drivers/input/touchscreen/tps6507x-ts.c - linux - Git at Google

 /*
  * Touchscreen driver for the tps6507x chip.
  *
  * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
  *
  * Credits:
  *
  *    Using code from tsc2007, MtekVision Co., Ltd.
  *
  * For licencing details see kernel-base/COPYING
  *
  * TPS65070, TPS65073, TPS650731, and TPS650732 support
  * 10 bit touch screen interface.
  */

 #include <linux/module.h>
 #include <linux/workqueue.h>
 #include <linux/slab.h>
 #include <linux/input.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/tps6507x.h>
 #include <linux/input/tps6507x-ts.h>
 #include <linux/delay.h>

 #define TSC_DEFAULT_POLL_PERIOD 30 /* ms */
 #define TPS_DEFAULT_MIN_PRESSURE 0x30
 #define MAX_10BIT ((1 << 10) - 1)

 #define	TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \
 					 TPS6507X_ADCONFIG_START_CONVERSION | \
 					 TPS6507X_ADCONFIG_INPUT_REAL_TSC)
 #define	TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC)

 struct ts_event {
 	u16	x;
 	u16	y;
 	u16	pressure;
 };

 struct tps6507x_ts {
 	struct device		*dev;
 	struct input_dev	*input;
 	struct tps6507x_dev	*mfd;
 	char			phys[32];
 	struct ts_event		tc;
 	u16			min_pressure;
 	bool			pendown;
 };

 static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data)
 {
 	return tsc->mfd->read_dev(tsc->mfd, reg, 1, data);
 }

 static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data)
 {
 	return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data);
 }

 static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc,
 				   u8 tsc_mode, u16 *value)
 {
 	s32 ret;
 	u8 adc_status;
 	u8 result;

 	/* Route input signal to A/D converter */

 	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode);
 	if (ret) {
 		dev_err(tsc->dev, "TSC mode read failed\n");
 		goto err;
 	}

 	/* Start A/D conversion */

 	ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
 				TPS6507X_ADCONFIG_CONVERT_TS);
 	if (ret) {
 		dev_err(tsc->dev, "ADC config write failed\n");
 		return ret;
 	}

 	do {
 		ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG,
 				       &adc_status);
 		if (ret) {
 			dev_err(tsc->dev, "ADC config read failed\n");
 			goto err;
 		}
 	} while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION);

 	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result);
 	if (ret) {
 		dev_err(tsc->dev, "ADC result 2 read failed\n");
 		goto err;
 	}

 	*value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8;

 	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result);
 	if (ret) {
 		dev_err(tsc->dev, "ADC result 1 read failed\n");
 		goto err;
 	}

 	*value |= result;

 	dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value);

 err:
 	return ret;
 }

 /* Need to call tps6507x_adc_standby() after using A/D converter for the
  * touch screen interrupt to work properly.
  */

 static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc)
 {
 	s32 ret;
 	s32 loops = 0;
 	u8 val;

 	ret = tps6507x_write_u8(tsc,  TPS6507X_REG_ADCONFIG,
 				TPS6507X_ADCONFIG_INPUT_TSC);
 	if (ret)
 		return ret;

 	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE,
 				TPS6507X_TSCMODE_STANDBY);
 	if (ret)
 		return ret;

 	ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
 	if (ret)
 		return ret;

 	while (val & TPS6507X_REG_TSC_INT) {
 		mdelay(10);
 		ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
 		if (ret)
 			return ret;
 		loops++;
 	}

 	return ret;
 }

 static void tps6507x_ts_poll(struct input_dev *input_dev)
 {
 	struct tps6507x_ts *tsc = input_get_drvdata(input_dev);
 	bool pendown;
 	s32 ret;

 	ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE,
 				      &tsc->tc.pressure);
 	if (ret)
 		goto done;

 	pendown = tsc->tc.pressure > tsc->min_pressure;

 	if (unlikely(!pendown && tsc->pendown)) {
 		dev_dbg(tsc->dev, "UP\n");
 		input_report_key(input_dev, BTN_TOUCH, 0);
 		input_report_abs(input_dev, ABS_PRESSURE, 0);
 		input_sync(input_dev);
 		tsc->pendown = false;
 	}

 	if (pendown) {

 		if (!tsc->pendown) {
 			dev_dbg(tsc->dev, "DOWN\n");
 			input_report_key(input_dev, BTN_TOUCH, 1);
 		} else
 			dev_dbg(tsc->dev, "still down\n");

 		ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION,
 					       &tsc->tc.x);
 		if (ret)
 			goto done;

 		ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION,
 					       &tsc->tc.y);
 		if (ret)
 			goto done;

 		input_report_abs(input_dev, ABS_X, tsc->tc.x);
 		input_report_abs(input_dev, ABS_Y, tsc->tc.y);
 		input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure);
 		input_sync(input_dev);
 		tsc->pendown = true;
 	}

 done:
 	tps6507x_adc_standby(tsc);
 }

 static int tps6507x_ts_probe(struct platform_device *pdev)
 {
 	struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);
 	const struct tps6507x_board *tps_board;
 	const struct touchscreen_init_data *init_data;
 	struct tps6507x_ts *tsc;
 	struct input_dev *input_dev;
 	int error;

