drivers/misc/c55_ctrl.c - kernel/omap - Git at Google

 /*
  * Copyright (C) 2013 Motorola Mobility LLC
  *
  * 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/err.h>
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/m4sensorhub.h>
 #include <linux/m4sensorhub/MemMapUserSettings.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/wakelock.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/clk.h>

 enum {
 	C55_OFF,
 	C55_ON,
 	C55_MODE_MAX
 };

 struct c55_ctrl_data {
 	int c55_ap_int_gpio;
 	int ap_c55_int_gpio;
 	int c55_ap_int_enabled;
 	struct wake_lock wake_lock;
 	struct regulator *reg_vddc;
 	struct regulator *reg_vddldo;
 	struct pinctrl *pctrl;
 	struct pinctrl_state *states[C55_MODE_MAX];
 	int c55_mode;
 	struct mutex ctrl_mutex;	/* mutex to handle critical area */
 	int fw_verified;
 };

 const char *c55_pin_state_labels[C55_MODE_MAX] = {
 	"off",
 	"on"
 };

 #define NUM_GPIOS 2

 const char *gpio_labels[NUM_GPIOS] = {
 	"gpio_ap_int",
 	"gpio_c55_int"
 };

 static irqreturn_t c55_ctrl_isr(int irq, void *data)
 {
 	struct c55_ctrl_data *cdata = data;

 	pr_debug("%s: value=%d\n", __func__,
 		 gpio_get_value(cdata->c55_ap_int_gpio));

 	/* Interrupt is active low */
 	if (gpio_get_value(cdata->c55_ap_int_gpio) == 0)
 		wake_lock(&cdata->wake_lock);
 	else
 		wake_unlock(&cdata->wake_lock);

 	return IRQ_HANDLED;
 }

 static void c55_ctrl_int_setup(struct c55_ctrl_data *cdata, int gpio)
 {
 	int ret;
 	int irq = __gpio_to_irq(gpio);
 	unsigned int flags = 0;

 	if (cdata->c55_ap_int_gpio >= 0) {
 		/* Interrupt already registered */
 		return;
 	}

 	/* Interrupt is shared with user space */
 	flags |= IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 	flags |= IRQF_SHARED;

 	cdata->c55_ap_int_enabled = 1;
 	ret = request_threaded_irq(irq, c55_ctrl_isr, NULL,
 				   flags, "c55_ctrl", cdata);
 	if (ret) {
 		pr_err("%s: IRQ request failed: %d\n", __func__, ret);
 		return;
 	}

 	cdata->c55_ap_int_gpio = gpio;
 }

 static int c55_ctrl_gpio_setup(struct c55_ctrl_data *cdata, struct device *dev)
 {
 	int i;

 	if (of_gpio_count(dev->of_node) != NUM_GPIOS) {
 		dev_err(dev, "%s: gpio count is not %d.\n", __func__, NUM_GPIOS);
 		return -EINVAL;
 	}

 	for (i = 0; i < NUM_GPIOS; i++) {
 		enum of_gpio_flags flags;
 		int gpio;

 		gpio = of_get_gpio_flags(dev->of_node, i, &flags);
 		if (gpio < 0) {
 			pr_err("%s: of_get_gpio failed: %d\n", __func__, gpio);
 			return gpio;
 		}

 		gpio_request(gpio, gpio_labels[i]);

 		gpio_export(gpio, false);
 		gpio_export_link(dev, gpio_labels[i], gpio);

 		if ((flags & GPIOF_IN) == GPIOF_IN) {
 			gpio_direction_input(gpio);
 			c55_ctrl_int_setup(cdata, gpio);
 		} else {
 			cdata->ap_c55_int_gpio = gpio;
 			if ((flags & GPIOF_OUT_INIT_HIGH) == GPIOF_OUT_INIT_HIGH)
 				gpio_direction_output(gpio, 1);
 			else
 				gpio_direction_output(gpio, 0);
 		}
 	}

 	return 0;
 }

 static ssize_t c55_ctrl_enable(struct device *dev,
 	struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct c55_ctrl_data *cdata = dev_get_drvdata(dev);
 	int mode;

