drivers/thermal/generic_adc_thermal.c - kernel/tegra - Git at Google

 /*
  * drivers/staging/iio/generic_adc_thermal.c
  *
  * Generic ADC thermal driver
  *
  * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
  *
  * Author: Jinyoung Park <jinyoungp@nvidia.com>
  *
  * 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 version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  * whether express or implied; 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
  */
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <linux/module.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/err.h>
 #include <linux/thermal.h>
 #include <linux/iio/consumer.h>
 #include <linux/iio/types.h>
 #include <linux/generic_adc_thermal.h>

 struct gadc_thermal_driver_data {
 	struct device *dev;
 	struct thermal_zone_device *tz;
 	struct iio_channel *channel;
 	struct gadc_thermal_platform_data *pdata;
 	struct dentry *dentry;
 	int *adc_temp_lookup;
 	unsigned int lookup_table_size;
 	int first_index_temp;
 	int last_index_temp;
 	int temp_offset;
 	bool dual_mode;
 };

 static int gadc_thermal_thermistor_adc_to_temp(
 	struct gadc_thermal_driver_data *drvdata, int adc_raw)
 {

 	int *lookup_table = drvdata->adc_temp_lookup;
 	int table_size = drvdata->lookup_table_size;
 	int first_index_temp = drvdata->first_index_temp;
 	int last_index_temp = drvdata->last_index_temp;
 	int i;
 	int temp, adc_low, adc_high, diff_temp;
 	int temp_decrement = (first_index_temp > last_index_temp);

 	for (i = 0; i < table_size - 1; ++i) {
 		if (temp_decrement) {
 			if (adc_raw <= lookup_table[i])
 				break;
 		} else {
 			if (adc_raw >= lookup_table[i])
 				break;
 		}
 	}

 	if (i == 0)
 		return first_index_temp;
 	if (i == table_size)
 		return last_index_temp;

 	/* Find temp with interpolate reading */
 	adc_low = lookup_table[i-1];
 	adc_high = lookup_table[i];
 	diff_temp = (adc_high - adc_low) * 1000;
 	if (temp_decrement) {
 		temp = (first_index_temp - i) * 1000;
 		temp += ((adc_high - adc_raw) * 1000) / (adc_high - adc_low);
 	} else {
 		temp = (first_index_temp + i - 1) * 1000;
 		temp += (adc_low - adc_raw) * 1000 / (adc_high - adc_low);
 	}
 	return temp;
 }

 static int gadc_thermal_read_channel(struct gadc_thermal_driver_data *drvdata,
 				     int *val, int *val2)
 {
 	int ret;

 	if (drvdata->dual_mode) {
 		ret = iio_read_channel_processed_dual(drvdata->channel, val,
 						      val2);
 		if (ret < 0)
 			ret = iio_read_channel_raw_dual(drvdata->channel, val,
 							val2);
 	} else {
 		ret = iio_read_channel_processed(drvdata->channel, val);
 		if (ret < 0)
 			ret = iio_read_channel_raw(drvdata->channel, val);
 	}
 	return ret;
 }

 static int gadc_thermal_get_temp(struct thermal_zone_device *tz,
 				 unsigned long *temp)
 {
 	struct gadc_thermal_driver_data *drvdata = tz->devdata;
 	int val = 0, val2 = 0;
 	int ret;

 	ret = gadc_thermal_read_channel(drvdata, &val, &val2);
 	if (ret < 0) {
 		dev_err(drvdata->dev, "%s: Failed to read channel, %d\n",
 			__func__, ret);
 		return ret;
 	}

 	if (drvdata->pdata->adc_to_temp)
 		*temp = drvdata->pdata->adc_to_temp(drvdata->pdata, val, val2);
 	else if (drvdata->pdata->adc_temp_lookup)
 		*temp = gadc_thermal_thermistor_adc_to_temp(drvdata, val);
 	else
 		*temp = val;

 	*temp += drvdata->temp_offset;
 	return 0;
 }

 static struct thermal_zone_device_ops gadc_thermal_ops = {
 	.get_temp = gadc_thermal_get_temp,
 };

