drivers/hwmon/epm_adc.c - kernel/msm - Git at Google

 /* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only version 2 as published by the Free Software Foundation.
  *
  * 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/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/mutex.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
 #include <linux/hwmon.h>
 #include <linux/delay.h>
 #include <linux/epm_adc.h>
 #include <linux/uaccess.h>
 #include <linux/spi/spi.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/miscdevice.h>
 #include <linux/platform_device.h>

 #define EPM_ADC_DRIVER_NAME		"epm_adc"
 #define EPM_ADC_MAX_FNAME		20
 #define EPM_ADC_CONVERSION_DELAY	100 /* milliseconds */

 #define EPM_ADC_SPI_BITS_PER_WORD	8
 #define GPIO_EPM_GLOBAL_ENABLE		86
 #define GPIO_EPM_MARKER1		96
 #define GPIO_EPM_MARKER2		85
 #define EPM_ADC_CONVERSION_TIME_MIN	50000
 #define EPM_ADC_CONVERSION_TIME_MAX	51000
 /* PSoc Commands */

 #define EPM_PSOC_GLOBAL_ENABLE				81
 #define EPM_PSOC_VREF_VOLTAGE				2048
 #define EPM_PSOC_MAX_ADC_CODE_15_BIT			32767
 #define EPM_PSOC_MAX_ADC_CODE_12_BIT			4096
 #define EPM_GLOBAL_ENABLE_MIN_DELAY			5000
 #define EPM_GLOBAL_ENABLE_MAX_DELAY			5100

 struct epm_adc_drv {
 	struct platform_device		*pdev;
 	struct device			*hwmon;
 	struct spi_device		*epm_spi_client;
 	struct mutex			conv_lock;
 	uint32_t			bus_id;
 	struct miscdevice		misc;
 	uint32_t			channel_mask;
 	uint32_t			epm_global_en_gpio;
 	struct epm_chan_properties	epm_psoc_ch_prop[0];
 };

 static struct epm_adc_drv *epm_adc_drv;

 static int epm_adc_psoc_gpio_init(struct epm_adc_drv *epm_adc,
 							bool enable)
 {
 	int rc = 0;

 	if (enable) {
 		rc = gpio_request(epm_adc->epm_global_en_gpio,
 							"EPM_PSOC_GLOBAL_EN");
 		if (!rc) {
 			gpio_direction_output(epm_adc->epm_global_en_gpio, 1);
 		} else {
 			pr_err("%s: Configure EPM_GLOBAL_EN Failed\n",
 								__func__);
 			return rc;
 		}
 	} else {
 		gpio_direction_output(epm_adc->epm_global_en_gpio, 0);
 		gpio_free(epm_adc->epm_global_en_gpio);
 	}

 	return 0;
 }

 static int epm_request_marker1(void)
 {
 	int rc = 0;

 	rc = gpio_request(GPIO_EPM_MARKER1, "EPM_MARKER1");
 	if (!rc) {
 		gpio_direction_output(GPIO_EPM_MARKER1, 1);
 	} else {
 		pr_err("%s: Configure MARKER1 GPIO Failed\n",
 							__func__);
 		return rc;
 	}

 	return 0;
 }

 static int epm_set_marker1(struct epm_marker_level *marker_init)
 {
 	gpio_set_value(GPIO_EPM_MARKER1, marker_init->level);

 	return 0;
 }

 static int epm_request_marker2(void)
 {
 	int rc = 0;

 	rc = gpio_request(GPIO_EPM_MARKER2, "EPM_MARKER2");
 	if (!rc) {
 		gpio_direction_output(GPIO_EPM_MARKER2, 1);
 	} else {
 		pr_err("%s: Configure MARKER2 GPIO Failed\n",
 							__func__);
 		return rc;
 	}

 	return 0;
 }

 static int epm_set_marker2(struct epm_marker_level *marker_init)
 {
 	gpio_set_value(GPIO_EPM_MARKER2, marker_init->level);

 	return 0;
 }

 static int epm_marker1_release(void)
 {
 	gpio_free(GPIO_EPM_MARKER1);

 	return 0;
 }

 static int epm_marker2_release(void)
 {
 	gpio_free(GPIO_EPM_MARKER2);