 	if (kstrtoint(buf, 10, &mode) < 0)
 		return -EINVAL;

 	if (mode >= C55_MODE_MAX) {
 		dev_err(dev, "%s: Invalid mode %d\n", __func__, mode);
 		return -EINVAL;
 	}

 	if (m4sensorhub_get_current_mode() != NORMALMODE) {
 		dev_err(dev, "M4 not ready, Unable to set screen status\n");
 		return -EINVAL;
 	}

 	if (mode == cdata->c55_mode)
 		return count;

 	mutex_lock(&cdata->ctrl_mutex);

 	if (mode == C55_ON) {
 		pinctrl_select_state(cdata->pctrl, cdata->states[C55_ON]);

 		gpio_set_value(cdata->ap_c55_int_gpio, 1);

 		if (m4sensorhub_extern_set_audio_status(AUDIO_STATUS_ON) < 0) {
 			dev_err(dev, "Unable to set screen status to 0x01\n");
 			mutex_unlock(&cdata->ctrl_mutex);
 			return -EINVAL;
 		}

 		if (!cdata->c55_ap_int_enabled) {
 			cdata->c55_ap_int_enabled = 1;
 			enable_irq(__gpio_to_irq(cdata->c55_ap_int_gpio));
 		}
 	} else {
 		/* Disable C55->AP IRQ when turning off C55 */
 		if (cdata->c55_ap_int_enabled) {
 			disable_irq_nosync(
 				__gpio_to_irq(cdata->c55_ap_int_gpio));
 			cdata->c55_ap_int_enabled = 0;
 		}

 		if (m4sensorhub_extern_set_audio_status(AUDIO_STATUS_OFF) < 0) {
 			dev_err(dev, "Unable to set screen status to 0x00\n");
 			mutex_unlock(&cdata->ctrl_mutex);
 			return -EINVAL;
 		}

 		/* AP->C55 interrupt needs to be set low when C55 is off
 		 * for current drain reasons */
 		gpio_set_value(cdata->ap_c55_int_gpio, 0);

 		pinctrl_select_state(cdata->pctrl, cdata->states[C55_OFF]);

 		/* Unlock wake lock in case it is active */
 		wake_unlock(&cdata->wake_lock);
 	}

 	cdata->c55_mode = mode;

 	mutex_unlock(&cdata->ctrl_mutex);

 	dev_info(dev, "%s: enable = %d\n", __func__, mode);

 	return count;
 }

 static DEVICE_ATTR(enable, S_IWUSR | S_IWGRP, NULL, c55_ctrl_enable);

 static ssize_t c55_fw_verified_write(struct device *dev,
 	struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct c55_ctrl_data *cdata = dev_get_drvdata(dev);
 	int verified = 0;

 	if (kstrtoint(buf, 10, &verified) < 0)
 		return -EINVAL;

 	mutex_lock(&cdata->ctrl_mutex);
 	cdata->fw_verified = verified;
 	mutex_unlock(&cdata->ctrl_mutex);

 	return count;
 }

 static ssize_t c55_fw_verified_read(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct c55_ctrl_data *cdata = dev_get_drvdata(dev);
 	int ret;

 	mutex_lock(&cdata->ctrl_mutex);
 	ret = sprintf(buf, "%d\n", cdata->fw_verified);
 	mutex_unlock(&cdata->ctrl_mutex);

 	return ret;
 }

 static DEVICE_ATTR(fw_verified, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,
 	c55_fw_verified_read, c55_fw_verified_write);

 static int c55_ctrl_pin_setup(struct device *dev, struct c55_ctrl_data *cdata)
 {
 	int i, ret = 0;

 	cdata->pctrl = devm_pinctrl_get(dev);
 	if (IS_ERR(cdata->pctrl)) {
 		ret = PTR_ERR(cdata->pctrl);
 		dev_dbg(dev, "no pinctrl handle\n");
 	}

 	for (i = 0; !ret && (i < C55_MODE_MAX); i++) {
 		cdata->states[i] = pinctrl_lookup_state(cdata->pctrl,
 			c55_pin_state_labels[i]);
 		if (IS_ERR(cdata->states[i])) {
 			ret = PTR_ERR(cdata->states[i]);
 			dev_dbg(dev, "no %s pinctrl state\n",
 				c55_pin_state_labels[i]);
 		}
 	}

