[PATCH 09/10] leds: Support custom sysfs groups on multicolor and flash LEDs

[Armin Wolf <W_Armin@gmx.de>]

Drivers registering multicolor/flash LEDs currently cannot use
led_cdev->groups due to said field being overwritten by the
multicolor/flash LED registration functions. Fix this by assigning
each LED type a seperate device type ("multicolor" and "flash")
that carries the sysfs attributes instead.

Also assign a device type for standard LEDs ("standard") for symmetry.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/leds/led-class-flash.c      | 108 ++++++++++++++--------------
 drivers/leds/led-class-multicolor.c |  18 ++++-
 drivers/leds/led-class.c            |   5 ++
 include/linux/led-class-flash.h     |   5 --
 4 files changed, 73 insertions(+), 63 deletions(-)

diff --git a/drivers/leds/led-class-flash.c b/drivers/leds/led-class-flash.c
index 953265fddb7d..e023511cea1c 100644
--- a/drivers/leds/led-class-flash.c
+++ b/drivers/leds/led-class-flash.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
+#include "leds.h"
 
 #define has_flash_op(fled_cdev, op)				\
 	(fled_cdev && fled_cdev->ops->op)
@@ -207,42 +208,56 @@ static ssize_t flash_fault_show(struct device *dev, const struct device_attribut
 }
 static const DEVICE_ATTR_RO(flash_fault);
 
-static const struct attribute *const led_flash_strobe_attrs[] = {
+static const struct attribute *const led_flash_attrs[] = {
 	&dev_attr_flash_strobe.attr,
-	NULL,
-};
-
-static const struct attribute *const led_flash_timeout_attrs[] = {
 	&dev_attr_flash_timeout.attr,
 	&dev_attr_max_flash_timeout.attr,
-	NULL,
-};
-
-static const struct attribute *const led_flash_brightness_attrs[] = {
 	&dev_attr_flash_brightness.attr,
 	&dev_attr_max_flash_brightness.attr,
-	NULL,
-};
-
-static const struct attribute *const led_flash_fault_attrs[] = {
 	&dev_attr_flash_fault.attr,
 	NULL,
 };
 
-static const struct attribute_group led_flash_strobe_group = {
-	.attrs_const = led_flash_strobe_attrs,
-};
+static umode_t led_flash_is_visible(struct kobject *kobj, const struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+
+	if (attr == &dev_attr_flash_strobe.attr)
+		return attr->mode;
+
+        if (attr == &dev_attr_flash_timeout.attr && fled_cdev->ops->timeout_set)
+                return attr->mode;
 
-static const struct attribute_group led_flash_timeout_group = {
-	.attrs_const = led_flash_timeout_attrs,
+	if (attr == &dev_attr_max_flash_timeout.attr && fled_cdev->ops->timeout_set)
+		return attr->mode;
+
+	if (attr == &dev_attr_flash_brightness.attr && fled_cdev->ops->flash_brightness_set)
+		return attr->mode;
+
+	if (attr == &dev_attr_max_flash_brightness.attr && fled_cdev->ops->flash_brightness_set)
+		return attr->mode;
+
+	if (attr == &dev_attr_flash_fault.attr && fled_cdev->ops->fault_get)
+		return attr->mode;
+
+        return 0;
+}
+
+static const struct attribute_group led_flash_group = {
+	.is_visible_const = led_flash_is_visible,
+	.attrs_const = led_flash_attrs,
 };
 
-static const struct attribute_group led_flash_brightness_group = {
-	.attrs_const = led_flash_brightness_attrs,
+static const struct attribute_group *led_flash_groups[] = {
+	&led_flash_group,
+	NULL,
 };
 
-static const struct attribute_group led_flash_fault_group = {
-	.attrs_const = led_flash_fault_attrs,
+static const struct device_type led_flash_device_type = {
+	.name = "flash",
+	.groups = led_flash_groups,
 };
 
 static void led_flash_resume(struct led_classdev *led_cdev)
@@ -254,28 +269,6 @@ static void led_flash_resume(struct led_classdev *led_cdev)
 	call_flash_op(fled_cdev, timeout_set, fled_cdev->timeout.val);
 }
 
-static void led_flash_init_sysfs_groups(struct led_classdev_flash *fled_cdev)
-{
-	struct led_classdev *led_cdev = &fled_cdev->led_cdev;
-	const struct led_flash_ops *ops = fled_cdev->ops;
-	const struct attribute_group **flash_groups = fled_cdev->sysfs_groups;
-
-	int num_sysfs_groups = 0;
-
-	flash_groups[num_sysfs_groups++] = &led_flash_strobe_group;
-
-	if (ops->flash_brightness_set)
-		flash_groups[num_sysfs_groups++] = &led_flash_brightness_group;
-
-	if (ops->timeout_set)
-		flash_groups[num_sysfs_groups++] = &led_flash_timeout_group;
-
-	if (ops->fault_get)
-		flash_groups[num_sysfs_groups++] = &led_flash_fault_group;
-
-	led_cdev->groups = flash_groups;
-}
-
 int led_classdev_flash_register_ext(struct device *parent,
 				    struct led_classdev_flash *fled_cdev,
 				    struct led_init_data *init_data)
@@ -289,26 +282,29 @@ int led_classdev_flash_register_ext(struct device *parent,
 
 	led_cdev = &fled_cdev->led_cdev;
 
