Re: [PATCH v4 2/2] eeprom: at24: Add support for address-width property

From: Andy Shevchenko
Date: Fri Jun 29 2018 - 12:15:08 EST


On Fri, 2018-06-29 at 15:21 +0800, alanx.chiang@xxxxxxxxx wrote:
> From: Alan Chiang <alanx.chiang@xxxxxxxxx>
>
> Provide a flexible way to determine the addressing bits of eeprom.
> Pass the addressing bits to driver through address-width property.
>

Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

> Signed-off-by: Alan Chiang <alanx.chiang@xxxxxxxxx>
> Signed-off-by: Andy Yeh <andy.yeh@xxxxxxxxx>
>
> ---
> since v1
> -- Add a warn message for 8-bit addressing.
> since v2
> -- Modify the warning message for clear.
> -- Move the clearing bit operation outside of a statement.
> since v3
> -- Merge the warning message into one line.
>
> ---
> drivers/misc/eeprom/at24.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index 0c125f2..7ea640b 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -478,6 +478,23 @@ static void at24_properties_to_pdata(struct
> device *dev,
> if (device_property_present(dev, "no-read-rollover"))
> chip->flags |= AT24_FLAG_NO_RDROL;
>
> + err = device_property_read_u32(dev, "address-width", &val);
> + if (!err) {
> + switch (val) {
> + case 8:
> + if (chip->flags & AT24_FLAG_ADDR16)
> + dev_warn(dev, "Override address width
> to be 8, while default is 16\n");
> + chip->flags &= ~AT24_FLAG_ADDR16;
> + break;
> + case 16:
> + chip->flags |= AT24_FLAG_ADDR16;
> + break;
> + default:
> + dev_warn(dev, "Bad \"address-width\"
> property: %u\n",
> + val);
> + }
> + }
> +
> err = device_property_read_u32(dev, "size", &val);
> if (!err)
> chip->byte_len = val;

--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy