drivers/misc/m4sensorhub_display.c - kernel/omap - Git at Google

 /*
  *  Copyright (C) 2013 Motorola, Inc.
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  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.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  *  Adds ability to program periodic interrupts from user space that
  *  can wake the phone out of low power modes.
  *
  */

 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
 #include <linux/platform_device.h>
 #include <linux/proc_fs.h>
 #include <linux/input.h>
 #include <linux/regulator/consumer.h>
 #include <linux/m4sensorhub.h>
 #include <linux/m4sensorhub_client_ioctl.h>
 #include <linux/uaccess.h>
 #include <linux/time.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>

 #define DISPLAY_CLIENT_DRIVER_NAME "m4sensorhub_display"
 #define SENSORHUB_MIPI_DRIVER_REGULATOR "vcsi"
 #define SYNC_CLOCK_RETRY_TIMES		3
 #define INVALID_UTC_TIME		0xFFFFFFFF

 struct display_client {
 	struct m4sensorhub_data *m4sensorhub;
 	struct regulator *regulator;
 	atomic_t m4_lockcnt;
 	struct mutex m4_mutex;
 	int gpio_mipi_mux;
 	int m4_control;
 	int m4_enable;
 	int timezone_offset;
 	int m4_timezone_offset;
 	int dailystep_offset;
 	int m4_dailystep_offset;
 };

 struct display_client *global_display_data;

 static u32 m4_display_get_clock(void);
 static u32 m4_display_get_kernel_clock(void);
 static int m4_display_set_clock(u32 ms);
 static int m4_display_sync_timezone(struct display_client *data);
 static int m4_display_sync_dailystep(struct display_client *data);
 static int m4_display_sync_clock(void);
 static int m4_display_sync_state(struct display_client *display_data);
 static int m4_display_lock(struct display_client *display_data, int lock);
 static int m4_display_set_control(int m4_ctrl, int gpio_mipi_mux);

 static int display_client_open(struct inode *inode, struct file *file)
 {
 	int ret = -EFAULT;
 	KDEBUG(M4SH_DEBUG, "%s:\n", __func__);
 	if (global_display_data) {
 		ret = nonseekable_open(inode, file);
 		if (ret >= 0) {
 			file->private_data = global_display_data;
 			ret = 0;
 		}
 	}
 	if (ret)
 		KDEBUG(M4SH_ERROR, "%s: failed, err=%d\n", __func__, -ret);
 	return ret;
 }

 static int display_client_close(struct inode *inode, struct file *file)
 {
 	KDEBUG(M4SH_DEBUG, "%s:\n", __func__);
 	file->private_data = NULL;
 	return 0;
 }

 static long display_client_ioctl(
 	struct file *filp,
 	unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	struct display_client *display_data = filp->private_data;
 	int value;

 	switch (cmd) {
 	case M4_SENSOR_IOCTL_SET_TIMEZONE_OFFSET:
 		if (copy_from_user(&value, argp, sizeof(value)))
 			return -EFAULT;
 		KDEBUG(M4SH_INFO, "%s update timezone offset %d\n",\
 				__func__, value);
 		m4_display_lock(display_data, true);
 		display_data->timezone_offset = value;
 		value = m4_display_sync_timezone(display_data);
 		/* sync M4 clock every time when app set timezone offset */
 		/* FIXME:Setting rtc clock on M4 happens in M4 ISR and leads to
 		* i2c timeout for the first clock set, this causes the bus to
 		* fail for a few mins on klockworks,hence commenting this part
 		* of the code until fixed for klockworks
 		if (value == 0)
 			m4_display_sync_clock();
 		*/
 		m4_display_lock(display_data, false);
 		return value;
 	case M4_SENSOR_IOCTL_SET_DAILYSTEP_OFFSET:
 		if (copy_from_user(&value, argp, sizeof(value)))
 			return -EFAULT;
 		KDEBUG(M4SH_INFO, "%s update dailystep offset %d\n",\
 				__func__, value);
 		display_data->dailystep_offset = value;
 		return m4_display_sync_dailystep(display_data);
 	case M4_SENSOR_IOCTL_LOCK_CLOCKFACE:
 		if (copy_from_user(&value, argp, sizeof(value)))
 			return -EFAULT;
 		return m4_display_lock(display_data, value);
 	default:
 		KDEBUG(M4SH_ERROR, "%s Invaild ioctl cmd %d\n", __func__, cmd);
 		break;
 	}
 	return -EINVAL;
 }

