arch/arm/mach-msm/board-sapphire-h2w.c - android_kernel_htc_msm8974 - Gitiles

 /*
  *  H2W device detection driver.
  *
  * Copyright (C) 2008 HTC Corporation.
  * Copyright (C) 2008 Google, Inc.
  *
  * Authors:
  *  Laurence Chen <Laurence_Chen@htc.com>
  *  Nick Pelly <npelly@google.com>
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  */


 #include <linux/module.h>
 #include <linux/sysdev.h>
 #include <linux/fs.h>
 #include <linux/interrupt.h>
 #include <linux/workqueue.h>
 #include <linux/irq.h>
 #include <linux/delay.h>
 #include <linux/types.h>
 #include <linux/input.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/hrtimer.h>
 #include <linux/switch.h>
 #include <linux/input.h>
 #include <linux/debugfs.h>
 #include <linux/gpio.h>
 #include <asm/atomic.h>
 #include <mach/board.h>
 #include <mach/vreg.h>
 #include <asm/mach-types.h>
 #include "board-sapphire.h"

 #ifdef CONFIG_DEBUG_SAPPHIRE_H2W
 #define H2W_DBG(fmt, arg...) printk(KERN_INFO "[H2W] %s " fmt "\n", __FUNCTION__, ## arg)
 #else
 #define H2W_DBG(fmt, arg...) do {} while (0)
 #endif

 static struct workqueue_struct *g_detection_work_queue;
 static void detection_work(struct work_struct *work);
 static DECLARE_WORK(g_detection_work, detection_work);
 enum {
 	NO_DEVICE	= 0,
 	HTC_HEADSET	= 1,
 };

 enum {
 	UART3		= 0,
 	GPIO		= 1,
 };

 struct h2w_info {
 	struct switch_dev sdev;
 	struct input_dev *input;

 	atomic_t btn_state;
 	int ignore_btn;

 	unsigned int irq;
 	unsigned int irq_btn;

 	struct hrtimer timer;
 	ktime_t debounce_time;

 	struct hrtimer btn_timer;
 	ktime_t btn_debounce_time;
 };
 static struct h2w_info *hi;

 static ssize_t sapphire_h2w_print_name(struct switch_dev *sdev, char *buf)
 {
 	switch (switch_get_state(&hi->sdev)) {
 	case NO_DEVICE:
 		return sprintf(buf, "No Device\n");
 	case HTC_HEADSET:
 		return sprintf(buf, "Headset\n");
 	}
 	return -EINVAL;
 }

 static void configure_cpld(int route)
 {
 	H2W_DBG(" route = %s", route == UART3 ? "UART3" : "GPIO");
 	switch (route) {
 	case UART3:
 		gpio_set_value(SAPPHIRE_GPIO_H2W_SEL0, 0);
 		gpio_set_value(SAPPHIRE_GPIO_H2W_SEL1, 1);
 		break;
 	case GPIO:
 		gpio_set_value(SAPPHIRE_GPIO_H2W_SEL0, 0);
 		gpio_set_value(SAPPHIRE_GPIO_H2W_SEL1, 0);
 		break;
 	}
 }

 static void button_pressed(void)
 {
 	H2W_DBG("");
 	atomic_set(&hi->btn_state, 1);
 	input_report_key(hi->input, KEY_MEDIA, 1);
 	input_sync(hi->input);
 }

 static void button_released(void)
 {
 	H2W_DBG("");
 	atomic_set(&hi->btn_state, 0);
 	input_report_key(hi->input, KEY_MEDIA, 0);
 	input_sync(hi->input);
 }

 #ifdef CONFIG_MSM_SERIAL_DEBUGGER
 extern void msm_serial_debug_enable(int);
 #endif

 static void insert_headset(void)
 {
 	unsigned long irq_flags;

 	H2W_DBG("");

 	switch_set_state(&hi->sdev, HTC_HEADSET);
 	configure_cpld(GPIO);

