n900 gpio-switch patch

gistfile1.txt

--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -63,6 +63,13 @@ config OMAP_RESET_CLOCKS
 	  probably do not want this option enabled until your
 	  device drivers work properly.
 
+config OMAP_GPIO_SWITCH
+       bool "GPIO switch support"
+       default n
+       help
+         Say Y, if you want to have support for reporting of GPIO
+         switches (e.g. cover switches) via sysfs.
+
 config OMAP_MPU_TIMER
 	bool "Use mpu timer"
 	depends on ARCH_OMAP1
--- a/arch/arm/plat-omap/Makefile
+++ b/arch/arm/plat-omap/Makefile
@@ -11,3 +11,4 @@ obj-y := sram.o dma.o counter_32k.o
 
 obj-$(CONFIG_OMAP_DM_TIMER) += dmtimer.o
 obj-$(CONFIG_OMAP_DEBUG_LEDS) += debug-leds.o
+obj-$(CONFIG_OMAP_GPIO_SWITCH) += gpio-switch.o
--- a/arch/arm/plat-omap/gpio-switch.c
+++ b/arch/arm/plat-omap/gpio-switch.c
@@ -0,0 +1,571 @@
+/*
+ *  linux/arch/arm/plat-omap/gpio-switch.c
+ *
+ *  Copyright (C) 2004-2006 Nokia Corporation
+ *  Written by Juha Yrj�l� <[email protected]>
+ *         and Paul Mundt <[email protected]>
+ *
+ * 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/sched.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/timer.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <plat/gpio-switch.h>
+
+struct gpio_switch {
+	char		name[14];
+	u16		gpio;
+	unsigned	flags:4;
+	unsigned	type:4;
+	unsigned	state:1;
+	unsigned	both_edges:1;
+
+	u16		debounce_rising;
+	u16		debounce_falling;
+
+	int		disabled;
+
+	void (* notify)(void *data, int state);
+	void *notify_data;
+
+	struct work_struct	work;
+	struct timer_list	timer;
+	struct platform_device	pdev;
+
+	struct list_head	node;
+
+	bool		failed;
+};
+
+static LIST_HEAD(gpio_switches);
+static struct platform_device *gpio_sw_platform_dev;
+static struct platform_driver gpio_sw_driver;
+
+static const struct omap_gpio_switch *board_gpio_sw_table;
+static int board_gpio_sw_count;
+
+static const char *cover_str[2] = { "open", "closed" };
+static const char *connection_str[2] = { "disconnected", "connected" };
+static const char *activity_str[2] = { "inactive", "active" };
+
+/*
+ * GPIO switch state default debounce delay in ms
+ */
+#define OMAP_GPIO_SW_DEFAULT_DEBOUNCE		10
+
+static const char **get_sw_str(struct gpio_switch *sw)
+{
+	switch (sw->type) {
+	case OMAP_GPIO_SWITCH_TYPE_COVER:
+		return cover_str;
+	case OMAP_GPIO_SWITCH_TYPE_CONNECTION:
+		return connection_str;
+	case OMAP_GPIO_SWITCH_TYPE_ACTIVITY:
+		return activity_str;
+	default:
+		BUG();
+		return NULL;
+	}
+}
+
+static const char *get_sw_type(struct gpio_switch *sw)
+{
+	switch (sw->type) {
+	case OMAP_GPIO_SWITCH_TYPE_COVER:
+		return "cover";
+	case OMAP_GPIO_SWITCH_TYPE_CONNECTION:
+		return "connection";
+	case OMAP_GPIO_SWITCH_TYPE_ACTIVITY:
+		return "activity";
+	default:
+		BUG();
+		return NULL;
+	}
+}
+
+static void print_sw_state(struct gpio_switch *sw, int state)
+{
+	const char **str;
+
+	str = get_sw_str(sw);
+	if (str != NULL)
+		printk(KERN_INFO "%s (GPIO %d) is now %s\n", sw->name, sw->gpio, str[state]);
+}
+
+static int gpio_sw_get_state(struct gpio_switch *sw)