 #ifdef CONFIG_DEBUG_FS
 static int adc_temp_show(struct seq_file *s, void *p)
 {
 	struct gadc_thermal_driver_data *drvdata = s->private;
 	int val = 0, val2 = 0, temp = 0;
 	int ret;

 	ret = gadc_thermal_read_channel(drvdata, &val, &val2);
 	if (ret < 0) {
 		dev_err(drvdata->dev, "%s: Failed to read channel, %d\n",
 			__func__, ret);
 		return ret;
 	}

 	if (drvdata->pdata->adc_to_temp)
 		temp = drvdata->pdata->adc_to_temp(drvdata->pdata, val, val2);
 	else if (drvdata->pdata->adc_temp_lookup)
 		temp = gadc_thermal_thermistor_adc_to_temp(drvdata, val);
 	else
 		temp = val;

 	temp += drvdata->temp_offset;
 	seq_printf(s, "%d %d %d\n", val, val2, temp);
 	return 0;
 }

 static int adc_temp_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, adc_temp_show, inode->i_private);
 }

 static const struct file_operations adc_temp_fops = {
 	.open		= adc_temp_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 static int temp_offset_write(struct file *file, const char __user *user_buf,
 			     size_t count, loff_t *ppos)
 {
 	struct gadc_thermal_driver_data *drvdata =
 			((struct seq_file *)(file->private_data))->private;
 	char buf[32];
 	ssize_t buf_size;
 	char *start = buf;
 	long val;

 	buf_size = min(count, (sizeof(buf)-1));
 	if (copy_from_user(buf, user_buf, buf_size)) {
 		dev_err(drvdata->dev, "%s: Failed to copy from user\n",
 			__func__);
 		return -EFAULT;
 	}
 	buf[buf_size] = 0;

 	while (*start == ' ')
 		start++;

 	if (kstrtol(start, 10, &val))
 		return -EINVAL;

 	drvdata->pdata->temp_offset = val;
 	return buf_size;
 }

 static int temp_offset_show(struct seq_file *s, void *p)
 {
 	struct gadc_thermal_driver_data *drvdata = s->private;

 	seq_printf(s, "%d\n", drvdata->pdata->temp_offset);
 	return 0;
 }

 static int temp_offset_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, temp_offset_show, inode->i_private);
 }

 static const struct file_operations temp_offset_fops = {
 	.open		= temp_offset_open,
 	.write		= temp_offset_write,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 static int gadc_thermal_debugfs_init(struct gadc_thermal_driver_data *drvdata)
 {
 	struct dentry *d_file;

 	drvdata->dentry = debugfs_create_dir(dev_name(drvdata->dev), NULL);
 	if (!drvdata->dentry)
 		return -ENOMEM;

 	d_file = debugfs_create_file("adc_temp", 0444, drvdata->dentry,
 				     drvdata, &adc_temp_fops);
 	if (!d_file)
 		goto error;

 	d_file = debugfs_create_file("temp_offset", 0644, drvdata->dentry,
 				     drvdata, &temp_offset_fops);
 	if (!d_file)
 		goto error;

 	return 0;

 error:
 	debugfs_remove_recursive(drvdata->dentry);
 	return -ENOMEM;
 }
 #endif /*  CONFIG_DEBUG_FS */

 static int gadc_thermal_probe(struct platform_device *pdev)
 {
 	struct gadc_thermal_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct gadc_thermal_driver_data *drvdata;
 	int ret;

 	if (!pdata) {
 		dev_err(&pdev->dev, "%s: No platform data\n", __func__);
 		return -ENODEV;
 	}

 	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
 	if (!drvdata) {
 		dev_err(&pdev->dev,
 			"%s: Failed to alloc memory for driver data\n",
 			__func__);
 		return -ENOMEM;
 	}
 	if (pdata->lookup_table_size) {
 		drvdata->adc_temp_lookup =  devm_kzalloc(&pdev->dev,
 				pdata->lookup_table_size * sizeof(unsigned int),
 				GFP_KERNEL);
 		if (!drvdata->adc_temp_lookup)
 			return -ENOMEM;
 	}

 	platform_set_drvdata(pdev, drvdata);
 	drvdata->dev = &pdev->dev;
 	drvdata->pdata = pdata;
 	drvdata->lookup_table_size = pdata->lookup_table_size;
 	drvdata->first_index_temp = pdata->first_index_temp;
 	drvdata->last_index_temp = pdata->last_index_temp;
 	drvdata->temp_offset = pdata->temp_offset;
 	drvdata->dual_mode = pdata->dual_mode;
 	if (drvdata->lookup_table_size)
 		memcpy(drvdata->adc_temp_lookup, pdata->adc_temp_lookup,
 			pdata->lookup_table_size * sizeof(unsigned int));

