[PATCH v2 2/4] alienware-wmi: Improves sysfs groups creation

[Kurt Borja <kuurtb@gmail.com>]

Devices with hdmi_mux, amplifier or deepslp quirks create a sysfs group
for each available feature. To accomplish this, helper create/remove
functions were called on module init, but they had the following
problems:

 - Create helpers called remove helpers on failure, which in turn tried
   to remove the sysfs group that failed to be created
 - If group creation failed mid way, previous successfully created groups
   were not cleaned up
 - Module exit only removed hdmi_mux group

To improve this, drop all helpers and let the platform driver manage these
sysfs groups, while controlling visibility with their respective quirks.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
v2:
 - Drop the helpers approach in favor of letting the driver manage the
   wmax sysfs groups
---

Again I think not cleaning up created sysfs group is not actually a bug
so this is only an improvement.

---
 drivers/platform/x86/dell/alienware-wmi.c | 112 +++++++---------------
 1 file changed, 36 insertions(+), 76 deletions(-)

diff --git a/drivers/platform/x86/dell/alienware-wmi.c b/drivers/platform/x86/dell/alienware-wmi.c
index 6760c7627f62..ecab14d90b27 100644
--- a/drivers/platform/x86/dell/alienware-wmi.c
+++ b/drivers/platform/x86/dell/alienware-wmi.c
@@ -410,17 +410,12 @@ struct wmax_u32_args {
 	u8 arg3;
 };
 
+
 static struct platform_device *platform_device;
 static struct platform_zone *zone_data;
 static struct platform_profile_handler pp_handler;
 static enum wmax_thermal_mode supported_thermal_profiles[PLATFORM_PROFILE_LAST];
 
-static struct platform_driver platform_driver = {
-	.driver = {
-		.name = "alienware-wmi",
-	}
-};
-
 static struct attribute_group zone_attribute_group = {
 	.name = "rgb_zones",
 };
@@ -781,6 +776,12 @@ static ssize_t toggle_hdmi_source(struct device *dev,
 	return count;
 }
 
+static bool hdmi_group_visible(struct kobject *kobj)
+{
+	return quirks->hdmi_mux;
+}
+DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(hdmi);
+
 static DEVICE_ATTR(cable, S_IRUGO, show_hdmi_cable, NULL);
 static DEVICE_ATTR(source, S_IRUGO | S_IWUSR, show_hdmi_source,
 		   toggle_hdmi_source);
@@ -793,25 +794,10 @@ static struct attribute *hdmi_attrs[] = {
 
 static const struct attribute_group hdmi_attribute_group = {
 	.name = "hdmi",
+	.is_visible = SYSFS_GROUP_VISIBLE(hdmi),
 	.attrs = hdmi_attrs,
 };
 
-static void remove_hdmi(struct platform_device *dev)
-{
-	if (quirks->hdmi_mux > 0)
-		sysfs_remove_group(&dev->dev.kobj, &hdmi_attribute_group);
-}
-
-static int create_hdmi(struct platform_device *dev)
-{
-	int ret;
-
-	ret = sysfs_create_group(&dev->dev.kobj, &hdmi_attribute_group);
-	if (ret)
-		remove_hdmi(dev);
-	return ret;
-}
-
 /*
  * Alienware GFX amplifier support
  * - Currently supports reading cable status
@@ -838,6 +824,12 @@ static ssize_t show_amplifier_status(struct device *dev,
 	return sysfs_emit(buf, "unconnected connected [unknown]\n");
 }
 
+static bool amplifier_group_visible(struct kobject *kobj)
+{
+	return quirks->amplifier;
+}
+DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(amplifier);
+
 static DEVICE_ATTR(status, S_IRUGO, show_amplifier_status, NULL);
 
 static struct attribute *amplifier_attrs[] = {
@@ -847,25 +839,10 @@ static struct attribute *amplifier_attrs[] = {
 
 static const struct attribute_group amplifier_attribute_group = {
 	.name = "amplifier",
+	.is_visible = SYSFS_GROUP_VISIBLE(amplifier),
 	.attrs = amplifier_attrs,
 };
 