 #ifdef CONFIG_MSM_SERIAL_DEBUGGER
 	msm_serial_debug_enable(false);
 #endif


 	hi->ignore_btn = !gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2);


 	local_irq_save(irq_flags);
 	enable_irq(hi->irq_btn);
 	local_irq_restore(irq_flags);

 	hi->debounce_time = ktime_set(0, 20000000);
 }

 static void remove_headset(void)
 {
 	unsigned long irq_flags;

 	H2W_DBG("");

 	switch_set_state(&hi->sdev, NO_DEVICE);
 	configure_cpld(UART3);


 	local_irq_save(irq_flags);
 	disable_irq(hi->irq_btn);
 	local_irq_restore(irq_flags);

 	if (atomic_read(&hi->btn_state))
 		button_released();

 	hi->debounce_time = ktime_set(0, 100000000);
 }

 static void detection_work(struct work_struct *work)
 {
 	unsigned long irq_flags;
 	int clk, cable_in1;

 	H2W_DBG("");

 	if (gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1) != 0) {

 		if (switch_get_state(&hi->sdev) == HTC_HEADSET)
 			remove_headset();
 		return;
 	}


 	configure_cpld(GPIO);

 	local_irq_save(irq_flags);
 	disable_irq(hi->irq);
 	local_irq_restore(irq_flags);


 	gpio_direction_output(SAPPHIRE_GPIO_CABLE_IN1, 1);

 	msleep(10);

 	clk = gpio_get_value(SAPPHIRE_GPIO_H2W_CLK_GPI);

 	gpio_direction_input(SAPPHIRE_GPIO_CABLE_IN1);


 	local_irq_save(irq_flags);
 	enable_irq(hi->irq);
 	local_irq_restore(irq_flags);

 	cable_in1 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1);

 	if (cable_in1 == 0 && clk == 0) {
 		if (switch_get_state(&hi->sdev) == NO_DEVICE)
 			insert_headset();
 	} else {
 		configure_cpld(UART3);
 		H2W_DBG("CABLE_IN1 was low, but not a headset "
 			"(recent cable_in1 = %d, clk = %d)", cable_in1, clk);
 	}
 }

 static enum hrtimer_restart button_event_timer_func(struct hrtimer *data)
 {
 	H2W_DBG("");

 	if (switch_get_state(&hi->sdev) == HTC_HEADSET) {
 		if (gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2)) {
 			if (hi->ignore_btn)
 				hi->ignore_btn = 0;
 			else if (atomic_read(&hi->btn_state))
 				button_released();
 		} else {
 			if (!hi->ignore_btn && !atomic_read(&hi->btn_state))
 				button_pressed();
 		}
 	}

 	return HRTIMER_NORESTART;
 }

 static enum hrtimer_restart detect_event_timer_func(struct hrtimer *data)
 {
 	H2W_DBG("");

 	queue_work(g_detection_work_queue, &g_detection_work);
 	return HRTIMER_NORESTART;
 }

 static irqreturn_t detect_irq_handler(int irq, void *dev_id)
 {
 	int value1, value2;
 	int retry_limit = 10;

 	H2W_DBG("");
 	do {
 		value1 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1);
 		set_irq_type(hi->irq, value1 ?
 				IRQF_TRIGGER_LOW : IRQF_TRIGGER_HIGH);
 		value2 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1);
 	} while (value1 != value2 && retry_limit-- > 0);

 	H2W_DBG("value2 = %d (%d retries)", value2, (10-retry_limit));

 	if ((switch_get_state(&hi->sdev) == NO_DEVICE) ^ value2) {
 		if (switch_get_state(&hi->sdev) == HTC_HEADSET)
 			hi->ignore_btn = 1;

 		hrtimer_start(&hi->timer, hi->debounce_time, HRTIMER_MODE_REL);
 	}

 	return IRQ_HANDLED;
 }

 static irqreturn_t button_irq_handler(int irq, void *dev_id)
 {
 	int value1, value2;
 	int retry_limit = 10;

