Re: gpio-mcp23s08: i2c: auto-select base if no DT match or platform data

From: Lars Poeschel
Date: Mon Jul 29 2013 - 05:20:54 EST


On Friday 19 July 2013 at 06:19:58, Daniel M. Weeks wrote:
> The call to gpiochip_add made by this driver is capable of
> auto-selecting a base if one is not provided. However, it was not
> called unless there was already a DT entry or platform data. This patch
> calls it even if the base is not already known so that gpiochip_add can
> attempt to find a usable base.

Nitpick:
You describe what your patch changes in the commit message. This is good,
but I can see the changes looking at the code. Can you please add a few
lines describing WHY your patch is needed ? (That'd be to be able to
instantiate a device from userspace with sysfs, right ?)

The code is ok, so with a modified commit message feel free to add my

Acked-by: Lars Poeschel <poeschel@xxxxxxxxxxx>

> Signed-off-by: Daniel M. Weeks <dan@xxxxxxxxxxxx>
>
> ---
> drivers/gpio/gpio-mcp23s08.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpio/gpio-mcp23s08.c b/drivers/gpio/gpio-mcp23s08.c
> index 6a4470b..87ed6bf 100644
> --- a/drivers/gpio/gpio-mcp23s08.c
> +++ b/drivers/gpio/gpio-mcp23s08.c
> @@ -520,14 +520,13 @@ static int mcp230xx_probe(struct i2c_client
> *client,
>
> match = of_match_device(of_match_ptr(mcp23s08_i2c_of_match),
> &client->dev);
> - if (match) {
> + pdata = client->dev.platform_data;
> + if (match || !pdata) {
> base = -1;
> pullups = 0;
> } else {
> - pdata = client->dev.platform_data;
> - if (!pdata || !gpio_is_valid(pdata->base)) {
> - dev_dbg(&client->dev,
> - "invalid or missing platform data\n");
> + if (!gpio_is_valid(pdata->base)) {
> + dev_dbg(&client->dev, "invalid platform data\n");
> return -EINVAL;
> }
> base = pdata->base;

Thanks,
Lars

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