On Fri, Oct 08, 2021 at 10:17:36AM +0200, Bartosz Golaszewski wrote:

Implement a new, modern GPIO testing module controlled by configfs
attributes instead of module parameters. The goal of this driver is
to provide a replacement for gpio-mockup that will be easily extensible
with new features and doesn't require reloading the module to change
the setup.

Signed-off-by: Bartosz Golaszewski <redacted>
[Andy: Initialize attribute allocated on the heap]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Colin: Fix dereference of free'd pointer config]
Signed-off-by: Colin Ian King <redacted>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <redacted>

Some nit-picks below, up to you to address.

...

+	ret = gpio_sim_setup_sysfs(chip);
+	if (ret)
+		return ret;
+
+	return 0;

return gpio_sim_...(chip); ?

...

+

Redundant empty line.

+CONFIGFS_ATTR_RO(gpio_sim_config_, dev_name);

...

+

Ditto.

+CONFIGFS_ATTR_RO(gpio_sim_config_, chip_name);

...

+

Ditto.

+CONFIGFS_ATTR(gpio_sim_config_, label);

...

+

Ditto.

+CONFIGFS_ATTR(gpio_sim_config_, num_lines);

...

+

Ditto.

+CONFIGFS_ATTR(gpio_sim_config_, line_names);

...

+	fwnode = fwnode_create_software_node(properties, NULL);
+	if (IS_ERR(fwnode))
+		return PTR_ERR(fwnode);

+	fwnode = dev_fwnode(&config->pdev->dev);
+	platform_device_unregister(config->pdev);
+	fwnode_remove_software_node(fwnode);

This seems correct, thank you for modifying the code.

...

+	config->pdev = NULL;
+	mutex_unlock(&config->lock);

mutex_destroy() ?
Or is it done in the upper level?

-- 
With Best Regards,
Andy Shevchenko