drivers/iio/adc/ti_am335x_adc.c - kernel/msm-4.19 - Gitiles

 /*
  * TI ADC MFD driver
  *
  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.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.
  */

 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/iio/iio.h>

 #include <linux/mfd/ti_am335x_tscadc.h>
 #include <linux/platform_data/ti_am335x_adc.h>

 struct tiadc_device {
 	struct ti_tscadc_dev *mfd_tscadc;
 	int channels;
 };

 static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
 {
 	return readl(adc->mfd_tscadc->tscadc_base + reg);
 }

 static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
 					unsigned int val)
 {
 	writel(val, adc->mfd_tscadc->tscadc_base + reg);
 }

 static void tiadc_step_config(struct tiadc_device *adc_dev)
 {
 	unsigned int stepconfig;
 	int i, channels = 0, steps;

 	/*
 	 * There are 16 configurable steps and 8 analog input
 	 * lines available which are shared between Touchscreen and ADC.
 	 *
 	 * Steps backwards i.e. from 16 towards 0 are used by ADC
 	 * depending on number of input lines needed.
 	 * Channel would represent which analog input
 	 * needs to be given to ADC to digitalize data.
 	 */

 	steps = TOTAL_STEPS - adc_dev->channels;
 	channels = TOTAL_CHANNELS - adc_dev->channels;

 	stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;

 	for (i = (steps + 1); i <= TOTAL_STEPS; i++) {
 		tiadc_writel(adc_dev, REG_STEPCONFIG(i),
 				stepconfig | STEPCONFIG_INP(channels));
 		tiadc_writel(adc_dev, REG_STEPDELAY(i),
 				STEPCONFIG_OPENDLY);
 		channels++;
 	}
 	tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
 }

 static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
 {
 	struct iio_chan_spec *chan_array;
 	int i;

 	indio_dev->num_channels = channels;
 	chan_array = kcalloc(indio_dev->num_channels,
 			sizeof(struct iio_chan_spec), GFP_KERNEL);

 	if (chan_array == NULL)
 		return -ENOMEM;

 	for (i = 0; i < (indio_dev->num_channels); i++) {
 		struct iio_chan_spec *chan = chan_array + i;
 		chan->type = IIO_VOLTAGE;
 		chan->indexed = 1;
 		chan->channel = i;
 		chan->info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT;
 	}

 	indio_dev->channels = chan_array;

 	return indio_dev->num_channels;
 }

 static void tiadc_channels_remove(struct iio_dev *indio_dev)
 {
 	kfree(indio_dev->channels);
 }

 static int tiadc_read_raw(struct iio_dev *indio_dev,
 		struct iio_chan_spec const *chan,
 		int *val, int *val2, long mask)
 {
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
 	int i;
 	unsigned int fifo1count, readx1;

 	/*
 	 * When the sub-system is first enabled,
 	 * the sequencer will always start with the
 	 * lowest step (1) and continue until step (16).
 	 * For ex: If we have enabled 4 ADC channels and
 	 * currently use only 1 out of them, the
 	 * sequencer still configures all the 4 steps,
 	 * leading to 3 unwanted data.
 	 * Hence we need to flush out this data.
 	 */

 	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 	for (i = 0; i < fifo1count; i++) {
 		readx1 = tiadc_readl(adc_dev, REG_FIFO1);
 		if (i == chan->channel)
 			*val = readx1 & 0xfff;
 	}
 	tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);

 	return IIO_VAL_INT;
 }

 static const struct iio_info tiadc_info = {
 	.read_raw = &tiadc_read_raw,
 };

 static int __devinit tiadc_probe(struct platform_device *pdev)
 {
 	struct iio_dev		*indio_dev;
 	struct tiadc_device	*adc_dev;
 	struct ti_tscadc_dev	*tscadc_dev = pdev->dev.platform_data;
 	struct mfd_tscadc_board	*pdata;
 	int			err;

 	pdata = tscadc_dev->dev->platform_data;
 	if (!pdata || !pdata->adc_init) {
 		dev_err(&pdev->dev, "Could not find platform data\n");
 		return -EINVAL;
 	}

 	indio_dev = iio_device_alloc(sizeof(struct tiadc_device));
 	if (indio_dev == NULL) {
 		dev_err(&pdev->dev, "failed to allocate iio device\n");
 		err = -ENOMEM;
 		goto err_ret;
 	}
 	adc_dev = iio_priv(indio_dev);

 	adc_dev->mfd_tscadc = tscadc_dev;
 	adc_dev->channels = pdata->adc_init->adc_channels;