 	return 0;
 }

 static int epm_psoc_generic_request(struct epm_adc_drv *epm_adc,
 			struct epm_generic_request *psoc_get_data)
 {
 	struct spi_message m;
 	struct spi_transfer t;
 	char tx_buf[64], rx_buf[64];
 	int rc = 0, data_loop = 0;

 	spi_setup(epm_adc->epm_spi_client);

 	memset(&t, 0, sizeof(t));
 	memset(tx_buf, 0, sizeof(tx_buf));
 	memset(rx_buf, 0, sizeof(tx_buf));
 	t.tx_buf = tx_buf;
 	t.rx_buf = rx_buf;
 	spi_message_init(&m);
 	spi_message_add_tail(&t, &m);

 	for (data_loop = 0; data_loop < 64; data_loop++)
 		tx_buf[data_loop] = psoc_get_data->buf[data_loop];

 	t.len = sizeof(tx_buf);
 	t.bits_per_word = EPM_ADC_SPI_BITS_PER_WORD;

 	rc = spi_sync(epm_adc->epm_spi_client, &m);
 	if (rc)
 		return rc;

 	for (data_loop = 0; data_loop < 64; data_loop++)
 		psoc_get_data->buf[data_loop] = rx_buf[data_loop];

 	return rc;
 }

 static long epm_adc_ioctl(struct file *file, unsigned int cmd,
 						unsigned long arg)
 {
 	struct epm_adc_drv *epm_adc = epm_adc_drv;

 	switch (cmd) {
 	case EPM_MARKER1_REQUEST:
 		{
 			uint32_t result;
 			result = epm_request_marker1();

 			if (copy_to_user((void __user *)arg, &result,
 						sizeof(uint32_t)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_MARKER2_REQUEST:
 		{
 			uint32_t result;
 			result = epm_request_marker2();

 			if (copy_to_user((void __user *)arg, &result,
 						sizeof(uint32_t)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_MARKER1_SET_LEVEL:
 		{
 			struct epm_marker_level marker_init;
 			uint32_t result;

 			if (copy_from_user(&marker_init, (void __user *)arg,
 					sizeof(struct epm_marker_level)))
 				return -EFAULT;

 			result = epm_set_marker1(&marker_init);

 			if (copy_to_user((void __user *)arg, &result,
 						sizeof(uint32_t)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_MARKER2_SET_LEVEL:
 		{
 			struct epm_marker_level marker_init;
 			uint32_t result;

 			if (copy_from_user(&marker_init, (void __user *)arg,
 					sizeof(struct epm_marker_level)))
 				return -EFAULT;

 			result = epm_set_marker2(&marker_init);

 			if (copy_to_user((void __user *)arg, &result,
 						sizeof(uint32_t)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_MARKER1_RELEASE:
 		{
 			uint32_t result;
 			result = epm_marker1_release();

 			if (copy_to_user((void __user *)arg, &result,
 						sizeof(uint32_t)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_MARKER2_RELEASE:
 		{
 			uint32_t result;
 			result = epm_marker2_release();

 			if (copy_to_user((void __user *)arg, &result,
 						sizeof(uint32_t)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_PSOC_ADC_INIT:
 		{
 			int rc;

 			rc = epm_adc_psoc_gpio_init(epm_adc, true);
 			if (rc)
 				pr_err("GPIO init failed with %d\n", rc);

 			if (copy_to_user((void __user *)arg, &rc,
 						sizeof(int)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_PSOC_ADC_DEINIT:
 		{
 			int rc;
 			rc = epm_adc_psoc_gpio_init(epm_adc, false);

 			if (copy_to_user((void __user *)arg, &rc,
 						sizeof(int)))
 				return -EFAULT;
 			break;
 		}
 	case EPM_PSOC_GENERIC_REQUEST:
 		{
 			struct epm_generic_request psoc_get_data;
 			int rc;

 			if (copy_from_user(&psoc_get_data,
 				(void __user *)arg,
 				sizeof(struct
 				epm_generic_request)))
 				return -EFAULT;

 			rc = epm_psoc_generic_request(epm_adc, &psoc_get_data);
 			if (rc)
 				pr_err("Generic request failed\n");

