* [PATCHv3 0/3] backlight: led-backlight driver
@ 2015-09-11 13:07 ` Tomi Valkeinen
0 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen
This series aims to add a led-backlight driver, similar to pwm-backlight, but
using a LED class device underneath.
LED framework has no support for DT or getting a LED class driver from another
kernel driver, so I added minimal functionality to led-class to get
led-backlight working.
Changes to v2:
- power supply is now optional
- cosmetic changes
- no-op function for led_put() when !CONFIG_LEDS_CLASS
Changes to v1:
- Split LED OF parts into separate .h and .c files
- Check for CONFIG_OF and CONFIG_LEDS_CLASS where relevant to leave unused code
out.
- Improved error prints and comments a bit
- Added put_device() into led_put(), as the device was gotten from
class_find_device() which requires a put_device() call.
Tomi
Tomi Valkeinen (3):
leds: Add of_led_get() and led_put()
backlight: add led-backlight driver
devicetree: Add led-backlight binding
.../bindings/video/backlight/led-backlight.txt | 30 +++
drivers/leds/Makefile | 6 +-
drivers/leds/led-class.c | 13 +-
drivers/leds/led-of.c | 85 +++++++
drivers/leds/leds.h | 1 +
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++
include/linux/leds.h | 10 +
include/linux/of_leds.h | 26 +++
10 files changed, 423 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/video/backlight/led-backlight.txt
create mode 100644 drivers/leds/led-of.c
create mode 100644 drivers/video/backlight/led_bl.c
create mode 100644 include/linux/of_leds.h
--
2.1.4
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCHv3 0/3] backlight: led-backlight driver
@ 2015-09-11 13:07 ` Tomi Valkeinen
0 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen
This series aims to add a led-backlight driver, similar to pwm-backlight, but
using a LED class device underneath.
LED framework has no support for DT or getting a LED class driver from another
kernel driver, so I added minimal functionality to led-class to get
led-backlight working.
Changes to v2:
- power supply is now optional
- cosmetic changes
- no-op function for led_put() when !CONFIG_LEDS_CLASS
Changes to v1:
- Split LED OF parts into separate .h and .c files
- Check for CONFIG_OF and CONFIG_LEDS_CLASS where relevant to leave unused code
out.
- Improved error prints and comments a bit
- Added put_device() into led_put(), as the device was gotten from
class_find_device() which requires a put_device() call.
Tomi
Tomi Valkeinen (3):
leds: Add of_led_get() and led_put()
backlight: add led-backlight driver
devicetree: Add led-backlight binding
.../bindings/video/backlight/led-backlight.txt | 30 +++
drivers/leds/Makefile | 6 +-
drivers/leds/led-class.c | 13 +-
drivers/leds/led-of.c | 85 +++++++
drivers/leds/leds.h | 1 +
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++
include/linux/leds.h | 10 +
include/linux/of_leds.h | 26 +++
10 files changed, 423 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/video/backlight/led-backlight.txt
create mode 100644 drivers/leds/led-of.c
create mode 100644 drivers/video/backlight/led_bl.c
create mode 100644 include/linux/of_leds.h
--
2.1.4
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCHv3 1/3] leds: Add of_led_get() and led_put()
2015-09-11 13:07 ` Tomi Valkeinen
@ 2015-09-11 13:07 ` Tomi Valkeinen
-1 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen
This patch adds basic support for a kernel driver to get a LED device.
This will be used by the led-backlight driver.
Only OF version is implemented for now, and the behavior is similar to
PWM's of_pwm_get() and pwm_put().
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
---
drivers/leds/Makefile | 6 +++-
drivers/leds/led-class.c | 13 +++++++-
drivers/leds/led-of.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/leds/leds.h | 1 +
include/linux/leds.h | 10 ++++++
include/linux/of_leds.h | 26 +++++++++++++++
6 files changed, 139 insertions(+), 2 deletions(-)
create mode 100644 drivers/leds/led-of.c
create mode 100644 include/linux/of_leds.h
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 8d6a24a2f513..6fd22e411810 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -1,7 +1,11 @@
# LED Core
obj-$(CONFIG_NEW_LEDS) += led-core.o
-obj-$(CONFIG_LEDS_CLASS) += led-class.o
+
+obj-$(CONFIG_LEDS_CLASS) += led-class-objs.o
+led-class-objs-y := led-class.o
+led-class-objs-$(CONFIG_OF) += led-of.o
+
obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o
obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index beabfbc6f7cd..1234f9dc3537 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -22,7 +22,7 @@
#include <linux/timer.h>
#include "leds.h"
-static struct class *leds_class;
+struct class *leds_class;
static ssize_t brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -216,6 +216,17 @@ static int led_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
+/**
+ * led_put() - release a LED device, reserved with led_get()
+ * @led_cdev: LED device
+ */
+void led_put(struct led_classdev *led_cdev)
+{
+ put_device(led_cdev->dev);
+ module_put(led_cdev->dev->parent->driver->owner);
+}
+EXPORT_SYMBOL_GPL(led_put);
+
static int match_name(struct device *dev, const void *data)
{
if (!dev_name(dev))
diff --git a/drivers/leds/led-of.c b/drivers/leds/led-of.c
new file mode 100644
index 000000000000..6e96fee9adf1
--- /dev/null
+++ b/drivers/leds/led-of.c
@@ -0,0 +1,85 @@
+/*
+ * LED Class Core OF support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_leds.h>
+
+#include "leds.h"
+
+/* find OF node for the given led_cdev */
+static struct device_node *find_led_of_node(struct led_classdev *led_cdev)
+{
+ struct device *led_dev = led_cdev->dev;
+ struct device_node *child;
+
+ for_each_child_of_node(led_dev->parent->of_node, child) {
+ int idx;
+
+ idx = of_property_match_string(child, "label", led_cdev->name);
+ if (idx == 0)
+ return child;
+ }
+
+ return NULL;
+}
+
+static int led_match_led_node(struct device *led_dev, const void *data)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(led_dev);
+ const struct device_node *target_node = data;
+ struct device_node *led_node;
+
+ led_node = find_led_of_node(led_cdev);
+ if (!led_node)
+ return 0;
+
+ of_node_put(led_node);
+
+ return led_node == target_node;
+}
+
+/**
+ * of_led_get() - request a LED device via the LED framework
+ * @np: device node to get the LED device from
+ *
+ * Returns the LED device parsed from the phandle specified in the "leds"
+ * property of a device tree node or a negative error-code on failure.
