drivers/mfd/twl6030-madc.c - kernel/omap - Git at Google

 /*
  *
  * TWL6030 MADC module driver-This driver only implements the ADC read
  * functions
  *
  * Copyright (C) 2011 Samsung Telecommunications of America
  *
  * Based on twl4030-madc.c
  * Copyright (C) 2008 Nokia Corporation
  * Mikko Ylinen <mikko.k.ylinen@nokia.com>
  *
  * Amit Kucheria <amit.kucheria@canonical.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * 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.
  *
  * 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., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA
  *
  */

 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/i2c/twl.h>
 #include <linux/i2c/twl6030-madc.h>
 #include <linux/module.h>
 #include <linux/stddef.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/mutex.h>
 #include <linux/bitops.h>
 #include <linux/jiffies.h>
 #include <linux/types.h>
 #include <linux/gfp.h>
 #include <linux/err.h>
 #include <linux/wakelock.h>

 #define GPADCS		(1 << 1)
 #define GPADCR		(1 << 0)
 #define REG_TOGGLE1	0x90

 #define DRIVER_NAME	(twl6030_madc_driver.driver.name)
 static struct platform_driver twl6030_madc_driver;

 /*
  * struct twl6030_madc_data - a container for madc info
  * @dev - pointer to device structure for madc
  * @lock - mutex protecting this data structure
  */
 struct twl6030_madc_data {
 	struct device *dev;
 	struct mutex lock;
 	struct dentry		*file;
 	struct wake_lock wakelock;
 };

 static struct twl6030_madc_data *twl6030_madc;
 static u8 gpadc_ctrl_reg;

 static inline int twl6030_madc_start_conversion(struct twl6030_madc_data *madc)
 {
 	int ret;

 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, GPADCS, REG_TOGGLE1);
 	if (ret) {
 		dev_err(madc->dev, "unable to write register 0x%X\n",
 			REG_TOGGLE1);
 		return ret;
 	}

 	udelay(100);
 	ret = twl_i2c_write_u8(TWL_MODULE_MADC, TWL6030_MADC_SP1,
 				TWL6030_MADC_CTRL_P1);
 	if (ret) {
 		dev_err(madc->dev, "unable to write register 0x%X\n",
 			TWL6030_MADC_CTRL_P1);
 		return ret;
 	}
 	return 0;
 }

 /*
  * Function that waits for conversion to be ready
  * @madc - pointer to twl4030_madc_data struct
  * @timeout_ms - timeout value in milliseconds
  * @status_reg - ctrl register
  * returns 0 if succeeds else a negative error value
  */
 static int twl6030_madc_wait_conversion_ready(struct twl6030_madc_data *madc,
 					      unsigned int timeout_ms,
 					      u8 status_reg)
 {
 	unsigned long timeout;
 	unsigned long delta;
 	u8 reg;
 	int ret;

 	delta = msecs_to_jiffies(timeout_ms);

 	if (delta < 2)
 		delta = 2;

 	wake_lock(&madc->wakelock);
 	timeout = jiffies + delta;
 	do {
 		ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &reg, status_reg);
 		if (ret) {
 			dev_err(madc->dev,
 				"unable to read status register 0x%X\n",
 				status_reg);
 			goto unlock;
 		}
 		if (!(reg & TWL6030_MADC_BUSY) && (reg & TWL6030_MADC_EOCP1)) {
 			ret = 0;
 			goto unlock;
 		}

 		if (time_after(jiffies, timeout))
 			break;

 		usleep_range(500, 2000);
 	} while (1);

 	dev_err(madc->dev, "conversion timeout, ctrl_px=0x%08x\n", reg);
 	ret = -EAGAIN;

 unlock:
 	wake_unlock(&madc->wakelock);
 	return ret;
 }

 /*
  * Function to read a particular channel value.
  * @madc - pointer to struct twl6030_madc_data
  * @reg - lsb of ADC Channel
  * If the i2c read fails it returns an error else returns 0.
  */
 static int twl6030_madc_channel_raw_read(struct twl6030_madc_data *madc,
 					u8 reg)
 {
 	u8 msb, lsb;
 	int ret;

 	mutex_lock(&madc->lock);
 	ret = twl6030_madc_start_conversion(twl6030_madc);
 	if (ret)
 		goto unlock;

 	ret = twl6030_madc_wait_conversion_ready(twl6030_madc, 5,
 						TWL6030_MADC_CTRL_P1);
 	if (ret)
 		goto unlock;