+{
+	int state = 0;
+
+	if (!sw->failed)
+		state = gpio_get_value(sw->gpio);
+
+	if (sw->flags & OMAP_GPIO_SWITCH_FLAG_INVERTED)
+		state = !state;
+
+	return state;
+}
+
+static ssize_t gpio_sw_state_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf,
+				   size_t count)
+{
+	struct gpio_switch *sw = dev_get_drvdata(dev);
+	const char **str;
+	char state[16];
+	int enable;
+
+	if (!(sw->flags & OMAP_GPIO_SWITCH_FLAG_OUTPUT))
+		return -EPERM;
+
+	if (sscanf(buf, "%15s", state) != 1)
+		return -EINVAL;
+
+	str = get_sw_str(sw);
+	if (strcmp(state, str[0]) == 0)
+		sw->state = enable = 0;
+	else if (strcmp(state, str[1]) == 0)
+		sw->state = enable = 1;
+	else
+		return -EINVAL;
+
+	if (sw->flags & OMAP_GPIO_SWITCH_FLAG_INVERTED)
+		enable = !enable;
+
+	if (!sw->failed)
+		gpio_set_value(sw->gpio, enable);
+
+	return count;
+}
+
+static ssize_t gpio_sw_state_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct gpio_switch *sw = dev_get_drvdata(dev);
+	const char **str;
+
+	if (sw->disabled)
+		sw->state = gpio_sw_get_state(sw);
+	str = get_sw_str(sw);
+	return sprintf(buf, "%s\n", str[sw->state]);
+}
+
+static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, gpio_sw_state_show,
+		   gpio_sw_state_store);
+
+static ssize_t gpio_sw_type_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct gpio_switch *sw = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", get_sw_type(sw));
+}
+
+static DEVICE_ATTR(type, S_IRUGO, gpio_sw_type_show, NULL);
+
+static ssize_t gpio_sw_direction_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct gpio_switch *sw = dev_get_drvdata(dev);
+	int is_output;
+
+	is_output = sw->flags & OMAP_GPIO_SWITCH_FLAG_OUTPUT;
+	return sprintf(buf, "%s\n", is_output ? "output" : "input");
+}
+
+static DEVICE_ATTR(direction, S_IRUGO, gpio_sw_direction_show, NULL);
+
+static ssize_t gpio_sw_disable_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf,
+				   size_t count)
+{
+	struct gpio_switch *sw = dev_get_drvdata(dev);
+	unsigned long res;
+
+	if (kstrtoul(buf, 10, &res) < 0)
+		return -EINVAL;
+
+	if (!!res == sw->disabled)
+		goto out;
+	sw->disabled = !!res;
+
+	if (sw->failed)
+		goto out;
+
+	if (res) {
+		disable_irq(gpio_to_irq(sw->gpio));
+	} else {
+		sw->state = gpio_sw_get_state(sw);
+		enable_irq(gpio_to_irq(sw->gpio));
+	}
+out:
+	return count;
+}
+
+static ssize_t gpio_sw_disable_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct gpio_switch *sw = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", sw->disabled);
+}
+
+static DEVICE_ATTR(disable, S_IRUGO | S_IWUSR, gpio_sw_disable_show,
+		   gpio_sw_disable_store);
+
+static irqreturn_t gpio_sw_irq_handler(int irq, void *arg)
+{
+	struct gpio_switch *sw = arg;
+	unsigned long timeout;
+	int state;
+
+	if (!sw->both_edges && !sw->failed) {
+		if (gpio_get_value(sw->gpio))
+			irq_set_irq_type(gpio_to_irq(sw->gpio), IRQ_TYPE_EDGE_FALLING);
+		else
+			irq_set_irq_type(gpio_to_irq(sw->gpio), IRQ_TYPE_EDGE_RISING);
+	}
+
+	state = gpio_sw_get_state(sw);
+	if (sw->state == state)
+		return IRQ_HANDLED;
+
+	if (state)