 /* Get current M4 RTC time of seconds elapsed since 00:00:00
  *   on January 1, 1970, Coordinated Universal Time
  * return 0xFFFFFFFF if it's something wrong
  */
 static u32 m4_display_get_clock(void)
 {
 	u32 seconds;
 	struct display_client *data = global_display_data;
 	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
 		M4SH_REG_GENERAL_UTC) != m4sensorhub_reg_read(\
 		data->m4sensorhub, M4SH_REG_GENERAL_UTC,\
 		(char *)&seconds)) {
 		seconds = INVALID_UTC_TIME;
 		KDEBUG(M4SH_ERROR, "%s: Failed get M4 clock!\n", __func__);
 	}
 	return seconds;
 }

 /* Set current M4 RTC time of seconds elapsed since 00:00:00
  *   on January 1, 1970, Coordinated Universal Time
  * return < 0 if it's something wrong
  */
 static int m4_display_set_clock(u32 seconds)
 {
 	struct display_client *data = global_display_data;
 	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
 		M4SH_REG_GENERAL_UTC) != m4sensorhub_reg_write(\
 		data->m4sensorhub, M4SH_REG_GENERAL_UTC,\
 		(char *)&seconds, m4sh_no_mask)) {
 		KDEBUG(M4SH_ERROR, "%s: Failed set M4 clock!\n", __func__);
 		return -EIO;
 	}
 	return 0;
 }

 static void m4_notify_clock_change(void)
 {
 	struct display_client *data = global_display_data;
 	char notify = 1;
 	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
 		M4SH_REG_USERSETTINGS_RTCRESET) != m4sensorhub_reg_write(\
 		data->m4sensorhub, M4SH_REG_USERSETTINGS_RTCRESET,\
 		&notify, m4sh_no_mask)) {
 		KDEBUG(M4SH_ERROR, "Failed to notify clock change");
 	}
 }

 /* Get current Kernel RTC time of seconds elapsed since 00:00:00
  *   on January 1, 1970, Coordinated Universal Time
  */
 static u32 m4_display_get_kernel_clock(void)
 {
 	struct timespec now = current_kernel_time();
 	/* adjust with 500ms */
 	if (now.tv_nsec > 500000000)
 		now.tv_sec++;
 	return (u32)now.tv_sec;
 }

 void print_time(char *info, u32 time)
 {
 	struct tm t; /* it convert to year since 1900 */
 	time_to_tm((time_t)(time), 0, &t);
 	KDEBUG(M4SH_INFO, "%s(%d) %02d:%02d:%02d %02d/%02d/%04d\n",\
 		info, (int)time, t.tm_hour, t.tm_min, t.tm_sec,\
 		t.tm_mon+1, t.tm_mday, (int)t.tm_year+1900);
 }

 /* Sync M4 clock with current kernel time */
 static int m4_display_sync_clock(void)
 {
 	int retry = 0;
 	do {
 		u32 m4_time = m4_display_get_clock();
 		u32 kernel_time = m4_display_get_kernel_clock();
 		u32 diff_time = m4_time > kernel_time \
 			? m4_time-kernel_time : kernel_time-m4_time;
 #ifdef	DEBUG_CLOCK
 		print_time("M4 :", m4_time);
 		print_time("KNL:", kernel_time);
 #endif
 		/* it needs adjust M4 time if different large than 1 second */
 		if (diff_time < 2) {
 			if (retry) {
 				print_time("Synced M4 clock to", m4_time);
 				m4_notify_clock_change();
 			}
 			return 0;
 		}
 		m4_display_set_clock(kernel_time);
 	} while (retry++ < SYNC_CLOCK_RETRY_TIMES);
 	KDEBUG(M4SH_ERROR, "%s: Failed to sync M4 clock!\n",  __func__);
 	return -EIO;
 }

 /* Sync M4 TimeZone offset */
 static int m4_display_sync_timezone(struct display_client *data)
 {
 	if (data->m4_timezone_offset == data->timezone_offset)
 		return 0;
 	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
 		M4SH_REG_GENERAL_LOCALTIMEZONE) != m4sensorhub_reg_write(\
 		data->m4sensorhub, M4SH_REG_GENERAL_LOCALTIMEZONE,\
 		(char *)&(data->timezone_offset), m4sh_no_mask)) {
 		KDEBUG(M4SH_ERROR, "%s: Failed set M4 timezone!\n", __func__);
 		return -EIO;
 	}
 	data->m4_timezone_offset = data->timezone_offset;
 	return 0;
 }

 /* Sync M4 Daily Steps offset */
 static int m4_display_sync_dailystep(struct display_client *data)
 {
 	if (data->m4_dailystep_offset == data->dailystep_offset)
 		return 0;
 	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
 		M4SH_REG_TIMEPIECE_OFFSETSTEPS) != m4sensorhub_reg_write(\
 		data->m4sensorhub, M4SH_REG_TIMEPIECE_OFFSETSTEPS,\
 		(char *)&(data->dailystep_offset), m4sh_no_mask)) {
 		KDEBUG(M4SH_ERROR, "%s: Failed set M4 dailystep!\n", __func__);
 		return -EIO;
 	}
 	data->m4_dailystep_offset = data->dailystep_offset;
 	return 0;
 }