+ *
+ * The caller must use led_put() to release the device after use.
+ */
+struct led_classdev *of_led_get(struct device_node *np)
+{
+ struct device *led_dev;
+ struct led_classdev *led_cdev;
+ struct device_node *led_node;
+
+ led_node = of_parse_phandle(np, "leds", 0);
+ if (!led_node)
+ return ERR_PTR(-ENODEV);
+
+ led_dev = class_find_device(leds_class, NULL, led_node,
+ led_match_led_node);
+
+ of_node_put(led_node);
+
+ if (!led_dev) {
+ pr_err("failed to find led device for node %s, deferring probe\n",
+ of_node_full_name(led_node));
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ led_cdev = dev_get_drvdata(led_dev);
+
+ if (!try_module_get(led_cdev->dev->parent->driver->owner))
+ return ERR_PTR(-ENODEV);
+
+ return led_cdev;
+}
+EXPORT_SYMBOL_GPL(of_led_get);
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index bc89d7ace2c4..ccc3abb417d4 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -46,6 +46,7 @@ static inline int led_get_brightness(struct led_classdev *led_cdev)
void led_stop_software_blink(struct led_classdev *led_cdev);
+extern struct class *leds_class;
extern struct rw_semaphore leds_list_lock;
extern struct list_head leds_list;
diff --git a/include/linux/leds.h b/include/linux/leds.h
index b122eeafb5dc..fbad4ce78e6e 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -113,6 +113,16 @@ extern void devm_led_classdev_unregister(struct device *parent,
extern void led_classdev_suspend(struct led_classdev *led_cdev);
extern void led_classdev_resume(struct led_classdev *led_cdev);
+#if IS_ENABLED(CONFIG_LEDS_CLASS)
+
+extern void led_put(struct led_classdev *led_cdev);
+
+#else
+
+static inline void led_put(struct led_classdev *led_cdev) { }
+
+#endif /* IS_ENABLED(CONFIG_LEDS_CLASS) */
+
/**
* led_blink_set - set blinking with software fallback
* @led_cdev: the LED to start blinking
diff --git a/include/linux/of_leds.h b/include/linux/of_leds.h
new file mode 100644
index 000000000000..7e8e64bd9811
--- /dev/null
+++ b/include/linux/of_leds.h
@@ -0,0 +1,26 @@
+/*
+ * OF support for leds
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __LINUX_LEDS_OF_H_INCLUDED
+#define __LINUX_LEDS_OF_H_INCLUDED
+
+#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_LEDS_CLASS)
+
+extern struct led_classdev *of_led_get(struct device_node *np);
+
+#else
+
+static inline struct led_classdev *of_led_get(struct device_node *np)
+{
+ return -ENODEV;
+}
+
+#endif
+
+#endif /* __LINUX_LEDS_OF_H_INCLUDED */
--
2.1.4
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCHv3 1/3] leds: Add of_led_get() and led_put()
@ 2015-09-11 13:07 ` Tomi Valkeinen
0 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen
This patch adds basic support for a kernel driver to get a LED device.
This will be used by the led-backlight driver.
Only OF version is implemented for now, and the behavior is similar to
PWM's of_pwm_get() and pwm_put().
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
---
drivers/leds/Makefile | 6 +++-
drivers/leds/led-class.c | 13 +++++++-
drivers/leds/led-of.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/leds/leds.h | 1 +
include/linux/leds.h | 10 ++++++
include/linux/of_leds.h | 26 +++++++++++++++
6 files changed, 139 insertions(+), 2 deletions(-)
create mode 100644 drivers/leds/led-of.c
create mode 100644 include/linux/of_leds.h
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 8d6a24a2f513..6fd22e411810 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -1,7 +1,11 @@
# LED Core
obj-$(CONFIG_NEW_LEDS) += led-core.o
-obj-$(CONFIG_LEDS_CLASS) += led-class.o
+
+obj-$(CONFIG_LEDS_CLASS) += led-class-objs.o
+led-class-objs-y := led-class.o
+led-class-objs-$(CONFIG_OF) += led-of.o
+
obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o
obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index beabfbc6f7cd..1234f9dc3537 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -22,7 +22,7 @@
#include <linux/timer.h>
#include "leds.h"
-static struct class *leds_class;
+struct class *leds_class;
static ssize_t brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -216,6 +216,17 @@ static int led_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
+/**
+ * led_put() - release a LED device, reserved with led_get()
+ * @led_cdev: LED device
+ */
+void led_put(struct led_classdev *led_cdev)
+{
+ put_device(led_cdev->dev);
+ module_put(led_cdev->dev->parent->driver->owner);
+}
+EXPORT_SYMBOL_GPL(led_put);
+
static int match_name(struct device *dev, const void *data)
{
if (!dev_name(dev))
diff --git a/drivers/leds/led-of.c b/drivers/leds/led-of.c
new file mode 100644
index 000000000000..6e96fee9adf1
--- /dev/null
+++ b/drivers/leds/led-of.c
@@ -0,0 +1,85 @@
+/*
+ * LED Class Core OF support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_leds.h>
+
+#include "leds.h"
+
+/* find OF node for the given led_cdev */
+static struct device_node *find_led_of_node(struct led_classdev *led_cdev)
+{
+ struct device *led_dev = led_cdev->dev;
+ struct device_node *child;
+
+ for_each_child_of_node(led_dev->parent->of_node, child) {
+ int idx;
+
+ idx = of_property_match_string(child, "label", led_cdev->name);
+ if (idx = 0)
+ return child;
+ }
+
+ return NULL;
+}
+
+static int led_match_led_node(struct device *led_dev, const void *data)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(led_dev);
+ const struct device_node *target_node = data;
+ struct device_node *led_node;
+
+ led_node = find_led_of_node(led_cdev);
+ if (!led_node)
+ return 0;
+
+ of_node_put(led_node);
+
+ return led_node = target_node;
+}
+
+/**
+ * of_led_get() - request a LED device via the LED framework
+ * @np: device node to get the LED device from
+ *
+ * Returns the LED device parsed from the phandle specified in the "leds"
+ * property of a device tree node or a negative error-code on failure.
+ *
+ * The caller must use led_put() to release the device after use.
