[linux-2.6-block.git] / drivers / input / touchscreen / ti_am335x_tsc.c

/*
 * TI Touch Screen driver
 *
 * Copyright (C) 2011 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/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/sort.h>

#include <linux/mfd/ti_am335x_tscadc.h>

#define ADCFSM_STEPID		0x10
#define SEQ_SETTLE		275
#define MAX_12BIT		((1 << 12) - 1)

#define TSC_IRQENB_MASK		(IRQENB_FIFO0THRES | IRQENB_EOS | IRQENB_HW_PEN)

static const int config_pins[] = {
	STEPCONFIG_XPP,
	STEPCONFIG_XNN,
	STEPCONFIG_YPP,
	STEPCONFIG_YNN,
};

struct titsc {
	struct input_dev	*input;
	struct ti_tscadc_dev	*mfd_tscadc;
	struct device		*dev;
	unsigned int		irq;
	unsigned int		wires;
	unsigned int		x_plate_resistance;
	bool			pen_down;
	int			coordinate_readouts;
	u32			config_inp[4];
	u32			bit_xp, bit_xn, bit_yp, bit_yn;
	u32			inp_xp, inp_xn, inp_yp, inp_yn;
	u32			step_mask;
	u32			charge_delay;
};

static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
{
	return readl(ts->mfd_tscadc->tscadc_base + reg);
}

static void titsc_writel(struct titsc *tsc, unsigned int reg,
					unsigned int val)
{
	writel(val, tsc->mfd_tscadc->tscadc_base + reg);
}

static int titsc_config_wires(struct titsc *ts_dev)
{
	u32 analog_line[4];
	u32 wire_order[4];
	int i, bit_cfg;

	for (i = 0; i < 4; i++) {
		/*
		 * Get the order in which TSC wires are attached
		 * w.r.t. each of the analog input lines on the EVM.
		 */
		analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
		wire_order[i] = ts_dev->config_inp[i] & 0x0F;
		if (WARN_ON(analog_line[i] > 7))
			return -EINVAL;
		if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
			return -EINVAL;
	}

	for (i = 0; i < 4; i++) {
		int an_line;
		int wi_order;

		an_line = analog_line[i];
		wi_order = wire_order[i];
		bit_cfg = config_pins[wi_order];
		if (bit_cfg == 0)
			return -EINVAL;
		switch (wi_order) {
		case 0:
			ts_dev->bit_xp = bit_cfg;
			ts_dev->inp_xp = an_line;
			break;

		case 1:
			ts_dev->bit_xn = bit_cfg;
			ts_dev->inp_xn = an_line;
			break;

		case 2:
			ts_dev->bit_yp = bit_cfg;
			ts_dev->inp_yp = an_line;
			break;
		case 3:
			ts_dev->bit_yn = bit_cfg;
			ts_dev->inp_yn = an_line;
			break;
		}
	}
	return 0;
}

static void titsc_step_config(struct titsc *ts_dev)
{
	unsigned int	config;
	int i;
	int end_step, first_step, tsc_steps;
	u32 stepenable;

	config = STEPCONFIG_MODE_HWSYNC |
			STEPCONFIG_AVG_16 | ts_dev->bit_xp;
	switch (ts_dev->wires) {
	case 4:
		config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
		break;
	case 5:
		config |= ts_dev->bit_yn |
				STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
				ts_dev->bit_yp;
		break;
	case 8:
		config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
		break;
	}

	tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
	first_step = TOTAL_STEPS - tsc_steps;
	/* Steps 16 to 16-coordinate_readouts is for X */
	end_step = first_step + tsc_steps;
	for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
		titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
		titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
	}

	config = 0;
	config = STEPCONFIG_MODE_HWSYNC |
			STEPCONFIG_AVG_16 | ts_dev->bit_yn |
			STEPCONFIG_INM_ADCREFM;
	switch (ts_dev->wires) {
	case 4:
		config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
		break;
	case 5:
		config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
				STEPCONFIG_XNP | STEPCONFIG_YPN;
		break;
	case 8:
		config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
		break;
	}