 	if (!ret) {
 		ret = pinctrl_select_state(cdata->pctrl,
 			cdata->states[C55_OFF]);
 		if (ret)
 			dev_dbg(dev, "failed to activate %s pinctrl state\n",
 				c55_pin_state_labels[C55_OFF]);
 	}

 	return ret;
 }


 static int c55_ctrl_probe(struct platform_device *pdev)
 {
 	struct c55_ctrl_data *cdata;
 	int ret;
 	if (!pdev->dev.of_node) {
 		/* Platform data not currently supported */
 		dev_err(&pdev->dev, "%s: of devtree data not found\n", __func__);
 		return -EINVAL;
 	}

 	cdata = devm_kzalloc(&pdev->dev, sizeof(*cdata), GFP_KERNEL);
 	if (cdata == NULL) {
 		dev_err(&pdev->dev, "%s: devm_kzalloc failed.\n", __func__);
 		return -ENOMEM;
 	}

 	mutex_init(&cdata->ctrl_mutex);

 	ret = c55_ctrl_pin_setup(&pdev->dev, cdata);
 	if (ret) {
 		dev_err(&pdev->dev, "%s: c55_ctrl_pin_setup failed.\n",
 			__func__);
 		return ret;
 	}

 	cdata->c55_ap_int_gpio = -1;
 	cdata->ap_c55_int_gpio = -1;
 	ret = c55_ctrl_gpio_setup(cdata, &pdev->dev);

 	if (ret) {
 		dev_err(&pdev->dev, "%s: c55_ctrl_gpio_setup failed.\n", __func__);
 		return ret;
 	}

 	cdata->reg_vddc = devm_regulator_get(&pdev->dev, "vddc");
 	if (IS_ERR(cdata->reg_vddc))
 		cdata->reg_vddc = NULL;
 	else if (regulator_enable(cdata->reg_vddc))
 		dev_err(&pdev->dev, "regulator_enable failed for vddc\n");

 	cdata->reg_vddldo = devm_regulator_get(&pdev->dev, "vddldo");
 	if (IS_ERR(cdata->reg_vddldo))
 		cdata->reg_vddldo = NULL;
 	else if (regulator_enable(cdata->reg_vddldo))
 		dev_err(&pdev->dev, "regulator_enable failed for vddldo\n");

 	/* M4 by default has C55 ON at power up */
 	cdata->c55_mode = C55_ON;

 	ret = device_create_file(&pdev->dev, &dev_attr_enable);
 	if (ret) {
 		dev_err(&pdev->dev, "%s: c55_ctrl creating set_mode failed.\n",
 			__func__);
 		return ret;
 	}

 	cdata->fw_verified = 0;

 	ret = device_create_file(&pdev->dev, &dev_attr_fw_verified);
 	if (ret) {
 		dev_err(&pdev->dev, "%s: c55_ctrl creating fw_verified failed.\n",
 			__func__);
 		return ret;
 	}

 	wake_lock_init(&cdata->wake_lock, WAKE_LOCK_SUSPEND, "c55_ctrl");

 	platform_set_drvdata(pdev, cdata);
 	return 0;
 }

 static int c55_ctrl_remove(struct platform_device *pdev)
 {
 	device_remove_file(&pdev->dev, &dev_attr_enable);
 	return 0;
 }

 #ifdef CONFIG_PM
 static int c55_ctrl_suspend(struct platform_device *dev, pm_message_t state)
 {
 	struct c55_ctrl_data *cdata = dev_get_drvdata(&dev->dev);

 	if (cdata->c55_mode != C55_OFF) {
 		dev_warn(&dev->dev, "C55 still ON when going into suspend\n");

 		/* Disable C55->AP IRQ when turning off C55 */
 		if (cdata->c55_ap_int_enabled) {
 			disable_irq_nosync(
 				__gpio_to_irq(cdata->c55_ap_int_gpio));
 			cdata->c55_ap_int_enabled = 0;
 		}

 		if (m4sensorhub_extern_set_audio_status(AUDIO_STATUS_OFF) < 0) {
 			dev_err(&dev->dev,
 				"Unable to set screen status to 0x00\n");
 		}

