[U-Boot] [PATCH 3/5] mmc: uniphier-sd: Add support for 64bit FIFO

[Masahiro Yamada]

Hi Marek,


2017-07-22 6:24 GMT+09:00 Marek Vasut <marek.vasut at gmail.com>:
> The Renesas RCar Gen3 contains the same controller, originally
> Matsushita. This patch adds support for handling of the 64bit
> FIFO on this controller.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas at gmail.com>
> Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> ---
>  drivers/mmc/uniphier-sd.c | 84 +++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 74 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/mmc/uniphier-sd.c b/drivers/mmc/uniphier-sd.c
> index 93a2c6becd..07436f6ef6 100644
> --- a/drivers/mmc/uniphier-sd.c
> +++ b/drivers/mmc/uniphier-sd.c
> @@ -135,6 +135,23 @@ struct uniphier_sd_priv {
>  #define UNIPHIER_SD_CAP_64BIT          BIT(3)  /* Controller is 64bit */
>  };
>
> +static u64 uniphier_sd_readq(struct uniphier_sd_priv *priv, const u32 reg)
> +{
> +       if (priv->caps & UNIPHIER_SD_CAP_64BIT)
> +               return readq(priv->regbase + (reg << 1));
> +       else
> +               return readq(priv->regbase + reg);
> +}
> +
> +static void uniphier_sd_writeq(struct uniphier_sd_priv *priv,
> +                              const u64 val, const u32 reg)
> +{
> +       if (priv->caps & UNIPHIER_SD_CAP_64BIT)
> +               writeq(val, priv->regbase + (reg << 1));
> +       else
> +               writeq(val, priv->regbase + reg);
> +}
> +
>  static u32 uniphier_sd_readl(struct uniphier_sd_priv *priv, const u32 reg)
>  {
>         if (priv->caps & UNIPHIER_SD_CAP_64BIT)
> @@ -248,12 +265,37 @@ static int uniphier_sd_pio_read_one_block(struct udevice *dev, u32 **pbuf,


This 'u32 **pbuf' was optimized for my case.
This is pointless for 64bit platform.

you can change it 'char **pbuf'



>         uniphier_sd_writel(priv, 0, UNIPHIER_SD_INFO2);
>
>         if (likely(IS_ALIGNED((unsigned long)*pbuf, 4))) {
> -               for (i = 0; i < blocksize / 4; i++)
> -                       *(*pbuf)++ = uniphier_sd_readl(priv, UNIPHIER_SD_BUF);
> +               if (priv->caps & UNIPHIER_SD_CAP_64BIT) {
> +                       for (i = 0; i < blocksize / 8; i++) {
> +                               u64 data;
> +                               data = uniphier_sd_readq(priv,
> +                                                        UNIPHIER_SD_BUF);
> +                               *(*pbuf)++ = data;
> +                               *(*pbuf)++ = data >> 32;


I do not think this code is efficient for your 64 bit platform.

Perhaps, you can do as follows:


Prepare a 64bit pointer.

      u64 **pbuf64 = (u64 **)pbuf;

Then,

*(*pbuf64)++ = uniphier_sd_readq(priv, UNIPHIER_SD_BUF);



In this case, please be careful for

if (likely(IS_ALIGNED((unsigned long)*pbuf, 4))) {

You will need 8 byte alignment.


-- 
Best Regards
Masahiro Yamada