This series aims to add a led-backlight driver, similar to pwm-backlight,
but using a LED class device underneath.
A few years ago (2015), Tomi Valkeinen posted a series implementing a
backlight driver on top of a LED device:
https://patchwork.kernel.org/patch/7293991/
https://patchwork.kernel.org/patch/7294001/
https://patchwork.kernel.org/patch/7293981/
The discussion stopped because Tomi lacked the time to work on it.
changes in v7:
- rebased on top of linux-leds/for-next
- populate the of_node member of the LED device if fwnode is a of_node
(this is a new patch and the first of the series).
- devm_led_get() works only when the device tree is used. Add a few checks
for that.
changes in v6:
- trim the list of included headers
- remove useless definition of BKL_FULL_BRIGHTNESS
changes in v5:
- removed LED brightness scaling
- disable sysfs the interface of the LEDs when used by the backlight device
changes in v4:
- fix dev_err() messages and commit logs following the advices of Pavel
- cosmetic changes (indents, getting rid of "? 1 : 0" in
led_match_led_node())
changes in v3:
- dt binding: don't limit the brightness range to 0-255. Use the range of
the underlying LEDs. as a side-effect, all LEDs must now have the same
range
- driver: Adapt to dt binding update.
- driver: rework probe() for clarity and remove the remaining goto.
changes in v2:
- handle more than one LED.
- don't make the backlight device a child of the LED controller.
- make brightness-levels and default-brightness-level optional
- removed the option to use a GPIO enable.
- removed the option to use a regulator. It should be handled by the LED
core
- don't make any change to the LED core (not needed anymore)
Jean-Jacques Hiblot (3):
leds: populate the device's of_node when possible
leds: Add managed API to get a LED from a device driver
dt-bindings: backlight: Add led-backlight binding
Tomi Valkeinen (2):
leds: Add of_led_get() and led_put()
backlight: add led-backlight driver
.../bindings/leds/backlight/led-backlight.txt | 28 ++
drivers/leds/led-class.c | 106 ++++++-
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/led_bl.c | 260 ++++++++++++++++++
include/linux/leds.h | 6 +
6 files changed, 407 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
create mode 100644 drivers/video/backlight/led_bl.c
--
2.17.1
If the LED is acquired by a consumer device with devm_led_get(), it is
automatically released when the device is detached.
Signed-off-by: Jean-Jacques Hiblot <[email protected]>
Acked-by: Pavel Machek <[email protected]>
---
drivers/leds/led-class.c | 51 ++++++++++++++++++++++++++++++++++++++++
include/linux/leds.h | 2 ++
2 files changed, 53 insertions(+)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 2b8f20f94128..e11177d77b4c 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -264,6 +264,57 @@ void led_put(struct led_classdev *led_cdev)
}
EXPORT_SYMBOL_GPL(led_put);
+static void devm_led_release(struct device *dev, void *res)
+{
+ struct led_classdev **p = res;
+
+ led_put(*p);
+}
+
+/**
+ * devm_led_get - Resource-managed request of a LED device
+ * @dev: LED consumer
+ * @idx: index of the LED to obtain in the consumer
+ *
+ * The device node of the device is parse to find the request LED device.
+ * The LED device returned from this function is automatically released
+ * on driver detach.
+ *
+ * NOTE: At the moment, it supports only device-tree based LED lookup
+ *
+ * @return a pointer to a LED device or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *__must_check devm_led_get(struct device *dev,
+ int index)
+{
+ struct led_classdev *led;
+ struct led_classdev **dr;
+
+ if (!dev)
+ return ERR_PTR(-EINVAL);
+
+ /* Not using device tree? */
+ if (!IS_ENABLED(CONFIG_OF) || !dev->of_node)
+ return ERR_PTR(-ENOTSUPP);
+
+ led = of_led_get(dev->of_node, index);
+ 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;
+}
+EXPORT_SYMBOL_GPL(devm_led_get);
+
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 6f7371bc7757..88bf2ceaabe6 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -199,6 +199,8 @@ extern void led_classdev_resume(struct led_classdev *led_cdev);
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_led_get(struct device *dev,
+ int index);
/**
* led_blink_set - set blinking with software fallback
--
2.17.1
Add DT binding for led-backlight.
