From 445110941eb94709216363f9d807d2508e64abd7 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 20 Jan 2023 12:45:14 +0100
Subject: [PATCH 1/4] leds: led-class: Add missing put_device() to led_put()
led_put() is used to "undo" a successful of_led_get() call,
of_led_get() uses class_find_device_by_of_node() which returns
a reference to the device which must be free-ed with put_device()
when the caller is done with it.
Add a put_device() call to led_put() to free the reference returned
by class_find_device_by_of_node().
And also add a put_device() in the error-exit case of try_module_get()
failing.
Fixes: 699a8c7c4bd3 ("leds: Add of_led_get() and led_put()")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230120114524.408368-2-hdegoede@redhat.com
---
drivers/leds/led-class.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 6a8ea94834fa3..7391d2cf1370a 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -241,8 +241,10 @@ struct led_classdev *of_led_get(struct device_node *np, int index)
led_cdev = dev_get_drvdata(led_dev);
- if (!try_module_get(led_cdev->dev->parent->driver->owner))
+ if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
+ put_device(led_cdev->dev);
return ERR_PTR(-ENODEV);
+ }
return led_cdev;
}
@@ -255,6 +257,7 @@ EXPORT_SYMBOL_GPL(of_led_get);
void led_put(struct led_classdev *led_cdev)
{
module_put(led_cdev->dev->parent->driver->owner);
+ put_device(led_cdev->dev);
}
EXPORT_SYMBOL_GPL(led_put);
From fafef58ef419f08bb761714a109870b617ac0bc0 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 20 Jan 2023 12:45:15 +0100
Subject: [PATCH 2/4] leds: led-class: Add led_module_get() helper
Split out part of of_led_get() into a generic led_module_get() helper
function.
This is a preparation patch for adding a generic (non devicetree specific)
led_get() function.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230120114524.408368-3-hdegoede@redhat.com
---
drivers/leds/led-class.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 7391d2cf1370a..743d97b082dcb 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -215,6 +215,23 @@ static int led_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
+static struct led_classdev *led_module_get(struct device *led_dev)
+{
+ struct led_classdev *led_cdev;
+
+ if (!led_dev)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ led_cdev = dev_get_drvdata(led_dev);
+
+ if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
+ put_device(led_cdev->dev);
+ return ERR_PTR(-ENODEV);
+ }
+
+ return led_cdev;
+}
+
/**
* of_led_get() - request a LED device via the LED framework
* @np: device node to get the LED device from
@@ -226,7 +243,6 @@ static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
struct led_classdev *of_led_get(struct device_node *np, int index)
{
struct device *led_dev;
- struct led_classdev *led_cdev;
struct device_node *led_node;
led_node = of_parse_phandle(np, "leds", index);
@@ -236,17 +252,7 @@ struct led_classdev *of_led_get(struct device_node *np, int index)
led_dev = class_find_device_by_of_node(leds_class, led_node);
of_node_put(led_node);
- if (!led_dev)
- return ERR_PTR(-EPROBE_DEFER);
-
- led_cdev = dev_get_drvdata(led_dev);
-
- if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
- put_device(led_cdev->dev);
- return ERR_PTR(-ENODEV);
- }
-
- return led_cdev;
+ return led_module_get(led_dev);
}
EXPORT_SYMBOL_GPL(of_led_get);
From 537bdca2a085f524b74ac2aa83822d081c585ca6 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 20 Jan 2023 12:45:16 +0100
Subject: [PATCH 3/4] leds: led-class: Add __devm_led_get() helper
Add a __devm_led_get() helper which registers a passed in led_classdev
with devm for unregistration.
This is a preparation patch for adding a generic (non devicetree specific)
devm_led_get() function.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230120114524.408368-4-hdegoede@redhat.com
---
drivers/leds/led-class.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 743d97b082dcb..4904d140a560a 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -274,6 +274,22 @@ static void devm_led_release(struct device *dev, void *res)
led_put(*p);
}
+static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led)
+{
+ struct led_classdev **dr;
+
+ dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL);
+ if (!dr) {
+ led_put(led);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ *dr = led;
+ devres_add(dev, dr);
+
+ return led;
+}
+
/**
* devm_of_led_get - Resource-managed request of a LED device
* @dev: LED consumer
@@ -289,7 +305,6 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
int index)
{
struct led_classdev *led;
- struct led_classdev **dr;
if (!dev)
return ERR_PTR(-EINVAL);
@@ -298,17 +313,7 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
if (IS_ERR(led))
return led;
- dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
- GFP_KERNEL);
- if (!dr) {
- led_put(led);
- return ERR_PTR(-ENOMEM);
- }
-
- *dr = led;
- devres_add(dev, dr);
-
- return led;
+ return __devm_led_get(dev, led);
}
EXPORT_SYMBOL_GPL(devm_of_led_get);
From abc3100fcba6827444ef4bdb17065ac3b6619dff Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 20 Jan 2023 12:45:17 +0100
Subject: [PATCH 4/4] leds: led-class: Add generic [devm_]led_get()
Add a generic [devm_]led_get() method which can be used on both devicetree
and non devicetree platforms to get a LED classdev associated with
a specific function on a specific device, e.g. the privacy LED associated
with a specific camera sensor.