 		/* AP->C55 interrupt needs to be set low when C55 is off
 		 * for current drain reasons */
 		gpio_set_value(cdata->ap_c55_int_gpio, 0);

 		cdata->c55_mode = C55_OFF;
 	}

 	pinctrl_select_state(cdata->pctrl, cdata->states[C55_OFF]);

 	return 0;
 }

 static int c55_ctrl_resume(struct platform_device *dev)
 {
 	struct c55_ctrl_data *cdata = dev_get_drvdata(&dev->dev);

 	pinctrl_select_state(cdata->pctrl, cdata->states[C55_ON]);

 	return 0;
 }
 #else
 #define c55_ctrl_suspend NULL
 #define c55_ctrl_resume NULL
 #endif

 static struct of_device_id c55_ctrl_match[] = {
 	{.compatible = "ti,c55-ctrl",},
 	{},
 };
 MODULE_DEVICE_TABLE(of, c55_ctrl_match);

 static const struct platform_device_id c55_ctrl_id_table[] = {
 	{"c55_ctrl", 0},
 	{},
 };
 MODULE_DEVICE_TABLE(of, c55_ctrl_id_table);

 static struct platform_driver c55_ctrl_driver = {
 	.driver = {
 		.name = "c55_ctrl",
 		.owner = THIS_MODULE,
 		.of_match_table = c55_ctrl_match,
 	},
 	.probe = c55_ctrl_probe,
 	.remove = c55_ctrl_remove,
 	.suspend = c55_ctrl_suspend,
 	.resume = c55_ctrl_resume,
 	.id_table = c55_ctrl_id_table,
 };

 static int __init c55_ctrl_init(void)
 {
 	return platform_driver_register(&c55_ctrl_driver);
 }

 static void __exit c55_ctrl_exit(void)
 {
 	platform_driver_unregister(&c55_ctrl_driver);
 }

 module_init(c55_ctrl_init);
 module_exit(c55_ctrl_exit);

 MODULE_ALIAS("platform:c55_ctrl");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Motorola");
 MODULE_DESCRIPTION("TI C55 control driver");
	/*
	* Copyright (C) 2013 Motorola Mobility LLC
	*
	* 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/err.h>
	#include <linux/gpio.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/m4sensorhub.h>
	#include <linux/m4sensorhub/MemMapUserSettings.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/consumer.h>
	#include <linux/slab.h>
	#include <linux/wakelock.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/clk.h>

	enum {
	C55_OFF,
	C55_ON,
	C55_MODE_MAX
	};

	struct c55_ctrl_data {
	int c55_ap_int_gpio;
	int ap_c55_int_gpio;
	int c55_ap_int_enabled;
	struct wake_lock wake_lock;
	struct regulator *reg_vddc;
	struct regulator *reg_vddldo;
	struct pinctrl *pctrl;
	struct pinctrl_state *states[C55_MODE_MAX];
	int c55_mode;
	struct mutex ctrl_mutex; /* mutex to handle critical area */
	int fw_verified;
	};

	const char *c55_pin_state_labels[C55_MODE_MAX] = {
	"off",
	"on"
	};

	#define NUM_GPIOS 2

	const char *gpio_labels[NUM_GPIOS] = {
	"gpio_ap_int",
	"gpio_c55_int"
	};

	static irqreturn_t c55_ctrl_isr(int irq, void *data)
	{
	struct c55_ctrl_data *cdata = data;

	pr_debug("%s: value=%d\n", __func__,
	gpio_get_value(cdata->c55_ap_int_gpio));

	/* Interrupt is active low */
	if (gpio_get_value(cdata->c55_ap_int_gpio) == 0)
	wake_lock(&cdata->wake_lock);
	else
	wake_unlock(&cdata->wake_lock);

	return IRQ_HANDLED;
	}

	static void c55_ctrl_int_setup(struct c55_ctrl_data *cdata, int gpio)
	{
	int ret;
	int irq = __gpio_to_irq(gpio);
	unsigned int flags = 0;

	if (cdata->c55_ap_int_gpio >= 0) {
	/* Interrupt already registered */
	return;
	}

