This rewrites the platform-data GPIO LED trigger to instead
use fwnode trigger-sources to describe the LED used.
This will work out-of-the-box with e.g. device tree.
Signed-off-by: Linus Walleij <[email protected]>
---
Linus Walleij (2):
dt-bindings: leds: Mention GPIO triggers
leds: triggers: gpio: Rewrite to use trigger-sources
Documentation/devicetree/bindings/leds/common.yaml | 2 +
drivers/leds/trigger/Kconfig | 5 +-
drivers/leds/trigger/ledtrig-gpio.c | 136 ++++++---------------
3 files changed, 42 insertions(+), 101 deletions(-)
---
base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
change-id: 20230911-gpio-led-trigger-dt-922bbe21fa22
Best regards,
--
Linus Walleij <[email protected]>
By providing a GPIO line as "trigger-sources" in the FWNODE
(such as from the device tree) and combining with the
GPIO trigger, we can support a GPIO LED trigger in a natural
way from the hardware description instead of using the
custom sysfs and deprecated global GPIO numberspace.
Example:
gpio: gpio@0 {
compatible "my-gpio";
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
#trigger-source-cells = <2>;
};
leds {
compatible = "gpio-leds";
led-my-gpio {
label = "device:blue:myled";
gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
default-state = "off";
linux,default-trigger = "gpio";
trigger-sources = <&gpio 1 GPIO_ACTIVE_HIGH>;
};
};
Make this the norm, unmark the driver as broken.
Delete the sysfs handling of GPIOs.
Since GPIO descriptors inherently can describe inversion,
the inversion handling can just be deleted.
Signed-off-by: Linus Walleij <[email protected]>
---
drivers/leds/trigger/Kconfig | 5 +-
drivers/leds/trigger/ledtrig-gpio.c | 136 +++++++++++-------------------------
2 files changed, 40 insertions(+), 101 deletions(-)
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index 2a57328eca20..d11d80176fc0 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig
@@ -83,13 +83,10 @@ config LEDS_TRIGGER_ACTIVITY
config LEDS_TRIGGER_GPIO
tristate "LED GPIO Trigger"
depends on GPIOLIB || COMPILE_TEST
- depends on BROKEN
help
This allows LEDs to be controlled by gpio events. It's good
when using gpios as switches and triggering the needed LEDs
- from there. One use case is n810's keypad LEDs that could
- be triggered by this trigger when user slides up to show
- keypad.
+ from there. Triggers are defined as device properties.
If unsure, say N.
diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c
index 0120faa3dafa..a9caab7998a9 100644
--- a/drivers/leds/trigger/ledtrig-gpio.c
+++ b/drivers/leds/trigger/ledtrig-gpio.c
@@ -3,12 +3,13 @@
* ledtrig-gio.c - LED Trigger Based on GPIO events
*
* Copyright 2009 Felipe Balbi <[email protected]>
+ * Copyright 2023 Linus Walleij <[email protected]>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/leds.h>
#include <linux/slab.h>
@@ -16,10 +17,8 @@
struct gpio_trig_data {
struct led_classdev *led;
-
unsigned desired_brightness; /* desired brightness when led is on */
- unsigned inverted; /* true when gpio is inverted */
- unsigned gpio; /* gpio that triggers the leds */
+ struct gpio_desc *gpiod; /* gpio that triggers the led */
};
static irqreturn_t gpio_trig_irq(int irq, void *_led)