Note unlike of_led_get() this takes a string describing the function
rather then an index. This is done because e.g. camera sensors might
have a privacy LED, or a flash LED, or both and using an index
approach leaves it unclear what the function of index 0 is if there is
only 1 LED.
This uses a lookup-table mechanism for non devicetree platforms.
This allows the platform code to map specific LED class_dev-s to a specific
device,function combinations this way.
For devicetree platforms getting the LED by function-name could be made
to work using the standard devicetree pattern of adding a -names string
array to map names to the indexes.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230120114524.408368-5-hdegoede@redhat.com
---
drivers/leds/led-class.c | 84 ++++++++++++++++++++++++++++++++++++++++
include/linux/leds.h | 21 ++++++++++
2 files changed, 105 insertions(+)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 4904d140a560a..0c4b8d8d2b4fe 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -23,6 +23,8 @@
#include "leds.h"
static struct class *leds_class;
+static DEFINE_MUTEX(leds_lookup_lock);
+static LIST_HEAD(leds_lookup_list);
static ssize_t brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -317,6 +319,88 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_of_led_get);
+/**
+ * led_get() - request a LED device via the LED framework
+ * @dev: device for which to get the LED device
+ * @con_id: name of the LED from the device's point of view
+ *
+ * @return a pointer to a LED device or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *led_get(struct device *dev, char *con_id)
+{
+ struct led_lookup_data *lookup;
+ const char *provider = NULL;
+ struct device *led_dev;
+
+ mutex_lock(&leds_lookup_lock);
+ list_for_each_entry(lookup, &leds_lookup_list, list) {
+ if (!strcmp(lookup->dev_id, dev_name(dev)) &&
+ !strcmp(lookup->con_id, con_id)) {
+ provider = kstrdup_const(lookup->provider, GFP_KERNEL);
+ break;
+ }
+ }
+ mutex_unlock(&leds_lookup_lock);
+
+ if (!provider)
+ return ERR_PTR(-ENOENT);
+
+ led_dev = class_find_device_by_name(leds_class, provider);
+ kfree_const(provider);
+
+ return led_module_get(led_dev);
+}
+EXPORT_SYMBOL_GPL(led_get);
+
+/**
+ * devm_led_get() - request a LED device via the LED framework
+ * @dev: device for which to get the LED device
+ * @con_id: name of the LED from the device's point of view
+ *
+ * The LED device returned from this function is automatically released
+ * on driver detach.
+ *
+ * @return a pointer to a LED device or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *devm_led_get(struct device *dev, char *con_id)
+{
+ struct led_classdev *led;
+
+ led = led_get(dev, con_id);
+ if (IS_ERR(led))
+ return led;
+
+ return __devm_led_get(dev, led);
+}
+EXPORT_SYMBOL_GPL(devm_led_get);
+
+/**
+ * led_add_lookup() - Add a LED lookup table entry
+ * @led_lookup: the lookup table entry to add
+ *
+ * Add a LED lookup table entry. On systems without devicetree the lookup table
+ * is used by led_get() to find LEDs.
+ */
+void led_add_lookup(struct led_lookup_data *led_lookup)
+{
+ mutex_lock(&leds_lookup_lock);
+ list_add_tail(&led_lookup->list, &leds_lookup_list);
+ mutex_unlock(&leds_lookup_lock);
+}
+EXPORT_SYMBOL_GPL(led_add_lookup);
+
+/**
+ * led_remove_lookup() - Remove a LED lookup table entry
+ * @led_lookup: the lookup table entry to remove
+ */
+void led_remove_lookup(struct led_lookup_data *led_lookup)
+{
+ mutex_lock(&leds_lookup_lock);
+ list_del(&led_lookup->list);
+ mutex_unlock(&leds_lookup_lock);
+}
+EXPORT_SYMBOL_GPL(led_remove_lookup);
+
static int led_classdev_next_name(const char *init_name, char *name,
size_t len)
{
diff --git a/include/linux/leds.h b/include/linux/leds.h
index ba4861ec73d30..31cb74b90ffcd 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -39,6 +39,21 @@ enum led_default_state {
LEDS_DEFSTATE_KEEP = 2,
};
+/**
+ * struct led_lookup_data - represents a single LED lookup entry
+ *
+ * @list: internal list of all LED lookup entries
+ * @provider: name of led_classdev providing the LED
+ * @dev_id: name of the device associated with this LED
+ * @con_id: name of the LED from the device's point of view
+ */
+struct led_lookup_data {
+ struct list_head list;
+ const char *provider;
+ const char *dev_id;
+ const char *con_id;
+};
+
struct led_init_data {
/* device fwnode handle */
struct fwnode_handle *fwnode;
@@ -211,6 +226,12 @@ void devm_led_classdev_unregister(struct device *parent,
void led_classdev_suspend(struct led_classdev *led_cdev);
void led_classdev_resume(struct led_classdev *led_cdev);
+void led_add_lookup(struct led_lookup_data *led_lookup);
+void led_remove_lookup(struct led_lookup_data *led_lookup);
+
+struct led_classdev *__must_check led_get(struct device *dev, char *con_id);
+struct led_classdev *__must_check devm_led_get(struct device *dev, char *con_id);
+
extern struct led_classdev *of_led_get(struct device_node *np, int index);
extern void led_put(struct led_classdev *led_cdev);
struct led_classdev *__must_check devm_of_led_get(struct device *dev,