	/* Interrupt is shared with user space */
	flags \|= IRQF_TRIGGER_RISING \| IRQF_TRIGGER_FALLING;
	flags \|= IRQF_SHARED;

	cdata->c55_ap_int_enabled = 1;
	ret = request_threaded_irq(irq, c55_ctrl_isr, NULL,
	flags, "c55_ctrl", cdata);
	if (ret) {
	pr_err("%s: IRQ request failed: %d\n", __func__, ret);
	return;
	}

	cdata->c55_ap_int_gpio = gpio;
	}

	static int c55_ctrl_gpio_setup(struct c55_ctrl_data cdata, struct device dev)
	{
	int i;

	if (of_gpio_count(dev->of_node) != NUM_GPIOS) {
	dev_err(dev, "%s: gpio count is not %d.\n", __func__, NUM_GPIOS);
	return -EINVAL;
	}

	for (i = 0; i < NUM_GPIOS; i++) {
	enum of_gpio_flags flags;
	int gpio;

	gpio = of_get_gpio_flags(dev->of_node, i, &flags);
	if (gpio < 0) {
	pr_err("%s: of_get_gpio failed: %d\n", __func__, gpio);
	return gpio;
	}

	gpio_request(gpio, gpio_labels[i]);

	gpio_export(gpio, false);
	gpio_export_link(dev, gpio_labels[i], gpio);

	if ((flags & GPIOF_IN) == GPIOF_IN) {
	gpio_direction_input(gpio);
	c55_ctrl_int_setup(cdata, gpio);
	} else {
	cdata->ap_c55_int_gpio = gpio;
	if ((flags & GPIOF_OUT_INIT_HIGH) == GPIOF_OUT_INIT_HIGH)
	gpio_direction_output(gpio, 1);
	else
	gpio_direction_output(gpio, 0);
	}
	}

	return 0;
	}

	static ssize_t c55_ctrl_enable(struct device *dev,
	struct device_attribute attr, const char buf, size_t count)
	{
	struct c55_ctrl_data *cdata = dev_get_drvdata(dev);
	int mode;

	if (kstrtoint(buf, 10, &mode) < 0)
	return -EINVAL;

	if (mode >= C55_MODE_MAX) {
	dev_err(dev, "%s: Invalid mode %d\n", __func__, mode);
	return -EINVAL;
	}

	if (m4sensorhub_get_current_mode() != NORMALMODE) {
	dev_err(dev, "M4 not ready, Unable to set screen status\n");
	return -EINVAL;
	}

	if (mode == cdata->c55_mode)
	return count;

	mutex_lock(&cdata->ctrl_mutex);

	if (mode == C55_ON) {
	pinctrl_select_state(cdata->pctrl, cdata->states[C55_ON]);

	gpio_set_value(cdata->ap_c55_int_gpio, 1);

	if (m4sensorhub_extern_set_audio_status(AUDIO_STATUS_ON) < 0) {
	dev_err(dev, "Unable to set screen status to 0x01\n");
	mutex_unlock(&cdata->ctrl_mutex);
	return -EINVAL;
	}

	if (!cdata->c55_ap_int_enabled) {
	cdata->c55_ap_int_enabled = 1;
	enable_irq(__gpio_to_irq(cdata->c55_ap_int_gpio));
	}
	} else {
	/* Disable C55->AP IRQ when turning off C55 */
	if (cdata->c55_ap_int_enabled) {
	disable_irq_nosync(
	__gpio_to_irq(cdata->c55_ap_int_gpio));
	cdata->c55_ap_int_enabled = 0;
	}

	if (m4sensorhub_extern_set_audio_status(AUDIO_STATUS_OFF) < 0) {
	dev_err(dev, "Unable to set screen status to 0x00\n");
	mutex_unlock(&cdata->ctrl_mutex);
	return -EINVAL;
	}

	/* AP->C55 interrupt needs to be set low when C55 is off
	* for current drain reasons */
	gpio_set_value(cdata->ap_c55_int_gpio, 0);

	pinctrl_select_state(cdata->pctrl, cdata->states[C55_OFF]);