+		timeout = sw->debounce_rising;
+	else
+		timeout = sw->debounce_falling;
+	if (!timeout)
+		schedule_work(&sw->work);
+	else
+		mod_timer(&sw->timer, jiffies + msecs_to_jiffies(timeout));
+
+	return IRQ_HANDLED;
+}
+
+static void gpio_sw_timer(unsigned long arg)
+{
+	struct gpio_switch *sw = (struct gpio_switch *) arg;
+
+	schedule_work(&sw->work);
+}
+
+static void gpio_sw_handler(struct work_struct *work)
+{
+	struct gpio_switch *sw = container_of(work, struct gpio_switch, work);
+	int state;
+
+	state = gpio_sw_get_state(sw);
+	if (sw->state == state)
+		return;
+
+	sw->state = state;
+	if (sw->notify != NULL)
+		sw->notify(sw->notify_data, state);
+	sysfs_notify(&sw->pdev.dev.kobj, NULL, "state");
+	print_sw_state(sw, state);
+}
+
+static void gpio_sw_release(struct device *dev)
+{
+}
+
+static int __init new_switch(struct gpio_switch *sw)
+{
+	int r, direction, trigger;
+
+	switch (sw->type) {
+	case OMAP_GPIO_SWITCH_TYPE_COVER:
+	case OMAP_GPIO_SWITCH_TYPE_CONNECTION:
+	case OMAP_GPIO_SWITCH_TYPE_ACTIVITY:
+		break;
+	default:
+		printk(KERN_ERR "invalid GPIO switch type: %d\n", sw->type);
+		return -EINVAL;
+	}
+
+	sw->pdev.name	= sw->name;
+	sw->pdev.id	= -1;
+
+	sw->pdev.dev.parent = &gpio_sw_platform_dev->dev;
+	sw->pdev.dev.driver = &gpio_sw_driver.driver;
+	sw->pdev.dev.release = gpio_sw_release;
+
+	r = platform_device_register(&sw->pdev);
+	if (r) {
+		printk(KERN_ERR "gpio-switch: platform device registration "
+		       "failed for %s", sw->name);
+		return r;
+	}
+	dev_set_drvdata(&sw->pdev.dev, sw);
+
+	if (!sw->failed)
+		r = gpio_request(sw->gpio, sw->name);
+	else
+		r = -EINVAL;
+	if (r < 0) {
+		printk(KERN_ERR "gpio-switch: gpio_reguest failed for %s %d\n",
+				sw->name, sw->gpio);
+		sw->failed = true;
+	}
+
+	/* input: 1, output: 0 */
+	direction = !(sw->flags & OMAP_GPIO_SWITCH_FLAG_OUTPUT);
+	if (!sw->failed) {
+		if (direction) {
+			gpio_direction_input(sw->gpio);
+			sw->state = gpio_sw_get_state(sw);
+		} else {
+			int state = sw->state = !!(sw->flags &
+				OMAP_GPIO_SWITCH_FLAG_OUTPUT_INIT_ACTIVE);
+
+			if (sw->flags & OMAP_GPIO_SWITCH_FLAG_INVERTED)
+				state = !state;
+			gpio_direction_output(sw->gpio, state);
+		}
+	}
+
+	r = 0;
+	r |= device_create_file(&sw->pdev.dev, &dev_attr_state);
+	r |= device_create_file(&sw->pdev.dev, &dev_attr_type);
+	r |= device_create_file(&sw->pdev.dev, &dev_attr_direction);
+	if (direction)
+		r |= device_create_file(&sw->pdev.dev, &dev_attr_disable);
+	if (r)
+		printk(KERN_ERR "gpio-switch: attribute file creation "
+		       "failed for %s\n", sw->name);
+
+	if (!direction)
+		return 0;
+
+	trigger = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING;
+	sw->both_edges = 1;
+
+	if (!sw->failed) {
+		r = request_irq(gpio_to_irq(sw->gpio), gpio_sw_irq_handler,
+				IRQF_SHARED | trigger, sw->name, sw);
+		if (r < 0) {
+			printk(KERN_ERR "gpio-switch: request_irq() failed "
+			       "for GPIO %d\n", sw->gpio);
+			sw->failed = true;
+			gpio_free(sw->gpio);
+		}
+	}
+
+	if (!sw->failed) {
+		INIT_WORK(&sw->work, gpio_sw_handler);
+		init_timer(&sw->timer);
+