+ */
+struct led_classdev *of_led_get(struct device_node *np)
+{
+ struct device *led_dev;
+ struct led_classdev *led_cdev;
+ struct device_node *led_node;
+
+ led_node = of_parse_phandle(np, "leds", 0);
+ if (!led_node)
+ return ERR_PTR(-ENODEV);
+
+ led_dev = class_find_device(leds_class, NULL, led_node,
+ led_match_led_node);
+
+ of_node_put(led_node);
+
+ if (!led_dev) {
+ pr_err("failed to find led device for node %s, deferring probe\n",
+ of_node_full_name(led_node));
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ led_cdev = dev_get_drvdata(led_dev);
+
+ if (!try_module_get(led_cdev->dev->parent->driver->owner))
+ return ERR_PTR(-ENODEV);
+
+ return led_cdev;
+}
+EXPORT_SYMBOL_GPL(of_led_get);
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index bc89d7ace2c4..ccc3abb417d4 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -46,6 +46,7 @@ static inline int led_get_brightness(struct led_classdev *led_cdev)
void led_stop_software_blink(struct led_classdev *led_cdev);
+extern struct class *leds_class;
extern struct rw_semaphore leds_list_lock;
extern struct list_head leds_list;
diff --git a/include/linux/leds.h b/include/linux/leds.h
index b122eeafb5dc..fbad4ce78e6e 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -113,6 +113,16 @@ extern void devm_led_classdev_unregister(struct device *parent,
extern void led_classdev_suspend(struct led_classdev *led_cdev);
extern void led_classdev_resume(struct led_classdev *led_cdev);
+#if IS_ENABLED(CONFIG_LEDS_CLASS)
+
+extern void led_put(struct led_classdev *led_cdev);
+
+#else
+
+static inline void led_put(struct led_classdev *led_cdev) { }
+
+#endif /* IS_ENABLED(CONFIG_LEDS_CLASS) */
+
/**
* led_blink_set - set blinking with software fallback
* @led_cdev: the LED to start blinking
diff --git a/include/linux/of_leds.h b/include/linux/of_leds.h
new file mode 100644
index 000000000000..7e8e64bd9811
--- /dev/null
+++ b/include/linux/of_leds.h
@@ -0,0 +1,26 @@
+/*
+ * OF support for leds
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __LINUX_LEDS_OF_H_INCLUDED
+#define __LINUX_LEDS_OF_H_INCLUDED
+
+#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_LEDS_CLASS)
+
+extern struct led_classdev *of_led_get(struct device_node *np);
+
+#else
+
+static inline struct led_classdev *of_led_get(struct device_node *np)
+{
+ return -ENODEV;
+}
+
+#endif
+
+#endif /* __LINUX_LEDS_OF_H_INCLUDED */
--
2.1.4
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCHv3 2/3] backlight: add led-backlight driver
2015-09-11 13:07 ` Tomi Valkeinen
@ 2015-09-11 13:07 ` Tomi Valkeinen
-1 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen
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.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
---
drivers/video/backlight/Kconfig | 7 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++++++++++++++++++++
3 files changed, 254 insertions(+)
create mode 100644 drivers/video/backlight/led_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 0505b796d743..d1336196aba2 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -453,6 +453,13 @@ config BACKLIGHT_BD6107
help
If you have a Rohm BD6107 say Y to enable the backlight driver.
+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
endif # BACKLIGHT_LCD_SUPPORT
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index d67073f9d421..ecd321daee21 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -54,3 +54,4 @@ obj-$(CONFIG_BACKLIGHT_SKY81452) += sky81452-backlight.o
obj-$(CONFIG_BACKLIGHT_TOSA) += tosa_bl.o
obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o
obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.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..1befc8ce5964
--- /dev/null
+++ b/drivers/video/backlight/led_bl.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright 2015 Texas Instruments
+ *
+ * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
+ *
+ * Based on pwm_bl.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <linux/leds.h>
+#include <linux/of_leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+struct led_bl_data {
+ struct device *dev;
+ struct backlight_device *bl_dev;
+
+ unsigned int *levels;
+ bool enabled;
+ struct regulator *power_supply;
+ struct gpio_desc *enable_gpio;
+
+ struct led_classdev *led_cdev;
+
+ unsigned int max_brightness;
+ unsigned int default_brightness;
+};
+
+static void led_bl_set_brightness(struct led_bl_data *priv, int brightness)
+{
+ int err;
+
+ if (!priv->enabled) {
+ if (priv->power_supply) {
+ err = regulator_enable(priv->power_supply);
+
+ if (err < 0)
+ dev_err(priv->dev,
+ "failed to enable power supply\n");
+ }
+
+ if (priv->enable_gpio)
+ gpiod_set_value_cansleep(priv->enable_gpio, 1);
+ }
+
+ led_set_brightness(priv->led_cdev, priv->levels[brightness]);
+
+ priv->enabled = true;
+}
+
+static void led_bl_power_off(struct led_bl_data *priv)
+{
+ if (!priv->enabled)
+ return;
+
+ led_set_brightness(priv->led_cdev, LED_OFF);
+
+ if (priv->enable_gpio)
+ gpiod_set_value_cansleep(priv->enable_gpio, 0);
+
+ if (priv->power_supply)
+ regulator_disable(priv->power_supply);
+
+ 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_parse_dt(struct device *dev,
+ struct led_bl_data *priv)
+{
+ struct device_node *node = dev->of_node;
+ int num_levels;
+ u32 *levels;
+ u32 value;
+ int ret;
+
+ if (!node)
+ return -ENODEV;
+
+ num_levels = of_property_count_u32_elems(node, "brightness-levels");
+ if (num_levels < 0) {
+ dev_err(dev, "failed to find 'brightness-levels'\n");
+ return num_levels;
+ }
+
+ 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) {
+ dev_err(dev, "failed to parse 'brightness-levels'\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(node, "default-brightness-level", &value);
+ if (ret < 0) {
+ dev_err(dev, "failed to parse 'default-brightness-level'\n");
+ return ret;
+ }
+
+ if (value >= num_levels) {
+ dev_err(dev, "invalid default-brightness-level\n");
+ return -EINVAL;
+ }
+
+ priv->levels = levels;
+ priv->max_brightness = num_levels - 1;
+ priv->default_brightness = value;
+
+ priv->led_cdev = of_led_get(node);
+ if (IS_ERR(priv->led_cdev)) {
+ dev_err(dev, "failed to get LED device\n");
+ return PTR_ERR(priv->led_cdev);
+ }
+
+ return 0;
+}
+
+static int led_bl_probe(struct platform_device *pdev)
+{
+ struct backlight_properties props;
+ struct led_bl_data *priv;
+ int ret;
+
+ 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_parse_dt(&pdev->dev, priv);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to parse DT data\n");
+ return ret;
+ }
+
+ priv->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(priv->enable_gpio)) {
+ ret = PTR_ERR(priv->enable_gpio);
+ goto err;
+ }
+
+ priv->power_supply = devm_regulator_get_optional(&pdev->dev, "power");
+ if (IS_ERR(priv->power_supply)) {
+ ret = PTR_ERR(priv->power_supply);
+
+ if (ret == -ENODEV) {
+ priv->power_supply = NULL;
+ } else {
+ ret = PTR_ERR(priv->power_supply);
+ goto err;
+ }
+ }
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = priv->max_brightness;
+ 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");
+ ret = PTR_ERR(priv->bl_dev);
+ goto err;
+ }
+
+ priv->bl_dev->props.brightness = priv->default_brightness;
+ backlight_update_status(priv->bl_dev);
+
+ return 0;
+
+err:
+ if (priv->led_cdev)
+ led_put(priv->led_cdev);
+
+ return ret;
+}
+
+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;
+
+ backlight_device_unregister(bl);
+
+ led_bl_power_off(priv);
+
+ led_put(priv->led_cdev);
+
+ 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");
--
2.1.4
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCHv3 2/3] backlight: add led-backlight driver
@ 2015-09-11 13:07 ` Tomi Valkeinen
0 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen
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.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
---
drivers/video/backlight/Kconfig | 7 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++++++++++++++++++++
3 files changed, 254 insertions(+)
create mode 100644 drivers/video/backlight/led_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 0505b796d743..d1336196aba2 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -453,6 +453,13 @@ config BACKLIGHT_BD6107
help
If you have a Rohm BD6107 say Y to enable the backlight driver.
