* [PATCH v2 1/3] gpiolib: of: Allow "trigger-sources" to reference a GPIO
2023-09-26 21:48 [PATCH v2 0/3] Rewrite GPIO LED trigger to use trigger-sources Linus Walleij
@ 2023-09-26 21:48 ` Linus Walleij
2023-09-28 21:15 ` Linus Walleij
2023-10-02 7:45 ` Bartosz Golaszewski
2023-09-26 21:48 ` [PATCH v2 2/3] dt-bindings: leds: Mention GPIO triggers Linus Walleij
` (2 subsequent siblings)
3 siblings, 2 replies; 7+ messages in thread
From: Linus Walleij @ 2023-09-26 21:48 UTC (permalink / raw)
To: Jan Kundrát, Pavel Machek, Lee Jones, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Jacek Anaszewski
Cc: linux-leds, linux-gpio, devicetree, Linus Walleij
The "trigger-sources" phandle used for LED triggers are special:
the DT bindings mandate that such triggers have the same phandle
references no matter what the trigger is. A GPIO is just another
kind of device that can trigger a LED.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/gpio/gpiolib-of.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 531faabead0f..f4a660bf11fd 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -611,6 +611,33 @@ static struct gpio_desc *of_find_mt2701_gpio(struct device_node *np,
return desc;
}
+/*
+ * Trigger sources are special, they allow us to use any GPIO as a LED trigger
+ * and have the name "trigger-sources" no matter which kind of phandle it is
+ * pointing to, whether to a GPIO, a USB host, a network PHY etc. So in this case
+ * we allow looking something up that is not named "foo-gpios".
+ */
+static struct gpio_desc *of_find_trigger_gpio(struct device_node *np,
+ const char *con_id,
+ unsigned int idx,
+ enum of_gpio_flags *of_flags)
+{
+ struct gpio_desc *desc;
+
+ if (!IS_ENABLED(CONFIG_LEDS_TRIGGER_GPIO))
+ return ERR_PTR(-ENOENT);
+
+ if (!con_id || strcmp(con_id, "trigger-sources"))
+ return ERR_PTR(-ENOENT);
+
+ desc = of_get_named_gpiod_flags(np, con_id, idx, of_flags);
+ if (!gpiod_not_found(desc))
+ pr_debug("%s is used as a trigger\n", of_node_full_name(np));
+
+ return desc;
+}
+
+
typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np,
const char *con_id,
unsigned int idx,
@@ -618,6 +645,7 @@ typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np,
static const of_find_gpio_quirk of_find_gpio_quirks[] = {
of_find_gpio_rename,
of_find_mt2701_gpio,
+ of_find_trigger_gpio,
NULL
};
--
2.34.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 3/3] leds: triggers: gpio: Rewrite to use trigger-sources
2023-09-26 21:48 [PATCH v2 0/3] Rewrite GPIO LED trigger to use trigger-sources Linus Walleij
2023-09-26 21:48 ` [PATCH v2 1/3] gpiolib: of: Allow "trigger-sources" to reference a GPIO Linus Walleij
2023-09-26 21:48 ` [PATCH v2 2/3] dt-bindings: leds: Mention GPIO triggers Linus Walleij
@ 2023-09-26 21:48 ` Linus Walleij
2023-09-28 14:12 ` (subset) [PATCH v2 0/3] Rewrite GPIO LED trigger " Lee Jones
3 siblings, 0 replies; 7+ messages in thread
From: Linus Walleij @ 2023-09-26 21:48 UTC (permalink / raw)
To: Jan Kundrát, Pavel Machek, Lee Jones, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Jacek Anaszewski
Cc: linux-leds, linux-gpio, devicetree, Linus Walleij
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 <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Fix a use-after-free bug found by Dan Carpenter
---
drivers/leds/trigger/Kconfig | 5 +-
drivers/leds/trigger/ledtrig-gpio.c | 137 +++++++++++-------------------------
2 files changed, 41 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..9b7fe5dd5208 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 <me@felipebalbi.com>
+ * Copyright 2023 Linus Walleij <linus.walleij@linaro.org>
*/
#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 +78,48 @@ 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)) {
+ ret = PTR_ERR(gpio_data->gpiod);
+ kfree(gpio_data);
+ return ret;
+ }
+ 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 +127,8 @@ 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
^ permalink raw reply related [flat|nested] 7+ messages in thread