 	drvdata->channel = iio_channel_get(dev_name(&pdev->dev),
 					pdata->iio_channel_name);
 	if (IS_ERR(drvdata->channel)) {
 		dev_err(&pdev->dev, "%s: Failed to get channel %s, %ld\n",
 			__func__, pdata->iio_channel_name,
 			PTR_ERR(drvdata->channel));
 		return PTR_ERR(drvdata->channel);
 	}

 	drvdata->tz = thermal_zone_device_register(pdata->tz_name, 0, 0,
 					drvdata, &gadc_thermal_ops, NULL, 0, 0);
 	if (IS_ERR(drvdata->tz)) {
 		dev_err(&pdev->dev,
 			"%s: Failed to register thermal zone %s, %ld\n",
 			__func__, pdata->tz_name, PTR_ERR(drvdata->tz));
 		ret = PTR_ERR(drvdata->tz);
 		goto error_release_channel;
 	}

 	gadc_thermal_debugfs_init(drvdata);

 	return 0;

 error_release_channel:
 	iio_channel_release(drvdata->channel);
 	return ret;
 }

 static int gadc_thermal_remove(struct platform_device *pdev)
 {
 	struct gadc_thermal_driver_data *drvdata = platform_get_drvdata(pdev);

 	if (drvdata->dentry)
 		debugfs_remove_recursive(drvdata->dentry);
 	thermal_zone_device_unregister(drvdata->tz);
 	iio_channel_release(drvdata->channel);
 	return 0;
 }

 static struct platform_driver gadc_thermal_driver = {
 	.driver = {
 		.name = "generic-adc-thermal",
 		.owner = THIS_MODULE,
 	},
 	.probe = gadc_thermal_probe,
 	.remove = gadc_thermal_remove,
 };

 module_platform_driver(gadc_thermal_driver);

 MODULE_AUTHOR("Jinyoung Park <jinyoungp@nvidia.com>");
 MODULE_DESCRIPTION("Generic ADC thermal driver using IIO framework");
 MODULE_LICENSE("GPL v2");
	/*
	* drivers/staging/iio/generic_adc_thermal.c
	*
	* Generic ADC thermal driver
	*
	* Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
	*
	* Author: Jinyoung Park <jinyoungp@nvidia.com>
	*
	* 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 version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
	* whether express or implied; 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
	*/
	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/uaccess.h>
	#include <linux/module.h>
	#include <linux/debugfs.h>
	#include <linux/seq_file.h>
	#include <linux/err.h>
	#include <linux/thermal.h>
	#include <linux/iio/consumer.h>
	#include <linux/iio/types.h>
	#include <linux/generic_adc_thermal.h>

	struct gadc_thermal_driver_data {
	struct device *dev;
	struct thermal_zone_device *tz;
	struct iio_channel *channel;
	struct gadc_thermal_platform_data *pdata;
	struct dentry *dentry;
	int *adc_temp_lookup;
	unsigned int lookup_table_size;
	int first_index_temp;
	int last_index_temp;
	int temp_offset;
	bool dual_mode;
	};

	static int gadc_thermal_thermistor_adc_to_temp(
	struct gadc_thermal_driver_data *drvdata, int adc_raw)
	{

	int *lookup_table = drvdata->adc_temp_lookup;
	int table_size = drvdata->lookup_table_size;
	int first_index_temp = drvdata->first_index_temp;
	int last_index_temp = drvdata->last_index_temp;
	int i;
	int temp, adc_low, adc_high, diff_temp;
	int temp_decrement = (first_index_temp > last_index_temp);

	for (i = 0; i < table_size - 1; ++i) {
	if (temp_decrement) {
	if (adc_raw <= lookup_table[i])
	break;
	} else {
	if (adc_raw >= lookup_table[i])
	break;
	}
	}

	if (i == 0)
	return first_index_temp;
	if (i == table_size)
	return last_index_temp;

