On Tue, Nov 9, 2021 at 11:30 AM Andy Shevchenko
[off-list ref] wrote:

On Tue, Nov 09, 2021 at 11:02:05AM +0100, Arnd Bergmann wrote:

quoted

From: Arnd Bergmann <arnd@arndb.de>

There are only a handful of users of gpio_export() and
related functions.

As these are just wrappers around the modern gpiod_export()
helper, remove the wrappers and open-code the gpio_to_desc
in all callers to shrink the legacy API.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

What I wish to see meanwhile is a section in the TODO list somewhere to clean
up those modules that have gpio.h. Linus, do we have one in the kernel or is
it your personal TODO?

In case we have one in the kernel, please add there modules you modified in
a way that they still need further attention.

I think the TODO list is in Linus' head, but it would include all the files
that use one of the interfaces in linux/gpio.h. I found about 350 of them,
so there is little point in listing them one at a time. IIRC Linus is going
through those one subsystem at a time.

It might help to make it harder to get new users if we add some pattern
matching to scripts/checkpatch.pl, and/or something for scripts/coccinelle/.
I don't think it's possible to convert a gpio_request() user to gpio_get()
in a scripted way because you usually have to change the platform side
at the same time as the driver side.

I also found that we have a ton of users of linux/of_gpio.h, which is
somewhere inbetween the linux/gpio.h interface and the
linux/gpio/consumer.h version.

quoted

@@ -259,17 +259,19 @@ static int evm_sw_setup(struct i2c_client *client, int gpio,
      char label[10];

      for (i = 0; i < 4; ++i) {
+             struct gpio_desc *desc = gpio_to_desc(gpio + i);
+
              snprintf(label, 10, "user_sw%d", i);
-             status = gpio_request(gpio, label);
+             status = gpio_request(gpio + i, label);

Shouldn't be gpiod_get() or so at the end?

Yes, but that would be a more invasive change that I think should be done
separately.

        Arnd