Signed-off-by: Jean-Jacques Hiblot <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
---
.../bindings/leds/backlight/led-backlight.txt | 28 +++++++++++++++++++
1 file changed, 28 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
diff --git a/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
new file mode 100644
index 000000000000..4c7dfbe7f67a
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
@@ -0,0 +1,28 @@
+led-backlight bindings
+
+This binding is used to describe a basic backlight device made of LEDs.
+It can also be used to describe a backlight device controlled by the output of
+a LED driver.
+
+Required properties:
+ - compatible: "led-backlight"
+ - leds: a list of LEDs
+
+Optional properties:
+ - brightness-levels: Array of distinct brightness levels. The levels must be
+ in the range accepted by the underlying LED devices.
+ This is used to translate a backlight brightness level
+ into a LED brightness level. If it is not provided, the
+ identity mapping is used.
+
+ - default-brightness-level: The default brightness level.
+
+Example:
+
+ backlight {
+ compatible = "led-backlight";
+
+ leds = <&led1>, <&led2>;
+ brightness-levels = <0 4 8 16 32 64 128 255>;
+ default-brightness-level = <6>;
+ };
--
2.17.1
From: Tomi Valkeinen <[email protected]>
This patch adds a led-backlight driver (led_bl), which is similar to
pwm_bl except the driver uses a LED class driver to adjust the
brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen <[email protected]>
Signed-off-by: Jean-Jacques Hiblot <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
---
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++
3 files changed, 268 insertions(+)
create mode 100644 drivers/video/backlight/led_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 8b081d61773e..585a1787618c 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -458,6 +458,13 @@ config BACKLIGHT_RAVE_SP
help
Support for backlight control on RAVE SP device.
+config BACKLIGHT_LED
+ tristate "Generic LED based Backlight Driver"
+ depends on LEDS_CLASS && OF
+ help
+ If you have a LCD backlight adjustable by LED class driver, say Y
+ to enable this driver.
+
endif # BACKLIGHT_CLASS_DEVICE
endmenu
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 63c507c07437..2a67642966a5 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o
obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o
obj-$(CONFIG_BACKLIGHT_ARCXCNN) += arcxcnn_bl.o
obj-$(CONFIG_BACKLIGHT_RAVE_SP) += rave-sp-backlight.o
+obj-$(CONFIG_BACKLIGHT_LED) += led_bl.o
diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c
new file mode 100644
index 000000000000..6044390d8b88
--- /dev/null
+++ b/drivers/video/backlight/led_bl.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.ti.com/
+ * Author: Tomi Valkeinen <[email protected]>
+ *
+ * Based on pwm_bl.c
+ */
+
+#include <linux/backlight.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+struct led_bl_data {
+ struct device *dev;
+ struct backlight_device *bl_dev;
+ struct led_classdev **leds;
+ bool enabled;
+ int nb_leds;
+ unsigned int *levels;
+ unsigned int default_brightness;
+ unsigned int max_brightness;
+};
+
+static void led_bl_set_brightness(struct led_bl_data *priv, int level)
+{
+ int i;
+ int bkl_brightness;
+
+ if (priv->levels)
+ bkl_brightness = priv->levels[level];
+ else
+ bkl_brightness = level;
+
+ for (i = 0; i < priv->nb_leds; i++)
+ led_set_brightness(priv->leds[i], bkl_brightness);
+
+ priv->enabled = true;
+}
+
+static void led_bl_power_off(struct led_bl_data *priv)
+{
+ int i;
+
+ if (!priv->enabled)
+ return;
+
+ for (i = 0; i < priv->nb_leds; i++)
+ led_set_brightness(priv->leds[i], LED_OFF);
+
+ priv->enabled = false;
+}
+
+static int led_bl_update_status(struct backlight_device *bl)
+{
+ struct led_bl_data *priv = bl_get_data(bl);
+ int brightness = bl->props.brightness;
+