	/* Find temp with interpolate reading */
	adc_low = lookup_table[i-1];
	adc_high = lookup_table[i];
	diff_temp = (adc_high - adc_low) * 1000;
	if (temp_decrement) {
	temp = (first_index_temp - i) * 1000;
	temp += ((adc_high - adc_raw) * 1000) / (adc_high - adc_low);
	} else {
	temp = (first_index_temp + i - 1) * 1000;
	temp += (adc_low - adc_raw) * 1000 / (adc_high - adc_low);
	}
	return temp;
	}

	static int gadc_thermal_read_channel(struct gadc_thermal_driver_data *drvdata,
	int val, int val2)
	{
	int ret;

	if (drvdata->dual_mode) {
	ret = iio_read_channel_processed_dual(drvdata->channel, val,
	val2);
	if (ret < 0)
	ret = iio_read_channel_raw_dual(drvdata->channel, val,
	val2);
	} else {
	ret = iio_read_channel_processed(drvdata->channel, val);
	if (ret < 0)
	ret = iio_read_channel_raw(drvdata->channel, val);
	}
	return ret;
	}

	static int gadc_thermal_get_temp(struct thermal_zone_device *tz,
	unsigned long *temp)
	{
	struct gadc_thermal_driver_data *drvdata = tz->devdata;
	int val = 0, val2 = 0;
	int ret;

	ret = gadc_thermal_read_channel(drvdata, &val, &val2);
	if (ret < 0) {
	dev_err(drvdata->dev, "%s: Failed to read channel, %d\n",
	__func__, ret);
	return ret;
	}

	if (drvdata->pdata->adc_to_temp)
	*temp = drvdata->pdata->adc_to_temp(drvdata->pdata, val, val2);
	else if (drvdata->pdata->adc_temp_lookup)
	*temp = gadc_thermal_thermistor_adc_to_temp(drvdata, val);
	else
	*temp = val;

	*temp += drvdata->temp_offset;
	return 0;
	}

	static struct thermal_zone_device_ops gadc_thermal_ops = {
	.get_temp = gadc_thermal_get_temp,
	};

	#ifdef CONFIG_DEBUG_FS
	static int adc_temp_show(struct seq_file s, void p)
	{
	struct gadc_thermal_driver_data *drvdata = s->private;
	int val = 0, val2 = 0, temp = 0;
	int ret;

	ret = gadc_thermal_read_channel(drvdata, &val, &val2);
	if (ret < 0) {
	dev_err(drvdata->dev, "%s: Failed to read channel, %d\n",
	__func__, ret);
	return ret;
	}

	if (drvdata->pdata->adc_to_temp)
	temp = drvdata->pdata->adc_to_temp(drvdata->pdata, val, val2);
	else if (drvdata->pdata->adc_temp_lookup)
	temp = gadc_thermal_thermistor_adc_to_temp(drvdata, val);
	else
	temp = val;

	temp += drvdata->temp_offset;
	seq_printf(s, "%d %d %d\n", val, val2, temp);
	return 0;
	}

	static int adc_temp_open(struct inode inode, struct file file)
	{
	return single_open(file, adc_temp_show, inode->i_private);
	}

	static const struct file_operations adc_temp_fops = {
	.open = adc_temp_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int temp_offset_write(struct file file, const char __user user_buf,
	size_t count, loff_t *ppos)
	{
	struct gadc_thermal_driver_data *drvdata =
	((struct seq_file *)(file->private_data))->private;
	char buf[32];
	ssize_t buf_size;
	char *start = buf;
	long val;

	buf_size = min(count, (sizeof(buf)-1));
	if (copy_from_user(buf, user_buf, buf_size)) {
	dev_err(drvdata->dev, "%s: Failed to copy from user\n",
	__func__);
	return -EFAULT;
	}
	buf[buf_size] = 0;

	while (*start == ' ')
	start++;

	if (kstrtol(start, 10, &val))
	return -EINVAL;

	drvdata->pdata->temp_offset = val;
	return buf_size;
	}

	static int temp_offset_show(struct seq_file s, void p)
	{
	struct gadc_thermal_driver_data *drvdata = s->private;

	seq_printf(s, "%d\n", drvdata->pdata->temp_offset);
	return 0;
	}

	static int temp_offset_open(struct inode inode, struct file file)
	{
	return single_open(file, temp_offset_show, inode->i_private);
	}