 /* Sync M4 clockface state, it will be enable only when clockface is unlocked
  */
 static int m4_display_sync_state(struct display_client *display_data)
 {
 	int enable = !!display_data->m4_control;
 	if (atomic_inc_return(&(display_data->m4_lockcnt)) != 1)
 		enable = 0;
 	atomic_dec(&(display_data->m4_lockcnt));

 	mutex_lock(&(display_data->m4_mutex));
 	if (enable == display_data->m4_enable)
 		goto __done__;
 	if (enable) {
 		/* switch display control to M4 */
 		m4_display_sync_clock();
 		m4_display_sync_timezone(display_data);
 		m4_display_sync_dailystep(display_data);
 		gpio_set_value(display_data->gpio_mipi_mux, 1);
 		if (regulator_enable(display_data->regulator)) {
 			KDEBUG(M4SH_ERROR, "Failed enable regulator!\n");
 			goto __error__;
 		}
 	}
 	/* comunicate with M4 via I2C */
 	if (1 != m4sensorhub_reg_write_1byte(\
 		display_data->m4sensorhub,\
 		M4SH_REG_TIMEPIECE_ENABLE, enable, 0xFF)) {
 		KDEBUG(M4SH_ERROR, "Failed set m4 display!\n");
 		goto __error__;
 	}
 	if (!enable) {
 		mdelay(2);
 		/* switch display control to OMAP */
 		regulator_disable(display_data->regulator);
 		gpio_set_value(display_data->gpio_mipi_mux, 0);
 	}
 	display_data->m4_enable = enable;
 	KDEBUG(M4SH_INFO, "Synced M4 display state(%d)\n", enable);
 __done__:
 	mutex_unlock(&(display_data->m4_mutex));
 	return 0;
 __error__:
 	/* when error occured, it always set control to OMAP */
 	regulator_disable(display_data->regulator);
 	gpio_set_value(display_data->gpio_mipi_mux, 0);
 	mutex_unlock(&(display_data->m4_mutex));
 	KDEBUG(M4SH_ERROR, "Failed sync m4 with state(%d)!\n", enable);
 	return -EIO;
 }

 /* M4 clockface lock/unlock */
 static int m4_display_lock(struct display_client *display_data, int lock)
 {
 	if (lock) {
 		atomic_inc(&(display_data->m4_lockcnt));
 	} else {
 		if (atomic_dec_return(&(display_data->m4_lockcnt)) == -1) {
 			atomic_inc(&(display_data->m4_lockcnt));
 			KDEBUG(M4SH_ERROR, "%s zero unlock count!\n",\
 				__func__);
 			return -EINVAL;
 		}
 	}
 	return m4_display_sync_state(display_data);
 }

 static int m4_display_set_control(int m4_ctrl, int gpio_mipi_mux)
 {
 	struct display_client *display_data = global_display_data;
 	KDEBUG(M4SH_INFO, "%s(%d)\n", __func__, m4_ctrl);

 	if (!display_data || !display_data->m4sensorhub || (gpio_mipi_mux < 0))
 		return -EINVAL;

 	if (m4_ctrl == display_data->m4_control) {
 		KDEBUG(M4SH_DEBUG, "%s is already set!\n", __func__);
 		return 0;
 	}

 	display_data->gpio_mipi_mux = gpio_mipi_mux;
 	display_data->m4_control = m4_ctrl;

 	return m4_display_sync_state(display_data);
 }

 int m4sensorhub_set_display_control(int m4_ctrl, int gpio_mipi_mux)
 {
 	return m4_display_set_control(m4_ctrl, gpio_mipi_mux);
 }
 EXPORT_SYMBOL_GPL(m4sensorhub_set_display_control);

 static const struct file_operations display_client_fops = {
 	.owner = THIS_MODULE,
 	.unlocked_ioctl = display_client_ioctl,
 	.open  = display_client_open,
 	.release = display_client_close,
 };

 static struct miscdevice display_client_miscdrv = {
 	.minor = MISC_DYNAMIC_MINOR,
 	.name  = DISPLAY_CLIENT_DRIVER_NAME,
 	.fops = &display_client_fops,
 };

 /* display_panic_restore()

