You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
170 lines
5.6 KiB
170 lines
5.6 KiB
From 211b0053ad2b173e646e4db1b5dd2f51a2da4ed7 Mon Sep 17 00:00:00 2001
|
|
From: Phil Elwell <phil@raspberrypi.org>
|
|
Date: Fri, 6 Feb 2015 13:50:57 +0000
|
|
Subject: [PATCH 073/381] BCM270x_DT: Add pwr_led, and the required "input"
|
|
trigger
|
|
|
|
The "input" trigger makes the associated GPIO an input. This is to support
|
|
the Raspberry Pi PWR LED, which is driven by external hardware in normal use.
|
|
|
|
N.B. pwr_led is not available on Model A or B boards.
|
|
|
|
leds-gpio: Implement the brightness_get method
|
|
|
|
The power LED uses some clever logic that means it is driven
|
|
by a voltage measuring circuit when configured as input, otherwise
|
|
it is driven by the GPIO output value. This patch wires up the
|
|
brightness_get method for leds-gpio so that user-space can monitor
|
|
the LED value via /sys/class/gpio/led1/brightness. Using the input
|
|
trigger this returns an indication of the system power health,
|
|
otherwise it is just whatever value the trigger has written most
|
|
recently.
|
|
|
|
See: https://github.com/raspberrypi/linux/issues/1064
|
|
---
|
|
drivers/leds/leds-gpio.c | 18 +++++++++++-
|
|
drivers/leds/trigger/Kconfig | 7 +++++
|
|
drivers/leds/trigger/Makefile | 1 +
|
|
drivers/leds/trigger/ledtrig-input.c | 54 ++++++++++++++++++++++++++++++++++++
|
|
include/linux/leds.h | 3 ++
|
|
5 files changed, 82 insertions(+), 1 deletion(-)
|
|
create mode 100644 drivers/leds/trigger/ledtrig-input.c
|
|
|
|
--- a/drivers/leds/leds-gpio.c
|
|
+++ b/drivers/leds/leds-gpio.c
|
|
@@ -42,6 +42,13 @@ static void gpio_led_work(struct work_st
|
|
led_dat->platform_gpio_blink_set(led_dat->gpiod,
|
|
led_dat->new_level, NULL, NULL);
|
|
led_dat->blinking = 0;
|
|
+ } else if (led_dat->cdev.flags & SET_GPIO_INPUT) {
|
|
+ gpiod_direction_input(led_dat->gpiod);
|
|
+ led_dat->cdev.flags &= ~SET_GPIO_INPUT;
|
|
+ }
|
|
+ else if (led_dat->cdev.flags & SET_GPIO_OUTPUT) {
|
|
+ gpiod_direction_output(led_dat->gpiod, led_dat->new_level);
|
|
+ led_dat->cdev.flags &= ~SET_GPIO_OUTPUT;
|
|
} else
|
|
gpiod_set_value_cansleep(led_dat->gpiod, led_dat->new_level);
|
|
}
|
|
@@ -62,7 +69,8 @@ static void gpio_led_set(struct led_clas
|
|
* seem to have a reliable way to know if we're already in one; so
|
|
* let's just assume the worst.
|
|
*/
|
|
- if (led_dat->can_sleep) {
|
|
+ if (led_dat->can_sleep ||
|
|
+ (led_dat->cdev.flags & (SET_GPIO_INPUT | SET_GPIO_OUTPUT) )) {
|
|
led_dat->new_level = level;
|
|
schedule_work(&led_dat->work);
|
|
} else {
|
|
@@ -75,6 +83,13 @@ static void gpio_led_set(struct led_clas
|
|
}
|
|
}
|
|
|
|
+static enum led_brightness gpio_led_get(struct led_classdev *led_cdev)
|
|
+{
|
|
+ struct gpio_led_data *led_dat =
|
|
+ container_of(led_cdev, struct gpio_led_data, cdev);
|
|
+ return gpiod_get_value_cansleep(led_dat->gpiod) ? LED_FULL : LED_OFF;
|
|
+}
|
|
+
|
|
static int gpio_blink_set(struct led_classdev *led_cdev,
|
|
unsigned long *delay_on, unsigned long *delay_off)
|
|
{
|
|
@@ -131,6 +146,7 @@ static int create_gpio_led(const struct
|
|
led_dat->cdev.blink_set = gpio_blink_set;
|
|
}
|
|
led_dat->cdev.brightness_set = gpio_led_set;
|
|
+ led_dat->cdev.brightness_get = gpio_led_get;
|
|
if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
|
|
state = !!gpiod_get_value_cansleep(led_dat->gpiod);
|
|
else
|
|
--- a/drivers/leds/trigger/Kconfig
|
|
+++ b/drivers/leds/trigger/Kconfig
|
|
@@ -126,4 +126,11 @@ config LEDS_TRIGGER_USBDEV
|
|
This allows LEDs to be controlled by the presence/activity of
|
|
an USB device. If unsure, say N.