-static void remove_amplifier(struct platform_device *dev)
-{
-	if (quirks->amplifier > 0)
-		sysfs_remove_group(&dev->dev.kobj, &amplifier_attribute_group);
-}
-
-static int create_amplifier(struct platform_device *dev)
-{
-	int ret;
-
-	ret = sysfs_create_group(&dev->dev.kobj, &amplifier_attribute_group);
-	if (ret)
-		remove_amplifier(dev);
-	return ret;
-}
-
 /*
  * Deep Sleep Control support
  * - Modifies BIOS setting for deep sleep control allowing extra wakeup events
@@ -916,6 +893,12 @@ static ssize_t toggle_deepsleep(struct device *dev,
 	return count;
 }
 
+static bool deepsleep_group_visible(struct kobject *kobj)
+{
+	return quirks->deepslp;
+}
+DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(deepsleep);
+
 static DEVICE_ATTR(deepsleep, S_IRUGO | S_IWUSR, show_deepsleep_status, toggle_deepsleep);
 
 static struct attribute *deepsleep_attrs[] = {
@@ -925,25 +908,10 @@ static struct attribute *deepsleep_attrs[] = {
 
 static const struct attribute_group deepsleep_attribute_group = {
 	.name = "deepsleep",
+	.is_visible = SYSFS_GROUP_VISIBLE(deepsleep),
 	.attrs = deepsleep_attrs,
 };
 
-static void remove_deepsleep(struct platform_device *dev)
-{
-	if (quirks->deepslp > 0)
-		sysfs_remove_group(&dev->dev.kobj, &deepsleep_attribute_group);
-}
-
-static int create_deepsleep(struct platform_device *dev)
-{
-	int ret;
-
-	ret = sysfs_create_group(&dev->dev.kobj, &deepsleep_attribute_group);
-	if (ret)
-		remove_deepsleep(dev);
-	return ret;
-}
-
 /*
  * Thermal Profile control
  *  - Provides thermal profile control through the Platform Profile API
@@ -1151,6 +1119,20 @@ static void remove_thermal_profile(void)
 		platform_profile_remove();
 }
 
+const struct attribute_group *wmax_groups[] = {
+	&hdmi_attribute_group,
+	&amplifier_attribute_group,
+	&deepsleep_attribute_group,
+	NULL
+};
+
+static struct platform_driver platform_driver = {
+	.driver = {
+		.name = "alienware-wmi",
+		.dev_groups = wmax_groups,
+	}
+};
+
 static int __init alienware_wmi_init(void)
 {
 	int ret;
@@ -1190,24 +1172,6 @@ static int __init alienware_wmi_init(void)
 	if (ret)
 		goto fail_platform_device2;
 
-	if (quirks->hdmi_mux > 0) {
-		ret = create_hdmi(platform_device);
-		if (ret)
-			goto fail_prep_hdmi;
-	}
-
-	if (quirks->amplifier > 0) {
-		ret = create_amplifier(platform_device);
-		if (ret)
-			goto fail_prep_amplifier;
-	}
-
-	if (quirks->deepslp > 0) {
-		ret = create_deepsleep(platform_device);
-		if (ret)
-			goto fail_prep_deepsleep;
-	}
-
 	if (quirks->thermal) {
 		ret = create_thermal_profile();
 		if (ret)
@@ -1223,9 +1187,6 @@ static int __init alienware_wmi_init(void)
 fail_prep_zones:
 	remove_thermal_profile();
 fail_prep_thermal_profile:
-fail_prep_deepsleep:
-fail_prep_amplifier:
-fail_prep_hdmi:
 	platform_device_del(platform_device);
 fail_platform_device2:
 	platform_device_put(platform_device);
@@ -1240,7 +1201,6 @@ module_init(alienware_wmi_init);
 static void __exit alienware_wmi_exit(void)
 {
 	if (platform_device) {
-		remove_hdmi(platform_device);
 		remove_thermal_profile();
 		platform_device_unregister(platform_device);
 		platform_driver_unregister(&platform_driver);
-- 
2.47.0