+ if (bl->props.power != FB_BLANK_UNBLANK ||
+ bl->props.fb_blank != FB_BLANK_UNBLANK ||
+ bl->props.state & BL_CORE_FBBLANK)
+ brightness = 0;
+
+ if (brightness > 0)
+ led_bl_set_brightness(priv, brightness);
+ else
+ led_bl_power_off(priv);
+
+ return 0;
+}
+
+static const struct backlight_ops led_bl_ops = {
+ .update_status = led_bl_update_status,
+};
+
+static int led_bl_get_leds(struct device *dev,
+ struct led_bl_data *priv)
+{
+ int i, nb_leds, ret;
+ struct device_node *node = dev->of_node;
+ struct led_classdev **leds;
+ unsigned int max_brightness;
+ unsigned int default_brightness;
+
+ ret = of_count_phandle_with_args(node, "leds", NULL);
+ if (ret < 0) {
+ dev_err(dev, "Unable to get led count\n");
+ return -EINVAL;
+ }
+
+ nb_leds = ret;
+ if (nb_leds < 1) {
+ dev_err(dev, "At least one LED must be specified!\n");
+ return -EINVAL;
+ }
+
+ leds = devm_kzalloc(dev, sizeof(struct led_classdev *) * nb_leds,
+ GFP_KERNEL);
+ if (!leds)
+ return -ENOMEM;
+
+ for (i = 0; i < nb_leds; i++) {
+ leds[i] = devm_led_get(dev, i);
+ if (IS_ERR(leds[i]))
+ return PTR_ERR(leds[i]);
+ }
+
+ /* check that the LEDs all have the same brightness range */
+ max_brightness = leds[0]->max_brightness;
+ for (i = 1; i < nb_leds; i++) {
+ if (max_brightness != leds[i]->max_brightness) {
+ dev_err(dev, "LEDs must have identical ranges\n");
+ return -EINVAL;
+ }
+ }
+
+ /* get the default brightness from the first LED from the list */
+ default_brightness = leds[0]->brightness;
+
+ priv->nb_leds = nb_leds;
+ priv->leds = leds;
+ priv->max_brightness = max_brightness;
+ priv->default_brightness = default_brightness;
+
+ return 0;
+}
+
+static int led_bl_parse_levels(struct device *dev,
+ struct led_bl_data *priv)
+{
+ struct device_node *node = dev->of_node;
+ int num_levels;
+ u32 value;
+ int ret;
+
+ if (!node)
+ return -ENODEV;
+
+ num_levels = of_property_count_u32_elems(node, "brightness-levels");
+ if (num_levels > 1) {
+ int i;
+ unsigned int db;
+ u32 *levels = NULL;
+
+ levels = devm_kzalloc(dev, sizeof(u32) * num_levels,
+ GFP_KERNEL);
+ if (!levels)
+ return -ENOMEM;
+
+ ret = of_property_read_u32_array(node, "brightness-levels",
+ levels,
+ num_levels);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Try to map actual LED brightness to backlight brightness
+ * level
+ */
+ db = priv->default_brightness;
+ for (i = 0 ; i < num_levels; i++) {
+ if ((i && db > levels[i-1]) && db <= levels[i])
+ break;
+ }
+ priv->default_brightness = i;
+ priv->max_brightness = num_levels - 1;
+ priv->levels = levels;
+ } else if (num_levels >= 0)
+ dev_warn(dev, "Not enough levels defined\n");
+
+ ret = of_property_read_u32(node, "default-brightness-level", &value);
+ if (!ret && value <= priv->max_brightness)
+ priv->default_brightness = value;
+ else if (!ret && value > priv->max_brightness)
+ dev_warn(dev, "Invalid default brightness. Ignoring it\n");
+
+ return 0;
+}
+
+static int led_bl_probe(struct platform_device *pdev)
+{
+ struct backlight_properties props;
+ struct led_bl_data *priv;
+ int ret, i;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, priv);
+
+ priv->dev = &pdev->dev;
+
+ ret = led_bl_get_leds(&pdev->dev, priv);
+ if (ret)
+ return ret;
+
+ ret = led_bl_parse_levels(&pdev->dev, priv);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to parse DT data\n");
+ return ret;
+ }
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = priv->max_brightness;
+ props.brightness = priv->default_brightness;
+ props.power = (priv->default_brightness > 0) ? FB_BLANK_POWERDOWN :
+ FB_BLANK_UNBLANK;
+ priv->bl_dev = backlight_device_register(dev_name(&pdev->dev),
+ &pdev->dev, priv, &led_bl_ops, &props);
+ if (IS_ERR(priv->bl_dev)) {
+ dev_err(&pdev->dev, "Failed to register backlight\n");
+ return PTR_ERR(priv->bl_dev);
+ }
+
+ for (i = 0; i < priv->nb_leds; i++)
+ led_sysfs_disable(priv->leds[i]);
