hwmon: (gpio-fan) Use is_visible to determine if attributes should be created

Simplify code and reduce object size by more than 300 bytes (x86_64).

Cc: Jamie Lentin <jm@lentin.co.uk>
Cc: Simon Guinot <simon.guinot@sequanux.org>
Tested-by: Simon Guinot <simon.guinot@sequanux.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 39 insertions, 65 deletions

diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index 4e02480b456a..3104149795c5 100644
--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -105,10 +105,6 @@ static int fan_alarm_init(struct gpio_fan_data *fan_data,
         if (err)
                 return err;
 
-        err = device_create_file(&pdev->dev, &dev_attr_fan1_alarm);
-        if (err)
-                return err;
-
         /*
          * If the alarm GPIO don't support interrupts, just leave
          * without initializing the fail notification support.
@@ -121,23 +117,9 @@ static int fan_alarm_init(struct gpio_fan_data *fan_data,
         irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
         err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
                                IRQF_SHARED, "GPIO fan alarm", fan_data);
-        if (err)
-                goto err_free_sysfs;
-
-        return 0;
-
-err_free_sysfs:
-        device_remove_file(&pdev->dev, &dev_attr_fan1_alarm);
         return err;
 }
 
-static void fan_alarm_free(struct gpio_fan_data *fan_data)
-{
-        struct platform_device *pdev = fan_data->pdev;
-
-        device_remove_file(&pdev->dev, &dev_attr_fan1_alarm);
-}
-
 /*
  * Control GPIOs.
  */
@@ -327,6 +309,12 @@ exit_unlock:
         return ret;
 }
 
+static ssize_t show_name(struct device *dev,
+                         struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "gpio-fan\n");
+}
+
 static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
 static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
                    show_pwm_enable, set_pwm_enable);
@@ -336,8 +324,26 @@ static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
 static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
 static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);
 
-static struct attribute *gpio_fan_ctrl_attributes[] = {
-        &dev_attr_pwm1.attr,
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static umode_t gpio_fan_is_visible(struct kobject *kobj,
+                                   struct attribute *attr, int index)
+{
+        struct device *dev = container_of(kobj, struct device, kobj);
+        struct gpio_fan_data *data = dev_get_drvdata(dev);
+
+        if (index == 1 && !data->alarm)
+                return 0;
+        if (index > 1 && !data->ctrl)
+                return 0;
+
+        return attr->mode;
+}
+
+static struct attribute *gpio_fan_attributes[] = {
+        &dev_attr_name.attr,
+        &dev_attr_fan1_alarm.attr,              /* 1 */
+        &dev_attr_pwm1.attr,                    /* 2 */
         &dev_attr_pwm1_enable.attr,
         &dev_attr_pwm1_mode.attr,
         &dev_attr_fan1_input.attr,
@@ -347,8 +353,9 @@ static struct attribute *gpio_fan_ctrl_attributes[] = {
         NULL
 };
 
-static const struct attribute_group gpio_fan_ctrl_group = {
-        .attrs = gpio_fan_ctrl_attributes,
+static const struct attribute_group gpio_fan_group = {
+        .attrs = gpio_fan_attributes,
+        .is_visible = gpio_fan_is_visible,
 };
 
 static int fan_ctrl_init(struct gpio_fan_data *fan_data,
@@ -379,30 +386,9 @@ static int fan_ctrl_init(struct gpio_fan_data *fan_data,
         if (fan_data->speed_index < 0)
                 return -ENODEV;
 
-        err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_ctrl_group);
-        return err;
-}
-
-static void fan_ctrl_free(struct gpio_fan_data *fan_data)
-{
-        struct platform_device *pdev = fan_data->pdev;
-
-        sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_ctrl_group);
-}
-
-/*
- * Platform driver.
- */
-
-static ssize_t show_name(struct device *dev,
-                         struct device_attribute *attr, char *buf)
-{
-        return sprintf(buf, "gpio-fan\n");
+        return 0;
 }
 
-static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
-
-
 #ifdef CONFIG_OF_GPIO
 /*
  * Translate OpenFirmware node properties into platform_data
@@ -546,38 +532,30 @@ static int gpio_fan_probe(struct platform_device *pdev)
 
         /* Configure control GPIOs if available. */
         if (pdata->ctrl && pdata->num_ctrl > 0) {
-                if (!pdata->speed || pdata->num_speed <= 1) {
-                        err = -EINVAL;
-                        goto err_free_alarm;
-                }
+                if (!pdata->speed || pdata->num_speed <= 1)
+                        return -EINVAL;
                 err = fan_ctrl_init(fan_data, pdata);
                 if (err)
-                        goto err_free_alarm;
+                        return err;
         }
 
-        err = device_create_file(&pdev->dev, &dev_attr_name);
+        err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_group);
         if (err)
-                goto err_free_ctrl;
+                return err;
 
         /* Make this driver part of hwmon class. */
         fan_data->hwmon_dev = hwmon_device_register(&pdev->dev);
         if (IS_ERR(fan_data->hwmon_dev)) {
                 err = PTR_ERR(fan_data->hwmon_dev);
-                goto err_remove_name;
+                goto err_remove;
         }
 
         dev_info(&pdev->dev, "GPIO fan initialized\n");
 
         return 0;
 
-err_remove_name:
-        device_remove_file(&pdev->dev, &dev_attr_name);
-err_free_ctrl:
-        if (fan_data->ctrl)
-                fan_ctrl_free(fan_data);
-err_free_alarm:
-        if (fan_data->alarm)
-                fan_alarm_free(fan_data);
+err_remove:
+        sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_group);
         return err;
 }
 
@@ -586,11 +564,7 @@ static int gpio_fan_remove(struct platform_device *pdev)
         struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
 
         hwmon_device_unregister(fan_data->hwmon_dev);
-        device_remove_file(&pdev->dev, &dev_attr_name);
-        if (fan_data->alarm)
-                fan_alarm_free(fan_data);
-        if (fan_data->ctrl)
-                fan_ctrl_free(fan_data);
+        sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_group);
 
         return 0;
 }