@@ -28,10 +27,7 @@ static irqreturn_t gpio_trig_irq(int irq, void *_led)
struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
int tmp;
- tmp = gpio_get_value_cansleep(gpio_data->gpio);
- if (gpio_data->inverted)
- tmp = !tmp;
-
+ tmp = gpiod_get_value_cansleep(gpio_data->gpiod);
if (tmp) {
if (gpio_data->desired_brightness)
led_set_brightness_nosleep(gpio_data->led,
@@ -73,93 +69,8 @@ static ssize_t gpio_trig_brightness_store(struct device *dev,
static DEVICE_ATTR(desired_brightness, 0644, gpio_trig_brightness_show,
gpio_trig_brightness_store);
-static ssize_t gpio_trig_inverted_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
-
- return sprintf(buf, "%u\n", gpio_data->inverted);
-}
-
-static ssize_t gpio_trig_inverted_store(struct device *dev,
- struct device_attribute *attr, const char *buf, size_t n)
-{
- struct led_classdev *led = led_trigger_get_led(dev);
- struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
- unsigned long inverted;
- int ret;
-
- ret = kstrtoul(buf, 10, &inverted);
- if (ret < 0)
- return ret;
-
- if (inverted > 1)
- return -EINVAL;
-
- gpio_data->inverted = inverted;
-
- /* After inverting, we need to update the LED. */
- if (gpio_is_valid(gpio_data->gpio))
- gpio_trig_irq(0, led);
-
- return n;
-}
-static DEVICE_ATTR(inverted, 0644, gpio_trig_inverted_show,
- gpio_trig_inverted_store);
-
-static ssize_t gpio_trig_gpio_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
-
- return sprintf(buf, "%u\n", gpio_data->gpio);
-}
-
-static ssize_t gpio_trig_gpio_store(struct device *dev,
- struct device_attribute *attr, const char *buf, size_t n)
-{
- struct led_classdev *led = led_trigger_get_led(dev);
- struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
- unsigned gpio;
- int ret;
-
- ret = sscanf(buf, "%u", &gpio);
- if (ret < 1) {
- dev_err(dev, "couldn't read gpio number\n");
- return -EINVAL;
- }
-
- if (gpio_data->gpio == gpio)
- return n;
-
- if (!gpio_is_valid(gpio)) {
- if (gpio_is_valid(gpio_data->gpio))
- free_irq(gpio_to_irq(gpio_data->gpio), led);
- gpio_data->gpio = gpio;
- return n;
- }
-
- ret = request_threaded_irq(gpio_to_irq(gpio), NULL, gpio_trig_irq,
- IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_RISING
- | IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
- if (ret) {
- dev_err(dev, "request_irq failed with error %d\n", ret);
- } else {
- if (gpio_is_valid(gpio_data->gpio))
- free_irq(gpio_to_irq(gpio_data->gpio), led);
- gpio_data->gpio = gpio;
- /* After changing the GPIO, we need to update the LED. */
- gpio_trig_irq(0, led);
- }
-
- return ret ? ret : n;
-}
-static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store);
-
static struct attribute *gpio_trig_attrs[] = {
&dev_attr_desired_brightness.attr,
- &dev_attr_inverted.attr,
- &dev_attr_gpio.attr,
NULL
};
ATTRIBUTE_GROUPS(gpio_trig);
@@ -167,16 +78,47 @@ ATTRIBUTE_GROUPS(gpio_trig);
static int gpio_trig_activate(struct led_classdev *led)
{
struct gpio_trig_data *gpio_data;
+ struct device *dev = led->dev;
+ int ret;
gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
if (!gpio_data)
return -ENOMEM;
- gpio_data->led = led;
- gpio_data->gpio = -ENOENT;
+ /*
+ * The generic property "trigger-sources" is followed,
+ * and we hope that this is a GPIO.
