From a4c686a6a8cc5938de37451714add5ea872f67c2 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Fri, 6 Feb 2015 13:50:57 +0000
Subject: [PATCH 053/203] 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.
---
 drivers/leds/trigger/Kconfig         |  7 ++++
 drivers/leds/trigger/Makefile        |  1 +
 drivers/leds/trigger/ledtrig-input.c | 65 ++++++++++++++++++++++++++++++++++++
 3 files changed, 73 insertions(+)
 create mode 100644 drivers/leds/trigger/ledtrig-input.c

--- 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 +1,65 @@
+/*
+ * 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"
+
+/* This is a hack to get at the private 'gpio' member */
+
+struct gpio_led_data {
+	struct led_classdev cdev;
+	unsigned gpio;
+};
+
+static void input_trig_activate(struct led_classdev *led_cdev)
+{
+	struct gpio_led_data *led_dat =
+		container_of(led_cdev, struct gpio_led_data, cdev);
+	if (gpio_is_valid(led_dat->gpio))
+		gpio_direction_input(led_dat->gpio);
+}
+
+static void input_trig_deactivate(struct led_classdev *led_cdev)
+{
+	struct gpio_led_data *led_dat =
+		container_of(led_cdev, struct gpio_led_data, cdev);
+	if (gpio_is_valid(led_dat->gpio))
+		gpio_direction_output(led_dat->gpio, 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");