 	/*
 	 * tps_board points to pmic related constants
 	 * coming from the board-evm file.
 	 */
 	tps_board = dev_get_platdata(tps6507x_dev->dev);
 	if (!tps_board) {
 		dev_err(tps6507x_dev->dev,
 			"Could not find tps6507x platform data\n");
 		return -ENODEV;
 	}

 	/*
 	 * init_data points to array of regulator_init structures
 	 * coming from the board-evm file.
 	 */
 	init_data = tps_board->tps6507x_ts_init_data;

 	tsc = devm_kzalloc(&pdev->dev, sizeof(struct tps6507x_ts), GFP_KERNEL);
 	if (!tsc) {
 		dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");
 		return -ENOMEM;
 	}

 	tsc->mfd = tps6507x_dev;
 	tsc->dev = tps6507x_dev->dev;
 	tsc->min_pressure = init_data ?
 			init_data->min_pressure : TPS_DEFAULT_MIN_PRESSURE;

 	snprintf(tsc->phys, sizeof(tsc->phys),
 		 "%s/input0", dev_name(tsc->dev));

 	input_dev = devm_input_allocate_device(&pdev->dev);
 	if (!input_dev) {
 		dev_err(tsc->dev, "Failed to allocate polled input device.\n");
 		return -ENOMEM;
 	}

 	tsc->input = input_dev;
 	input_set_drvdata(input_dev, tsc);

 	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
 	input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0);
 	input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0);
 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0);

 	input_dev->name = "TPS6507x Touchscreen";
 	input_dev->phys = tsc->phys;
 	input_dev->dev.parent = tsc->dev;
 	input_dev->id.bustype = BUS_I2C;
 	if (init_data) {
 		input_dev->id.vendor = init_data->vendor;
 		input_dev->id.product = init_data->product;
 		input_dev->id.version = init_data->version;
 	}

 	error = tps6507x_adc_standby(tsc);
 	if (error)
 		return error;

 	error = input_setup_polling(input_dev, tps6507x_ts_poll);
 	if (error)
 		return error;

 	input_set_poll_interval(input_dev,
 				init_data ? init_data->poll_period :
 					    TSC_DEFAULT_POLL_PERIOD);

 	error = input_register_device(input_dev);
 	if (error)
 		return error;

 	return 0;
 }

 static struct platform_driver tps6507x_ts_driver = {
 	.driver = {
 		.name = "tps6507x-ts",
 	},
 	.probe = tps6507x_ts_probe,
 };
 module_platform_driver(tps6507x_ts_driver);

 MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");
 MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:tps6507x-ts");
	/*
	* Touchscreen driver for the tps6507x chip.
	*
	* Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
	*
	* Credits:
	*
	* Using code from tsc2007, MtekVision Co., Ltd.
	*
	* For licencing details see kernel-base/COPYING
	*
	* TPS65070, TPS65073, TPS650731, and TPS650732 support
	* 10 bit touch screen interface.
	*/

	#include <linux/module.h>
	#include <linux/workqueue.h>
	#include <linux/slab.h>
	#include <linux/input.h>
	#include <linux/platform_device.h>
	#include <linux/mfd/tps6507x.h>
	#include <linux/input/tps6507x-ts.h>
	#include <linux/delay.h>

	#define TSC_DEFAULT_POLL_PERIOD 30 /* ms */
	#define TPS_DEFAULT_MIN_PRESSURE 0x30
	#define MAX_10BIT ((1 << 10) - 1)

	#define TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE \| \
	TPS6507X_ADCONFIG_START_CONVERSION \| \
	TPS6507X_ADCONFIG_INPUT_REAL_TSC)
	#define TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC)

	struct ts_event {
	u16 x;
	u16 y;
	u16 pressure;
	};

	struct tps6507x_ts {
	struct device *dev;
	struct input_dev *input;
	struct tps6507x_dev *mfd;
	char phys[32];
	struct ts_event tc;
	u16 min_pressure;
	bool pendown;
	};

	static int tps6507x_read_u8(struct tps6507x_ts tsc, u8 reg, u8 data)
	{
	return tsc->mfd->read_dev(tsc->mfd, reg, 1, data);
	}

	static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data)
	{
	return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data);
	}

	static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc,
	u8 tsc_mode, u16 *value)
	{
	s32 ret;
	u8 adc_status;
	u8 result;

	/* Route input signal to A/D converter */

	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode);
	if (ret) {
	dev_err(tsc->dev, "TSC mode read failed\n");
	goto err;
	}

	/* Start A/D conversion */

	ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
	TPS6507X_ADCONFIG_CONVERT_TS);
	if (ret) {
	dev_err(tsc->dev, "ADC config write failed\n");
	return ret;
	}

	do {
	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG,
	&adc_status);
	if (ret) {
	dev_err(tsc->dev, "ADC config read failed\n");
	goto err;
	}
	} while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION);