 	/*
 	 * For each ADC channel, we have MSB and LSB register
 	 * pair. MSB address is always LSB address+1. reg parameter is
 	 * the address of LSB register
 	 */
 	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &msb, reg + 1);
 	if (ret) {
 		dev_err(madc->dev, "unable to read MSB register 0x%X\n",
 			reg + 1);
 		goto unlock;
 	}
 	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &lsb, reg);
 	if (ret) {
 		dev_err(madc->dev, "unable to read LSB register 0x%X\n", reg);
 		goto unlock;
 	}
 	ret = (int)((msb << 8) | lsb);
 unlock:
 	/* Disable GPADC for power savings. */
 	twl_i2c_write_u8(TWL6030_MODULE_ID1, GPADCR, REG_TOGGLE1);
 	mutex_unlock(&madc->lock);
 	return ret;
 }

 /*
  * Return channel value
  * Or < 0 on failure.
  */
 int twl6030_get_madc_conversion(int channel_no)
 {
 	u8 reg = TWL6030_MADC_GPCH0_LSB + (2 * channel_no);
 	if (!twl6030_madc) {
 		pr_err("%s: No ADC device\n", __func__);
 		return -EINVAL;
 	}
 	if (channel_no >= TWL6030_MADC_MAX_CHANNELS) {
 		dev_err(twl6030_madc->dev,
 			"%s: Channel number (%d) exceeds max (%d)\n",
 			__func__, channel_no, TWL6030_MADC_MAX_CHANNELS);
 		return -EINVAL;
 	}

 	return twl6030_madc_channel_raw_read(twl6030_madc, reg);
 }
 EXPORT_SYMBOL_GPL(twl6030_get_madc_conversion);

 #ifdef CONFIG_DEBUG_FS

 static int debug_twl6030_madc_show(struct seq_file *s, void *_)
 {
 	int i, result;
 	for (i = 0; i < TWL6030_MADC_MAX_CHANNELS; i++) {
 		result = twl6030_get_madc_conversion(i);
 		seq_printf(s, "channel %3d returns result %d\n",
 			i, result);
 	}
 	return 0;
 }

 static int debug_twl6030_madc_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, debug_twl6030_madc_show, inode->i_private);
 }

 static const struct file_operations debug_fops = {
 	.open		= debug_twl6030_madc_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 #define DEBUG_FOPS	(&debug_fops)

 #else
 #define DEBUG_FOPS	NULL
 #endif

 /*
  * Initialize MADC
  */
 static int __devinit twl6030_madc_probe(struct platform_device *pdev)
 {
 	struct twl6030_madc_data *madc;
 	struct twl4030_madc_platform_data *pdata = pdev->dev.platform_data;

 	if (!pdata) {
 		dev_err(&pdev->dev, "platform_data not available\n");
 		return -EINVAL;
 	}
 	madc = kzalloc(sizeof(*madc), GFP_KERNEL);
 	if (!madc)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, madc);
 	madc->dev = &pdev->dev;
 	mutex_init(&madc->lock);
 	madc->file = debugfs_create_file(DRIVER_NAME, S_IRUGO, NULL,
 					madc, DEBUG_FOPS);
 	wake_lock_init(&madc->wakelock, WAKE_LOCK_SUSPEND, "twl6030 adc");
 	twl6030_madc = madc;
 	return 0;
 }

 static int __devexit twl6030_madc_remove(struct platform_device *pdev)
 {
 	struct twl6030_madc_data *madc = platform_get_drvdata(pdev);

 	wake_lock_destroy(&madc->wakelock);
 	mutex_destroy(&madc->lock);
 	free_irq(platform_get_irq(pdev, 0), madc);
 	platform_set_drvdata(pdev, NULL);
 	twl6030_madc = NULL;
 	debugfs_remove(madc->file);
 	kfree(madc);

 	return 0;
 }

 static int twl6030_madc_suspend(struct device *pdev)
 {
 	int ret;
 	u8 reg_val;