 	H2W_DBG("");
 	do {
 		value1 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2);
 		set_irq_type(hi->irq_btn, value1 ?
 				IRQF_TRIGGER_LOW : IRQF_TRIGGER_HIGH);
 		value2 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2);
 	} while (value1 != value2 && retry_limit-- > 0);

 	H2W_DBG("value2 = %d (%d retries)", value2, (10-retry_limit));

 	hrtimer_start(&hi->btn_timer, hi->btn_debounce_time, HRTIMER_MODE_REL);

 	return IRQ_HANDLED;
 }

 #if defined(CONFIG_DEBUG_FS)
 static void h2w_debug_set(void *data, u64 val)
 {
 	switch_set_state(&hi->sdev, (int)val);
 }

 static u64 h2w_debug_get(void *data)
 {
 	return 0;
 }

 DEFINE_SIMPLE_ATTRIBUTE(h2w_debug_fops, h2w_debug_get, h2w_debug_set, "%llu\n");
 static int __init h2w_debug_init(void)
 {
 	struct dentry *dent;

 	dent = debugfs_create_dir("h2w", 0);
 	if (IS_ERR(dent))
 		return PTR_ERR(dent);

 	debugfs_create_file("state", 0644, dent, NULL, &h2w_debug_fops);

 	return 0;
 }

 device_initcall(h2w_debug_init);
 #endif

 static int sapphire_h2w_probe(struct platform_device *pdev)
 {
 	int ret;
 	unsigned long irq_flags;

 	printk(KERN_INFO "H2W: Registering H2W (headset) driver\n");
 	hi = kzalloc(sizeof(struct h2w_info), GFP_KERNEL);
 	if (!hi)
 		return -ENOMEM;

 	atomic_set(&hi->btn_state, 0);
 	hi->ignore_btn = 0;

 	hi->debounce_time = ktime_set(0, 100000000);
 	hi->btn_debounce_time = ktime_set(0, 10000000);
 	hi->sdev.name = "h2w";
 	hi->sdev.print_name = sapphire_h2w_print_name;

 	ret = switch_dev_register(&hi->sdev);
 	if (ret < 0)
 		goto err_switch_dev_register;

 	g_detection_work_queue = create_workqueue("detection");
 	if (g_detection_work_queue == NULL) {
 		ret = -ENOMEM;
 		goto err_create_work_queue;
 	}

 	ret = gpio_request(SAPPHIRE_GPIO_CABLE_IN1, "h2w_detect");
 	if (ret < 0)
 		goto err_request_detect_gpio;

 	ret = gpio_request(SAPPHIRE_GPIO_CABLE_IN2, "h2w_button");
 	if (ret < 0)
 		goto err_request_button_gpio;

 	ret = gpio_direction_input(SAPPHIRE_GPIO_CABLE_IN1);
 	if (ret < 0)
 		goto err_set_detect_gpio;

 	ret = gpio_direction_input(SAPPHIRE_GPIO_CABLE_IN2);
 	if (ret < 0)
 		goto err_set_button_gpio;

 	hi->irq = gpio_to_irq(SAPPHIRE_GPIO_CABLE_IN1);
 	if (hi->irq < 0) {
 		ret = hi->irq;
 		goto err_get_h2w_detect_irq_num_failed;
 	}

 	hi->irq_btn = gpio_to_irq(SAPPHIRE_GPIO_CABLE_IN2);
 	if (hi->irq_btn < 0) {
 		ret = hi->irq_btn;
 		goto err_get_button_irq_num_failed;
 	}


 	configure_cpld(UART3);

 	gpio_set_value(SAPPHIRE_GPIO_H2W_CLK_DIR, 0);
 	gpio_set_value(SAPPHIRE_GPIO_H2W_DAT_DIR, 0);