+ */
+ gpio_data->gpiod = fwnode_gpiod_get_index(dev->fwnode,
+ "trigger-sources",
+ 0, GPIOD_IN,
+ "led-trigger");
+ if (IS_ERR(gpio_data->gpiod)) {
+ kfree(gpio_data);
+ return PTR_ERR(gpio_data->gpiod);
+ }
+ if (!gpio_data->gpiod) {
+ dev_err(dev, "no valid GPIO for the trigger\n");
+ kfree(gpio_data);
+ return -EINVAL;
+ }
+ gpio_data->led = led;
led_set_trigger_data(led, gpio_data);
+ ret = request_threaded_irq(gpiod_to_irq(gpio_data->gpiod), NULL, gpio_trig_irq,
+ IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_RISING
+ | IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
+ if (ret) {
+ dev_err(dev, "request_irq failed with error %d\n", ret);
+ gpiod_put(gpio_data->gpiod);
+ kfree(gpio_data);
+ return ret;
+ }
+
+ /* Finally update the LED to initial status */
+ gpio_trig_irq(0, led);
+
return 0;
}
@@ -184,8 +126,8 @@ static void gpio_trig_deactivate(struct led_classdev *led)
{
struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
- if (gpio_is_valid(gpio_data->gpio))
- free_irq(gpio_to_irq(gpio_data->gpio), led);
+ free_irq(gpiod_to_irq(gpio_data->gpiod), led);
+ gpiod_put(gpio_data->gpiod);
kfree(gpio_data);
}
--
2.34.1
We reuse the trigger-sources phandle to just point to
GPIOs we may want to use as LED triggers.
Example:
gpio: gpio@0 {
compatible "my-gpio";
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
#trigger-source-cells = <2>;
};
leds {
compatible = "gpio-leds";
led-my-gpio {
label = "device:blue:myled";
gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
default-state = "off";
linux,default-trigger = "gpio";
trigger-sources = <&gpio 1 GPIO_ACTIVE_HIGH>;
};
};
Signed-off-by: Linus Walleij <[email protected]>
---
Documentation/devicetree/bindings/leds/common.yaml | 2 ++
1 file changed, 2 insertions(+)
diff --git a/Documentation/devicetree/bindings/leds/common.yaml b/Documentation/devicetree/bindings/leds/common.yaml
index 5fb7007f3618..b42950643b9d 100644
--- a/Documentation/devicetree/bindings/leds/common.yaml
+++ b/Documentation/devicetree/bindings/leds/common.yaml
@@ -191,6 +191,8 @@ properties:
each of them having its own LED assigned (assuming they are not
hardwired). In such cases this property should contain phandle(s) of
related source device(s).
+ Another example is a GPIO line that will be monitored and mirror the
+ state of the line (with or without inversion flags) to the LED.
In many cases LED can be related to more than one device (e.g. one USB LED
vs. multiple USB ports). Each source should be represented by a node in
the device tree and be referenced by a phandle and a set of phandle
--
2.34.1
Hi Linus,
kernel test robot noticed the following build warnings:
url: https://github.com/intel-lab-lkp/linux/commits/Linus-Walleij/dt-bindings-leds-Mention-GPIO-triggers/20230912-214554
base: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
patch link: https://lore.kernel.org/r/20230912-gpio-led-trigger-dt-v1-2-1b50e3756dda%40linaro.org
patch subject: [PATCH 2/2] leds: triggers: gpio: Rewrite to use trigger-sources
config: x86_64-randconfig-161-20230913 (https://download.01.org/0day-ci/archive/20230914/[email protected]/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230914/[email protected]/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Reported-by: Dan Carpenter <[email protected]>
| Closes: https://lore.kernel.org/r/[email protected]/
smatch warnings:
drivers/leds/trigger/ledtrig-gpio.c:98 gpio_trig_activate() error: dereferencing freed memory 'gpio_data'
vim +/gpio_data +98 drivers/leds/trigger/ledtrig-gpio.c
2282e125a406e0 drivers/leds/trigger/ledtrig-gpio.c Uwe Kleine-K?nig 2018-07-02 78 static int gpio_trig_activate(struct led_classdev *led)
17354bfe85275f drivers/leds/ledtrig-gpio.c Felipe Balbi 2009-02-17 79 {
17354bfe85275f drivers/leds/ledtrig-gpio.c Felipe Balbi 2009-02-17 80 struct gpio_trig_data *gpio_data;
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 81 struct device *dev = led->dev;
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 82 int ret;
17354bfe85275f drivers/leds/ledtrig-gpio.c Felipe Balbi 2009-02-17 83
17354bfe85275f drivers/leds/ledtrig-gpio.c Felipe Balbi 2009-02-17 84 gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
17354bfe85275f drivers/leds/ledtrig-gpio.c Felipe Balbi 2009-02-17 85 if (!gpio_data)
9bfd7d9e5d6353 drivers/leds/trigger/ledtrig-gpio.c Uwe Kleine-K?nig 2018-07-02 86 return -ENOMEM;
17354bfe85275f drivers/leds/ledtrig-gpio.c Felipe Balbi 2009-02-17 87
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 88 /*
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 89 * The generic property "trigger-sources" is followed,
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 90 * and we hope that this is a GPIO.