	/* Unlock wake lock in case it is active */
	wake_unlock(&cdata->wake_lock);
	}

	cdata->c55_mode = mode;

	mutex_unlock(&cdata->ctrl_mutex);

	dev_info(dev, "%s: enable = %d\n", __func__, mode);

	return count;
	}

	static DEVICE_ATTR(enable, S_IWUSR \| S_IWGRP, NULL, c55_ctrl_enable);

	static ssize_t c55_fw_verified_write(struct device *dev,
	struct device_attribute attr, const char buf, size_t count)
	{
	struct c55_ctrl_data *cdata = dev_get_drvdata(dev);
	int verified = 0;

	if (kstrtoint(buf, 10, &verified) < 0)
	return -EINVAL;

	mutex_lock(&cdata->ctrl_mutex);
	cdata->fw_verified = verified;
	mutex_unlock(&cdata->ctrl_mutex);

	return count;
	}

	static ssize_t c55_fw_verified_read(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct c55_ctrl_data *cdata = dev_get_drvdata(dev);
	int ret;

	mutex_lock(&cdata->ctrl_mutex);
	ret = sprintf(buf, "%d\n", cdata->fw_verified);
	mutex_unlock(&cdata->ctrl_mutex);

	return ret;
	}

	static DEVICE_ATTR(fw_verified, S_IRUSR \| S_IRGRP \| S_IWUSR \| S_IWGRP,
	c55_fw_verified_read, c55_fw_verified_write);

	static int c55_ctrl_pin_setup(struct device dev, struct c55_ctrl_data cdata)
	{
	int i, ret = 0;

	cdata->pctrl = devm_pinctrl_get(dev);
	if (IS_ERR(cdata->pctrl)) {
	ret = PTR_ERR(cdata->pctrl);
	dev_dbg(dev, "no pinctrl handle\n");
	}

	for (i = 0; !ret && (i < C55_MODE_MAX); i++) {
	cdata->states[i] = pinctrl_lookup_state(cdata->pctrl,
	c55_pin_state_labels[i]);
	if (IS_ERR(cdata->states[i])) {
	ret = PTR_ERR(cdata->states[i]);
	dev_dbg(dev, "no %s pinctrl state\n",
	c55_pin_state_labels[i]);
	}
	}

	if (!ret) {
	ret = pinctrl_select_state(cdata->pctrl,
	cdata->states[C55_OFF]);
	if (ret)
	dev_dbg(dev, "failed to activate %s pinctrl state\n",
	c55_pin_state_labels[C55_OFF]);
	}

	return ret;
	}


	static int c55_ctrl_probe(struct platform_device *pdev)
	{
	struct c55_ctrl_data *cdata;
	int ret;
	if (!pdev->dev.of_node) {
	/* Platform data not currently supported */
	dev_err(&pdev->dev, "%s: of devtree data not found\n", __func__);
	return -EINVAL;
	}

	cdata = devm_kzalloc(&pdev->dev, sizeof(*cdata), GFP_KERNEL);
	if (cdata == NULL) {
	dev_err(&pdev->dev, "%s: devm_kzalloc failed.\n", __func__);
	return -ENOMEM;
	}

	mutex_init(&cdata->ctrl_mutex);

	ret = c55_ctrl_pin_setup(&pdev->dev, cdata);
	if (ret) {
	dev_err(&pdev->dev, "%s: c55_ctrl_pin_setup failed.\n",
	__func__);
	return ret;
	}

	cdata->c55_ap_int_gpio = -1;
	cdata->ap_c55_int_gpio = -1;
	ret = c55_ctrl_gpio_setup(cdata, &pdev->dev);

	if (ret) {
	dev_err(&pdev->dev, "%s: c55_ctrl_gpio_setup failed.\n", __func__);
	return ret;
	}

	cdata->reg_vddc = devm_regulator_get(&pdev->dev, "vddc");
	if (IS_ERR(cdata->reg_vddc))
	cdata->reg_vddc = NULL;
	else if (regulator_enable(cdata->reg_vddc))
	dev_err(&pdev->dev, "regulator_enable failed for vddc\n");

	cdata->reg_vddldo = devm_regulator_get(&pdev->dev, "vddldo");
	if (IS_ERR(cdata->reg_vddldo))
	cdata->reg_vddldo = NULL;
	else if (regulator_enable(cdata->reg_vddldo))
	dev_err(&pdev->dev, "regulator_enable failed for vddldo\n");