 	hrtimer_init(&hi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hi->timer.function = detect_event_timer_func;
 	hrtimer_init(&hi->btn_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hi->btn_timer.function = button_event_timer_func;

 	ret = request_irq(hi->irq, detect_irq_handler,
 			  IRQF_TRIGGER_LOW, "h2w_detect", NULL);
 	if (ret < 0)
 		goto err_request_detect_irq;


 	set_irq_flags(hi->irq_btn, IRQF_VALID | IRQF_NOAUTOEN);
 	ret = request_irq(hi->irq_btn, button_irq_handler,
 			  IRQF_TRIGGER_LOW, "h2w_button", NULL);
 	if (ret < 0)
 		goto err_request_h2w_headset_button_irq;

 	ret = set_irq_wake(hi->irq, 1);
 	if (ret < 0)
 		goto err_request_input_dev;
 	ret = set_irq_wake(hi->irq_btn, 1);
 	if (ret < 0)
 		goto err_request_input_dev;

 	hi->input = input_allocate_device();
 	if (!hi->input) {
 		ret = -ENOMEM;
 		goto err_request_input_dev;
 	}

 	hi->input->name = "h2w headset";
 	hi->input->evbit[0] = BIT_MASK(EV_KEY);
 	hi->input->keybit[BIT_WORD(KEY_MEDIA)] = BIT_MASK(KEY_MEDIA);

 	ret = input_register_device(hi->input);
 	if (ret < 0)
 		goto err_register_input_dev;

 	return 0;

 err_register_input_dev:
 	input_free_device(hi->input);
 err_request_input_dev:
 	free_irq(hi->irq_btn, 0);
 err_request_h2w_headset_button_irq:
 	free_irq(hi->irq, 0);
 err_request_detect_irq:
 err_get_button_irq_num_failed:
 err_get_h2w_detect_irq_num_failed:
 err_set_button_gpio:
 err_set_detect_gpio:
 	gpio_free(SAPPHIRE_GPIO_CABLE_IN2);
 err_request_button_gpio:
 	gpio_free(SAPPHIRE_GPIO_CABLE_IN1);
 err_request_detect_gpio:
 	destroy_workqueue(g_detection_work_queue);
 err_create_work_queue:
 	switch_dev_unregister(&hi->sdev);
 err_switch_dev_register:
 	printk(KERN_ERR "H2W: Failed to register driver\n");

 	return ret;
 }

 static int sapphire_h2w_remove(struct platform_device *pdev)
 {
 	H2W_DBG("");
 	if (switch_get_state(&hi->sdev))
 		remove_headset();
 	input_unregister_device(hi->input);
 	gpio_free(SAPPHIRE_GPIO_CABLE_IN2);
 	gpio_free(SAPPHIRE_GPIO_CABLE_IN1);
 	free_irq(hi->irq_btn, 0);
 	free_irq(hi->irq, 0);
 	destroy_workqueue(g_detection_work_queue);
 	switch_dev_unregister(&hi->sdev);

 	return 0;
 }

 static struct platform_device sapphire_h2w_device = {
 	.name		= "sapphire-h2w",
 };

 static struct platform_driver sapphire_h2w_driver = {
 	.probe		= sapphire_h2w_probe,
 	.remove		= sapphire_h2w_remove,
 	.driver		= {
 		.name		= "sapphire-h2w",
 		.owner		= THIS_MODULE,
 	},
 };

 static int __init sapphire_h2w_init(void)
 {
 	if (!machine_is_sapphire())
 		return 0;
 	int ret;
 	H2W_DBG("");
 	ret = platform_driver_register(&sapphire_h2w_driver);
 	if (ret)
 		return ret;
 	return platform_device_register(&sapphire_h2w_device);
 }

 static void __exit sapphire_h2w_exit(void)
 {
 	platform_device_unregister(&sapphire_h2w_device);
 	platform_driver_unregister(&sapphire_h2w_driver);
 }

 module_init(sapphire_h2w_init);
 module_exit(sapphire_h2w_exit);