 	ret = twl_i2c_read_u8(TWL_MODULE_MADC, &reg_val, TWL6030_MADC_CTRL);
 	if (!ret) {
 		reg_val &= ~(TWL6030_MADC_TEMP1_EN);
 		ret = twl_i2c_write_u8(TWL_MODULE_MADC, reg_val,
 					TWL6030_MADC_CTRL);
 	}

 	if (ret) {
 		dev_err(twl6030_madc->dev, "unable to disable madc temp1!\n");
 		gpadc_ctrl_reg = TWL6030_MADC_TEMP1_EN;
 	} else
 		gpadc_ctrl_reg = reg_val;

 	return 0;
 };

 static int twl6030_madc_resume(struct device *pdev)
 {
 	int ret;

 	if (!(gpadc_ctrl_reg & TWL6030_MADC_TEMP1_EN)) {
 		gpadc_ctrl_reg |= TWL6030_MADC_TEMP1_EN;
 		ret = twl_i2c_write_u8(TWL_MODULE_MADC, gpadc_ctrl_reg,
 					TWL6030_MADC_CTRL);
 		if (ret)
 			dev_err(twl6030_madc->dev,
 				"unable to enable madc temp1!\n");
 	}

 	return 0;
 };

 static const struct dev_pm_ops twl6030_madc_pm_ops = {
 	.suspend = twl6030_madc_suspend,
 	.resume = twl6030_madc_resume,
 };

 static struct platform_driver twl6030_madc_driver = {
 	.probe = twl6030_madc_probe,
 	.remove = __exit_p(twl6030_madc_remove),
 	.driver = {
 		   .name = "twl6030_madc",
 		   .owner = THIS_MODULE,
 		   .pm = &twl6030_madc_pm_ops,
 		   },
 };

 static int __init twl6030_madc_init(void)
 {
 	return platform_driver_register(&twl6030_madc_driver);
 }

 module_init(twl6030_madc_init);

 static void __exit twl6030_madc_exit(void)
 {
 	platform_driver_unregister(&twl6030_madc_driver);
 }

 module_exit(twl6030_madc_exit);

 MODULE_DESCRIPTION("TWL6030 ADC driver");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("J Keerthy");
 MODULE_ALIAS("platform:twl6030_madc");
	/*
	*
	* TWL6030 MADC module driver-This driver only implements the ADC read
	* functions
	*
	* Copyright (C) 2011 Samsung Telecommunications of America
	*
	* Based on twl4030-madc.c
	* Copyright (C) 2008 Nokia Corporation
	* Mikko Ylinen <mikko.k.ylinen@nokia.com>
	*
	* Amit Kucheria <amit.kucheria@canonical.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* 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.
	*
	* 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., 51 Franklin St, Fifth Floor, Boston, MA
	* 02110-1301 USA
	*
	*/

	#include <linux/init.h>
	#include <linux/device.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <linux/delay.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/i2c/twl.h>
	#include <linux/i2c/twl6030-madc.h>
	#include <linux/module.h>
	#include <linux/stddef.h>
	#include <linux/debugfs.h>
	#include <linux/seq_file.h>
	#include <linux/mutex.h>
	#include <linux/bitops.h>
	#include <linux/jiffies.h>
	#include <linux/types.h>
	#include <linux/gfp.h>
	#include <linux/err.h>
	#include <linux/wakelock.h>

	#define GPADCS (1 << 1)
	#define GPADCR (1 << 0)
	#define REG_TOGGLE1 0x90

	#define DRIVER_NAME (twl6030_madc_driver.driver.name)
	static struct platform_driver twl6030_madc_driver;

	/*
	* struct twl6030_madc_data - a container for madc info
	* @dev - pointer to device structure for madc
	* @lock - mutex protecting this data structure
	*/
	struct twl6030_madc_data {
	struct device *dev;
	struct mutex lock;
	struct dentry *file;
	struct wake_lock wakelock;
	};

	static struct twl6030_madc_data *twl6030_madc;
	static u8 gpadc_ctrl_reg;

	static inline int twl6030_madc_start_conversion(struct twl6030_madc_data *madc)
	{
	int ret;