	/* 1 ... coordinate_readouts is for Y */
	end_step = first_step + ts_dev->coordinate_readouts;
	for (i = first_step; i < end_step; i++) {
		titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
		titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
	}

	/* Make CHARGECONFIG same as IDLECONFIG */

	config = titsc_readl(ts_dev, REG_IDLECONFIG);
	titsc_writel(ts_dev, REG_CHARGECONFIG, config);
	titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);

	/* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
	config = STEPCONFIG_MODE_HWSYNC |
			STEPCONFIG_AVG_16 | ts_dev->bit_yp |
			ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
			STEPCONFIG_INP(ts_dev->inp_xp);
	titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
	titsc_writel(ts_dev, REG_STEPDELAY(end_step),
			STEPCONFIG_OPENDLY);

	end_step++;
	config |= STEPCONFIG_INP(ts_dev->inp_yn);
	titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
	titsc_writel(ts_dev, REG_STEPDELAY(end_step),
			STEPCONFIG_OPENDLY);

	/* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
	stepenable = 1;
	for (i = 0; i < tsc_steps; i++)
		stepenable |= 1 << (first_step + i + 1);

	ts_dev->step_mask = stepenable;
	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
}

static int titsc_cmp_coord(const void *a, const void *b)
{
	return *(int *)a - *(int *)b;
}

static void titsc_read_coordinates(struct titsc *ts_dev,
		u32 *x, u32 *y, u32 *z1, u32 *z2)
{
	unsigned int yvals[7], xvals[7];
	unsigned int i, xsum = 0, ysum = 0;
	unsigned int creads = ts_dev->coordinate_readouts;

	for (i = 0; i < creads; i++) {
		yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
		yvals[i] &= 0xfff;
	}

	*z1 = titsc_readl(ts_dev, REG_FIFO0);
	*z1 &= 0xfff;
	*z2 = titsc_readl(ts_dev, REG_FIFO0);
	*z2 &= 0xfff;

	for (i = 0; i < creads; i++) {
		xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
		xvals[i] &= 0xfff;
	}

	/*
	 * If co-ordinates readouts is less than 4 then
	 * report the average. In case of 4 or more
	 * readouts, sort the co-ordinate samples, drop
	 * min and max values and report the average of
	 * remaining values.
	 */
	if (creads <=  3) {
		for (i = 0; i < creads; i++) {
			ysum += yvals[i];
			xsum += xvals[i];
		}
		ysum /= creads;
		xsum /= creads;
	} else {
		sort(yvals, creads, sizeof(unsigned int),
		     titsc_cmp_coord, NULL);
		sort(xvals, creads, sizeof(unsigned int),
		     titsc_cmp_coord, NULL);
		for (i = 1; i < creads - 1; i++) {
			ysum += yvals[i];
			xsum += xvals[i];
		}
		ysum /= creads - 2;
		xsum /= creads - 2;
	}
	*y = ysum;
	*x = xsum;
}

static irqreturn_t titsc_irq(int irq, void *dev)
{
	struct titsc *ts_dev = dev;
	struct input_dev *input_dev = ts_dev->input;
	unsigned int fsm, status, irqclr = 0;
	unsigned int x = 0, y = 0;
	unsigned int z1, z2, z;

	status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
	if (status & IRQENB_HW_PEN) {
		ts_dev->pen_down = true;
		irqclr |= IRQENB_HW_PEN;
		pm_stay_awake(ts_dev->dev);
	}

	if (status & IRQENB_PENUP) {
		fsm = titsc_readl(ts_dev, REG_ADCFSM);
		if (fsm == ADCFSM_STEPID) {
			ts_dev->pen_down = false;
			input_report_key(input_dev, BTN_TOUCH, 0);
			input_report_abs(input_dev, ABS_PRESSURE, 0);
			input_sync(input_dev);
			pm_relax(ts_dev->dev);
		} else {
			ts_dev->pen_down = true;
		}
		irqclr |= IRQENB_PENUP;
	}

	if (status & IRQENB_EOS)
		irqclr |= IRQENB_EOS;