	static const struct file_operations temp_offset_fops = {
	.open = temp_offset_open,
	.write = temp_offset_write,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int gadc_thermal_debugfs_init(struct gadc_thermal_driver_data *drvdata)
	{
	struct dentry *d_file;

	drvdata->dentry = debugfs_create_dir(dev_name(drvdata->dev), NULL);
	if (!drvdata->dentry)
	return -ENOMEM;

	d_file = debugfs_create_file("adc_temp", 0444, drvdata->dentry,
	drvdata, &adc_temp_fops);
	if (!d_file)
	goto error;

	d_file = debugfs_create_file("temp_offset", 0644, drvdata->dentry,
	drvdata, &temp_offset_fops);
	if (!d_file)
	goto error;

	return 0;

	error:
	debugfs_remove_recursive(drvdata->dentry);
	return -ENOMEM;
	}
	#endif /* CONFIG_DEBUG_FS */

	static int gadc_thermal_probe(struct platform_device *pdev)
	{
	struct gadc_thermal_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct gadc_thermal_driver_data *drvdata;
	int ret;

	if (!pdata) {
	dev_err(&pdev->dev, "%s: No platform data\n", __func__);
	return -ENODEV;
	}

	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
	if (!drvdata) {
	dev_err(&pdev->dev,
	"%s: Failed to alloc memory for driver data\n",
	__func__);
	return -ENOMEM;
	}
	if (pdata->lookup_table_size) {
	drvdata->adc_temp_lookup = devm_kzalloc(&pdev->dev,
	pdata->lookup_table_size * sizeof(unsigned int),
	GFP_KERNEL);
	if (!drvdata->adc_temp_lookup)
	return -ENOMEM;
	}

	platform_set_drvdata(pdev, drvdata);
	drvdata->dev = &pdev->dev;
	drvdata->pdata = pdata;
	drvdata->lookup_table_size = pdata->lookup_table_size;
	drvdata->first_index_temp = pdata->first_index_temp;
	drvdata->last_index_temp = pdata->last_index_temp;
	drvdata->temp_offset = pdata->temp_offset;
	drvdata->dual_mode = pdata->dual_mode;
	if (drvdata->lookup_table_size)
	memcpy(drvdata->adc_temp_lookup, pdata->adc_temp_lookup,
	pdata->lookup_table_size * sizeof(unsigned int));

	drvdata->channel = iio_channel_get(dev_name(&pdev->dev),
	pdata->iio_channel_name);
	if (IS_ERR(drvdata->channel)) {
	dev_err(&pdev->dev, "%s: Failed to get channel %s, %ld\n",
	__func__, pdata->iio_channel_name,
	PTR_ERR(drvdata->channel));
	return PTR_ERR(drvdata->channel);
	}

	drvdata->tz = thermal_zone_device_register(pdata->tz_name, 0, 0,
	drvdata, &gadc_thermal_ops, NULL, 0, 0);
	if (IS_ERR(drvdata->tz)) {
	dev_err(&pdev->dev,
	"%s: Failed to register thermal zone %s, %ld\n",
	__func__, pdata->tz_name, PTR_ERR(drvdata->tz));
	ret = PTR_ERR(drvdata->tz);
	goto error_release_channel;
	}

	gadc_thermal_debugfs_init(drvdata);

	return 0;

	error_release_channel:
	iio_channel_release(drvdata->channel);
	return ret;
	}

	static int gadc_thermal_remove(struct platform_device *pdev)
	{
	struct gadc_thermal_driver_data *drvdata = platform_get_drvdata(pdev);

	if (drvdata->dentry)
	debugfs_remove_recursive(drvdata->dentry);
	thermal_zone_device_unregister(drvdata->tz);
	iio_channel_release(drvdata->channel);
	return 0;
	}

	static struct platform_driver gadc_thermal_driver = {
	.driver = {
	.name = "generic-adc-thermal",
	.owner = THIS_MODULE,
	},
	.probe = gadc_thermal_probe,
	.remove = gadc_thermal_remove,
	};

	module_platform_driver(gadc_thermal_driver);

	MODULE_AUTHOR("Jinyoung Park <jinyoungp@nvidia.com>");
	MODULE_DESCRIPTION("Generic ADC thermal driver using IIO framework");
	MODULE_LICENSE("GPL v2");