    Panic Callback Handler is called after M4 has been restarted

 */
 static void display_panic_restore(\
 	struct m4sensorhub_data *m4sensorhub, void *data)
 {
 	struct display_client *display_data = (struct display_client *)data;
 	display_data->m4_timezone_offset = 0;
 	display_data->m4_dailystep_offset = 0;
 	if (display_data->m4_enable) {
 		m4_display_sync_clock();
 		m4_display_sync_timezone(display_data);
 		m4_display_sync_dailystep(display_data);
 		/* comunicate with M4 via I2C */
 		if (1 != m4sensorhub_reg_write_1byte(\
 			display_data->m4sensorhub,\
 			M4SH_REG_TIMEPIECE_ENABLE, 1, 0xFF)) {
 			KDEBUG(M4SH_ERROR, "Failed re-enable m4 display!\n");
 			/* TODO retry ? */
 		}
 	}
 }

 static int display_driver_init(struct init_calldata *p_arg)
 {
 	int err;
 	struct m4sensorhub_data *m4sensorhub = p_arg->p_m4sensorhub_data;

 	err = m4sensorhub_panic_register(m4sensorhub, PANICHDL_DISPLAY_RESTORE,
 		display_panic_restore, global_display_data);
 	if (err < 0)
 		KDEBUG(M4SH_ERROR, "Display driver init failed\n");

 	return err;
 }

 static int display_client_probe(struct platform_device *pdev)
 {
 	int ret = -EINVAL;
 	struct display_client *display_data;
 	struct m4sensorhub_data *m4sensorhub = m4sensorhub_client_get_drvdata();

 	if (!m4sensorhub)
 		return -EFAULT;

 	display_data = kzalloc(sizeof(*display_data),
 						GFP_KERNEL);
 	if (!display_data)
 		return -ENOMEM;

 	display_data->m4sensorhub = m4sensorhub;
 	display_data->timezone_offset = 0;
 	display_data->dailystep_offset = 0;
 	display_data->m4_timezone_offset = 0;
 	display_data->m4_dailystep_offset = 0;

 	platform_set_drvdata(pdev, display_data);

 	display_data->regulator = regulator_get(NULL,
 					    SENSORHUB_MIPI_DRIVER_REGULATOR);
 	if (IS_ERR(display_data->regulator)) {
 		KDEBUG(M4SH_ERROR, "Error requesting %s regulator\n",
 			SENSORHUB_MIPI_DRIVER_REGULATOR);
 		ret = -EFAULT;
 		goto free_mem;
 	}

 	ret = misc_register(&display_client_miscdrv);
 	if (ret < 0) {
 		KDEBUG(M4SH_ERROR, "Error registering %s driver\n",
 				 DISPLAY_CLIENT_DRIVER_NAME);
 		goto disable_regulator;
 	}

 	/* default to host control */
 	display_data->m4_control = 0;
 	display_data->m4_enable = 0;
 	atomic_set(&(display_data->m4_lockcnt), 0);
 	mutex_init(&(display_data->m4_mutex));

 	global_display_data = display_data;
 	ret = m4sensorhub_register_initcall(display_driver_init, display_data);
 	if (ret < 0) {
 		KDEBUG(M4SH_ERROR, "Unable to register init function "
 			"for display client = %d\n", ret);
 		goto unregister_misc_device;
 	}

 	KDEBUG(M4SH_INFO, "Initialized %s driver\n", __func__);
 	return 0;

 unregister_misc_device:
 	misc_deregister(&display_client_miscdrv);
 disable_regulator:
 	regulator_put(display_data->regulator);
 free_mem:
 	global_display_data = NULL;
 	platform_set_drvdata(pdev, NULL);
 	kfree(display_data);
 	return ret;
 }

 static int __exit display_client_remove(struct platform_device *pdev)
 {
 	struct display_client *display_data =
 						platform_get_drvdata(pdev);

 	m4sensorhub_unregister_initcall(display_driver_init);
 	misc_deregister(&display_client_miscdrv);
 	global_display_data = NULL;
 	regulator_put(display_data->regulator);
 	platform_set_drvdata(pdev, NULL);
 	display_data->m4sensorhub = NULL;
 	kfree(display_data);
 	return 0;
 }

 static void display_client_shutdown(struct platform_device *pdev)
 {
 	return;
 }

 static struct of_device_id m4display_match_tbl[] = {
 	{ .compatible = "mot,m4display" },
 	{},
 };

 static struct platform_driver display_client_driver = {
 	.probe		= display_client_probe,
 	.remove		= __exit_p(display_client_remove),
 	.shutdown	= display_client_shutdown,
 	.suspend	= NULL,
 	.resume		= NULL,
 	.driver		= {
 		.name	= DISPLAY_CLIENT_DRIVER_NAME,
 		.owner	= THIS_MODULE,
 		.of_match_table = of_match_ptr(m4display_match_tbl),
 	},
 };

 static int __init display_client_init(void)
 {
 	return platform_driver_register(&display_client_driver);
 }

 static void __exit display_client_exit(void)
 {
 	platform_driver_unregister(&display_client_driver);
 }

 module_init(display_client_init);
 module_exit(display_client_exit);