 MODULE_AUTHOR("Laurence Chen <Laurence_Chen@htc.com>");
 MODULE_DESCRIPTION("HTC 2 Wire detection driver for sapphire");
 MODULE_LICENSE("GPL");
	/*
	* H2W device detection driver.
	*
	* Copyright (C) 2008 HTC Corporation.
	* Copyright (C) 2008 Google, Inc.
	*
	* Authors:
	* Laurence Chen <Laurence_Chen@htc.com>
	* Nick Pelly <npelly@google.com>
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	*/



	#include <linux/module.h>
	#include <linux/sysdev.h>
	#include <linux/fs.h>
	#include <linux/interrupt.h>
	#include <linux/workqueue.h>
	#include <linux/irq.h>
	#include <linux/delay.h>
	#include <linux/types.h>
	#include <linux/input.h>
	#include <linux/platform_device.h>
	#include <linux/mutex.h>
	#include <linux/errno.h>
	#include <linux/err.h>
	#include <linux/hrtimer.h>
	#include <linux/switch.h>
	#include <linux/input.h>
	#include <linux/debugfs.h>
	#include <linux/gpio.h>
	#include <asm/atomic.h>
	#include <mach/board.h>
	#include <mach/vreg.h>
	#include <asm/mach-types.h>
	#include "board-sapphire.h"

	#ifdef CONFIG_DEBUG_SAPPHIRE_H2W
	#define H2W_DBG(fmt, arg...) printk(KERN_INFO "[H2W] %s " fmt "\n", __FUNCTION__, ## arg)
	#else
	#define H2W_DBG(fmt, arg...) do {} while (0)
	#endif

	static struct workqueue_struct *g_detection_work_queue;
	static void detection_work(struct work_struct *work);
	static DECLARE_WORK(g_detection_work, detection_work);
	enum {
	NO_DEVICE = 0,
	HTC_HEADSET = 1,
	};

	enum {
	UART3 = 0,
	GPIO = 1,
	};

	struct h2w_info {
	struct switch_dev sdev;
	struct input_dev *input;

	atomic_t btn_state;
	int ignore_btn;

	unsigned int irq;
	unsigned int irq_btn;

	struct hrtimer timer;
	ktime_t debounce_time;

	struct hrtimer btn_timer;
	ktime_t btn_debounce_time;
	};
	static struct h2w_info *hi;

	static ssize_t sapphire_h2w_print_name(struct switch_dev sdev, char buf)
	{
	switch (switch_get_state(&hi->sdev)) {
	case NO_DEVICE:
	return sprintf(buf, "No Device\n");
	case HTC_HEADSET:
	return sprintf(buf, "Headset\n");
	}
	return -EINVAL;
	}

	static void configure_cpld(int route)
	{
	H2W_DBG(" route = %s", route == UART3 ? "UART3" : "GPIO");
	switch (route) {
	case UART3:
	gpio_set_value(SAPPHIRE_GPIO_H2W_SEL0, 0);
	gpio_set_value(SAPPHIRE_GPIO_H2W_SEL1, 1);
	break;
	case GPIO:
	gpio_set_value(SAPPHIRE_GPIO_H2W_SEL0, 0);
	gpio_set_value(SAPPHIRE_GPIO_H2W_SEL1, 0);
	break;
	}
	}

	static void button_pressed(void)
	{
	H2W_DBG("");
	atomic_set(&hi->btn_state, 1);
	input_report_key(hi->input, KEY_MEDIA, 1);
	input_sync(hi->input);
	}

	static void button_released(void)
	{
	H2W_DBG("");
	atomic_set(&hi->btn_state, 0);
	input_report_key(hi->input, KEY_MEDIA, 0);
	input_sync(hi->input);
	}

	#ifdef CONFIG_MSM_SERIAL_DEBUGGER
	extern void msm_serial_debug_enable(int);
	#endif

	static void insert_headset(void)
	{
	unsigned long irq_flags;

