[U-Boot] [PATCH V2 2/7] mmc: uniphier-sd: Properly handle pin voltage configuration

[Masahiro Yamada]

2018-01-17 2:16 GMT+09:00 Marek Vasut <marek.vasut at gmail.com>:
> Factor out the regulator handling into set_ios and add support for
> selecting pin configuration based on the voltage to support UHS modes.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas at gmail.com>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
> ---
> V2: Protect vqmmc_dev access in uniphier_sd_set_pins() with an ifdef
>     just like everywhere else
> ---
>  drivers/mmc/uniphier-sd.c | 35 ++++++++++++++++++++++++++---------
>  1 file changed, 26 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/uniphier-sd.c b/drivers/mmc/uniphier-sd.c
> index 552e37d852..e6c610a22a 100644
> --- a/drivers/mmc/uniphier-sd.c
> +++ b/drivers/mmc/uniphier-sd.c
> @@ -10,6 +10,7 @@
>  #include <fdtdec.h>
>  #include <mmc.h>
>  #include <dm.h>
> +#include <dm/pinctrl.h>
>  #include <linux/compat.h>
>  #include <linux/dma-direction.h>
>  #include <linux/io.h>
> @@ -134,6 +135,9 @@ struct uniphier_sd_priv {
>  #define UNIPHIER_SD_CAP_DMA_INTERNAL   BIT(1)  /* have internal DMA engine */
>  #define UNIPHIER_SD_CAP_DIV1024                BIT(2)  /* divisor 1024 is available */
>  #define UNIPHIER_SD_CAP_64BIT          BIT(3)  /* Controller is 64bit */
> +#ifdef CONFIG_DM_REGULATOR
> +       struct udevice *vqmmc_dev;
> +#endif
>  };
>
>  static u64 uniphier_sd_readq(struct uniphier_sd_priv *priv, unsigned int reg)
> @@ -676,6 +680,26 @@ static void uniphier_sd_set_clk_rate(struct uniphier_sd_priv *priv,
>         udelay(1000);
>  }
>
> +static void uniphier_sd_set_pins(struct udevice *dev)
> +{
> +       struct uniphier_sd_priv *priv = dev_get_priv(dev);
> +       struct mmc *mmc = mmc_get_mmc_dev(dev);


This gives me a new warning for my board, where CONFIG_DM_REGULATOR is disabled.

drivers/mmc/uniphier-sd.c:685:27: warning: unused variable ‘priv’
[-Wunused-variable]
  struct uniphier_sd_priv *priv = dev_get_priv(dev);
                           ^~~~

Is it reasonable to surround the whole this function by
#if CONFIG_IS_ENABLED(MMC_IO_VOLTAGE) ?


> +#ifdef CONFIG_DM_REGULATOR
> +       if (priv->vqmmc_dev) {
> +               if (mmc->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
> +                       regulator_set_value(priv->vqmmc_dev, 1800000);
> +               else
> +                       regulator_set_value(priv->vqmmc_dev, 3300000);
> +       }
> +#endif
> +
> +       if (mmc->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
> +               pinctrl_select_state(dev, "state_uhs");
> +       else
> +               pinctrl_select_state(dev, "default");
> +}

I am not sure about this code.
If MMC_SIGNAL_VOLTAGE_180 is set, is it always UHS?
eMMC also can do 1.8V signaling.





>  static int uniphier_sd_set_ios(struct udevice *dev)
>  {
>         struct uniphier_sd_priv *priv = dev_get_priv(dev);
> @@ -690,6 +714,7 @@ static int uniphier_sd_set_ios(struct udevice *dev)
>                 return ret;
>         uniphier_sd_set_ddr_mode(priv, mmc);
>         uniphier_sd_set_clk_rate(priv, mmc);
> +       uniphier_sd_set_pins(dev);
>
>         return 0;
>  }
> @@ -757,9 +782,6 @@ static int uniphier_sd_probe(struct udevice *dev)
>         fdt_addr_t base;
>         struct clk clk;
>         int ret;
> -#ifdef CONFIG_DM_REGULATOR
> -       struct udevice *vqmmc_dev;
> -#endif
>
>         base = devfdt_get_addr(dev);
>         if (base == FDT_ADDR_T_NONE)
> @@ -770,12 +792,7 @@ static int uniphier_sd_probe(struct udevice *dev)
>                 return -ENOMEM;
>
>  #ifdef CONFIG_DM_REGULATOR
> -       ret = device_get_supply_regulator(dev, "vqmmc-supply", &vqmmc_dev);
> -       if (!ret) {
> -               /* Set the regulator to 3.3V until we support 1.8V modes */
> -               regulator_set_value(vqmmc_dev, 3300000);
> -               regulator_set_enable(vqmmc_dev, true);
> -       }
> +       ret = device_get_supply_regulator(dev, "vqmmc-supply", &priv->vqmmc_dev);
>  #endif
>
>         ret = clk_get_by_index(dev, 0, &clk);


The return value from device_get_supply_regulator()
is overwritten by the following clk_get_by_index().

Shouldn't it be checked?


-- 
Best Regards
Masahiro Yamada