+
+ backlight_update_status(priv->bl_dev);
+
+ return 0;
+}
+
+static int led_bl_remove(struct platform_device *pdev)
+{
+ struct led_bl_data *priv = platform_get_drvdata(pdev);
+ struct backlight_device *bl = priv->bl_dev;
+ int i;
+
+ backlight_device_unregister(bl);
+
+ led_bl_power_off(priv);
+ for (i = 0; i < priv->nb_leds; i++)
+ led_sysfs_enable(priv->leds[i]);
+
+ return 0;
+}
+
+static const struct of_device_id led_bl_of_match[] = {
+ { .compatible = "led-backlight" },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, led_bl_of_match);
+
+static struct platform_driver led_bl_driver = {
+ .driver = {
+ .name = "led-backlight",
+ .of_match_table = of_match_ptr(led_bl_of_match),
+ },
+ .probe = led_bl_probe,
+ .remove = led_bl_remove,
+};
+
+module_platform_driver(led_bl_driver);
+
+MODULE_DESCRIPTION("LED based Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:led-backlight");
--
2.17.1
If initialization data is available and its fwnode is actually a of_node,
store this information in the led device's structure. This will allow the
device to use or provide OF-based API such (devm_xxx).
Signed-off-by: Jean-Jacques Hiblot <[email protected]>
---
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 647b1263c579..c2167b66b61f 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -276,8 +276,11 @@ int led_classdev_register_ext(struct device *parent,
mutex_unlock(&led_cdev->led_access);
return PTR_ERR(led_cdev->dev);
}
- if (init_data && init_data->fwnode)
+ if (init_data && init_data->fwnode) {
led_cdev->dev->fwnode = init_data->fwnode;
+ if (is_of_node(init_data->fwnode))
+ led_cdev->dev->of_node = to_of_node(init_data->fwnode);
+ }
if (ret)
dev_warn(parent, "Led %s renamed to %s due to name collision",
--
2.17.1
Hi Jean,
Thank you for rebasing the set
On 9/18/19 4:57 PM, Jean-Jacques Hiblot wrote:
> If initialization data is available and its fwnode is actually a of_node,
> store this information in the led device's structure. This will allow the
> device to use or provide OF-based API such (devm_xxx).
>
> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
> ---
> 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 647b1263c579..c2167b66b61f 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -276,8 +276,11 @@ int led_classdev_register_ext(struct device *parent,
> mutex_unlock(&led_cdev->led_access);
> return PTR_ERR(led_cdev->dev);
> }
> - if (init_data && init_data->fwnode)
> + if (init_data && init_data->fwnode) {
> led_cdev->dev->fwnode = init_data->fwnode;
> + if (is_of_node(init_data->fwnode))
> + led_cdev->dev->of_node = to_of_node(init_data->fwnode);
It would be step backwards. You can do the conversion in the place of
use i.e. in devm_led_get().
> + }
>
> if (ret)
> dev_warn(parent, "Led %s renamed to %s due to name collision",
>
--
Best regards,
Jacek Anaszewski
Jean,
On 9/18/19 4:57 PM, Jean-Jacques Hiblot wrote:
> If the LED is acquired by a consumer device with devm_led_get(), it is
> automatically released when the device is detached.
>
> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
> Acked-by: Pavel Machek <[email protected]>
> ---
> drivers/leds/led-class.c | 51 ++++++++++++++++++++++++++++++++++++++++
> include/linux/leds.h | 2 ++
> 2 files changed, 53 insertions(+)
>
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 2b8f20f94128..e11177d77b4c 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -264,6 +264,57 @@ void led_put(struct led_classdev *led_cdev)
> }
> EXPORT_SYMBOL_GPL(led_put);
>
> +static void devm_led_release(struct device *dev, void *res)
> +{
> + struct led_classdev **p = res;
> +
> + led_put(*p);
> +}
> +
> +/**
> + * devm_led_get - Resource-managed request of a LED device
> + * @dev: LED consumer
> + * @idx: index of the LED to obtain in the consumer
> + *
> + * The device node of the device is parse to find the request LED device.