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 91 */
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 92 gpio_data->gpiod = fwnode_gpiod_get_index(dev->fwnode,
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 93 "trigger-sources",
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 94 0, GPIOD_IN,
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 95 "led-trigger");
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 96 if (IS_ERR(gpio_data->gpiod)) {
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 97 kfree(gpio_data);
^^^^^^^^^^^^^^^^
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 @98 return PTR_ERR(gpio_data->gpiod);
^^^^^^^^^^^^^^^^
Dereferencing freed memory.
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 99 }
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 100 if (!gpio_data->gpiod) {
2689cea6283a47 drivers/leds/trigger/ledtrig-gpio.c Linus Walleij 2023-09-12 101 dev_err(dev, "no valid GPIO for the trigger\n");
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On Tue, Sep 12, 2023 at 03:44:31PM +0200, Linus Walleij wrote:
> By providing a GPIO line as "trigger-sources" in the FWNODE
> (such as from the device tree) and combining with the
> GPIO trigger, we can support a GPIO LED trigger in a natural
> way from the hardware description instead of using the
> custom sysfs and deprecated global GPIO numberspace.
>
> Example:
>
> gpio: gpio@0 {
> compatible "my-gpio";
> gpio-controller;
> #gpio-cells = <2>;
> interrupt-controller;
> #interrupt-cells = <2>;
> #trigger-source-cells = <2>;
> };
>
> leds {
> compatible = "gpio-leds";
> led-my-gpio {
> label = "device:blue:myled";
> gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
> default-state = "off";
> linux,default-trigger = "gpio";
> trigger-sources = <&gpio 1 GPIO_ACTIVE_HIGH>;
> };
> };
>
> Make this the norm, unmark the driver as broken.
>
> Delete the sysfs handling of GPIOs.
>
> Since GPIO descriptors inherently can describe inversion,
> the inversion handling can just be deleted.
>
> Signed-off-by: Linus Walleij <[email protected]>
> ---
[...]
> @@ -167,16 +78,47 @@ ATTRIBUTE_GROUPS(gpio_trig);
> static int gpio_trig_activate(struct led_classdev *led)
> {
> struct gpio_trig_data *gpio_data;
> + struct device *dev = led->dev;
> + int ret;
>
> gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
> if (!gpio_data)
> return -ENOMEM;
>
> - gpio_data->led = led;
> - gpio_data->gpio = -ENOENT;
> + /*
> + * The generic property "trigger-sources" is followed,
> + * and we hope that this is a GPIO.
> + */
> + gpio_data->gpiod = fwnode_gpiod_get_index(dev->fwnode,
> + "trigger-sources",
> + 0, GPIOD_IN,
> + "led-trigger");
Isn't this going to look for "trigger-sources-gpio" and
""trigger-sources-gpios"?
Rob
On Fri, Sep 15, 2023 at 4:15 PM Rob Herring <[email protected]> wrote:
> > + /*
> > + * The generic property "trigger-sources" is followed,
> > + * and we hope that this is a GPIO.
> > + */
> > + gpio_data->gpiod = fwnode_gpiod_get_index(dev->fwnode,
> > + "trigger-sources",
> > + 0, GPIOD_IN,
> > + "led-trigger");
>
> Isn't this going to look for "trigger-sources-gpio" and
> ""trigger-sources-gpios"?
Indeed. I'll simply code an exception for this into
gpiolib-of.c, it's an OF pecularity after all.
Yours,
Linus Walleij