 			if (copy_to_user((void __user *)arg, &psoc_get_data,
 				sizeof(struct
 				epm_generic_request)))
 				return -EFAULT;
 			break;
 		}
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 #ifdef CONFIG_COMPAT
 static long epm_adc_compat_ioctl_process(struct file *filep,
 				   unsigned int cmd, unsigned long arg)
 {
 	arg = (unsigned long)compat_ptr(arg);
 	return epm_adc_ioctl(filep, cmd, arg);
 }
 #endif	/* CONFIG_COMPAT */

 const struct file_operations epm_adc_fops = {
 	.unlocked_ioctl = epm_adc_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = epm_adc_compat_ioctl_process,
 #endif  /* CONFIG_COMPAT */
 };

 static int get_device_tree_data(struct spi_device *spi)
 {
 	const struct device_node *node = spi->dev.of_node;
 	struct epm_adc_drv *epm_adc;
 	u32 *epm_ch_gain, *epm_ch_rsense;
 	u32 rc = 0, epm_num_channels, i, channel_mask, epm_gpio_num;

 	if (!node)
 		return -EINVAL;

 	rc = of_property_read_u32(node,
 			"qcom,channels", &epm_num_channels);
 	if (rc) {
 		dev_err(&spi->dev, "missing channel numbers\n");
 		return -ENODEV;
 	}

 	epm_ch_gain = devm_kzalloc(&spi->dev,
 			epm_num_channels * sizeof(u32), GFP_KERNEL);
 	if (!epm_ch_gain) {
 		dev_err(&spi->dev, "cannot allocate gain\n");
 		return -ENOMEM;
 	}

 	epm_ch_rsense = devm_kzalloc(&spi->dev,
 			epm_num_channels * sizeof(u32), GFP_KERNEL);
 	if (!epm_ch_rsense) {
 		dev_err(&spi->dev, "cannot allocate rsense\n");
 		return -ENOMEM;
 	}

 	rc = of_property_read_u32_array(node,
 			"qcom,gain", epm_ch_gain, epm_num_channels);
 	if (rc) {
 		dev_err(&spi->dev, "invalid gain property:%d\n", rc);
 		return rc;
 	}

 	rc = of_property_read_u32_array(node,
 			"qcom,rsense", epm_ch_rsense, epm_num_channels);
 	if (rc) {
 		dev_err(&spi->dev, "invalid rsense property:%d\n", rc);
 		return rc;
 	}

 	rc = of_property_read_u32(node,
 			"qcom,channel-type", &channel_mask);
 	if (rc) {
 		dev_err(&spi->dev, "missing channel mask\n");
 		return -ENODEV;
 	}

 	epm_gpio_num = of_get_named_gpio(spi->dev.of_node,
 						"qcom,epm-enable-gpio", 0);
 	if (epm_gpio_num < 0) {
 		dev_err(&spi->dev, "missing global en gpio num\n");
 		return -ENODEV;
 	}

 	epm_adc = devm_kzalloc(&spi->dev,
 			sizeof(struct epm_adc_drv) +
 			(epm_num_channels *
 			sizeof(struct epm_chan_properties)),
 			GFP_KERNEL);
 	if (!epm_adc) {
 		dev_err(&spi->dev, "Unable to allocate memory\n");
 		return -ENOMEM;
 	}

 	for (i = 0; i < epm_num_channels; i++) {
 		epm_adc->epm_psoc_ch_prop[i].resistorvalue =
 							epm_ch_rsense[i];
 		epm_adc->epm_psoc_ch_prop[i].gain =
 							epm_ch_gain[i];
 	}

 	epm_adc->channel_mask = channel_mask;
 	epm_adc->epm_global_en_gpio = epm_gpio_num;
 	epm_adc_drv = epm_adc;

 	return 0;
 }

 static int epm_adc_psoc_spi_probe(struct spi_device *spi)
 {

 	struct epm_adc_drv *epm_adc;
 	struct device_node *node = spi->dev.of_node;
 	int rc = 0;

 	if (node) {
 		rc = get_device_tree_data(spi);
 		if (rc)
 			return rc;
 	} else {
 		epm_adc = epm_adc_drv;
 		epm_adc_drv->epm_spi_client = spi;
 		epm_adc_drv->epm_spi_client->bits_per_word =
 				EPM_ADC_SPI_BITS_PER_WORD;
 		return rc;
 	}