 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->name = dev_name(&pdev->dev);
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &tiadc_info;

 	tiadc_step_config(adc_dev);

 	err = tiadc_channel_init(indio_dev, adc_dev->channels);
 	if (err < 0)
 		goto err_free_device;

 	err = iio_device_register(indio_dev);
 	if (err)
 		goto err_free_channels;

 	platform_set_drvdata(pdev, indio_dev);

 	return 0;

 err_free_channels:
 	tiadc_channels_remove(indio_dev);
 err_free_device:
 	iio_device_free(indio_dev);
 err_ret:
 	return err;
 }

 static int __devexit tiadc_remove(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);

 	iio_device_unregister(indio_dev);
 	tiadc_channels_remove(indio_dev);

 	iio_device_free(indio_dev);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int tiadc_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
 	struct ti_tscadc_dev *tscadc_dev = dev->platform_data;
 	unsigned int idle;

 	if (!device_may_wakeup(tscadc_dev->dev)) {
 		idle = tiadc_readl(adc_dev, REG_CTRL);
 		idle &= ~(CNTRLREG_TSCSSENB);
 		tiadc_writel(adc_dev, REG_CTRL, (idle |
 				CNTRLREG_POWERDOWN));
 	}

 	return 0;
 }

 static int tiadc_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
 	unsigned int restore;

 	/* Make sure ADC is powered up */
 	restore = tiadc_readl(adc_dev, REG_CTRL);
 	restore &= ~(CNTRLREG_POWERDOWN);
 	tiadc_writel(adc_dev, REG_CTRL, restore);

 	tiadc_step_config(adc_dev);

 	return 0;
 }

 static const struct dev_pm_ops tiadc_pm_ops = {
 	.suspend = tiadc_suspend,
 	.resume = tiadc_resume,
 };
 #define TIADC_PM_OPS (&tiadc_pm_ops)
 #else
 #define TIADC_PM_OPS NULL
 #endif

 static struct platform_driver tiadc_driver = {
 	.driver = {
 		.name   = "tiadc",
 		.owner	= THIS_MODULE,
 		.pm	= TIADC_PM_OPS,
 	},
 	.probe	= tiadc_probe,
 	.remove	= __devexit_p(tiadc_remove),
 };

 module_platform_driver(tiadc_driver);

 MODULE_DESCRIPTION("TI ADC controller driver");
 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
 MODULE_LICENSE("GPL");
	/*
	* TI ADC MFD driver
	*
	* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.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.
	*/

	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/err.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/interrupt.h>
	#include <linux/platform_device.h>
	#include <linux/io.h>
	#include <linux/iio/iio.h>

	#include <linux/mfd/ti_am335x_tscadc.h>
	#include <linux/platform_data/ti_am335x_adc.h>

	struct tiadc_device {
	struct ti_tscadc_dev *mfd_tscadc;
	int channels;
	};

	static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
	{
	return readl(adc->mfd_tscadc->tscadc_base + reg);
	}

	static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
	unsigned int val)
	{
	writel(val, adc->mfd_tscadc->tscadc_base + reg);
	}

	static void tiadc_step_config(struct tiadc_device *adc_dev)
	{
	unsigned int stepconfig;
	int i, channels = 0, steps;

	/*
	* There are 16 configurable steps and 8 analog input
	* lines available which are shared between Touchscreen and ADC.
	*
	* Steps backwards i.e. from 16 towards 0 are used by ADC
	* depending on number of input lines needed.
	* Channel would represent which analog input
	* needs to be given to ADC to digitalize data.
	*/

	steps = TOTAL_STEPS - adc_dev->channels;
	channels = TOTAL_CHANNELS - adc_dev->channels;

	stepconfig = STEPCONFIG_AVG_16 \| STEPCONFIG_FIFO1;

	for (i = (steps + 1); i <= TOTAL_STEPS; i++) {
	tiadc_writel(adc_dev, REG_STEPCONFIG(i),
	stepconfig \| STEPCONFIG_INP(channels));
	tiadc_writel(adc_dev, REG_STEPDELAY(i),
	STEPCONFIG_OPENDLY);
	channels++;
	}
	tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
	}

	static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
	{
	struct iio_chan_spec *chan_array;
	int i;

	indio_dev->num_channels = channels;
	chan_array = kcalloc(indio_dev->num_channels,
	sizeof(struct iio_chan_spec), GFP_KERNEL);

	if (chan_array == NULL)
	return -ENOMEM;

	for (i = 0; i < (indio_dev->num_channels); i++) {
	struct iio_chan_spec *chan = chan_array + i;
	chan->type = IIO_VOLTAGE;
	chan->indexed = 1;
	chan->channel = i;
	chan->info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT;
	}

	indio_dev->channels = chan_array;

	return indio_dev->num_channels;
	}

	static void tiadc_channels_remove(struct iio_dev *indio_dev)
	{
	kfree(indio_dev->channels);
	}

	static int tiadc_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct tiadc_device *adc_dev = iio_priv(indio_dev);
	int i;
	unsigned int fifo1count, readx1;