+		sw->timer.function = gpio_sw_timer;
+		sw->timer.data = (unsigned long)sw;
+	}
+
+	list_add(&sw->node, &gpio_switches);
+
+	return 0;
+}
+
+static struct gpio_switch * __init find_switch(int gpio, const char *name)
+{
+	struct gpio_switch *sw;
+
+	list_for_each_entry(sw, &gpio_switches, node) {
+		if ((gpio < 0 || sw->gpio != gpio) &&
+		    (name == NULL || strcmp(sw->name, name) != 0))
+			continue;
+
+		if (gpio < 0 || name == NULL)
+			goto no_check;
+
+		if (strcmp(sw->name, name) != 0)
+			printk("gpio-switch: name mismatch for %d (%s, %s)\n",
+			       gpio, name, sw->name);
+		else if (sw->gpio != gpio)
+			printk("gpio-switch: GPIO mismatch for %s (%d, %d)\n",
+			       name, gpio, sw->gpio);
+no_check:
+		return sw;
+	}
+	return NULL;
+}
+
+static int __init add_board_switches(void)
+{
+	int i;
+
+	for (i = 0; i < board_gpio_sw_count; i++) {
+		const struct omap_gpio_switch *cfg;
+		struct gpio_switch *sw;
+		int r;
+
+		cfg = board_gpio_sw_table + i;
+		if (strlen(cfg->name) > sizeof(sw->name) - 1)
+			return -EINVAL;
+		/* Check whether we only update an existing switch
+		 * or add a new switch. */
+		sw = find_switch(cfg->gpio, cfg->name);
+		if (sw != NULL) {
+			sw->debounce_rising = cfg->debounce_rising;
+			sw->debounce_falling = cfg->debounce_falling;
+			sw->notify = cfg->notify;
+			sw->notify_data = cfg->notify_data;
+			continue;
+		} else {
+			if (cfg->gpio < 0 || cfg->name == NULL) {
+				printk("gpio-switch: required switch not "
+				       "found (%d, %s)\n", cfg->gpio,
+				       cfg->name);
+				continue;
+			}
+		}
+		sw = kzalloc(sizeof(*sw), GFP_KERNEL);
+		if (sw == NULL) {
+			printk(KERN_ERR "gpio-switch: kmalloc failed\n");
+			return -ENOMEM;
+		}
+		strlcpy(sw->name, cfg->name, sizeof(sw->name));
+		sw->gpio = cfg->gpio;
+		sw->flags = cfg->flags;
+		sw->type = cfg->type;
+		sw->debounce_rising = cfg->debounce_rising;
+		sw->debounce_falling = cfg->debounce_falling;
+		sw->notify = cfg->notify;
+		sw->notify_data = cfg->notify_data;
+		sw->failed = cfg->failed;
+		if ((r = new_switch(sw)) < 0) {
+			kfree(sw);
+		}
+	}
+	return 0;
+}
+
+static void gpio_sw_cleanup(void)
+{
+	struct gpio_switch *sw = NULL, *old = NULL;
+
+	list_for_each_entry(sw, &gpio_switches, node) {
+		if (old != NULL)
+			kfree(old);
+		flush_scheduled_work();
+		del_timer_sync(&sw->timer);
+
+		if (!sw->failed)
+			free_irq(gpio_to_irq(sw->gpio), sw);
+
+		device_remove_file(&sw->pdev.dev, &dev_attr_state);
+		device_remove_file(&sw->pdev.dev, &dev_attr_type);
+		device_remove_file(&sw->pdev.dev, &dev_attr_direction);
+
+		if (!(sw->flags & OMAP_GPIO_SWITCH_FLAG_OUTPUT))
+			device_remove_file(&sw->pdev.dev, &dev_attr_disable);
+
+		platform_device_unregister(&sw->pdev);
+		if (!sw->failed)
+			gpio_free(sw->gpio);
+		old = sw;
+	}
+	kfree(old);
+}
+
+static void __init report_initial_state(void)
+{
+	struct gpio_switch *sw;
+
+	list_for_each_entry(sw, &gpio_switches, node) {
+		int state = 0;
+
+		if (!sw->failed)
+			state = gpio_get_value(sw->gpio);
+		if (sw->flags & OMAP_GPIO_SWITCH_FLAG_INVERTED)
+			state = !state;
