Re: [PATCH V4 1/2] mmc: sdhci-msm: Add support to store supported vdd-io voltages

[Doug Anderson]

Hi,

On Wed, Mar 28, 2018 at 6:08 AM, Vijay Viswanath
<vviswana@xxxxxxxxxxxxxx> wrote:
> During probe check whether the vdd-io regulator of sdhc platform device
> can support 1.8V and 3V and store this information as a capability of
> platform device.
>
> Signed-off-by: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
> ---
>  drivers/mmc/host/sdhci-msm.c | 35 ++++++++++++++++++++++++++++++++++-
>  1 file changed, 34 insertions(+), 1 deletion(-)

Since I commented on v2, please copy me for this series going forward.  Thanks.


> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index c283291..2fcd9010 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -21,6 +21,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/slab.h>
>  #include <linux/iopoll.h>
> +#include <linux/regulator/consumer.h>
>
>  #include "sdhci-pltfm.h"
>
> @@ -81,6 +82,9 @@
>  #define CORE_HC_SELECT_IN_HS400        (6 << 19)
>  #define CORE_HC_SELECT_IN_MASK (7 << 19)
>
> +#define CORE_3_0V_SUPPORT      (1 << 25)
> +#define CORE_1_8V_SUPPORT      (1 << 26)
> +
>  #define CORE_CSR_CDC_CTLR_CFG0         0x130
>  #define CORE_SW_TRIG_FULL_CALIB                BIT(16)
>  #define CORE_HW_AUTOCAL_ENA            BIT(17)
> @@ -148,6 +152,7 @@ struct sdhci_msm_host {
>         u32 curr_io_level;
>         wait_queue_head_t pwr_irq_wait;
>         bool pwr_irq_flag;
> +       u32 caps_0;
>  };
>
>  static unsigned int msm_get_clock_rate_for_bus_mode(struct sdhci_host *host,
> @@ -1103,7 +1108,7 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
>         struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>         u32 irq_status, irq_ack = 0;
>         int retry = 10;
> -       int pwr_state = 0, io_level = 0;
> +       u32 pwr_state = 0, io_level = 0;
>
>
>         irq_status = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
> @@ -1313,6 +1318,30 @@ static void sdhci_msm_writeb(struct sdhci_host *host, u8 val, int reg)
>                 sdhci_msm_check_power_status(host, req_type);
>  }
>
> +static int sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)

This function always returns 0.  Make it void.


> +{
> +       struct mmc_host *mmc = msm_host->mmc;
> +       struct regulator *supply = mmc->supply.vqmmc;
> +       u32 caps = 0;
> +
> +       if (!IS_ERR(mmc->supply.vqmmc)) {
> +               if (regulator_is_supported_voltage(supply, 1700000, 1950000))
> +                       caps |= CORE_1_8V_SUPPORT;
> +               if (regulator_is_supported_voltage(supply, 2700000, 3600000))
> +                       caps |= CORE_3_0V_SUPPORT;
> +
> +               if (!caps)
> +                       pr_warn("%s: %s: 1.8/3V not supported for vqmmc\n",
> +                                       mmc_hostname(mmc), __func__);

Please remove __func__.  You already have the unique thing to find the
right driver (AKA mmc_hostname(mmc)) and the string itself should be
enough from there.


> +       }
> +
> +       msm_host->caps_0 |= caps;
> +       pr_debug("%s: %s: supported caps: 0x%08x\n", mmc_hostname(mmc),
> +                       __func__, caps);

Same, no need for __func__.


> +
> +       return 0;
> +}
> +
>  static const struct of_device_id sdhci_msm_dt_match[] = {
>         { .compatible = "qcom,sdhci-msm-v4" },
>         {},
> @@ -1530,6 +1559,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>         ret = sdhci_add_host(host);
>         if (ret)
>                 goto pm_runtime_disable;
> +       ret = sdhci_msm_set_regulator_caps(msm_host);
> +       if (ret)
> +               dev_err(&pdev->dev, "Failed to set regulator caps: %d\n",
> +                               ret);

If you find some reason _not_ to make sdhci_msm_set_regulator_caps()
return "void" as per above, you should actually do something about
this error.  You've used "dev_err" which makes me feel like you
consider this a serious error.  Presumably it should cause the probe
to fail?


-Doug