	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, GPADCS, REG_TOGGLE1);
	if (ret) {
	dev_err(madc->dev, "unable to write register 0x%X\n",
	REG_TOGGLE1);
	return ret;
	}

	udelay(100);
	ret = twl_i2c_write_u8(TWL_MODULE_MADC, TWL6030_MADC_SP1,
	TWL6030_MADC_CTRL_P1);
	if (ret) {
	dev_err(madc->dev, "unable to write register 0x%X\n",
	TWL6030_MADC_CTRL_P1);
	return ret;
	}
	return 0;
	}

	/*
	* Function that waits for conversion to be ready
	* @madc - pointer to twl4030_madc_data struct
	* @timeout_ms - timeout value in milliseconds
	* @status_reg - ctrl register
	* returns 0 if succeeds else a negative error value
	*/
	static int twl6030_madc_wait_conversion_ready(struct twl6030_madc_data *madc,
	unsigned int timeout_ms,
	u8 status_reg)
	{
	unsigned long timeout;
	unsigned long delta;
	u8 reg;
	int ret;

	delta = msecs_to_jiffies(timeout_ms);

	if (delta < 2)
	delta = 2;

	wake_lock(&madc->wakelock);
	timeout = jiffies + delta;
	do {
	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &reg, status_reg);
	if (ret) {
	dev_err(madc->dev,
	"unable to read status register 0x%X\n",
	status_reg);
	goto unlock;
	}
	if (!(reg & TWL6030_MADC_BUSY) && (reg & TWL6030_MADC_EOCP1)) {
	ret = 0;
	goto unlock;
	}

	if (time_after(jiffies, timeout))
	break;

	usleep_range(500, 2000);
	} while (1);

	dev_err(madc->dev, "conversion timeout, ctrl_px=0x%08x\n", reg);
	ret = -EAGAIN;

	unlock:
	wake_unlock(&madc->wakelock);
	return ret;
	}

	/*
	* Function to read a particular channel value.
	* @madc - pointer to struct twl6030_madc_data
	* @reg - lsb of ADC Channel
	* If the i2c read fails it returns an error else returns 0.
	*/
	static int twl6030_madc_channel_raw_read(struct twl6030_madc_data *madc,
	u8 reg)
	{
	u8 msb, lsb;
	int ret;

	mutex_lock(&madc->lock);
	ret = twl6030_madc_start_conversion(twl6030_madc);
	if (ret)
	goto unlock;

	ret = twl6030_madc_wait_conversion_ready(twl6030_madc, 5,
	TWL6030_MADC_CTRL_P1);
	if (ret)
	goto unlock;

	/*
	* For each ADC channel, we have MSB and LSB register
	* pair. MSB address is always LSB address+1. reg parameter is
	* the address of LSB register
	*/
	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &msb, reg + 1);
	if (ret) {
	dev_err(madc->dev, "unable to read MSB register 0x%X\n",
	reg + 1);
	goto unlock;
	}
	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &lsb, reg);
	if (ret) {
	dev_err(madc->dev, "unable to read LSB register 0x%X\n", reg);
	goto unlock;
	}
	ret = (int)((msb << 8) \| lsb);
	unlock:
	/* Disable GPADC for power savings. */
	twl_i2c_write_u8(TWL6030_MODULE_ID1, GPADCR, REG_TOGGLE1);
	mutex_unlock(&madc->lock);
	return ret;
	}

	/*
	* Return channel value
	* Or < 0 on failure.
	*/
	int twl6030_get_madc_conversion(int channel_no)
	{
	u8 reg = TWL6030_MADC_GPCH0_LSB + (2 * channel_no);
	if (!twl6030_madc) {
	pr_err("%s: No ADC device\n", __func__);
	return -EINVAL;
	}
	if (channel_no >= TWL6030_MADC_MAX_CHANNELS) {
	dev_err(twl6030_madc->dev,
	"%s: Channel number (%d) exceeds max (%d)\n",
	__func__, channel_no, TWL6030_MADC_MAX_CHANNELS);
	return -EINVAL;
	}

	return twl6030_madc_channel_raw_read(twl6030_madc, reg);
	}
	EXPORT_SYMBOL_GPL(twl6030_get_madc_conversion);