	H2W_DBG("");

	switch_set_state(&hi->sdev, HTC_HEADSET);
	configure_cpld(GPIO);

	#ifdef CONFIG_MSM_SERIAL_DEBUGGER
	msm_serial_debug_enable(false);
	#endif


	hi->ignore_btn = !gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2);


	local_irq_save(irq_flags);
	enable_irq(hi->irq_btn);
	local_irq_restore(irq_flags);

	hi->debounce_time = ktime_set(0, 20000000);
	}

	static void remove_headset(void)
	{
	unsigned long irq_flags;

	H2W_DBG("");

	switch_set_state(&hi->sdev, NO_DEVICE);
	configure_cpld(UART3);


	local_irq_save(irq_flags);
	disable_irq(hi->irq_btn);
	local_irq_restore(irq_flags);

	if (atomic_read(&hi->btn_state))
	button_released();

	hi->debounce_time = ktime_set(0, 100000000);
	}

	static void detection_work(struct work_struct *work)
	{
	unsigned long irq_flags;
	int clk, cable_in1;

	H2W_DBG("");

	if (gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1) != 0) {

	if (switch_get_state(&hi->sdev) == HTC_HEADSET)
	remove_headset();
	return;
	}




	configure_cpld(GPIO);

	local_irq_save(irq_flags);
	disable_irq(hi->irq);
	local_irq_restore(irq_flags);


	gpio_direction_output(SAPPHIRE_GPIO_CABLE_IN1, 1);

	msleep(10);

	clk = gpio_get_value(SAPPHIRE_GPIO_H2W_CLK_GPI);

	gpio_direction_input(SAPPHIRE_GPIO_CABLE_IN1);


	local_irq_save(irq_flags);
	enable_irq(hi->irq);
	local_irq_restore(irq_flags);

	cable_in1 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1);

	if (cable_in1 == 0 && clk == 0) {
	if (switch_get_state(&hi->sdev) == NO_DEVICE)
	insert_headset();
	} else {
	configure_cpld(UART3);
	H2W_DBG("CABLE_IN1 was low, but not a headset "
	"(recent cable_in1 = %d, clk = %d)", cable_in1, clk);
	}
	}

	static enum hrtimer_restart button_event_timer_func(struct hrtimer *data)
	{
	H2W_DBG("");

	if (switch_get_state(&hi->sdev) == HTC_HEADSET) {
	if (gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2)) {
	if (hi->ignore_btn)
	hi->ignore_btn = 0;
	else if (atomic_read(&hi->btn_state))
	button_released();
	} else {
	if (!hi->ignore_btn && !atomic_read(&hi->btn_state))
	button_pressed();
	}
	}

	return HRTIMER_NORESTART;
	}

	static enum hrtimer_restart detect_event_timer_func(struct hrtimer *data)
	{
	H2W_DBG("");

	queue_work(g_detection_work_queue, &g_detection_work);
	return HRTIMER_NORESTART;
	}

	static irqreturn_t detect_irq_handler(int irq, void *dev_id)
	{
	int value1, value2;
	int retry_limit = 10;

	H2W_DBG("");
	do {
	value1 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1);
	set_irq_type(hi->irq, value1 ?
	IRQF_TRIGGER_LOW : IRQF_TRIGGER_HIGH);
	value2 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN1);
	} while (value1 != value2 && retry_limit-- > 0);

	H2W_DBG("value2 = %d (%d retries)", value2, (10-retry_limit));

	if ((switch_get_state(&hi->sdev) == NO_DEVICE) ^ value2) {
	if (switch_get_state(&hi->sdev) == HTC_HEADSET)
	hi->ignore_btn = 1;

	hrtimer_start(&hi->timer, hi->debounce_time, HRTIMER_MODE_REL);
	}

	return IRQ_HANDLED;
	}

	static irqreturn_t button_irq_handler(int irq, void *dev_id)
	{
	int value1, value2;
	int retry_limit = 10;