	/* M4 by default has C55 ON at power up */
	cdata->c55_mode = C55_ON;

	ret = device_create_file(&pdev->dev, &dev_attr_enable);
	if (ret) {
	dev_err(&pdev->dev, "%s: c55_ctrl creating set_mode failed.\n",
	__func__);
	return ret;
	}

	cdata->fw_verified = 0;

	ret = device_create_file(&pdev->dev, &dev_attr_fw_verified);
	if (ret) {
	dev_err(&pdev->dev, "%s: c55_ctrl creating fw_verified failed.\n",
	__func__);
	return ret;
	}

	wake_lock_init(&cdata->wake_lock, WAKE_LOCK_SUSPEND, "c55_ctrl");

	platform_set_drvdata(pdev, cdata);
	return 0;
	}

	static int c55_ctrl_remove(struct platform_device *pdev)
	{
	device_remove_file(&pdev->dev, &dev_attr_enable);
	return 0;
	}

	#ifdef CONFIG_PM
	static int c55_ctrl_suspend(struct platform_device *dev, pm_message_t state)
	{
	struct c55_ctrl_data *cdata = dev_get_drvdata(&dev->dev);

	if (cdata->c55_mode != C55_OFF) {
	dev_warn(&dev->dev, "C55 still ON when going into suspend\n");

	/* Disable C55->AP IRQ when turning off C55 */
	if (cdata->c55_ap_int_enabled) {
	disable_irq_nosync(
	__gpio_to_irq(cdata->c55_ap_int_gpio));
	cdata->c55_ap_int_enabled = 0;
	}

	if (m4sensorhub_extern_set_audio_status(AUDIO_STATUS_OFF) < 0) {
	dev_err(&dev->dev,
	"Unable to set screen status to 0x00\n");
	}

	/* AP->C55 interrupt needs to be set low when C55 is off
	* for current drain reasons */
	gpio_set_value(cdata->ap_c55_int_gpio, 0);

	cdata->c55_mode = C55_OFF;
	}

	pinctrl_select_state(cdata->pctrl, cdata->states[C55_OFF]);

	return 0;
	}

	static int c55_ctrl_resume(struct platform_device *dev)
	{
	struct c55_ctrl_data *cdata = dev_get_drvdata(&dev->dev);

	pinctrl_select_state(cdata->pctrl, cdata->states[C55_ON]);

	return 0;
	}
	#else
	#define c55_ctrl_suspend NULL
	#define c55_ctrl_resume NULL
	#endif

	static struct of_device_id c55_ctrl_match[] = {
	{.compatible = "ti,c55-ctrl",},
	{},
	};
	MODULE_DEVICE_TABLE(of, c55_ctrl_match);

	static const struct platform_device_id c55_ctrl_id_table[] = {
	{"c55_ctrl", 0},
	{},
	};
	MODULE_DEVICE_TABLE(of, c55_ctrl_id_table);

	static struct platform_driver c55_ctrl_driver = {
	.driver = {
	.name = "c55_ctrl",
	.owner = THIS_MODULE,
	.of_match_table = c55_ctrl_match,
	},
	.probe = c55_ctrl_probe,
	.remove = c55_ctrl_remove,
	.suspend = c55_ctrl_suspend,
	.resume = c55_ctrl_resume,
	.id_table = c55_ctrl_id_table,
	};

	static int __init c55_ctrl_init(void)
	{
	return platform_driver_register(&c55_ctrl_driver);
	}

	static void __exit c55_ctrl_exit(void)
	{
	platform_driver_unregister(&c55_ctrl_driver);
	}

	module_init(c55_ctrl_init);
	module_exit(c55_ctrl_exit);

	MODULE_ALIAS("platform:c55_ctrl");
	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Motorola");
	MODULE_DESCRIPTION("TI C55 control driver");