|
|
|
|
+config LEDS_TRIGGER_INPUT
|
|
+ tristate "LED Input Trigger"
|
|
+ depends on LEDS_TRIGGERS
|
|
+ help
|
|
+ This allows the GPIOs assigned to be LEDs to be initialised to inputs.
|
|
+ If unsure, say Y.
|
|
+
|
|
endif # LEDS_TRIGGERS
|
|
--- a/drivers/leds/trigger/Makefile
|
|
+++ b/drivers/leds/trigger/Makefile
|
|
@@ -8,3 +8,4 @@ obj-$(CONFIG_LEDS_TRIGGER_CPU) += ledtr
|
|
obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON) += ledtrig-default-on.o
|
|
obj-$(CONFIG_LEDS_TRIGGER_TRANSIENT) += ledtrig-transient.o
|
|
obj-$(CONFIG_LEDS_TRIGGER_CAMERA) += ledtrig-camera.o
|
|
+obj-$(CONFIG_LEDS_TRIGGER_INPUT) += ledtrig-input.o
|
|
--- /dev/null
|
|
+++ b/drivers/leds/trigger/ledtrig-input.c
|
|
@@ -0,0 +1,54 @@
|
|
+/*
|
|
+ * Set LED GPIO to Input "Trigger"
|
|
+ *
|
|
+ * Copyright 2015 Phil Elwell <phil@raspberrypi.org>
|
|
+ *
|
|
+ * Based on Nick Forbes's ledtrig-default-on.c.
|
|
+ *
|
|
+ * 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/module.h>
|
|
+#include <linux/kernel.h>
|
|
+#include <linux/init.h>
|
|
+#include <linux/leds.h>
|
|
+#include <linux/gpio.h>
|
|
+#include "../leds.h"
|
|
+
|
|
+static void input_trig_activate(struct led_classdev *led_cdev)
|
|
+{
|
|
+ led_cdev->flags |= SET_GPIO_INPUT;
|
|
+ led_set_brightness_async(led_cdev, 0);
|
|
+}
|
|
+
|
|
+static void input_trig_deactivate(struct led_classdev *led_cdev)
|
|
+{
|
|
+ led_cdev->flags |= SET_GPIO_OUTPUT;
|
|
+ led_set_brightness_async(led_cdev, 0);
|
|
+}
|
|
+
|
|
+static struct led_trigger input_led_trigger = {
|
|
+ .name = "input",
|
|
+ .activate = input_trig_activate,
|
|
+ .deactivate = input_trig_deactivate,
|
|
+};
|
|
+
|
|
+static int __init input_trig_init(void)
|
|
+{
|
|
+ return led_trigger_register(&input_led_trigger);
|
|
+}
|
|
+
|
|
+static void __exit input_trig_exit(void)
|
|
+{
|
|
+ led_trigger_unregister(&input_led_trigger);
|
|
+}
|
|
+
|
|
+module_init(input_trig_init);
|
|
+module_exit(input_trig_exit);
|
|
+
|
|
+MODULE_AUTHOR("Phil Elwell <phil@raspberrypi.org>");
|
|
+MODULE_DESCRIPTION("Set LED GPIO to Input \"trigger\"");
|
|
+MODULE_LICENSE("GPL");
|
|
--- a/include/linux/leds.h
|
|
+++ b/include/linux/leds.h
|
|
@@ -48,6 +48,9 @@ struct led_classdev {
|
|
#define SET_BRIGHTNESS_ASYNC (1 << 21)
|
|
#define SET_BRIGHTNESS_SYNC (1 << 22)
|
|
#define LED_DEV_CAP_FLASH (1 << 23)
|
|
+ /* Additions for Raspberry Pi PWR LED */
|
|
+#define SET_GPIO_INPUT (1 << 30)
|
|
+#define SET_GPIO_OUTPUT (1 << 31)
|
|
|
|
/* Set LED brightness level */
|
|
/* Must not sleep, use a workqueue if needed */
|
|
|