 MODULE_ALIAS("platform:display_client");
 MODULE_DESCRIPTION("M4 Sensor Hub AOD display driver");
 MODULE_AUTHOR("Motorola");
 MODULE_LICENSE("GPL");
	/*
	* Copyright (C) 2013 Motorola, Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* Adds ability to program periodic interrupts from user space that
	* can wake the phone out of low power modes.
	*
	*/

	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/miscdevice.h>
	#include <linux/platform_device.h>
	#include <linux/proc_fs.h>
	#include <linux/input.h>
	#include <linux/regulator/consumer.h>
	#include <linux/m4sensorhub.h>
	#include <linux/m4sensorhub_client_ioctl.h>
	#include <linux/uaccess.h>
	#include <linux/time.h>
	#include <linux/gpio.h>
	#include <linux/slab.h>

	#define DISPLAY_CLIENT_DRIVER_NAME "m4sensorhub_display"
	#define SENSORHUB_MIPI_DRIVER_REGULATOR "vcsi"
	#define SYNC_CLOCK_RETRY_TIMES 3
	#define INVALID_UTC_TIME 0xFFFFFFFF

	struct display_client {
	struct m4sensorhub_data *m4sensorhub;
	struct regulator *regulator;
	atomic_t m4_lockcnt;
	struct mutex m4_mutex;
	int gpio_mipi_mux;
	int m4_control;
	int m4_enable;
	int timezone_offset;
	int m4_timezone_offset;
	int dailystep_offset;
	int m4_dailystep_offset;
	};

	struct display_client *global_display_data;

	static u32 m4_display_get_clock(void);
	static u32 m4_display_get_kernel_clock(void);
	static int m4_display_set_clock(u32 ms);
	static int m4_display_sync_timezone(struct display_client *data);
	static int m4_display_sync_dailystep(struct display_client *data);
	static int m4_display_sync_clock(void);
	static int m4_display_sync_state(struct display_client *display_data);
	static int m4_display_lock(struct display_client *display_data, int lock);
	static int m4_display_set_control(int m4_ctrl, int gpio_mipi_mux);

	static int display_client_open(struct inode inode, struct file file)
	{
	int ret = -EFAULT;
	KDEBUG(M4SH_DEBUG, "%s:\n", __func__);
	if (global_display_data) {
	ret = nonseekable_open(inode, file);
	if (ret >= 0) {
	file->private_data = global_display_data;
	ret = 0;
	}
	}
	if (ret)
	KDEBUG(M4SH_ERROR, "%s: failed, err=%d\n", __func__, -ret);
	return ret;
	}

	static int display_client_close(struct inode inode, struct file file)
	{
	KDEBUG(M4SH_DEBUG, "%s:\n", __func__);
	file->private_data = NULL;
	return 0;
	}

	static long display_client_ioctl(
	struct file *filp,
	unsigned int cmd, unsigned long arg)
	{
	void __user argp = (void __user )arg;
	struct display_client *display_data = filp->private_data;
	int value;

	switch (cmd) {
	case M4_SENSOR_IOCTL_SET_TIMEZONE_OFFSET:
	if (copy_from_user(&value, argp, sizeof(value)))
	return -EFAULT;
	KDEBUG(M4SH_INFO, "%s update timezone offset %d\n",\
	__func__, value);
	m4_display_lock(display_data, true);
	display_data->timezone_offset = value;
	value = m4_display_sync_timezone(display_data);
	/* sync M4 clock every time when app set timezone offset */
	/* FIXME:Setting rtc clock on M4 happens in M4 ISR and leads to
	* i2c timeout for the first clock set, this causes the bus to
	* fail for a few mins on klockworks,hence commenting this part
	* of the code until fixed for klockworks
	if (value == 0)
	m4_display_sync_clock();
	*/
	m4_display_lock(display_data, false);
	return value;
	case M4_SENSOR_IOCTL_SET_DAILYSTEP_OFFSET:
	if (copy_from_user(&value, argp, sizeof(value)))
	return -EFAULT;
	KDEBUG(M4SH_INFO, "%s update dailystep offset %d\n",\
	__func__, value);
	display_data->dailystep_offset = value;
	return m4_display_sync_dailystep(display_data);
	case M4_SENSOR_IOCTL_LOCK_CLOCKFACE:
	if (copy_from_user(&value, argp, sizeof(value)))
	return -EFAULT;
	return m4_display_lock(display_data, value);
	default:
	KDEBUG(M4SH_ERROR, "%s Invaild ioctl cmd %d\n", __func__, cmd);
	break;
	}
	return -EINVAL;
	}