	/*
	 * ADC and touchscreen share the IRQ line.
	 * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
	 */
	if (status & IRQENB_FIFO0THRES) {

		titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);

		if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
			/*
			 * Calculate pressure using formula
			 * Resistance(touch) = x plate resistance *
			 * x postion/4096 * ((z2 / z1) - 1)
			 */
			z = z1 - z2;
			z *= x;
			z *= ts_dev->x_plate_resistance;
			z /= z2;
			z = (z + 2047) >> 12;

			if (z <= MAX_12BIT) {
				input_report_abs(input_dev, ABS_X, x);
				input_report_abs(input_dev, ABS_Y, y);
				input_report_abs(input_dev, ABS_PRESSURE, z);
				input_report_key(input_dev, BTN_TOUCH, 1);
				input_sync(input_dev);
			}
		}
		irqclr |= IRQENB_FIFO0THRES;
	}
	if (irqclr) {
		titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
		if (status & IRQENB_EOS)
			am335x_tsc_se_set_cache(ts_dev->mfd_tscadc,
						ts_dev->step_mask);
		return IRQ_HANDLED;
	}
	return IRQ_NONE;
}

static int titsc_parse_dt(struct platform_device *pdev,
					struct titsc *ts_dev)
{
	struct device_node *node = pdev->dev.of_node;
	int err;

	if (!node)
		return -EINVAL;

	err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
	if (err < 0)
		return err;
	switch (ts_dev->wires) {
	case 4:
	case 5:
	case 8:
		break;
	default:
		return -EINVAL;
	}

	err = of_property_read_u32(node, "ti,x-plate-resistance",
			&ts_dev->x_plate_resistance);
	if (err < 0)
		return err;

	/*
	 * Try with the new binding first. If it fails, try again with
	 * bogus, miss-spelled version.
	 */
	err = of_property_read_u32(node, "ti,coordinate-readouts",
			&ts_dev->coordinate_readouts);
	if (err < 0) {
		dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
		err = of_property_read_u32(node, "ti,coordiante-readouts",
				&ts_dev->coordinate_readouts);
	}

	if (err < 0)
		return err;

	if (ts_dev->coordinate_readouts <= 0) {
		dev_warn(&pdev->dev,
			 "invalid co-ordinate readouts, resetting it to 5\n");
		ts_dev->coordinate_readouts = 5;
	}

	err = of_property_read_u32(node, "ti,charge-delay",
				   &ts_dev->charge_delay);
	/*
	 * If ti,charge-delay value is not specified, then use
	 * CHARGEDLY_OPENDLY as the default value.
	 */
	if (err < 0) {
		ts_dev->charge_delay = CHARGEDLY_OPENDLY;
		dev_warn(&pdev->dev, "ti,charge-delay not specified\n");
	}

	return of_property_read_u32_array(node, "ti,wire-config",
			ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
}

/*
 * The functions for inserting/removing driver as a module.
 */

static int titsc_probe(struct platform_device *pdev)
{
	struct titsc *ts_dev;
	struct input_dev *input_dev;
	struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
	int err;

	/* Allocate memory for device */
	ts_dev = kzalloc(sizeof(*ts_dev), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!ts_dev || !input_dev) {
		dev_err(&pdev->dev, "failed to allocate memory.\n");
		err = -ENOMEM;
		goto err_free_mem;
	}

	tscadc_dev->tsc = ts_dev;
	ts_dev->mfd_tscadc = tscadc_dev;
	ts_dev->input = input_dev;
	ts_dev->irq = tscadc_dev->irq;
	ts_dev->dev = &pdev->dev;