+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
endif # BACKLIGHT_LCD_SUPPORT
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index d67073f9d421..ecd321daee21 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -54,3 +54,4 @@ obj-$(CONFIG_BACKLIGHT_SKY81452) += sky81452-backlight.o
obj-$(CONFIG_BACKLIGHT_TOSA) += tosa_bl.o
obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o
obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o
+obj-$(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..1befc8ce5964
--- /dev/null
+++ b/drivers/video/backlight/led_bl.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright 2015 Texas Instruments
+ *
+ * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
+ *
+ * Based on pwm_bl.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <linux/leds.h>
+#include <linux/of_leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+struct led_bl_data {
+ struct device *dev;
+ struct backlight_device *bl_dev;
+
+ unsigned int *levels;
+ bool enabled;
+ struct regulator *power_supply;
+ struct gpio_desc *enable_gpio;
+
+ struct led_classdev *led_cdev;
+
+ unsigned int max_brightness;
+ unsigned int default_brightness;
+};
+
+static void led_bl_set_brightness(struct led_bl_data *priv, int brightness)
+{
+ int err;
+
+ if (!priv->enabled) {
+ if (priv->power_supply) {
+ err = regulator_enable(priv->power_supply);
+
+ if (err < 0)
+ dev_err(priv->dev,
+ "failed to enable power supply\n");
+ }
+
+ if (priv->enable_gpio)
+ gpiod_set_value_cansleep(priv->enable_gpio, 1);
+ }
+
+ led_set_brightness(priv->led_cdev, priv->levels[brightness]);
+
+ priv->enabled = true;
+}
+
+static void led_bl_power_off(struct led_bl_data *priv)
+{
+ if (!priv->enabled)
+ return;
+
+ led_set_brightness(priv->led_cdev, LED_OFF);
+
+ if (priv->enable_gpio)
+ gpiod_set_value_cansleep(priv->enable_gpio, 0);
+
+ if (priv->power_supply)
+ regulator_disable(priv->power_supply);
+
+ 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_parse_dt(struct device *dev,
+ struct led_bl_data *priv)
+{
+ struct device_node *node = dev->of_node;
+ int num_levels;
+ u32 *levels;
+ u32 value;
+ int ret;
+
+ if (!node)
+ return -ENODEV;
+
+ num_levels = of_property_count_u32_elems(node, "brightness-levels");
+ if (num_levels < 0) {
+ dev_err(dev, "failed to find 'brightness-levels'\n");
+ return num_levels;
+ }
+
+ 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) {
+ dev_err(dev, "failed to parse 'brightness-levels'\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(node, "default-brightness-level", &value);
+ if (ret < 0) {
+ dev_err(dev, "failed to parse 'default-brightness-level'\n");
+ return ret;
+ }
+
+ if (value >= num_levels) {
+ dev_err(dev, "invalid default-brightness-level\n");
+ return -EINVAL;
+ }
+
+ priv->levels = levels;
+ priv->max_brightness = num_levels - 1;
+ priv->default_brightness = value;
+
+ priv->led_cdev = of_led_get(node);
+ if (IS_ERR(priv->led_cdev)) {
+ dev_err(dev, "failed to get LED device\n");
+ return PTR_ERR(priv->led_cdev);
+ }
+
+ return 0;
+}
+
+static int led_bl_probe(struct platform_device *pdev)
+{
+ struct backlight_properties props;
+ struct led_bl_data *priv;
+ int ret;
+
+ 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_parse_dt(&pdev->dev, priv);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to parse DT data\n");
+ return ret;
+ }
+
+ priv->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(priv->enable_gpio)) {
+ ret = PTR_ERR(priv->enable_gpio);
+ goto err;
+ }
+
+ priv->power_supply = devm_regulator_get_optional(&pdev->dev, "power");
+ if (IS_ERR(priv->power_supply)) {
+ ret = PTR_ERR(priv->power_supply);
+
+ if (ret = -ENODEV) {
+ priv->power_supply = NULL;
+ } else {
+ ret = PTR_ERR(priv->power_supply);
+ goto err;
+ }
+ }
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = priv->max_brightness;
+ 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");
+ ret = PTR_ERR(priv->bl_dev);
+ goto err;
+ }
+
+ priv->bl_dev->props.brightness = priv->default_brightness;
+ backlight_update_status(priv->bl_dev);
+
+ return 0;
+
+err:
+ if (priv->led_cdev)
+ led_put(priv->led_cdev);
+
+ return ret;
+}
+
+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;
+
+ backlight_device_unregister(bl);
+
+ led_bl_power_off(priv);
+
+ led_put(priv->led_cdev);
+
+ 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");
--
2.1.4
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCHv3 3/3] devicetree: Add led-backlight binding
2015-09-11 13:07 ` Tomi Valkeinen
@ 2015-09-11 13:07 ` Tomi Valkeinen
-1 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen, devicetree
Add DT binding for led-backlight.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: devicetree@vger.kernel.org
---
.../bindings/video/backlight/led-backlight.txt | 30 ++++++++++++++++++++++
1 file changed, 30 insertions(+)
create mode 100644 Documentation/devicetree/bindings/video/backlight/led-backlight.txt
diff --git a/Documentation/devicetree/bindings/video/backlight/led-backlight.txt b/Documentation/devicetree/bindings/video/backlight/led-backlight.txt
new file mode 100644
index 000000000000..d4621d7414bc
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/backlight/led-backlight.txt
@@ -0,0 +1,30 @@
+led-backlight bindings
+
+Required properties:
+ - compatible: "led-backlight"
+ - leds: phandle to a led OF node [0]
+ - brightness-levels: Array of distinct LED brightness levels. These
+ are in the range from 0 to 255, passed to the LED class driver.
