On Tue, Dec 07, 2021 at 10:34:09AM +0100, 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.

A couple of nit-picks, you may fix without resend.

...

+static const char *const gpio_sim_sysfs_pull_strings[] = {
+	[0]	= "pull-down",
+	[1]	= "pull-up"

+ Comma

+};
+
+static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+	struct gpio_sim_chip *chip = dev_get_drvdata(dev);
+	int pull;
+
+	mutex_lock(&chip->lock);
+	pull = !!test_bit(line_attr->offset, chip->pull_map);
+	mutex_unlock(&chip->lock);
+
+	return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]);
+}
+
+static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t len)
+{
+	struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+	struct gpio_sim_chip *chip = dev_get_drvdata(dev);
+	int ret, pull;
+
+	pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf);
+	if (pull < 0)

+		return -EINVAL;

	return pull;

+
+	ret = gpio_sim_apply_pull(chip, line_attr->offset, pull);
+	if (ret)
+		return ret;
+
+	return len;
+}

-- 
With Best Regards,
Andy Shevchenko