	err = titsc_parse_dt(pdev, ts_dev);
	if (err) {
		dev_err(&pdev->dev, "Could not find valid DT data.\n");
		goto err_free_mem;
	}

	err = request_irq(ts_dev->irq, titsc_irq,
			  IRQF_SHARED, pdev->dev.driver->name, ts_dev);
	if (err) {
		dev_err(&pdev->dev, "failed to allocate irq.\n");
		goto err_free_mem;
	}

	device_init_wakeup(&pdev->dev, true);

	titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
	err = titsc_config_wires(ts_dev);
	if (err) {
		dev_err(&pdev->dev, "wrong i/p wire configuration\n");
		goto err_free_irq;
	}
	titsc_step_config(ts_dev);
	titsc_writel(ts_dev, REG_FIFO0THR,
			ts_dev->coordinate_readouts * 2 + 2 - 1);

	input_dev->name = "ti-tsc";
	input_dev->dev.parent = &pdev->dev;

	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_12BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);

	/* register to the input system */
	err = input_register_device(input_dev);
	if (err)
		goto err_free_irq;

	platform_set_drvdata(pdev, ts_dev);
	return 0;

err_free_irq:
	device_init_wakeup(&pdev->dev, false);
	free_irq(ts_dev->irq, ts_dev);
err_free_mem:
	input_free_device(input_dev);
	kfree(ts_dev);
	return err;
}

static int titsc_remove(struct platform_device *pdev)
{
	struct titsc *ts_dev = platform_get_drvdata(pdev);
	u32 steps;

	device_init_wakeup(&pdev->dev, false);
	free_irq(ts_dev->irq, ts_dev);

	/* total steps followed by the enable mask */
	steps = 2 * ts_dev->coordinate_readouts + 2;
	steps = (1 << steps) - 1;
	am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);

	input_unregister_device(ts_dev->input);

	kfree(ts_dev);
	return 0;
}

static int __maybe_unused titsc_suspend(struct device *dev)
{
	struct titsc *ts_dev = dev_get_drvdata(dev);
	struct ti_tscadc_dev *tscadc_dev;
	unsigned int idle;

	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
	if (device_may_wakeup(dev)) {
		titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
		idle = titsc_readl(ts_dev, REG_IRQENABLE);
		titsc_writel(ts_dev, REG_IRQENABLE,
				(idle | IRQENB_HW_PEN));
		titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
	}
	return 0;
}

static int __maybe_unused titsc_resume(struct device *dev)
{
	struct titsc *ts_dev = dev_get_drvdata(dev);
	struct ti_tscadc_dev *tscadc_dev;

	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
	if (device_may_wakeup(dev)) {
		titsc_writel(ts_dev, REG_IRQWAKEUP,
				0x00);
		titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
		pm_relax(dev);
	}
	titsc_step_config(ts_dev);
	titsc_writel(ts_dev, REG_FIFO0THR,
			ts_dev->coordinate_readouts * 2 + 2 - 1);
	return 0;
}

static SIMPLE_DEV_PM_OPS(titsc_pm_ops, titsc_suspend, titsc_resume);

static const struct of_device_id ti_tsc_dt_ids[] = {
	{ .compatible = "ti,am3359-tsc", },
	{ }
};
MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);

static struct platform_driver ti_tsc_driver = {
	.probe	= titsc_probe,
	.remove	= titsc_remove,
	.driver	= {
		.name   = "TI-am335x-tsc",
		.pm	= &titsc_pm_ops,
		.of_match_table = ti_tsc_dt_ids,
	},
};
module_platform_driver(ti_tsc_driver);