	/*
	* When the sub-system is first enabled,
	* the sequencer will always start with the
	* lowest step (1) and continue until step (16).
	* For ex: If we have enabled 4 ADC channels and
	* currently use only 1 out of them, the
	* sequencer still configures all the 4 steps,
	* leading to 3 unwanted data.
	* Hence we need to flush out this data.
	*/

	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
	for (i = 0; i < fifo1count; i++) {
	readx1 = tiadc_readl(adc_dev, REG_FIFO1);
	if (i == chan->channel)
	*val = readx1 & 0xfff;
	}
	tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);

	return IIO_VAL_INT;
	}

	static const struct iio_info tiadc_info = {
	.read_raw = &tiadc_read_raw,
	};

	static int __devinit tiadc_probe(struct platform_device *pdev)
	{
	struct iio_dev *indio_dev;
	struct tiadc_device *adc_dev;
	struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
	struct mfd_tscadc_board *pdata;
	int err;

	pdata = tscadc_dev->dev->platform_data;
	if (!pdata \|\| !pdata->adc_init) {
	dev_err(&pdev->dev, "Could not find platform data\n");
	return -EINVAL;
	}

	indio_dev = iio_device_alloc(sizeof(struct tiadc_device));
	if (indio_dev == NULL) {
	dev_err(&pdev->dev, "failed to allocate iio device\n");
	err = -ENOMEM;
	goto err_ret;
	}
	adc_dev = iio_priv(indio_dev);

	adc_dev->mfd_tscadc = tscadc_dev;
	adc_dev->channels = pdata->adc_init->adc_channels;

	indio_dev->dev.parent = &pdev->dev;
	indio_dev->name = dev_name(&pdev->dev);
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &tiadc_info;

	tiadc_step_config(adc_dev);

	err = tiadc_channel_init(indio_dev, adc_dev->channels);
	if (err < 0)
	goto err_free_device;

	err = iio_device_register(indio_dev);
	if (err)
	goto err_free_channels;

	platform_set_drvdata(pdev, indio_dev);

	return 0;

	err_free_channels:
	tiadc_channels_remove(indio_dev);
	err_free_device:
	iio_device_free(indio_dev);
	err_ret:
	return err;
	}

	static int __devexit tiadc_remove(struct platform_device *pdev)
	{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);

	iio_device_unregister(indio_dev);
	tiadc_channels_remove(indio_dev);

	iio_device_free(indio_dev);

	return 0;
	}

	#ifdef CONFIG_PM
	static int tiadc_suspend(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct tiadc_device *adc_dev = iio_priv(indio_dev);
	struct ti_tscadc_dev *tscadc_dev = dev->platform_data;
	unsigned int idle;

	if (!device_may_wakeup(tscadc_dev->dev)) {
	idle = tiadc_readl(adc_dev, REG_CTRL);
	idle &= ~(CNTRLREG_TSCSSENB);
	tiadc_writel(adc_dev, REG_CTRL, (idle \|
	CNTRLREG_POWERDOWN));
	}

	return 0;
	}

	static int tiadc_resume(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct tiadc_device *adc_dev = iio_priv(indio_dev);
	unsigned int restore;

	/* Make sure ADC is powered up */
	restore = tiadc_readl(adc_dev, REG_CTRL);
	restore &= ~(CNTRLREG_POWERDOWN);
	tiadc_writel(adc_dev, REG_CTRL, restore);

	tiadc_step_config(adc_dev);

	return 0;
	}

	static const struct dev_pm_ops tiadc_pm_ops = {
	.suspend = tiadc_suspend,
	.resume = tiadc_resume,
	};
	#define TIADC_PM_OPS (&tiadc_pm_ops)
	#else
	#define TIADC_PM_OPS NULL
	#endif

	static struct platform_driver tiadc_driver = {
	.driver = {
	.name = "tiadc",
	.owner = THIS_MODULE,
	.pm = TIADC_PM_OPS,
	},
	.probe = tiadc_probe,
	.remove = __devexit_p(tiadc_remove),
	};

	module_platform_driver(tiadc_driver);

	MODULE_DESCRIPTION("TI ADC controller driver");
	MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
	MODULE_LICENSE("GPL");