	/* Get current M4 RTC time of seconds elapsed since 00:00:00
	* on January 1, 1970, Coordinated Universal Time
	* return 0xFFFFFFFF if it's something wrong
	*/
	static u32 m4_display_get_clock(void)
	{
	u32 seconds;
	struct display_client *data = global_display_data;
	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
	M4SH_REG_GENERAL_UTC) != m4sensorhub_reg_read(\
	data->m4sensorhub, M4SH_REG_GENERAL_UTC,\
	(char *)&seconds)) {
	seconds = INVALID_UTC_TIME;
	KDEBUG(M4SH_ERROR, "%s: Failed get M4 clock!\n", __func__);
	}
	return seconds;
	}

	/* Set current M4 RTC time of seconds elapsed since 00:00:00
	* on January 1, 1970, Coordinated Universal Time
	* return < 0 if it's something wrong
	*/
	static int m4_display_set_clock(u32 seconds)
	{
	struct display_client *data = global_display_data;
	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
	M4SH_REG_GENERAL_UTC) != m4sensorhub_reg_write(\
	data->m4sensorhub, M4SH_REG_GENERAL_UTC,\
	(char *)&seconds, m4sh_no_mask)) {
	KDEBUG(M4SH_ERROR, "%s: Failed set M4 clock!\n", __func__);
	return -EIO;
	}
	return 0;
	}

	static void m4_notify_clock_change(void)
	{
	struct display_client *data = global_display_data;
	char notify = 1;
	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
	M4SH_REG_USERSETTINGS_RTCRESET) != m4sensorhub_reg_write(\
	data->m4sensorhub, M4SH_REG_USERSETTINGS_RTCRESET,\
	&notify, m4sh_no_mask)) {
	KDEBUG(M4SH_ERROR, "Failed to notify clock change");
	}
	}

	/* Get current Kernel RTC time of seconds elapsed since 00:00:00
	* on January 1, 1970, Coordinated Universal Time
	*/
	static u32 m4_display_get_kernel_clock(void)
	{
	struct timespec now = current_kernel_time();
	/* adjust with 500ms */
	if (now.tv_nsec > 500000000)
	now.tv_sec++;
	return (u32)now.tv_sec;
	}

	void print_time(char *info, u32 time)
	{
	struct tm t; /* it convert to year since 1900 */
	time_to_tm((time_t)(time), 0, &t);
	KDEBUG(M4SH_INFO, "%s(%d) %02d:%02d:%02d %02d/%02d/%04d\n",\
	info, (int)time, t.tm_hour, t.tm_min, t.tm_sec,\
	t.tm_mon+1, t.tm_mday, (int)t.tm_year+1900);
	}

	/* Sync M4 clock with current kernel time */
	static int m4_display_sync_clock(void)
	{
	int retry = 0;
	do {
	u32 m4_time = m4_display_get_clock();
	u32 kernel_time = m4_display_get_kernel_clock();
	u32 diff_time = m4_time > kernel_time \
	? m4_time-kernel_time : kernel_time-m4_time;
	#ifdef DEBUG_CLOCK
	print_time("M4 :", m4_time);
	print_time("KNL:", kernel_time);
	#endif
	/* it needs adjust M4 time if different large than 1 second */
	if (diff_time < 2) {
	if (retry) {
	print_time("Synced M4 clock to", m4_time);
	m4_notify_clock_change();
	}
	return 0;
	}
	m4_display_set_clock(kernel_time);
	} while (retry++ < SYNC_CLOCK_RETRY_TIMES);
	KDEBUG(M4SH_ERROR, "%s: Failed to sync M4 clock!\n", __func__);
	return -EIO;
	}

	/* Sync M4 TimeZone offset */
	static int m4_display_sync_timezone(struct display_client *data)
	{
	if (data->m4_timezone_offset == data->timezone_offset)
	return 0;
	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
	M4SH_REG_GENERAL_LOCALTIMEZONE) != m4sensorhub_reg_write(\
	data->m4sensorhub, M4SH_REG_GENERAL_LOCALTIMEZONE,\
	(char *)&(data->timezone_offset), m4sh_no_mask)) {
	KDEBUG(M4SH_ERROR, "%s: Failed set M4 timezone!\n", __func__);
	return -EIO;
	}
	data->m4_timezone_offset = data->timezone_offset;
	return 0;
	}