 	epm_adc = epm_adc_drv;
 	epm_adc->misc.name = EPM_ADC_DRIVER_NAME;
 	epm_adc->misc.minor = MISC_DYNAMIC_MINOR;

 	if (node) {
 		epm_adc->misc.fops = &epm_adc_fops;
 		if (misc_register(&epm_adc->misc)) {
 			pr_err("Unable to register misc device!\n");
 			return -EFAULT;
 		}
 	}

 	epm_adc_drv->epm_spi_client = spi;
 	epm_adc_drv->epm_spi_client->bits_per_word =
 				EPM_ADC_SPI_BITS_PER_WORD;

 	epm_adc->hwmon = hwmon_device_register(&spi->dev);
 	if (IS_ERR(epm_adc->hwmon)) {
 		dev_err(&spi->dev, "hwmon_device_register failed\n");
 		return rc;
 	}

 	mutex_init(&epm_adc->conv_lock);
 	return rc;
 }

 static int epm_adc_psoc_spi_remove(struct spi_device *spi)
 {
 	epm_adc_drv->epm_spi_client = NULL;
 	return 0;
 }

 static const struct of_device_id epm_adc_psoc_match_table[] = {
 	{	.compatible = "cy,epm-adc-cy8c5568lti-114",
 	},
 	{}
 };

 static struct spi_driver epm_spi_driver = {
 	.probe = epm_adc_psoc_spi_probe,
 	.remove = epm_adc_psoc_spi_remove,
 	.driver = {
 		.name = EPM_ADC_DRIVER_NAME,
 		.of_match_table = epm_adc_psoc_match_table,
 	},
 };

 static int __init epm_adc_init(void)
 {
 	int ret = 0;

 	ret = spi_register_driver(&epm_spi_driver);
 	if (ret)
 		pr_err("%s: spi register failed: rc=%d\n", __func__, ret);

 	return ret;
 }

 static void __exit epm_adc_exit(void)
 {
 	spi_unregister_driver(&epm_spi_driver);
 }

 module_init(epm_adc_init);
 module_exit(epm_adc_exit);

 MODULE_DESCRIPTION("EPM ADC Driver");
 MODULE_ALIAS("platform:epm_adc");
 MODULE_LICENSE("GPL v2");
	/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only version 2 as published by the Free Software Foundation.
	*
	* 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/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/fs.h>
	#include <linux/mutex.h>
	#include <linux/err.h>
	#include <linux/slab.h>
	#include <linux/gpio.h>
	#include <linux/of_gpio.h>
	#include <linux/hwmon.h>
	#include <linux/delay.h>
	#include <linux/epm_adc.h>
	#include <linux/uaccess.h>
	#include <linux/spi/spi.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/miscdevice.h>
	#include <linux/platform_device.h>

	#define EPM_ADC_DRIVER_NAME "epm_adc"
	#define EPM_ADC_MAX_FNAME 20
	#define EPM_ADC_CONVERSION_DELAY 100 /* milliseconds */

	#define EPM_ADC_SPI_BITS_PER_WORD 8
	#define GPIO_EPM_GLOBAL_ENABLE 86
	#define GPIO_EPM_MARKER1 96
	#define GPIO_EPM_MARKER2 85
	#define EPM_ADC_CONVERSION_TIME_MIN 50000
	#define EPM_ADC_CONVERSION_TIME_MAX 51000
	/* PSoc Commands */

	#define EPM_PSOC_GLOBAL_ENABLE 81
	#define EPM_PSOC_VREF_VOLTAGE 2048
	#define EPM_PSOC_MAX_ADC_CODE_15_BIT 32767
	#define EPM_PSOC_MAX_ADC_CODE_12_BIT 4096
	#define EPM_GLOBAL_ENABLE_MIN_DELAY 5000
	#define EPM_GLOBAL_ENABLE_MAX_DELAY 5100

	struct epm_adc_drv {
	struct platform_device *pdev;
	struct device *hwmon;
	struct spi_device *epm_spi_client;
	struct mutex conv_lock;
	uint32_t bus_id;
	struct miscdevice misc;
	uint32_t channel_mask;
	uint32_t epm_global_en_gpio;
	struct epm_chan_properties epm_psoc_ch_prop[0];
	};

