = {
> @@ -545,6 +595,22 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>                                CORE_VENDOR_SPEC_CAPABILITIES0);
>         }
>
> +       /* Setup IRQ for handling power/voltage tasks with PMIC */
> +       msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
> +       if (msm_host->pwr_irq < 0) {
> +               dev_err(&pdev->dev, "Get pwr_irq failed (%d)\n",
> +                       msm_host->pwr_irq);
> +               goto clk_disable;
> +       }
> +
> +       ret = devm_request_threaded_irq(&pdev->dev, msm_host->pwr_irq, NULL,
> +                                       sdhci_msm_pwr_irq, IRQF_ONESHOT,
> +                                       dev_name(&pdev->dev), host);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Request IRQ failed (%d)\n", ret);
> +               goto clk_disable;
> +       }
> +
>         ret = sdhci_add_host(host);
>         if (ret)
>                 goto clk_disable;