	H2W_DBG("");
	do {
	value1 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2);
	set_irq_type(hi->irq_btn, value1 ?
	IRQF_TRIGGER_LOW : IRQF_TRIGGER_HIGH);
	value2 = gpio_get_value(SAPPHIRE_GPIO_CABLE_IN2);
	} while (value1 != value2 && retry_limit-- > 0);

	H2W_DBG("value2 = %d (%d retries)", value2, (10-retry_limit));

	hrtimer_start(&hi->btn_timer, hi->btn_debounce_time, HRTIMER_MODE_REL);

	return IRQ_HANDLED;
	}

	#if defined(CONFIG_DEBUG_FS)
	static void h2w_debug_set(void *data, u64 val)
	{
	switch_set_state(&hi->sdev, (int)val);
	}

	static u64 h2w_debug_get(void *data)
	{
	return 0;
	}

	DEFINE_SIMPLE_ATTRIBUTE(h2w_debug_fops, h2w_debug_get, h2w_debug_set, "%llu\n");
	static int __init h2w_debug_init(void)
	{
	struct dentry *dent;

	dent = debugfs_create_dir("h2w", 0);
	if (IS_ERR(dent))
	return PTR_ERR(dent);

	debugfs_create_file("state", 0644, dent, NULL, &h2w_debug_fops);

	return 0;
	}

	device_initcall(h2w_debug_init);
	#endif

	static int sapphire_h2w_probe(struct platform_device *pdev)
	{
	int ret;
	unsigned long irq_flags;

	printk(KERN_INFO "H2W: Registering H2W (headset) driver\n");
	hi = kzalloc(sizeof(struct h2w_info), GFP_KERNEL);
	if (!hi)
	return -ENOMEM;

	atomic_set(&hi->btn_state, 0);
	hi->ignore_btn = 0;

	hi->debounce_time = ktime_set(0, 100000000);
	hi->btn_debounce_time = ktime_set(0, 10000000);
	hi->sdev.name = "h2w";
	hi->sdev.print_name = sapphire_h2w_print_name;

	ret = switch_dev_register(&hi->sdev);
	if (ret < 0)
	goto err_switch_dev_register;

	g_detection_work_queue = create_workqueue("detection");
	if (g_detection_work_queue == NULL) {
	ret = -ENOMEM;
	goto err_create_work_queue;
	}

	ret = gpio_request(SAPPHIRE_GPIO_CABLE_IN1, "h2w_detect");
	if (ret < 0)
	goto err_request_detect_gpio;

	ret = gpio_request(SAPPHIRE_GPIO_CABLE_IN2, "h2w_button");
	if (ret < 0)
	goto err_request_button_gpio;

	ret = gpio_direction_input(SAPPHIRE_GPIO_CABLE_IN1);
	if (ret < 0)
	goto err_set_detect_gpio;

	ret = gpio_direction_input(SAPPHIRE_GPIO_CABLE_IN2);
	if (ret < 0)
	goto err_set_button_gpio;

	hi->irq = gpio_to_irq(SAPPHIRE_GPIO_CABLE_IN1);
	if (hi->irq < 0) {
	ret = hi->irq;
	goto err_get_h2w_detect_irq_num_failed;
	}

	hi->irq_btn = gpio_to_irq(SAPPHIRE_GPIO_CABLE_IN2);
	if (hi->irq_btn < 0) {
	ret = hi->irq_btn;
	goto err_get_button_irq_num_failed;
	}


	configure_cpld(UART3);

	gpio_set_value(SAPPHIRE_GPIO_H2W_CLK_DIR, 0);
	gpio_set_value(SAPPHIRE_GPIO_H2W_DAT_DIR, 0);

	hrtimer_init(&hi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	hi->timer.function = detect_event_timer_func;
	hrtimer_init(&hi->btn_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	hi->btn_timer.function = button_event_timer_func;