	static struct epm_adc_drv *epm_adc_drv;

	static int epm_adc_psoc_gpio_init(struct epm_adc_drv *epm_adc,
	bool enable)
	{
	int rc = 0;

	if (enable) {
	rc = gpio_request(epm_adc->epm_global_en_gpio,
	"EPM_PSOC_GLOBAL_EN");
	if (!rc) {
	gpio_direction_output(epm_adc->epm_global_en_gpio, 1);
	} else {
	pr_err("%s: Configure EPM_GLOBAL_EN Failed\n",
	__func__);
	return rc;
	}
	} else {
	gpio_direction_output(epm_adc->epm_global_en_gpio, 0);
	gpio_free(epm_adc->epm_global_en_gpio);
	}

	return 0;
	}

	static int epm_request_marker1(void)
	{
	int rc = 0;

	rc = gpio_request(GPIO_EPM_MARKER1, "EPM_MARKER1");
	if (!rc) {
	gpio_direction_output(GPIO_EPM_MARKER1, 1);
	} else {
	pr_err("%s: Configure MARKER1 GPIO Failed\n",
	__func__);
	return rc;
	}

	return 0;
	}

	static int epm_set_marker1(struct epm_marker_level *marker_init)
	{
	gpio_set_value(GPIO_EPM_MARKER1, marker_init->level);

	return 0;
	}

	static int epm_request_marker2(void)
	{
	int rc = 0;

	rc = gpio_request(GPIO_EPM_MARKER2, "EPM_MARKER2");
	if (!rc) {
	gpio_direction_output(GPIO_EPM_MARKER2, 1);
	} else {
	pr_err("%s: Configure MARKER2 GPIO Failed\n",
	__func__);
	return rc;
	}

	return 0;
	}

	static int epm_set_marker2(struct epm_marker_level *marker_init)
	{
	gpio_set_value(GPIO_EPM_MARKER2, marker_init->level);

	return 0;
	}

	static int epm_marker1_release(void)
	{
	gpio_free(GPIO_EPM_MARKER1);

	return 0;
	}

	static int epm_marker2_release(void)
	{
	gpio_free(GPIO_EPM_MARKER2);

	return 0;
	}

	static int epm_psoc_generic_request(struct epm_adc_drv *epm_adc,
	struct epm_generic_request *psoc_get_data)
	{
	struct spi_message m;
	struct spi_transfer t;
	char tx_buf[64], rx_buf[64];
	int rc = 0, data_loop = 0;

	spi_setup(epm_adc->epm_spi_client);

	memset(&t, 0, sizeof(t));
	memset(tx_buf, 0, sizeof(tx_buf));
	memset(rx_buf, 0, sizeof(tx_buf));
	t.tx_buf = tx_buf;
	t.rx_buf = rx_buf;
	spi_message_init(&m);
	spi_message_add_tail(&t, &m);

	for (data_loop = 0; data_loop < 64; data_loop++)
	tx_buf[data_loop] = psoc_get_data->buf[data_loop];

	t.len = sizeof(tx_buf);
	t.bits_per_word = EPM_ADC_SPI_BITS_PER_WORD;

	rc = spi_sync(epm_adc->epm_spi_client, &m);
	if (rc)
	return rc;

	for (data_loop = 0; data_loop < 64; data_loop++)
	psoc_get_data->buf[data_loop] = rx_buf[data_loop];

	return rc;
	}

	static long epm_adc_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	struct epm_adc_drv *epm_adc = epm_adc_drv;

	switch (cmd) {
	case EPM_MARKER1_REQUEST:
	{
	uint32_t result;
	result = epm_request_marker1();

	if (copy_to_user((void __user *)arg, &result,
	sizeof(uint32_t)))
	return -EFAULT;
	break;
	}
	case EPM_MARKER2_REQUEST:
	{
	uint32_t result;
	result = epm_request_marker2();

	if (copy_to_user((void __user *)arg, &result,
	sizeof(uint32_t)))
	return -EFAULT;
	break;
	}
	case EPM_MARKER1_SET_LEVEL:
	{
	struct epm_marker_level marker_init;
	uint32_t result;

	if (copy_from_user(&marker_init, (void __user *)arg,
	sizeof(struct epm_marker_level)))
	return -EFAULT;

