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

[Vijay Viswanath]

On 3/29/2018 4:22 AM, Doug Anderson wrote:
> 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.

Will do. Sorry I missed.

> > 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__.

will remove all unnecessary __func__ references.

> > +
> > +       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

yeah, we don't need to print anything here as a warning is printed in 
sdhci_msm_set_regulator_caps() anyway.