> + * The LED device returned from this function is automatically released
> + * on driver detach.
> + *
> + * NOTE: At the moment, it supports only device-tree based LED lookup
> + *
> + * @return a pointer to a LED device or ERR_PTR(errno) on failure.
> + */
> +struct led_classdev *__must_check devm_led_get(struct device *dev,
> + int index)
s/devm_led_get/devm_of_led_get/
> +{
> + struct led_classdev *led;
> + struct led_classdev **dr;
> +
> + if (!dev)
> + return ERR_PTR(-EINVAL);
> +
> + /* Not using device tree? */
> + if (!IS_ENABLED(CONFIG_OF) || !dev->of_node)
> + return ERR_PTR(-ENOTSUPP);
> +
> + led = of_led_get(dev->of_node, index);
> + 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;
> +}
> +EXPORT_SYMBOL_GPL(devm_led_get);
> +
> 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 6f7371bc7757..88bf2ceaabe6 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -199,6 +199,8 @@ extern void led_classdev_resume(struct led_classdev *led_cdev);
>
> 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_led_get(struct device *dev,
> + int index);
>
> /**
> * led_blink_set - set blinking with software fallback
>
--
Best regards,
Jacek Anaszewski
Hi Jacek,
On 24/09/2019 23:03, Jacek Anaszewski wrote:
> Hi Jean,
>
> Thank you for rebasing the set
>
> On 9/18/19 4:57 PM, Jean-Jacques Hiblot wrote:
>> If initialization data is available and its fwnode is actually a of_node,
>> store this information in the led device's structure. This will allow the
>> device to use or provide OF-based API such (devm_xxx).
>>
>> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
>> ---
>> 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 647b1263c579..c2167b66b61f 100644
>> --- a/drivers/leds/led-class.c
>> +++ b/drivers/leds/led-class.c
>> @@ -276,8 +276,11 @@ int led_classdev_register_ext(struct device *parent,
>> mutex_unlock(&led_cdev->led_access);
>> return PTR_ERR(led_cdev->dev);
>> }
>> - if (init_data && init_data->fwnode)
>> + if (init_data && init_data->fwnode) {
>> led_cdev->dev->fwnode = init_data->fwnode;
>> + if (is_of_node(init_data->fwnode))
>> + led_cdev->dev->of_node = to_of_node(init_data->fwnode);
> It would be step backwards. You can do the conversion in the place of
> use i.e. in devm_led_get().
Could be done. But it would break another use case I have. I'm also
working on the regulator support and for this one, of_node needs to be
populated.
Is there a problem populating of_node if the LED is indeed described in
the DT ?
JJ
>
>> + }
>>
>> if (ret)
>> dev_warn(parent, "Led %s renamed to %s due to name collision",
>>
Hi Jean,
On 10/2/19 3:58 PM, Jean-Jacques Hiblot wrote:
> Hi Jacek,
>
> On 24/09/2019 23:03, Jacek Anaszewski wrote:
>> Hi Jean,
>>
>> Thank you for rebasing the set
>>
>> On 9/18/19 4:57 PM, Jean-Jacques Hiblot wrote:
>>> If initialization data is available and its fwnode is actually a
>>> of_node,
>>> store this information in the led device's structure. This will allow
>>> the
>>> device to use or provide OF-based API such (devm_xxx).
>>>
>>> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
>>> ---
>>> 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 647b1263c579..c2167b66b61f 100644
>>> --- a/drivers/leds/led-class.c
>>> +++ b/drivers/leds/led-class.c
>>> @@ -276,8 +276,11 @@ int led_classdev_register_ext(struct device
>>> *parent,
>>> mutex_unlock(&led_cdev->led_access);
>>> return PTR_ERR(led_cdev->dev);
>>> }
>>> - if (init_data && init_data->fwnode)
>>> + if (init_data && init_data->fwnode) {
>>> led_cdev->dev->fwnode = init_data->fwnode;
>>> + if (is_of_node(init_data->fwnode))
>>> + led_cdev->dev->of_node = to_of_node(init_data->fwnode);
>> It would be step backwards. You can do the conversion in the place of
>> use i.e. in devm_led_get().