+ - default-brightness-level: the default brightness level (index into the
+ array defined by the "brightness-levels" property)
+
+Optional properties:
+ - power-supply: regulator for supply voltage
+ - enable-gpios: contains a single GPIO specifier for the GPIO which enables
+ and disables the backlight (see GPIO binding[1])
+
+[0]: Documentation/devicetree/bindings/leds/common.txt
+[1]: Documentation/devicetree/bindings/gpio/gpio.txt
+
+Example:
+
+ backlight {
+ compatible = "led-backlight";
+ leds = <&backlight_led>;
+
+ brightness-levels = <0 4 8 16 32 64 128 255>;
+ default-brightness-level = <6>;
+
+ power-supply = <&vdd_bl_reg>;
+ enable-gpios = <&gpio 58 0>;
+ };
--
2.1.4
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCHv3 3/3] devicetree: Add led-backlight binding
@ 2015-09-11 13:07 ` Tomi Valkeinen
0 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-11 13:07 UTC (permalink / raw)
To: Jacek Anaszewski, Jingoo Han, Lee Jones, linux-leds, linux-fbdev
Cc: Andrew Lunn, Tomi Valkeinen, devicetree
Add DT binding for led-backlight.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: devicetree@vger.kernel.org
---
.../bindings/video/backlight/led-backlight.txt | 30 ++++++++++++++++++++++
1 file changed, 30 insertions(+)
create mode 100644 Documentation/devicetree/bindings/video/backlight/led-backlight.txt
diff --git a/Documentation/devicetree/bindings/video/backlight/led-backlight.txt b/Documentation/devicetree/bindings/video/backlight/led-backlight.txt
new file mode 100644
index 000000000000..d4621d7414bc
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/backlight/led-backlight.txt
@@ -0,0 +1,30 @@
+led-backlight bindings
+
+Required properties:
+ - compatible: "led-backlight"
+ - leds: phandle to a led OF node [0]
+ - brightness-levels: Array of distinct LED brightness levels. These
+ are in the range from 0 to 255, passed to the LED class driver.
+ - default-brightness-level: the default brightness level (index into the
+ array defined by the "brightness-levels" property)
+
+Optional properties:
+ - power-supply: regulator for supply voltage
+ - enable-gpios: contains a single GPIO specifier for the GPIO which enables
+ and disables the backlight (see GPIO binding[1])
+
+[0]: Documentation/devicetree/bindings/leds/common.txt
+[1]: Documentation/devicetree/bindings/gpio/gpio.txt
+
+Example:
+
+ backlight {
+ compatible = "led-backlight";
+ leds = <&backlight_led>;
+
+ brightness-levels = <0 4 8 16 32 64 128 255>;
+ default-brightness-level = <6>;
+
+ power-supply = <&vdd_bl_reg>;
+ enable-gpios = <&gpio 58 0>;
+ };
--
2.1.4
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCHv3 1/3] leds: Add of_led_get() and led_put()
2015-09-11 13:07 ` Tomi Valkeinen
@ 2015-09-11 13:50 ` Jacek Anaszewski
-1 siblings, 0 replies; 16+ messages in thread
From: Jacek Anaszewski @ 2015-09-11 13:50 UTC (permalink / raw)
To: Tomi Valkeinen
Cc: Jingoo Han, Lee Jones, linux-leds, linux-fbdev, Andrew Lunn
On 09/11/2015 03:07 PM, Tomi Valkeinen wrote:
> This patch adds basic support for a kernel driver to get a LED device.
> This will be used by the led-backlight driver.
>
> Only OF version is implemented for now, and the behavior is similar to
> PWM's of_pwm_get() and pwm_put().
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
> drivers/leds/Makefile | 6 +++-
> drivers/leds/led-class.c | 13 +++++++-
> drivers/leds/led-of.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/leds/leds.h | 1 +
> include/linux/leds.h | 10 ++++++
> include/linux/of_leds.h | 26 +++++++++++++++
> 6 files changed, 139 insertions(+), 2 deletions(-)
> create mode 100644 drivers/leds/led-of.c
> create mode 100644 include/linux/of_leds.h
>
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 8d6a24a2f513..6fd22e411810 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -1,7 +1,11 @@
>
> # LED Core
> obj-$(CONFIG_NEW_LEDS) += led-core.o
> -obj-$(CONFIG_LEDS_CLASS) += led-class.o
> +
> +obj-$(CONFIG_LEDS_CLASS) += led-class-objs.o
> +led-class-objs-y := led-class.o
> +led-class-objs-$(CONFIG_OF) += led-of.o
> +
> obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o
> obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
>
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index beabfbc6f7cd..1234f9dc3537 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -22,7 +22,7 @@
> #include <linux/timer.h>
> #include "leds.h"
>
> -static struct class *leds_class;
> +struct class *leds_class;
>
> static ssize_t brightness_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> @@ -216,6 +216,17 @@ static int led_resume(struct device *dev)
>
> static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
>
> +/**
> + * led_put() - release a LED device, reserved with led_get()
s/led_get/of_led_get/
or we should add led_get, but since class_find_device, which increments
device ref count, takes led_node and led_match_led_node, it is tightly
coupled tightly with OF. OTOH we could have of_led_put for symmetry,
but it would have nothing to do with OF. Amending the comment is the
best option here, I think.