	result = epm_set_marker1(&marker_init);

	if (copy_to_user((void __user *)arg, &result,
	sizeof(uint32_t)))
	return -EFAULT;
	break;
	}
	case EPM_MARKER2_SET_LEVEL:
	{
	struct epm_marker_level marker_init;
	uint32_t result;

	if (copy_from_user(&marker_init, (void __user *)arg,
	sizeof(struct epm_marker_level)))
	return -EFAULT;

	result = epm_set_marker2(&marker_init);

	if (copy_to_user((void __user *)arg, &result,
	sizeof(uint32_t)))
	return -EFAULT;
	break;
	}
	case EPM_MARKER1_RELEASE:
	{
	uint32_t result;
	result = epm_marker1_release();

	if (copy_to_user((void __user *)arg, &result,
	sizeof(uint32_t)))
	return -EFAULT;
	break;
	}
	case EPM_MARKER2_RELEASE:
	{
	uint32_t result;
	result = epm_marker2_release();

	if (copy_to_user((void __user *)arg, &result,
	sizeof(uint32_t)))
	return -EFAULT;
	break;
	}
	case EPM_PSOC_ADC_INIT:
	{
	int rc;

	rc = epm_adc_psoc_gpio_init(epm_adc, true);
	if (rc)
	pr_err("GPIO init failed with %d\n", rc);

	if (copy_to_user((void __user *)arg, &rc,
	sizeof(int)))
	return -EFAULT;
	break;
	}
	case EPM_PSOC_ADC_DEINIT:
	{
	int rc;
	rc = epm_adc_psoc_gpio_init(epm_adc, false);

	if (copy_to_user((void __user *)arg, &rc,
	sizeof(int)))
	return -EFAULT;
	break;
	}
	case EPM_PSOC_GENERIC_REQUEST:
	{
	struct epm_generic_request psoc_get_data;
	int rc;

	if (copy_from_user(&psoc_get_data,
	(void __user *)arg,
	sizeof(struct
	epm_generic_request)))
	return -EFAULT;

	rc = epm_psoc_generic_request(epm_adc, &psoc_get_data);
	if (rc)
	pr_err("Generic request failed\n");

	if (copy_to_user((void __user *)arg, &psoc_get_data,
	sizeof(struct
	epm_generic_request)))
	return -EFAULT;
	break;
	}
	default:
	return -EINVAL;
	}

	return 0;
	}

	#ifdef CONFIG_COMPAT
	static long epm_adc_compat_ioctl_process(struct file *filep,
	unsigned int cmd, unsigned long arg)
	{
	arg = (unsigned long)compat_ptr(arg);
	return epm_adc_ioctl(filep, cmd, arg);
	}
	#endif /* CONFIG_COMPAT */

	const struct file_operations epm_adc_fops = {
	.unlocked_ioctl = epm_adc_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = epm_adc_compat_ioctl_process,
	#endif /* CONFIG_COMPAT */
	};

	static int get_device_tree_data(struct spi_device *spi)
	{
	const struct device_node *node = spi->dev.of_node;
	struct epm_adc_drv *epm_adc;
	u32 epm_ch_gain, epm_ch_rsense;
	u32 rc = 0, epm_num_channels, i, channel_mask, epm_gpio_num;

	if (!node)
	return -EINVAL;

	rc = of_property_read_u32(node,
	"qcom,channels", &epm_num_channels);
	if (rc) {
	dev_err(&spi->dev, "missing channel numbers\n");
	return -ENODEV;
	}

	epm_ch_gain = devm_kzalloc(&spi->dev,
	epm_num_channels * sizeof(u32), GFP_KERNEL);
	if (!epm_ch_gain) {
	dev_err(&spi->dev, "cannot allocate gain\n");
	return -ENOMEM;
	}

	epm_ch_rsense = devm_kzalloc(&spi->dev,
	epm_num_channels * sizeof(u32), GFP_KERNEL);
	if (!epm_ch_rsense) {
	dev_err(&spi->dev, "cannot allocate rsense\n");
	return -ENOMEM;
	}

	rc = of_property_read_u32_array(node,
	"qcom,gain", epm_ch_gain, epm_num_channels);
	if (rc) {
	dev_err(&spi->dev, "invalid gain property:%d\n", rc);
	return rc;
	}

