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Commit 75259966 authored by Todd Fischer's avatar Todd Fischer Committed by Samuel Ortiz
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input: Touchscreen driver for TPS6507x 



Add touch screen input driver for TPS6507x family of multi-function
chips.  Uses the TPS6507x MFD driver.  No interrupt support due to
testing limitations of current hardware.

Signed-off-by: default avatarTodd Fischer <todd.fischer@ridgerun.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent 31dd6a26

drivers/input/touchscreen/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -590,4 +590,17 @@ config TOUCHSCREEN_PCAP 


	  To compile this driver as a module, choose M here: the

	  module will be called pcap_ts.



config TOUCHSCREEN_TPS6507X

	tristate "TPS6507x based touchscreens"

	depends on I2C

	help

	  Say Y here if you have a TPS6507x based touchscreen

	  controller.



	  If unsure, say N.



	  To compile this driver as a module, choose M here: the

	  module will be called tps6507x_ts.



endif

drivers/input/touchscreen/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -46,3 +46,4 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_ATMEL) += atmel-wm97xx.o 
obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)	+= mainstone-wm97xx.o

obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)	+= zylonite-wm97xx.o

obj-$(CONFIG_TOUCHSCREEN_W90X900)	+= w90p910_ts.o

obj-$(CONFIG_TOUCHSCREEN_TPS6507X)	+= tps6507x-ts.o

drivers/input/touchscreen/tps6507x-ts.c

0 → 100644
+400 −0
Original line number Diff line number Diff line 
/*

 * drivers/input/touchscreen/tps6507x_ts.c

 *

 * 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 input_dev	*input_dev;

	struct device		*dev;

	char			phys[32];

	struct workqueue_struct *wq;

	struct delayed_work	work;

	unsigned		polling;	/* polling is active */

	struct ts_event		tc;

	struct tps6507x_dev	*mfd;

	u16			model;

	unsigned		pendown;

	int			irq;

	void			(*clear_penirq)(void);

	unsigned long		poll_period;	/* ms */

	u16			min_pressure;

	int			vref;		/* non-zero to leave vref on */

};



static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data)

{

	int err;



	err = tsc->mfd->read_dev(tsc->mfd, reg, 1, data);



	if (err)

		return err;



	return 0;

}



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_handler(struct work_struct *work)

{

	struct tps6507x_ts *tsc =  container_of(work,

				struct tps6507x_ts, work.work);

	struct input_dev *input_dev = tsc->input_dev;

	int pendown;

	int schd;

	int poll = 0;

	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 = 0;

	}



	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 = 1;

		poll = 1;

	}



done:

	/* always poll if not using interrupts */

	poll = 1;



	if (poll) {

		schd = queue_delayed_work(tsc->wq, &tsc->work,

					  tsc->poll_period * HZ / 1000);

		if (schd)

			tsc->polling = 1;

		else {

			tsc->polling = 0;

			dev_err(tsc->dev, "re-schedule failed");

		}

	} else

		tsc->polling = 0;



	ret = tps6507x_adc_standby(tsc);

}



static int tps6507x_ts_probe(struct platform_device *pdev)

{

	int error;

	struct tps6507x_ts *tsc;

	struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);

	struct touchscreen_init_data *init_data;

	struct input_dev *input_dev;

	struct tps6507x_board *tps_board;

	int schd;



	/**

	 * tps_board points to pmic related constants

	 * coming from the board-evm file.

	 */



	tps_board = (struct tps6507x_board *)tps6507x_dev->dev->platform_data;



	if (!tps_board) {

		dev_err(tps6507x_dev->dev,

			"Could not find tps6507x platform data\n");

		return -EIO;

	}



	/**

	 * init_data points to array of regulator_init structures

	 * coming from the board-evm file.