MODULE_DESCRIPTION("TI touchscreen controller driver");
MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
	1	/*
	2	* TI Touch Screen driver
	3	*
	4	* Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License as
	8	* published by the Free Software Foundation version 2.
	9	*
	10	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	11	* kind, whether express or implied; without even the implied warranty
	12	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*/
	15
	16
	17	#include <linux/kernel.h>
	18	#include <linux/err.h>
	19	#include <linux/module.h>
	20	#include <linux/input.h>
	21	#include <linux/slab.h>
	22	#include <linux/interrupt.h>
	23	#include <linux/clk.h>
	24	#include <linux/platform_device.h>
	25	#include <linux/io.h>
	26	#include <linux/delay.h>
	27	#include <linux/of.h>
	28	#include <linux/of_device.h>
	29	#include <linux/sort.h>
	30
	31	#include <linux/mfd/ti_am335x_tscadc.h>
	32
	33	#define ADCFSM_STEPID 0x10
	34	#define SEQ_SETTLE 275
	35	#define MAX_12BIT ((1 << 12) - 1)
	36
	37	#define TSC_IRQENB_MASK (IRQENB_FIFO0THRES \| IRQENB_EOS \| IRQENB_HW_PEN)
	38
	39	static const int config_pins[] = {
	40	STEPCONFIG_XPP,
	41	STEPCONFIG_XNN,
	42	STEPCONFIG_YPP,
	43	STEPCONFIG_YNN,
	44	};
	45
	46	struct titsc {
	47	struct input_dev *input;
	48	struct ti_tscadc_dev *mfd_tscadc;
	49	struct device *dev;
	50	unsigned int irq;
	51	unsigned int wires;
	52	unsigned int x_plate_resistance;
	53	bool pen_down;
	54	int coordinate_readouts;
	55	u32 config_inp[4];
	56	u32 bit_xp, bit_xn, bit_yp, bit_yn;
	57	u32 inp_xp, inp_xn, inp_yp, inp_yn;
	58	u32 step_mask;
	59	u32 charge_delay;
	60	};
	61
	62	static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
	63	{
	64	return readl(ts->mfd_tscadc->tscadc_base + reg);
	65	}
	66
	67	static void titsc_writel(struct titsc *tsc, unsigned int reg,
	68	unsigned int val)
	69	{
	70	writel(val, tsc->mfd_tscadc->tscadc_base + reg);
	71	}
	72
	73	static int titsc_config_wires(struct titsc *ts_dev)
	74	{
	75	u32 analog_line[4];
	76	u32 wire_order[4];
	77	int i, bit_cfg;
	78
	79	for (i = 0; i < 4; i++) {
	80	/*
	81	* Get the order in which TSC wires are attached
	82	* w.r.t. each of the analog input lines on the EVM.
	83	*/
	84	analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
	85	wire_order[i] = ts_dev->config_inp[i] & 0x0F;
	86	if (WARN_ON(analog_line[i] > 7))
	87	return -EINVAL;
	88	if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
	89	return -EINVAL;
	90	}
	91
	92	for (i = 0; i < 4; i++) {
	93	int an_line;
	94	int wi_order;
	95
	96	an_line = analog_line[i];
	97	wi_order = wire_order[i];
	98	bit_cfg = config_pins[wi_order];
	99	if (bit_cfg == 0)
	100	return -EINVAL;
	101	switch (wi_order) {
	102	case 0:
	103	ts_dev->bit_xp = bit_cfg;
	104	ts_dev->inp_xp = an_line;
	105	break;
	106
	107	case 1:
	108	ts_dev->bit_xn = bit_cfg;
	109	ts_dev->inp_xn = an_line;
	110	break;
	111
	112	case 2:
	113	ts_dev->bit_yp = bit_cfg;
	114	ts_dev->inp_yp = an_line;
	115	break;
	116	case 3:
	117	ts_dev->bit_yn = bit_cfg;
	118	ts_dev->inp_yn = an_line;
	119	break;
	120	}
	121	}
	122	return 0;
	123	}
	124
	125	static void titsc_step_config(struct titsc *ts_dev)
	126	{
	127	unsigned int config;