	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result);
	if (ret) {
	dev_err(tsc->dev, "ADC result 2 read failed\n");
	goto err;
	}

	*value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8;

	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result);
	if (ret) {
	dev_err(tsc->dev, "ADC result 1 read failed\n");
	goto err;
	}

	*value \|= result;

	dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value);

	err:
	return ret;
	}

	/* Need to call tps6507x_adc_standby() after using A/D converter for the
	* touch screen interrupt to work properly.
	*/

	static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc)
	{
	s32 ret;
	s32 loops = 0;
	u8 val;

	ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
	TPS6507X_ADCONFIG_INPUT_TSC);
	if (ret)
	return ret;

	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE,
	TPS6507X_TSCMODE_STANDBY);
	if (ret)
	return ret;

	ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
	if (ret)
	return ret;

	while (val & TPS6507X_REG_TSC_INT) {
	mdelay(10);
	ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
	if (ret)
	return ret;
	loops++;
	}

	return ret;
	}

	static void tps6507x_ts_poll(struct input_dev *input_dev)
	{
	struct tps6507x_ts *tsc = input_get_drvdata(input_dev);
	bool pendown;
	s32 ret;

	ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE,
	&tsc->tc.pressure);
	if (ret)
	goto done;

	pendown = tsc->tc.pressure > tsc->min_pressure;

	if (unlikely(!pendown && tsc->pendown)) {
	dev_dbg(tsc->dev, "UP\n");
	input_report_key(input_dev, BTN_TOUCH, 0);
	input_report_abs(input_dev, ABS_PRESSURE, 0);
	input_sync(input_dev);
	tsc->pendown = false;
	}

	if (pendown) {

	if (!tsc->pendown) {
	dev_dbg(tsc->dev, "DOWN\n");
	input_report_key(input_dev, BTN_TOUCH, 1);
	} else
	dev_dbg(tsc->dev, "still down\n");

	ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION,
	&tsc->tc.x);
	if (ret)
	goto done;

	ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION,
	&tsc->tc.y);
	if (ret)
	goto done;

	input_report_abs(input_dev, ABS_X, tsc->tc.x);
	input_report_abs(input_dev, ABS_Y, tsc->tc.y);
	input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure);
	input_sync(input_dev);
	tsc->pendown = true;
	}

	done:
	tps6507x_adc_standby(tsc);
	}

	static int tps6507x_ts_probe(struct platform_device *pdev)
	{
	struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);
	const struct tps6507x_board *tps_board;
	const struct touchscreen_init_data *init_data;
	struct tps6507x_ts *tsc;
	struct input_dev *input_dev;
	int error;

	/*
	* tps_board points to pmic related constants
	* coming from the board-evm file.
	*/
	tps_board = dev_get_platdata(tps6507x_dev->dev);
	if (!tps_board) {
	dev_err(tps6507x_dev->dev,
	"Could not find tps6507x platform data\n");
	return -ENODEV;
	}

	/*
	* init_data points to array of regulator_init structures
	* coming from the board-evm file.
	*/
	init_data = tps_board->tps6507x_ts_init_data;

	tsc = devm_kzalloc(&pdev->dev, sizeof(struct tps6507x_ts), GFP_KERNEL);
	if (!tsc) {
	dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");
	return -ENOMEM;
	}

	tsc->mfd = tps6507x_dev;
	tsc->dev = tps6507x_dev->dev;
	tsc->min_pressure = init_data ?
	init_data->min_pressure : TPS_DEFAULT_MIN_PRESSURE;

	snprintf(tsc->phys, sizeof(tsc->phys),
	"%s/input0", dev_name(tsc->dev));

	input_dev = devm_input_allocate_device(&pdev->dev);
	if (!input_dev) {
	dev_err(tsc->dev, "Failed to allocate polled input device.\n");
	return -ENOMEM;
	}

	tsc->input = input_dev;
	input_set_drvdata(input_dev, tsc);

	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
	input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0);

	input_dev->name = "TPS6507x Touchscreen";
	input_dev->phys = tsc->phys;
	input_dev->dev.parent = tsc->dev;
	input_dev->id.bustype = BUS_I2C;
	if (init_data) {
	input_dev->id.vendor = init_data->vendor;
	input_dev->id.product = init_data->product;
	input_dev->id.version = init_data->version;
	}

	error = tps6507x_adc_standby(tsc);
	if (error)
	return error;

	error = input_setup_polling(input_dev, tps6507x_ts_poll);
	if (error)
	return error;

	input_set_poll_interval(input_dev,
	init_data ? init_data->poll_period :
	TSC_DEFAULT_POLL_PERIOD);

	error = input_register_device(input_dev);
	if (error)
	return error;

	return 0;
	}

	static struct platform_driver tps6507x_ts_driver = {
	.driver = {
	.name = "tps6507x-ts",
	},
	.probe = tps6507x_ts_probe,
	};
	module_platform_driver(tps6507x_ts_driver);

	MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");
	MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:tps6507x-ts");