	 */



	init_data = tps_board->tps6507x_ts_init_data;



	tsc = kzalloc(sizeof(struct tps6507x_ts), GFP_KERNEL);

	if (!tsc) {

		dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");

		error = -ENOMEM;

		goto err0;

	}



	tps6507x_dev->ts = tsc;

	tsc->mfd = tps6507x_dev;

	tsc->dev = tps6507x_dev->dev;

	input_dev = input_allocate_device();

	if (!input_dev) {

		dev_err(tsc->dev, "Failed to allocate input device.\n");

		error = -ENOMEM;

		goto err1;

	}



	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);

	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(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->id.bustype = BUS_I2C;

	input_dev->dev.parent = tsc->dev;



	snprintf(tsc->phys, sizeof(tsc->phys),

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

	input_dev->phys = tsc->phys;



	dev_dbg(tsc->dev, "device: %s\n", input_dev->phys);



	input_set_drvdata(input_dev, tsc);



	tsc->input_dev = input_dev;



	INIT_DELAYED_WORK(&tsc->work, tps6507x_ts_handler);

	tsc->wq = create_workqueue("TPS6507x Touchscreen");



	if (init_data) {

		tsc->poll_period = init_data->poll_period;

		tsc->vref = init_data->vref;

		tsc->min_pressure = init_data->min_pressure;

		input_dev->id.vendor = init_data->vendor;

		input_dev->id.product = init_data->product;

		input_dev->id.version = init_data->version;

	} else {

		tsc->poll_period = TSC_DEFAULT_POLL_PERIOD;

		tsc->min_pressure = TPS_DEFAULT_MIN_PRESSURE;

	}



	error = tps6507x_adc_standby(tsc);

	if (error)

		goto err2;



	error = input_register_device(input_dev);

	if (error)

		goto err2;



	schd = queue_delayed_work(tsc->wq, &tsc->work,

				  tsc->poll_period * HZ / 1000);



	if (schd)

		tsc->polling = 1;

	else {

		tsc->polling = 0;

		dev_err(tsc->dev, "schedule failed");

		goto err2;

	 }



	return 0;



err2:

	cancel_delayed_work(&tsc->work);

	flush_workqueue(tsc->wq);

	destroy_workqueue(tsc->wq);

	tsc->wq = 0;

	input_free_device(input_dev);

err1:

	kfree(tsc);

	tps6507x_dev->ts = NULL;

err0:

	return error;

}



static int __devexit tps6507x_ts_remove(struct platform_device *pdev)

{

	struct tps6507x_dev *tps6507x_dev = platform_get_drvdata(pdev);

	struct tps6507x_ts *tsc = tps6507x_dev->ts;

	struct input_dev *input_dev = tsc->input_dev;



	if (!tsc)

		return 0;



	cancel_delayed_work(&tsc->work);

	flush_workqueue(tsc->wq);

	destroy_workqueue(tsc->wq);

	tsc->wq = 0;



	input_free_device(input_dev);



	tps6507x_dev->ts = NULL;

	kfree(tsc);



	return 0;

}



static struct platform_driver tps6507x_ts_driver = {

	.driver = {

		.name = "tps6507x-ts",

		.owner = THIS_MODULE,

	},

	.probe = tps6507x_ts_probe,

	.remove = __devexit_p(tps6507x_ts_remove),

};



static int __init tps6507x_ts_init(void)

{

	return platform_driver_register(&tps6507x_ts_driver);

}

module_init(tps6507x_ts_init);



static void __exit tps6507x_ts_exit(void)

{

	platform_driver_unregister(&tps6507x_ts_driver);

}

module_exit(tps6507x_ts_exit);



MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");

MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");

MODULE_LICENSE("GPL v2");

MODULE_ALIAS("platform:tps6507x-tsc");

drivers/mfd/tps6507x.c

+3 −0
Original line number Diff line number Diff line
@@ -26,6 +26,9 @@ static struct mfd_cell tps6507x_devs[] = { 
	{

		.name = "tps6507x-pmic",

	},

	{

		.name = "tps6507x-ts",

	},

};

include/linux/input/tps6507x-ts.h

0 → 100644
+24 −0
Original line number Diff line number Diff line 
/* linux/i2c/tps6507x-ts.h

 *

 * Functions to access TPS65070 touch screen chip.

 *

 * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)

 *

 *

 *  For licencing details see kernel-base/COPYING

 */



#ifndef __LINUX_I2C_TPS6507X_TS_H

#define __LINUX_I2C_TPS6507X_TS_H



/* Board specific touch screen initial values */

struct touchscreen_init_data {

	int	poll_period;	/* ms */

	int	vref;		/* non-zero to leave vref on */

	__u16	min_pressure;	/* min reading to be treated as a touch */

	__u16	vendor;

	__u16	product;

	__u16	version;

};



#endif /*  __LINUX_I2C_TPS6507X_TS_H */