+		if (sw->notify != NULL)
+			sw->notify(sw->notify_data, state);
+		print_sw_state(sw, state);
+	}
+}
+
+static int gpio_sw_remove(struct platform_device *dev)
+{
+	return 0;
+}
+
+static struct platform_driver gpio_sw_driver = {
+	.remove		= gpio_sw_remove,
+	.driver		= {
+		.name	= "gpio-switch",
+	},
+};
+
+void __init omap_register_gpio_switches(const struct omap_gpio_switch *tbl,
+					int count)
+{
+	BUG_ON(board_gpio_sw_table != NULL);
+
+	board_gpio_sw_table = tbl;
+	board_gpio_sw_count = count;
+}
+
+static int __init gpio_sw_init(void)
+{
+	int r;
+
+	printk(KERN_INFO "OMAP GPIO switch handler initializing\n");
+
+	r = platform_driver_register(&gpio_sw_driver);
+	if (r)
+		return r;
+
+	gpio_sw_platform_dev = platform_device_register_simple("gpio-switch",
+							       -1, NULL, 0);
+	if (IS_ERR(gpio_sw_platform_dev)) {
+		r = PTR_ERR(gpio_sw_platform_dev);
+		goto err1;
+	}
+
+	r = add_board_switches();
+	if (r < 0)
+		goto err2;
+
+	report_initial_state();
+
+	return 0;
+err2:
+	gpio_sw_cleanup();
+	platform_device_unregister(gpio_sw_platform_dev);
+err1:
+	platform_driver_unregister(&gpio_sw_driver);
+	return r;
+}
+
+static void __exit gpio_sw_exit(void)
+{
+	gpio_sw_cleanup();
+	platform_device_unregister(gpio_sw_platform_dev);
+	platform_driver_unregister(&gpio_sw_driver);
+}
+
+#ifndef MODULE
+late_initcall(gpio_sw_init);
+#else
+module_init(gpio_sw_init);
+#endif
+module_exit(gpio_sw_exit);
+
+MODULE_AUTHOR("Juha Yrj�l� <[email protected]>, Paul Mundt <[email protected]");
+MODULE_DESCRIPTION("GPIO switch driver");
+MODULE_LICENSE("GPL");
--- a/arch/arm/plat-omap/include/plat/gpio-switch.h
+++ b/arch/arm/plat-omap/include/plat/gpio-switch.h
@@ -0,0 +1,60 @@
+/*
+ * GPIO switch definitions
+ *
+ * Copyright (C) 2006 Nokia Corporation
+ *
+ * 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 __ASM_ARCH_OMAP_GPIO_SWITCH_H
+#define __ASM_ARCH_OMAP_GPIO_SWITCH_H
+
+#include <linux/types.h>
+
+/* Cover:
+ *	high -> closed
+ *	low  -> open
+ * Connection:
+ *	high -> connected
+ *	low  -> disconnected
+ * Activity:
+ *	high -> active
+ *	low  -> inactive
+ *
+ */
+#define OMAP_GPIO_SWITCH_TYPE_COVER			0x0000
+#define OMAP_GPIO_SWITCH_TYPE_CONNECTION		0x0001
+#define OMAP_GPIO_SWITCH_TYPE_ACTIVITY			0x0002
+#define OMAP_GPIO_SWITCH_FLAG_INVERTED			0x0001
+#define OMAP_GPIO_SWITCH_FLAG_OUTPUT			0x0002
+#define OMAP_GPIO_SWITCH_FLAG_OUTPUT_INIT_ACTIVE	0x0004
+
+struct omap_gpio_switch {
+	const char *name;
+	s16 gpio;
+	unsigned flags:4;
+	unsigned type:4;
+
+	/* Time in ms to debounce when transitioning from
+	 * inactive state to active state. */
+	u16 debounce_rising;
+	/* Same for transition from active to inactive state. */
+	u16 debounce_falling;
+
+	/* notify board-specific code about state changes */
+	void (* notify)(void *data, int state);
+	void *notify_data;
+	bool failed;
+};
+
+/* Call at init time only */
+#ifdef CONFIG_OMAP_GPIO_SWITCH
+extern void omap_register_gpio_switches(const struct omap_gpio_switch *tbl,
+					int count);
+#else
+#define omap_register_gpio_switches(tbl, count)	do { } while (0)
+#endif
+
+#endif