	/* Sync M4 Daily Steps offset */
	static int m4_display_sync_dailystep(struct display_client *data)
	{
	if (data->m4_dailystep_offset == data->dailystep_offset)
	return 0;
	if (m4sensorhub_reg_getsize(data->m4sensorhub,\
	M4SH_REG_TIMEPIECE_OFFSETSTEPS) != m4sensorhub_reg_write(\
	data->m4sensorhub, M4SH_REG_TIMEPIECE_OFFSETSTEPS,\
	(char *)&(data->dailystep_offset), m4sh_no_mask)) {
	KDEBUG(M4SH_ERROR, "%s: Failed set M4 dailystep!\n", __func__);
	return -EIO;
	}
	data->m4_dailystep_offset = data->dailystep_offset;
	return 0;
	}

	/* Sync M4 clockface state, it will be enable only when clockface is unlocked
	*/
	static int m4_display_sync_state(struct display_client *display_data)
	{
	int enable = !!display_data->m4_control;
	if (atomic_inc_return(&(display_data->m4_lockcnt)) != 1)
	enable = 0;
	atomic_dec(&(display_data->m4_lockcnt));

	mutex_lock(&(display_data->m4_mutex));
	if (enable == display_data->m4_enable)
	goto __done__;
	if (enable) {
	/* switch display control to M4 */
	m4_display_sync_clock();
	m4_display_sync_timezone(display_data);
	m4_display_sync_dailystep(display_data);
	gpio_set_value(display_data->gpio_mipi_mux, 1);
	if (regulator_enable(display_data->regulator)) {
	KDEBUG(M4SH_ERROR, "Failed enable regulator!\n");
	goto __error__;
	}
	}
	/* comunicate with M4 via I2C */
	if (1 != m4sensorhub_reg_write_1byte(\
	display_data->m4sensorhub,\
	M4SH_REG_TIMEPIECE_ENABLE, enable, 0xFF)) {
	KDEBUG(M4SH_ERROR, "Failed set m4 display!\n");
	goto __error__;
	}
	if (!enable) {
	mdelay(2);
	/* switch display control to OMAP */
	regulator_disable(display_data->regulator);
	gpio_set_value(display_data->gpio_mipi_mux, 0);
	}
	display_data->m4_enable = enable;
	KDEBUG(M4SH_INFO, "Synced M4 display state(%d)\n", enable);
	__done__:
	mutex_unlock(&(display_data->m4_mutex));
	return 0;
	__error__:
	/* when error occured, it always set control to OMAP */
	regulator_disable(display_data->regulator);
	gpio_set_value(display_data->gpio_mipi_mux, 0);
	mutex_unlock(&(display_data->m4_mutex));
	KDEBUG(M4SH_ERROR, "Failed sync m4 with state(%d)!\n", enable);
	return -EIO;
	}

	/* M4 clockface lock/unlock */
	static int m4_display_lock(struct display_client *display_data, int lock)
	{
	if (lock) {
	atomic_inc(&(display_data->m4_lockcnt));
	} else {
	if (atomic_dec_return(&(display_data->m4_lockcnt)) == -1) {
	atomic_inc(&(display_data->m4_lockcnt));
	KDEBUG(M4SH_ERROR, "%s zero unlock count!\n",\
	__func__);
	return -EINVAL;
	}
	}
	return m4_display_sync_state(display_data);
	}

	static int m4_display_set_control(int m4_ctrl, int gpio_mipi_mux)
	{
	struct display_client *display_data = global_display_data;
	KDEBUG(M4SH_INFO, "%s(%d)\n", __func__, m4_ctrl);

	if (!display_data \|\| !display_data->m4sensorhub \|\| (gpio_mipi_mux < 0))
	return -EINVAL;

	if (m4_ctrl == display_data->m4_control) {
	KDEBUG(M4SH_DEBUG, "%s is already set!\n", __func__);
	return 0;
	}

	display_data->gpio_mipi_mux = gpio_mipi_mux;
	display_data->m4_control = m4_ctrl;

	return m4_display_sync_state(display_data);
	}

	int m4sensorhub_set_display_control(int m4_ctrl, int gpio_mipi_mux)
	{
	return m4_display_set_control(m4_ctrl, gpio_mipi_mux);
	}
	EXPORT_SYMBOL_GPL(m4sensorhub_set_display_control);

	static const struct file_operations display_client_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = display_client_ioctl,
	.open = display_client_open,
	.release = display_client_close,
	};

	static struct miscdevice display_client_miscdrv = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = DISPLAY_CLIENT_DRIVER_NAME,
	.fops = &display_client_fops,
	};

	/* display_panic_restore()