	#ifdef CONFIG_DEBUG_FS

	static int debug_twl6030_madc_show(struct seq_file s, void _)
	{
	int i, result;
	for (i = 0; i < TWL6030_MADC_MAX_CHANNELS; i++) {
	result = twl6030_get_madc_conversion(i);
	seq_printf(s, "channel %3d returns result %d\n",
	i, result);
	}
	return 0;
	}

	static int debug_twl6030_madc_open(struct inode inode, struct file file)
	{
	return single_open(file, debug_twl6030_madc_show, inode->i_private);
	}

	static const struct file_operations debug_fops = {
	.open = debug_twl6030_madc_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	#define DEBUG_FOPS (&debug_fops)

	#else
	#define DEBUG_FOPS NULL
	#endif

	/*
	* Initialize MADC
	*/
	static int __devinit twl6030_madc_probe(struct platform_device *pdev)
	{
	struct twl6030_madc_data *madc;
	struct twl4030_madc_platform_data *pdata = pdev->dev.platform_data;

	if (!pdata) {
	dev_err(&pdev->dev, "platform_data not available\n");
	return -EINVAL;
	}
	madc = kzalloc(sizeof(*madc), GFP_KERNEL);
	if (!madc)
	return -ENOMEM;

	platform_set_drvdata(pdev, madc);
	madc->dev = &pdev->dev;
	mutex_init(&madc->lock);
	madc->file = debugfs_create_file(DRIVER_NAME, S_IRUGO, NULL,
	madc, DEBUG_FOPS);
	wake_lock_init(&madc->wakelock, WAKE_LOCK_SUSPEND, "twl6030 adc");
	twl6030_madc = madc;
	return 0;
	}

	static int __devexit twl6030_madc_remove(struct platform_device *pdev)
	{
	struct twl6030_madc_data *madc = platform_get_drvdata(pdev);

	wake_lock_destroy(&madc->wakelock);
	mutex_destroy(&madc->lock);
	free_irq(platform_get_irq(pdev, 0), madc);
	platform_set_drvdata(pdev, NULL);
	twl6030_madc = NULL;
	debugfs_remove(madc->file);
	kfree(madc);

	return 0;
	}

	static int twl6030_madc_suspend(struct device *pdev)
	{
	int ret;
	u8 reg_val;

	ret = twl_i2c_read_u8(TWL_MODULE_MADC, &reg_val, TWL6030_MADC_CTRL);
	if (!ret) {
	reg_val &= ~(TWL6030_MADC_TEMP1_EN);
	ret = twl_i2c_write_u8(TWL_MODULE_MADC, reg_val,
	TWL6030_MADC_CTRL);
	}

	if (ret) {
	dev_err(twl6030_madc->dev, "unable to disable madc temp1!\n");
	gpadc_ctrl_reg = TWL6030_MADC_TEMP1_EN;
	} else
	gpadc_ctrl_reg = reg_val;

	return 0;
	};

	static int twl6030_madc_resume(struct device *pdev)
	{
	int ret;

	if (!(gpadc_ctrl_reg & TWL6030_MADC_TEMP1_EN)) {
	gpadc_ctrl_reg \|= TWL6030_MADC_TEMP1_EN;
	ret = twl_i2c_write_u8(TWL_MODULE_MADC, gpadc_ctrl_reg,
	TWL6030_MADC_CTRL);
	if (ret)
	dev_err(twl6030_madc->dev,
	"unable to enable madc temp1!\n");
	}

	return 0;
	};

	static const struct dev_pm_ops twl6030_madc_pm_ops = {
	.suspend = twl6030_madc_suspend,
	.resume = twl6030_madc_resume,
	};

	static struct platform_driver twl6030_madc_driver = {
	.probe = twl6030_madc_probe,
	.remove = __exit_p(twl6030_madc_remove),
	.driver = {
	.name = "twl6030_madc",
	.owner = THIS_MODULE,
	.pm = &twl6030_madc_pm_ops,
	},
	};

	static int __init twl6030_madc_init(void)
	{
	return platform_driver_register(&twl6030_madc_driver);
	}

	module_init(twl6030_madc_init);

	static void __exit twl6030_madc_exit(void)
	{
	platform_driver_unregister(&twl6030_madc_driver);
	}

	module_exit(twl6030_madc_exit);

	MODULE_DESCRIPTION("TWL6030 ADC driver");
	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("J Keerthy");
	MODULE_ALIAS("platform:twl6030_madc");