> + * @led_cdev: LED device
> + */
> +void led_put(struct led_classdev *led_cdev)
> +{
> + put_device(led_cdev->dev);
> + module_put(led_cdev->dev->parent->driver->owner);
> +}
> +EXPORT_SYMBOL_GPL(led_put);
> +
> static int match_name(struct device *dev, const void *data)
> {
> if (!dev_name(dev))
> diff --git a/drivers/leds/led-of.c b/drivers/leds/led-of.c
> new file mode 100644
> index 000000000000..6e96fee9adf1
> --- /dev/null
> +++ b/drivers/leds/led-of.c
> @@ -0,0 +1,85 @@
> +/*
> + * LED Class Core OF support
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_leds.h>
> +
> +#include "leds.h"
> +
> +/* find OF node for the given led_cdev */
> +static struct device_node *find_led_of_node(struct led_classdev *led_cdev)
> +{
> + struct device *led_dev = led_cdev->dev;
> + struct device_node *child;
> +
> + for_each_child_of_node(led_dev->parent->of_node, child) {
> + int idx;
> +
> + idx = of_property_match_string(child, "label", led_cdev->name);
> + if (idx == 0)
> + return child;
> + }
> +
> + return NULL;
> +}
> +
> +static int led_match_led_node(struct device *led_dev, const void *data)
> +{
> + struct led_classdev *led_cdev = dev_get_drvdata(led_dev);
> + const struct device_node *target_node = data;
> + struct device_node *led_node;
> +
> + led_node = find_led_of_node(led_cdev);
> + if (!led_node)
> + return 0;
> +
> + of_node_put(led_node);
> +
> + return led_node == target_node;
> +}
> +
> +/**
> + * of_led_get() - request a LED device via the LED framework
> + * @np: device node to get the LED device from
> + *
> + * Returns the LED device parsed from the phandle specified in the "leds"
> + * property of a device tree node or a negative error-code on failure.
> + *
> + * The caller must use led_put() to release the device after use.
> + */
> +struct led_classdev *of_led_get(struct device_node *np)
> +{
> + struct device *led_dev;
> + struct led_classdev *led_cdev;
> + struct device_node *led_node;
> +
> + led_node = of_parse_phandle(np, "leds", 0);
> + if (!led_node)
> + return ERR_PTR(-ENODEV);
> +
> + led_dev = class_find_device(leds_class, NULL, led_node,
> + led_match_led_node);
> +
> + of_node_put(led_node);
> +
> + if (!led_dev) {
> + pr_err("failed to find led device for node %s, deferring probe\n",
> + of_node_full_name(led_node));
> + return ERR_PTR(-EPROBE_DEFER);
> + }
> +
> + led_cdev = dev_get_drvdata(led_dev);
> +
> + if (!try_module_get(led_cdev->dev->parent->driver->owner))
> + return ERR_PTR(-ENODEV);
> +
> + return led_cdev;
> +}
> +EXPORT_SYMBOL_GPL(of_led_get);
> diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
> index bc89d7ace2c4..ccc3abb417d4 100644
> --- a/drivers/leds/leds.h
> +++ b/drivers/leds/leds.h
> @@ -46,6 +46,7 @@ static inline int led_get_brightness(struct led_classdev *led_cdev)
>
> void led_stop_software_blink(struct led_classdev *led_cdev);
>
> +extern struct class *leds_class;
> extern struct rw_semaphore leds_list_lock;
> extern struct list_head leds_list;
>
> diff --git a/include/linux/leds.h b/include/linux/leds.h
> index b122eeafb5dc..fbad4ce78e6e 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -113,6 +113,16 @@ extern void devm_led_classdev_unregister(struct device *parent,
> extern void led_classdev_suspend(struct led_classdev *led_cdev);
> extern void led_classdev_resume(struct led_classdev *led_cdev);
>
> +#if IS_ENABLED(CONFIG_LEDS_CLASS)
> +
> +extern void led_put(struct led_classdev *led_cdev);
> +
> +#else
> +
> +static inline void led_put(struct led_classdev *led_cdev) { }
> +
> +#endif /* IS_ENABLED(CONFIG_LEDS_CLASS) */
> +
> /**
> * led_blink_set - set blinking with software fallback
> * @led_cdev: the LED to start blinking
> diff --git a/include/linux/of_leds.h b/include/linux/of_leds.h
> new file mode 100644
> index 000000000000..7e8e64bd9811
> --- /dev/null
> +++ b/include/linux/of_leds.h
> @@ -0,0 +1,26 @@
> +/*
> + * OF support for leds
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#ifndef __LINUX_LEDS_OF_H_INCLUDED
> +#define __LINUX_LEDS_OF_H_INCLUDED
> +
> +#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_LEDS_CLASS)
> +
> +extern struct led_classdev *of_led_get(struct device_node *np);
> +
> +#else
> +
> +static inline struct led_classdev *of_led_get(struct device_node *np)
> +{
> + return -ENODEV;
> +}
> +
> +#endif
> +
> +#endif /* __LINUX_LEDS_OF_H_INCLUDED */
>
--
Best Regards,
Jacek Anaszewski
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCHv3 1/3] leds: Add of_led_get() and led_put()
@ 2015-09-11 13:50 ` Jacek Anaszewski
0 siblings, 0 replies; 16+ messages in thread
From: Jacek Anaszewski @ 2015-09-11 13:50 UTC (permalink / raw)
To: Tomi Valkeinen
Cc: Jingoo Han, Lee Jones, linux-leds, linux-fbdev, Andrew Lunn
On 09/11/2015 03:07 PM, Tomi Valkeinen wrote:
> This patch adds basic support for a kernel driver to get a LED device.
> This will be used by the led-backlight driver.
>
> Only OF version is implemented for now, and the behavior is similar to
> PWM's of_pwm_get() and pwm_put().