	Panic Callback Handler is called after M4 has been restarted

	*/
	static void display_panic_restore(\
	struct m4sensorhub_data m4sensorhub, void data)
	{
	struct display_client display_data = (struct display_client )data;
	display_data->m4_timezone_offset = 0;
	display_data->m4_dailystep_offset = 0;
	if (display_data->m4_enable) {
	m4_display_sync_clock();
	m4_display_sync_timezone(display_data);
	m4_display_sync_dailystep(display_data);
	/* comunicate with M4 via I2C */
	if (1 != m4sensorhub_reg_write_1byte(\
	display_data->m4sensorhub,\
	M4SH_REG_TIMEPIECE_ENABLE, 1, 0xFF)) {
	KDEBUG(M4SH_ERROR, "Failed re-enable m4 display!\n");
	/* TODO retry ? */
	}
	}
	}

	static int display_driver_init(struct init_calldata *p_arg)
	{
	int err;
	struct m4sensorhub_data *m4sensorhub = p_arg->p_m4sensorhub_data;

	err = m4sensorhub_panic_register(m4sensorhub, PANICHDL_DISPLAY_RESTORE,
	display_panic_restore, global_display_data);
	if (err < 0)
	KDEBUG(M4SH_ERROR, "Display driver init failed\n");

	return err;
	}

	static int display_client_probe(struct platform_device *pdev)
	{
	int ret = -EINVAL;
	struct display_client *display_data;
	struct m4sensorhub_data *m4sensorhub = m4sensorhub_client_get_drvdata();

	if (!m4sensorhub)
	return -EFAULT;

	display_data = kzalloc(sizeof(*display_data),
	GFP_KERNEL);
	if (!display_data)
	return -ENOMEM;

	display_data->m4sensorhub = m4sensorhub;
	display_data->timezone_offset = 0;
	display_data->dailystep_offset = 0;
	display_data->m4_timezone_offset = 0;
	display_data->m4_dailystep_offset = 0;

	platform_set_drvdata(pdev, display_data);

	display_data->regulator = regulator_get(NULL,
	SENSORHUB_MIPI_DRIVER_REGULATOR);
	if (IS_ERR(display_data->regulator)) {
	KDEBUG(M4SH_ERROR, "Error requesting %s regulator\n",
	SENSORHUB_MIPI_DRIVER_REGULATOR);
	ret = -EFAULT;
	goto free_mem;
	}

	ret = misc_register(&display_client_miscdrv);
	if (ret < 0) {
	KDEBUG(M4SH_ERROR, "Error registering %s driver\n",
	DISPLAY_CLIENT_DRIVER_NAME);
	goto disable_regulator;
	}

	/* default to host control */
	display_data->m4_control = 0;
	display_data->m4_enable = 0;
	atomic_set(&(display_data->m4_lockcnt), 0);
	mutex_init(&(display_data->m4_mutex));

	global_display_data = display_data;
	ret = m4sensorhub_register_initcall(display_driver_init, display_data);
	if (ret < 0) {
	KDEBUG(M4SH_ERROR, "Unable to register init function "
	"for display client = %d\n", ret);
	goto unregister_misc_device;
	}

	KDEBUG(M4SH_INFO, "Initialized %s driver\n", __func__);
	return 0;

	unregister_misc_device:
	misc_deregister(&display_client_miscdrv);
	disable_regulator:
	regulator_put(display_data->regulator);
	free_mem:
	global_display_data = NULL;
	platform_set_drvdata(pdev, NULL);
	kfree(display_data);
	return ret;
	}

	static int __exit display_client_remove(struct platform_device *pdev)
	{
	struct display_client *display_data =
	platform_get_drvdata(pdev);

	m4sensorhub_unregister_initcall(display_driver_init);
	misc_deregister(&display_client_miscdrv);
	global_display_data = NULL;
	regulator_put(display_data->regulator);
	platform_set_drvdata(pdev, NULL);
	display_data->m4sensorhub = NULL;
	kfree(display_data);
	return 0;
	}

	static void display_client_shutdown(struct platform_device *pdev)
	{
	return;
	}

	static struct of_device_id m4display_match_tbl[] = {
	{ .compatible = "mot,m4display" },
	{},
	};

	static struct platform_driver display_client_driver = {
	.probe = display_client_probe,
	.remove = __exit_p(display_client_remove),
	.shutdown = display_client_shutdown,
	.suspend = NULL,
	.resume = NULL,
	.driver = {
	.name = DISPLAY_CLIENT_DRIVER_NAME,
	.owner = THIS_MODULE,
	.of_match_table = of_match_ptr(m4display_match_tbl),
	},
	};

	static int __init display_client_init(void)
	{
	return platform_driver_register(&display_client_driver);
	}

	static void __exit display_client_exit(void)
	{
	platform_driver_unregister(&display_client_driver);
	}

	module_init(display_client_init);
	module_exit(display_client_exit);

	MODULE_ALIAS("platform:display_client");
	MODULE_DESCRIPTION("M4 Sensor Hub AOD display driver");
	MODULE_AUTHOR("Motorola");
	MODULE_LICENSE("GPL");