>
> Could be done. But it would break another use case I have. I'm also
> working on the regulator support and for this one, of_node needs to be
> populated.
I thought that regulator core can do the conversion to of_node itself,
but this seems not to be the case.
> Is there a problem populating of_node if the LED is indeed described in
> the DT ?
No, if it is not possible to do it otherwise.
--
Best regards,
Jacek Anaszewski
On Wed, 18 Sep 2019, Jean-Jacques Hiblot wrote:
> From: Tomi Valkeinen <[email protected]>
>
> This patch adds a led-backlight driver (led_bl), which is similar to
> pwm_bl except the driver uses a LED class driver to adjust the
> brightness in the HW. Multiple LEDs can be used for a single backlight.
>
> Signed-off-by: Tomi Valkeinen <[email protected]>
> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
> Acked-by: Pavel Machek <[email protected]>
> Reviewed-by: Daniel Thompson <[email protected]>
> ---
> drivers/video/backlight/Kconfig | 7 +
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++
> 3 files changed, 268 insertions(+)
> create mode 100644 drivers/video/backlight/led_bl.c
Applied, thanks.
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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On Wed, 18 Sep 2019, Jean-Jacques Hiblot wrote:
> Add DT binding for led-backlight.
>
> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
> Reviewed-by: Daniel Thompson <[email protected]>
> ---
> .../bindings/leds/backlight/led-backlight.txt | 28 +++++++++++++++++++
> 1 file changed, 28 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
Applied, thanks.
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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Hi Lee,
On 04/10/2019 16:39, Lee Jones wrote:
> On Wed, 18 Sep 2019, Jean-Jacques Hiblot wrote:
>
>> From: Tomi Valkeinen <[email protected]>
>>
>> This patch adds a led-backlight driver (led_bl), which is similar to
>> pwm_bl except the driver uses a LED class driver to adjust the
>> brightness in the HW. Multiple LEDs can be used for a single backlight.
>>
>> Signed-off-by: Tomi Valkeinen <[email protected]>
>> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
>> Acked-by: Pavel Machek <[email protected]>
>> Reviewed-by: Daniel Thompson <[email protected]>
>> ---
>> drivers/video/backlight/Kconfig | 7 +
>> drivers/video/backlight/Makefile | 1 +
>> drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++
>> 3 files changed, 268 insertions(+)
>> create mode 100644 drivers/video/backlight/led_bl.c
> Applied, thanks.
It will break the build because it relies on functions not yet in the
LED core (devm_led_get() for v7 or devm_of_led_get() for v8)
JJ
>
On Fri, 04 Oct 2019, Jean-Jacques Hiblot wrote:
> Hi Lee,
>
> On 04/10/2019 16:39, Lee Jones wrote:
> > On Wed, 18 Sep 2019, Jean-Jacques Hiblot wrote:
> >
> > > From: Tomi Valkeinen <[email protected]>
> > >
> > > This patch adds a led-backlight driver (led_bl), which is similar to
> > > pwm_bl except the driver uses a LED class driver to adjust the
> > > brightness in the HW. Multiple LEDs can be used for a single backlight.
> > >
> > > Signed-off-by: Tomi Valkeinen <[email protected]>
> > > Signed-off-by: Jean-Jacques Hiblot <[email protected]>
> > > Acked-by: Pavel Machek <[email protected]>
> > > Reviewed-by: Daniel Thompson <[email protected]>
> > > ---
> > > drivers/video/backlight/Kconfig | 7 +
> > > drivers/video/backlight/Makefile | 1 +
> > > drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++
> > > 3 files changed, 268 insertions(+)
> > > create mode 100644 drivers/video/backlight/led_bl.c
> > Applied, thanks.
>
> It will break the build because it relies on functions not yet in the LED
> core (devm_led_get() for v7 or devm_of_led_get() for v8)
You're right, un-applied, thanks.
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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