	rc = of_property_read_u32_array(node,
	"qcom,rsense", epm_ch_rsense, epm_num_channels);
	if (rc) {
	dev_err(&spi->dev, "invalid rsense property:%d\n", rc);
	return rc;
	}

	rc = of_property_read_u32(node,
	"qcom,channel-type", &channel_mask);
	if (rc) {
	dev_err(&spi->dev, "missing channel mask\n");
	return -ENODEV;
	}

	epm_gpio_num = of_get_named_gpio(spi->dev.of_node,
	"qcom,epm-enable-gpio", 0);
	if (epm_gpio_num < 0) {
	dev_err(&spi->dev, "missing global en gpio num\n");
	return -ENODEV;
	}

	epm_adc = devm_kzalloc(&spi->dev,
	sizeof(struct epm_adc_drv) +
	(epm_num_channels *
	sizeof(struct epm_chan_properties)),
	GFP_KERNEL);
	if (!epm_adc) {
	dev_err(&spi->dev, "Unable to allocate memory\n");
	return -ENOMEM;
	}

	for (i = 0; i < epm_num_channels; i++) {
	epm_adc->epm_psoc_ch_prop[i].resistorvalue =
	epm_ch_rsense[i];
	epm_adc->epm_psoc_ch_prop[i].gain =
	epm_ch_gain[i];
	}

	epm_adc->channel_mask = channel_mask;
	epm_adc->epm_global_en_gpio = epm_gpio_num;
	epm_adc_drv = epm_adc;

	return 0;
	}

	static int epm_adc_psoc_spi_probe(struct spi_device *spi)
	{

	struct epm_adc_drv *epm_adc;
	struct device_node *node = spi->dev.of_node;
	int rc = 0;

	if (node) {
	rc = get_device_tree_data(spi);
	if (rc)
	return rc;
	} else {
	epm_adc = epm_adc_drv;
	epm_adc_drv->epm_spi_client = spi;
	epm_adc_drv->epm_spi_client->bits_per_word =
	EPM_ADC_SPI_BITS_PER_WORD;
	return rc;
	}

	epm_adc = epm_adc_drv;
	epm_adc->misc.name = EPM_ADC_DRIVER_NAME;
	epm_adc->misc.minor = MISC_DYNAMIC_MINOR;

	if (node) {
	epm_adc->misc.fops = &epm_adc_fops;
	if (misc_register(&epm_adc->misc)) {
	pr_err("Unable to register misc device!\n");
	return -EFAULT;
	}
	}

	epm_adc_drv->epm_spi_client = spi;
	epm_adc_drv->epm_spi_client->bits_per_word =
	EPM_ADC_SPI_BITS_PER_WORD;

	epm_adc->hwmon = hwmon_device_register(&spi->dev);
	if (IS_ERR(epm_adc->hwmon)) {
	dev_err(&spi->dev, "hwmon_device_register failed\n");
	return rc;
	}

	mutex_init(&epm_adc->conv_lock);
	return rc;
	}

	static int epm_adc_psoc_spi_remove(struct spi_device *spi)
	{
	epm_adc_drv->epm_spi_client = NULL;
	return 0;
	}

	static const struct of_device_id epm_adc_psoc_match_table[] = {
	{ .compatible = "cy,epm-adc-cy8c5568lti-114",
	},
	{}
	};

	static struct spi_driver epm_spi_driver = {
	.probe = epm_adc_psoc_spi_probe,
	.remove = epm_adc_psoc_spi_remove,
	.driver = {
	.name = EPM_ADC_DRIVER_NAME,
	.of_match_table = epm_adc_psoc_match_table,
	},
	};

	static int __init epm_adc_init(void)
	{
	int ret = 0;

	ret = spi_register_driver(&epm_spi_driver);
	if (ret)
	pr_err("%s: spi register failed: rc=%d\n", __func__, ret);

	return ret;
	}

	static void __exit epm_adc_exit(void)
	{
	spi_unregister_driver(&epm_spi_driver);
	}

	module_init(epm_adc_init);
	module_exit(epm_adc_exit);

	MODULE_DESCRIPTION("EPM ADC Driver");
	MODULE_ALIAS("platform:epm_adc");
	MODULE_LICENSE("GPL v2");