	ret = request_irq(hi->irq, detect_irq_handler,
	IRQF_TRIGGER_LOW, "h2w_detect", NULL);
	if (ret < 0)
	goto err_request_detect_irq;


	set_irq_flags(hi->irq_btn, IRQF_VALID \| IRQF_NOAUTOEN);
	ret = request_irq(hi->irq_btn, button_irq_handler,
	IRQF_TRIGGER_LOW, "h2w_button", NULL);
	if (ret < 0)
	goto err_request_h2w_headset_button_irq;

	ret = set_irq_wake(hi->irq, 1);
	if (ret < 0)
	goto err_request_input_dev;
	ret = set_irq_wake(hi->irq_btn, 1);
	if (ret < 0)
	goto err_request_input_dev;

	hi->input = input_allocate_device();
	if (!hi->input) {
	ret = -ENOMEM;
	goto err_request_input_dev;
	}

	hi->input->name = "h2w headset";
	hi->input->evbit[0] = BIT_MASK(EV_KEY);
	hi->input->keybit[BIT_WORD(KEY_MEDIA)] = BIT_MASK(KEY_MEDIA);

	ret = input_register_device(hi->input);
	if (ret < 0)
	goto err_register_input_dev;

	return 0;

	err_register_input_dev:
	input_free_device(hi->input);
	err_request_input_dev:
	free_irq(hi->irq_btn, 0);
	err_request_h2w_headset_button_irq:
	free_irq(hi->irq, 0);
	err_request_detect_irq:
	err_get_button_irq_num_failed:
	err_get_h2w_detect_irq_num_failed:
	err_set_button_gpio:
	err_set_detect_gpio:
	gpio_free(SAPPHIRE_GPIO_CABLE_IN2);
	err_request_button_gpio:
	gpio_free(SAPPHIRE_GPIO_CABLE_IN1);
	err_request_detect_gpio:
	destroy_workqueue(g_detection_work_queue);
	err_create_work_queue:
	switch_dev_unregister(&hi->sdev);
	err_switch_dev_register:
	printk(KERN_ERR "H2W: Failed to register driver\n");

	return ret;
	}

	static int sapphire_h2w_remove(struct platform_device *pdev)
	{
	H2W_DBG("");
	if (switch_get_state(&hi->sdev))
	remove_headset();
	input_unregister_device(hi->input);
	gpio_free(SAPPHIRE_GPIO_CABLE_IN2);
	gpio_free(SAPPHIRE_GPIO_CABLE_IN1);
	free_irq(hi->irq_btn, 0);
	free_irq(hi->irq, 0);
	destroy_workqueue(g_detection_work_queue);
	switch_dev_unregister(&hi->sdev);

	return 0;
	}

	static struct platform_device sapphire_h2w_device = {
	.name = "sapphire-h2w",
	};

	static struct platform_driver sapphire_h2w_driver = {
	.probe = sapphire_h2w_probe,
	.remove = sapphire_h2w_remove,
	.driver = {
	.name = "sapphire-h2w",
	.owner = THIS_MODULE,
	},
	};

	static int __init sapphire_h2w_init(void)
	{
	if (!machine_is_sapphire())
	return 0;
	int ret;
	H2W_DBG("");
	ret = platform_driver_register(&sapphire_h2w_driver);
	if (ret)
	return ret;
	return platform_device_register(&sapphire_h2w_device);
	}

	static void __exit sapphire_h2w_exit(void)
	{
	platform_device_unregister(&sapphire_h2w_device);
	platform_driver_unregister(&sapphire_h2w_driver);
	}

	module_init(sapphire_h2w_init);
	module_exit(sapphire_h2w_exit);

	MODULE_AUTHOR("Laurence Chen <Laurence_Chen@htc.com>");
	MODULE_DESCRIPTION("HTC 2 Wire detection driver for sapphire");
	MODULE_LICENSE("GPL");