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
> drivers/leds/Makefile | 6 +++-
> drivers/leds/led-class.c | 13 +++++++-
> drivers/leds/led-of.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/leds/leds.h | 1 +
> include/linux/leds.h | 10 ++++++
> include/linux/of_leds.h | 26 +++++++++++++++
> 6 files changed, 139 insertions(+), 2 deletions(-)
> create mode 100644 drivers/leds/led-of.c
> create mode 100644 include/linux/of_leds.h
>
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 8d6a24a2f513..6fd22e411810 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -1,7 +1,11 @@
>
> # LED Core
> obj-$(CONFIG_NEW_LEDS) += led-core.o
> -obj-$(CONFIG_LEDS_CLASS) += led-class.o
> +
> +obj-$(CONFIG_LEDS_CLASS) += led-class-objs.o
> +led-class-objs-y := led-class.o
> +led-class-objs-$(CONFIG_OF) += led-of.o
> +
> obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o
> obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
>
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index beabfbc6f7cd..1234f9dc3537 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -22,7 +22,7 @@
> #include <linux/timer.h>
> #include "leds.h"
>
> -static struct class *leds_class;
> +struct class *leds_class;
>
> static ssize_t brightness_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> @@ -216,6 +216,17 @@ static int led_resume(struct device *dev)
>
> static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
>
> +/**
> + * led_put() - release a LED device, reserved with led_get()
s/led_get/of_led_get/
or we should add led_get, but since class_find_device, which increments
device ref count, takes led_node and led_match_led_node, it is tightly
coupled tightly with OF. OTOH we could have of_led_put for symmetry,
but it would have nothing to do with OF. Amending the comment is the
best option here, I think.
> + * @led_cdev: LED device
> + */
> +void led_put(struct led_classdev *led_cdev)
> +{
> + put_device(led_cdev->dev);
> + module_put(led_cdev->dev->parent->driver->owner);
> +}
> +EXPORT_SYMBOL_GPL(led_put);
> +
> static int match_name(struct device *dev, const void *data)
> {
> if (!dev_name(dev))
> diff --git a/drivers/leds/led-of.c b/drivers/leds/led-of.c
> new file mode 100644
> index 000000000000..6e96fee9adf1
> --- /dev/null
> +++ b/drivers/leds/led-of.c
> @@ -0,0 +1,85 @@
> +/*
> + * LED Class Core OF support
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_leds.h>
> +
> +#include "leds.h"
> +
> +/* find OF node for the given led_cdev */
> +static struct device_node *find_led_of_node(struct led_classdev *led_cdev)
> +{
> + struct device *led_dev = led_cdev->dev;
> + struct device_node *child;
> +
> + for_each_child_of_node(led_dev->parent->of_node, child) {
> + int idx;
> +
> + idx = of_property_match_string(child, "label", led_cdev->name);
> + if (idx = 0)
> + return child;
> + }
> +
> + return NULL;
> +}
> +
> +static int led_match_led_node(struct device *led_dev, const void *data)
> +{
> + struct led_classdev *led_cdev = dev_get_drvdata(led_dev);
> + const struct device_node *target_node = data;
> + struct device_node *led_node;
> +
> + led_node = find_led_of_node(led_cdev);
> + if (!led_node)
> + return 0;
> +
> + of_node_put(led_node);
> +
> + return led_node = target_node;
> +}
> +
> +/**
> + * of_led_get() - request a LED device via the LED framework
> + * @np: device node to get the LED device from
> + *
> + * Returns the LED device parsed from the phandle specified in the "leds"
> + * property of a device tree node or a negative error-code on failure.
> + *
> + * The caller must use led_put() to release the device after use.
> + */
> +struct led_classdev *of_led_get(struct device_node *np)
> +{
> + struct device *led_dev;
> + struct led_classdev *led_cdev;
> + struct device_node *led_node;
> +
> + led_node = of_parse_phandle(np, "leds", 0);
> + if (!led_node)
> + return ERR_PTR(-ENODEV);
> +
> + led_dev = class_find_device(leds_class, NULL, led_node,
> + led_match_led_node);
> +
> + of_node_put(led_node);
> +
> + if (!led_dev) {
> + pr_err("failed to find led device for node %s, deferring probe\n",
> + of_node_full_name(led_node));
> + return ERR_PTR(-EPROBE_DEFER);
> + }
> +
> + led_cdev = dev_get_drvdata(led_dev);
> +
> + if (!try_module_get(led_cdev->dev->parent->driver->owner))
> + return ERR_PTR(-ENODEV);
> +
> + return led_cdev;
> +}
> +EXPORT_SYMBOL_GPL(of_led_get);
> diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
> index bc89d7ace2c4..ccc3abb417d4 100644
> --- a/drivers/leds/leds.h
> +++ b/drivers/leds/leds.h
> @@ -46,6 +46,7 @@ static inline int led_get_brightness(struct led_classdev *led_cdev)
>
> void led_stop_software_blink(struct led_classdev *led_cdev);
>
> +extern struct class *leds_class;
> extern struct rw_semaphore leds_list_lock;
> extern struct list_head leds_list;
>
> diff --git a/include/linux/leds.h b/include/linux/leds.h
> index b122eeafb5dc..fbad4ce78e6e 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -113,6 +113,16 @@ extern void devm_led_classdev_unregister(struct device *parent,
> extern void led_classdev_suspend(struct led_classdev *led_cdev);
> extern void led_classdev_resume(struct led_classdev *led_cdev);
>
> +#if IS_ENABLED(CONFIG_LEDS_CLASS)
> +
> +extern void led_put(struct led_classdev *led_cdev);
> +
> +#else
> +
> +static inline void led_put(struct led_classdev *led_cdev) { }
> +
> +#endif /* IS_ENABLED(CONFIG_LEDS_CLASS) */
> +
> /**
> * led_blink_set - set blinking with software fallback
> * @led_cdev: the LED to start blinking
> diff --git a/include/linux/of_leds.h b/include/linux/of_leds.h
> new file mode 100644
> index 000000000000..7e8e64bd9811
> --- /dev/null
> +++ b/include/linux/of_leds.h
> @@ -0,0 +1,26 @@
> +/*
> + * OF support for leds
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#ifndef __LINUX_LEDS_OF_H_INCLUDED
> +#define __LINUX_LEDS_OF_H_INCLUDED
> +
> +#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_LEDS_CLASS)
> +
> +extern struct led_classdev *of_led_get(struct device_node *np);
> +
> +#else
> +
> +static inline struct led_classdev *of_led_get(struct device_node *np)
> +{
> + return -ENODEV;
> +}
> +
> +#endif
> +
> +#endif /* __LINUX_LEDS_OF_H_INCLUDED */
>
--
Best Regards,
Jacek Anaszewski
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCHv3 1/3] leds: Add of_led_get() and led_put()
2015-09-11 13:50 ` Jacek Anaszewski
@ 2015-09-28 8:08 ` Tomi Valkeinen
-1 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-28 8:08 UTC (permalink / raw)
To: Jacek Anaszewski
Cc: Jingoo Han, Lee Jones, linux-leds, linux-fbdev, Andrew Lunn
[-- Attachment #1: Type: text/plain, Size: 530 bytes --]
On 11/09/15 16:50, Jacek Anaszewski wrote:
>> +/**
>> + * led_put() - release a LED device, reserved with led_get()
>
> s/led_get/of_led_get/
>
> or we should add led_get, but since class_find_device, which increments
> device ref count, takes led_node and led_match_led_node, it is tightly
> coupled tightly with OF. OTOH we could have of_led_put for symmetry,
> but it would have nothing to do with OF. Amending the comment is the
> best option here, I think.