-	if (led_cdev->flags & LED_DEV_CAP_FLASH) {
-		if (!led_cdev->brightness_set_blocking)
-			return -EINVAL;
+	if (!(led_cdev->flags & LED_DEV_CAP_FLASH))
+		return led_classdev_register_ext(parent, led_cdev, init_data);
 
-		ops = fled_cdev->ops;
-		if (!ops || !ops->strobe_set)
-			return -EINVAL;
+	if (!led_cdev->brightness_set_blocking)
+		return -EINVAL;
 
-		led_cdev->flash_resume = led_flash_resume;
+	ops = fled_cdev->ops;
+	if (!ops || !ops->strobe_set)
+		return -EINVAL;
 
-		/* Select the sysfs attributes to be created for the device */
-		led_flash_init_sysfs_groups(fled_cdev);
-	}
+	led_cdev->flash_resume = led_flash_resume;
 
 	/* Register led class device */
-	ret = led_classdev_register_ext(parent, led_cdev, init_data);
+	ret = led_classdev_init(parent, led_cdev, init_data);
 	if (ret < 0)
 		return ret;
 
-	return 0;
+	led_cdev->dev->type = &led_flash_device_type;
+	ret = led_classdev_add(led_cdev);
+	if (ret < 0)
+		put_device(led_cdev->dev);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(led_classdev_flash_register_ext);
 
diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c
index 57df0b2e785b..9b8c37f7bdf4 100644
--- a/drivers/leds/led-class-multicolor.c
+++ b/drivers/leds/led-class-multicolor.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/uaccess.h>
+#include "leds.h"
 
 static unsigned int led_mc_get_max_intensity(struct led_classdev_mc *mcled_cdev, size_t index)
 {
@@ -159,11 +160,17 @@ static const struct attribute *const led_multicolor_attrs[] = {
 };
 ATTRIBUTE_GROUPS(led_multicolor);
 
+static const struct device_type led_multicolor_device_type = {
+	.name = "multicolor",
+	.groups = led_multicolor_groups,
+};
+
 int led_classdev_multicolor_register_ext(struct device *parent,
 				     struct led_classdev_mc *mcled_cdev,
 				     struct led_init_data *init_data)
 {
 	struct led_classdev *led_cdev;
+	int ret;
 
 	if (!mcled_cdev)
 		return -EINVAL;
@@ -176,9 +183,16 @@ int led_classdev_multicolor_register_ext(struct device *parent,
 
 	led_cdev = &mcled_cdev->led_cdev;
 	led_cdev->flags |= LED_MULTI_COLOR;
-	mcled_cdev->led_cdev.groups = led_multicolor_groups;
+	ret = led_classdev_init(parent, led_cdev, init_data);
+	if (ret < 0)
+		return ret;
+
+	led_cdev->dev->type = &led_multicolor_device_type;
+	ret = led_classdev_add(led_cdev);
+	if (ret < 0)
+		put_device(led_cdev->dev);
 
-	return led_classdev_register_ext(parent, led_cdev, init_data);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(led_classdev_multicolor_register_ext);
 
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index ace417a2388e..49b321b3d863 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -613,6 +613,10 @@ int led_classdev_add(struct led_classdev *led_cdev)
 }
 EXPORT_SYMBOL_GPL(led_classdev_add);
 
+static const struct device_type led_device_type = {
+	.name = "standard",
+};
+
 /**
  * led_classdev_register_ext - register a new object of led_classdev class
  *                             with init data.
@@ -631,6 +635,7 @@ int led_classdev_register_ext(struct device *parent,
 	if (ret < 0)
 		return ret;
 
+	led_cdev->dev->type = &led_device_type;
 	ret = led_classdev_add(led_cdev);
 	if (ret < 0)
 		put_device(led_cdev->dev);
diff --git a/include/linux/led-class-flash.h b/include/linux/led-class-flash.h
index 775a96217518..5204ef60dc4b 100644
--- a/include/linux/led-class-flash.h
+++ b/include/linux/led-class-flash.h
@@ -28,8 +28,6 @@ struct led_classdev_flash;
 #define LED_FAULT_LED_OVER_TEMPERATURE	(1 << 8)
 #define LED_NUM_FLASH_FAULTS		9
 
-#define LED_FLASH_SYSFS_GROUPS_SIZE	5
-
 struct led_flash_ops {
 	/* set flash brightness */
 	int (*flash_brightness_set)(struct led_classdev_flash *fled_cdev,
@@ -79,9 +77,6 @@ struct led_classdev_flash {
 
 	/* flash timeout value in microseconds along with its constraints */
 	struct led_flash_setting duration;
-
-	/* LED Flash class sysfs groups */
-	const struct attribute_group *sysfs_groups[LED_FLASH_SYSFS_GROUPS_SIZE];
 };
 
 static inline struct led_classdev_flash *lcdev_to_flcdev(
-- 
2.56.0