	128	int i;
	129	int end_step, first_step, tsc_steps;
	130	u32 stepenable;
	131
	132	config = STEPCONFIG_MODE_HWSYNC \|
	133	STEPCONFIG_AVG_16 \| ts_dev->bit_xp;
	134	switch (ts_dev->wires) {
	135	case 4:
	136	config \|= STEPCONFIG_INP(ts_dev->inp_yp) \| ts_dev->bit_xn;
	137	break;
	138	case 5:
	139	config \|= ts_dev->bit_yn \|
	140	STEPCONFIG_INP_AN4 \| ts_dev->bit_xn \|
	141	ts_dev->bit_yp;
	142	break;
	143	case 8:
	144	config \|= STEPCONFIG_INP(ts_dev->inp_yp) \| ts_dev->bit_xn;
	145	break;
	146	}
	147
	148	tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
	149	first_step = TOTAL_STEPS - tsc_steps;
	150	/* Steps 16 to 16-coordinate_readouts is for X */
	151	end_step = first_step + tsc_steps;
	152	for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
	153	titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
	154	titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
	155	}
	156
	157	config = 0;
	158	config = STEPCONFIG_MODE_HWSYNC \|
	159	STEPCONFIG_AVG_16 \| ts_dev->bit_yn \|
	160	STEPCONFIG_INM_ADCREFM;
	161	switch (ts_dev->wires) {
	162	case 4:
	163	config \|= ts_dev->bit_yp \| STEPCONFIG_INP(ts_dev->inp_xp);
	164	break;
	165	case 5:
	166	config \|= ts_dev->bit_xp \| STEPCONFIG_INP_AN4 \|
	167	STEPCONFIG_XNP \| STEPCONFIG_YPN;
	168	break;
	169	case 8:
	170	config \|= ts_dev->bit_yp \| STEPCONFIG_INP(ts_dev->inp_xp);
	171	break;
	172	}
	173
	174	/* 1 ... coordinate_readouts is for Y */
	175	end_step = first_step + ts_dev->coordinate_readouts;
	176	for (i = first_step; i < end_step; i++) {
	177	titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
	178	titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
	179	}
	180
	181	/* Make CHARGECONFIG same as IDLECONFIG */
	182
	183	config = titsc_readl(ts_dev, REG_IDLECONFIG);
	184	titsc_writel(ts_dev, REG_CHARGECONFIG, config);
	185	titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);
	186
	187	/* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
	188	config = STEPCONFIG_MODE_HWSYNC \|
	189	STEPCONFIG_AVG_16 \| ts_dev->bit_yp \|
	190	ts_dev->bit_xn \| STEPCONFIG_INM_ADCREFM \|
	191	STEPCONFIG_INP(ts_dev->inp_xp);
	192	titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
	193	titsc_writel(ts_dev, REG_STEPDELAY(end_step),
	194	STEPCONFIG_OPENDLY);
	195
	196	end_step++;
	197	config \|= STEPCONFIG_INP(ts_dev->inp_yn);
	198	titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
	199	titsc_writel(ts_dev, REG_STEPDELAY(end_step),
	200	STEPCONFIG_OPENDLY);
	201
	202	/* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
	203	stepenable = 1;
	204	for (i = 0; i < tsc_steps; i++)
	205	stepenable \|= 1 << (first_step + i + 1);
	206
	207	ts_dev->step_mask = stepenable;
	208	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
	209	}
	210
	211	static int titsc_cmp_coord(const void a, const void b)
	212	{
	213	return (int )a - (int )b;
	214	}
	215
	216	static void titsc_read_coordinates(struct titsc *ts_dev,
	217	u32 x, u32 y, u32 z1, u32 z2)
	218	{
	219	unsigned int yvals[7], xvals[7];
	220	unsigned int i, xsum = 0, ysum = 0;
	221	unsigned int creads = ts_dev->coordinate_readouts;
	222
	223	for (i = 0; i < creads; i++) {
