[U-Boot] [PATCH v2 04/11] pmic: dm: Rewrite pmic_reg_{read|write|clrsetbits} to support 3 bytes transmissions

[Simon Glass <sjg@chromium.org>]

Hi Lukasz,

On 7 May 2018 at 06:26, Lukasz Majewski <lukma@denx.de> wrote:
> This commit provides support for transmissions larger than 1 byte for
> PMIC devices used with DM (e.g. MC34708 from NXP).
>
> Signed-off-by: Lukasz Majewski <lukma@denx.de>
>
> ---
>
> Changes in v2:
> - pmic_reg_* fixes to use uclass private structure
>
>  drivers/power/pmic/pmic-uclass.c | 44 +++++++++++++++++++++++++++++-----------
>  1 file changed, 32 insertions(+), 12 deletions(-)
>

Reviewed-by: Simon Glass <sjg@chromium.org>

with comments below

> diff --git a/drivers/power/pmic/pmic-uclass.c b/drivers/power/pmic/pmic-uclass.c
> index 88669533bd..c149b84a68 100644
> --- a/drivers/power/pmic/pmic-uclass.c
> +++ b/drivers/power/pmic/pmic-uclass.c
> @@ -131,23 +131,36 @@ int pmic_write(struct udevice *dev, uint reg, const uint8_t *buffer, int len)
>
>  int pmic_reg_read(struct udevice *dev, uint reg)
>  {
> -       u8 byte;
> +       struct dm_pmic_info *pmic_info = dev_get_uclass_priv(dev);
> +       int tx_num = pmic_info->trans_len;

Can you use trans_len instead of tx_num, which is confusing?

> +       u32 val = 0;
>         int ret;
>
> -       debug("%s: reg=%x", __func__, reg);
> -       ret = pmic_read(dev, reg, &byte, 1);
> -       debug(", value=%x, ret=%d\n", byte, ret);
> +       if (tx_num < 1 || tx_num > sizeof(val)) {
> +               printf("Wrong transmission size [%d]\n", tx_num);

debug()

> +               return -EINVAL;
> +       }
> +
> +       debug("%s: reg=%x tx_num:%d", __func__, reg, tx_num);
> +       ret = pmic_read(dev, reg, (uint8_t *)&val, tx_num);

This is assuming little-endian, isn't it? I think you need to build up
the number in a loop 8 bits at a time, or use some sort of unaligned
function.

> +       debug(", value=%x, ret=%d\n", val, ret);
>
> -       return ret ? ret : byte;
> +       return ret ? ret : val;
>  }
>
>  int pmic_reg_write(struct udevice *dev, uint reg, uint value)
>  {
> -       u8 byte = value;
> +       struct dm_pmic_info *pmic_info = dev_get_uclass_priv(dev);
> +       int tx_num = pmic_info->trans_len;
>         int ret;
>
> -       debug("%s: reg=%x, value=%x", __func__, reg, value);
> -       ret = pmic_write(dev, reg, &byte, 1);
> +       if (tx_num < 1 || tx_num > sizeof(value)) {
> +               printf("Wrong transmission size [%d]\n", tx_num);
> +               return -EINVAL;
> +       }
> +
> +       debug("%s: reg=%x, value=%x tx_num:%d", __func__, reg, value, tx_num);
> +       ret = pmic_write(dev, reg, (uint8_t *)&value, tx_num);
>         debug(", ret=%d\n", ret);
>
>         return ret;
> @@ -155,15 +168,22 @@ int pmic_reg_write(struct udevice *dev, uint reg, uint value)
>
>  int pmic_clrsetbits(struct udevice *dev, uint reg, uint clr, uint set)
>  {
> -       u8 byte;
> +       struct dm_pmic_info *pmic_info = dev_get_uclass_priv(dev);
> +       int tx_num = pmic_info->trans_len;
> +       u32 val = 0;
>         int ret;
>
> -       ret = pmic_reg_read(dev, reg);
> +       if (tx_num < 1 || tx_num > sizeof(val)) {
> +               printf("Wrong transmission size [%d]\n", tx_num);
> +               return -EINVAL;
> +       }
> +
> +       ret = pmic_read(dev, reg, (uint8_t *)&val, tx_num);
>         if (ret < 0)
>                 return ret;
> -       byte = (ret & ~clr) | set;
>
> -       return pmic_reg_write(dev, reg, byte);
> +       val = (val & ~clr) | set;
> +       return pmic_write(dev, reg, (uint8_t *)&val, tx_num);
>  }
>
>  static int pmic_pre_probe(struct udevice *dev)
> --
> 2.11.0
>

Regards,
Simon