I agree. I've changed the comment.
Tomi
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCHv3 1/3] leds: Add of_led_get() and led_put()
@ 2015-09-28 8:08 ` Tomi Valkeinen
0 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-28 8:08 UTC (permalink / raw)
To: Jacek Anaszewski
Cc: Jingoo Han, Lee Jones, linux-leds, linux-fbdev, Andrew Lunn
[-- Attachment #1: Type: text/plain, Size: 530 bytes --]
On 11/09/15 16:50, Jacek Anaszewski wrote:
>> +/**
>> + * led_put() - release a LED device, reserved with led_get()
>
> s/led_get/of_led_get/
>
> or we should add led_get, but since class_find_device, which increments
> device ref count, takes led_node and led_match_led_node, it is tightly
> coupled tightly with OF. OTOH we could have of_led_put for symmetry,
> but it would have nothing to do with OF. Amending the comment is the
> best option here, I think.
I agree. I've changed the comment.
Tomi
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCHv3 2/3] backlight: add led-backlight driver
2015-09-11 13:07 ` Tomi Valkeinen
@ 2015-09-28 8:12 ` Tomi Valkeinen
-1 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-28 8:12 UTC (permalink / raw)
To: Jingoo Han, Lee Jones
Cc: Jacek Anaszewski, linux-leds, linux-fbdev, Andrew Lunn
[-- Attachment #1: Type: text/plain, Size: 704 bytes --]
Hi Jingoo, Lee,
On 11/09/15 16:07, Tomi Valkeinen wrote:
> 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.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
> drivers/video/backlight/Kconfig | 7 ++
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 254 insertions(+)
> create mode 100644 drivers/video/backlight/led_bl.c
Any comments on the backlight side of this series? It is very similar to
the pwm_bl.c, so I presume the approach is acceptable?
Tomi
[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCHv3 2/3] backlight: add led-backlight driver
@ 2015-09-28 8:12 ` Tomi Valkeinen
0 siblings, 0 replies; 16+ messages in thread
From: Tomi Valkeinen @ 2015-09-28 8:12 UTC (permalink / raw)
To: Jingoo Han, Lee Jones
Cc: Jacek Anaszewski, linux-leds, linux-fbdev, Andrew Lunn
[-- Attachment #1: Type: text/plain, Size: 704 bytes --]
Hi Jingoo, Lee,
On 11/09/15 16:07, Tomi Valkeinen wrote:
> 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.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
> drivers/video/backlight/Kconfig | 7 ++
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 254 insertions(+)
> create mode 100644 drivers/video/backlight/led_bl.c
Any comments on the backlight side of this series? It is very similar to
the pwm_bl.c, so I presume the approach is acceptable?
Tomi
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCHv3 2/3] backlight: add led-backlight driver
2015-09-28 8:12 ` Tomi Valkeinen
@ 2015-09-28 10:31 ` Lee Jones
-1 siblings, 0 replies; 16+ messages in thread
From: Lee Jones @ 2015-09-28 10:31 UTC (permalink / raw)
To: Tomi Valkeinen
Cc: Jingoo Han, Jacek Anaszewski, linux-leds, linux-fbdev, Andrew Lunn
On Mon, 28 Sep 2015, Tomi Valkeinen wrote:
> > 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.
> >
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> > ---
> > drivers/video/backlight/Kconfig | 7 ++
> > drivers/video/backlight/Makefile | 1 +
> > drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 254 insertions(+)
> > create mode 100644 drivers/video/backlight/led_bl.c
>
> Any comments on the backlight side of this series? It is very similar to
> the pwm_bl.c, so I presume the approach is acceptable?
Jingoo?
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCHv3 2/3] backlight: add led-backlight driver
@ 2015-09-28 10:31 ` Lee Jones
0 siblings, 0 replies; 16+ messages in thread
From: Lee Jones @ 2015-09-28 10:31 UTC (permalink / raw)
To: Tomi Valkeinen
Cc: Jingoo Han, Jacek Anaszewski, linux-leds, linux-fbdev, Andrew Lunn
On Mon, 28 Sep 2015, Tomi Valkeinen wrote:
> > 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.
> >
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> > ---
> > drivers/video/backlight/Kconfig | 7 ++
> > drivers/video/backlight/Makefile | 1 +
> > drivers/video/backlight/led_bl.c | 246 +++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 254 insertions(+)
> > create mode 100644 drivers/video/backlight/led_bl.c
>
> Any comments on the backlight side of this series? It is very similar to
> the pwm_bl.c, so I presume the approach is acceptable?
Jingoo?
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 16+ messages in thread
end of thread, other threads:[~2015-09-28 10:31 UTC | newest]
Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-09-11 13:07 [PATCHv3 0/3] backlight: led-backlight driver Tomi Valkeinen
2015-09-11 13:07 ` Tomi Valkeinen
2015-09-11 13:07 ` [PATCHv3 1/3] leds: Add of_led_get() and led_put() Tomi Valkeinen
2015-09-11 13:07 ` Tomi Valkeinen
2015-09-11 13:50 ` Jacek Anaszewski
2015-09-11 13:50 ` Jacek Anaszewski
2015-09-28 8:08 ` Tomi Valkeinen
2015-09-28 8:08 ` Tomi Valkeinen
2015-09-11 13:07 ` [PATCHv3 2/3] backlight: add led-backlight driver Tomi Valkeinen
2015-09-11 13:07 ` Tomi Valkeinen
2015-09-28 8:12 ` Tomi Valkeinen
2015-09-28 8:12 ` Tomi Valkeinen
2015-09-28 10:31 ` Lee Jones
2015-09-28 10:31 ` Lee Jones
2015-09-11 13:07 ` [PATCHv3 3/3] devicetree: Add led-backlight binding Tomi Valkeinen
2015-09-11 13:07 ` Tomi Valkeinen
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