	224	yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
	225	yvals[i] &= 0xfff;
	226	}
	227
	228	*z1 = titsc_readl(ts_dev, REG_FIFO0);
	229	*z1 &= 0xfff;
	230	*z2 = titsc_readl(ts_dev, REG_FIFO0);
	231	*z2 &= 0xfff;
	232
	233	for (i = 0; i < creads; i++) {
	234	xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
	235	xvals[i] &= 0xfff;
	236	}
	237
	238	/*
	239	* If co-ordinates readouts is less than 4 then
	240	* report the average. In case of 4 or more
	241	* readouts, sort the co-ordinate samples, drop
	242	* min and max values and report the average of
	243	* remaining values.
	244	*/
	245	if (creads <= 3) {
	246	for (i = 0; i < creads; i++) {
	247	ysum += yvals[i];
	248	xsum += xvals[i];
	249	}
	250	ysum /= creads;
	251	xsum /= creads;
	252	} else {
	253	sort(yvals, creads, sizeof(unsigned int),
	254	titsc_cmp_coord, NULL);
	255	sort(xvals, creads, sizeof(unsigned int),
	256	titsc_cmp_coord, NULL);
	257	for (i = 1; i < creads - 1; i++) {
	258	ysum += yvals[i];
	259	xsum += xvals[i];
	260	}
	261	ysum /= creads - 2;
	262	xsum /= creads - 2;
	263	}
	264	*y = ysum;
	265	*x = xsum;
	266	}
	267
	268	static irqreturn_t titsc_irq(int irq, void *dev)
	269	{
	270	struct titsc *ts_dev = dev;
	271	struct input_dev *input_dev = ts_dev->input;
	272	unsigned int fsm, status, irqclr = 0;
	273	unsigned int x = 0, y = 0;
	274	unsigned int z1, z2, z;
	275
	276	status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
	277	if (status & IRQENB_HW_PEN) {
	278	ts_dev->pen_down = true;
	279	irqclr \|= IRQENB_HW_PEN;
	280	pm_stay_awake(ts_dev->dev);
	281	}
	282
	283	if (status & IRQENB_PENUP) {
	284	fsm = titsc_readl(ts_dev, REG_ADCFSM);
	285	if (fsm == ADCFSM_STEPID) {
	286	ts_dev->pen_down = false;
	287	input_report_key(input_dev, BTN_TOUCH, 0);
	288	input_report_abs(input_dev, ABS_PRESSURE, 0);
	289	input_sync(input_dev);
	290	pm_relax(ts_dev->dev);
	291	} else {
	292	ts_dev->pen_down = true;
	293	}
	294	irqclr \|= IRQENB_PENUP;
	295	}
	296
	297	if (status & IRQENB_EOS)
	298	irqclr \|= IRQENB_EOS;
	299
	300	/*
	301	* ADC and touchscreen share the IRQ line.
	302	* FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
	303	*/
	304	if (status & IRQENB_FIFO0THRES) {
	305
	306	titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
	307
	308	if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
	309	/*
	310	* Calculate pressure using formula
	311	* Resistance(touch) = x plate resistance *
	312	* x postion/4096 * ((z2 / z1) - 1)
	313	*/
	314	z = z1 - z2;
	315	z *= x;
	316	z *= ts_dev->x_plate_resistance;
	317	z /= z2;
	318	z = (z + 2047) >> 12;
	319
	320	if (z <= MAX_12BIT) {
	321	input_report_abs(input_dev, ABS_X, x);
	322	input_report_abs(input_dev, ABS_Y, y);
	323	input_report_abs(input_dev, ABS_PRESSURE, z);
	324	input_report_key(input_dev, BTN_TOUCH, 1);
	325	input_sync(input_dev);
	326	}
	327	}
	328	irqclr \|= IRQENB_FIFO0THRES;
	329	}
	330	if (irqclr) {
	331	titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
	332	if (status & IRQENB_EOS)
	333	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc,
	334	ts_dev->step_mask);
	335	return IRQ_HANDLED;
	336	}
	337	return IRQ_NONE;
	338	}
	339
	340	static int titsc_parse_dt(struct platform_device *pdev,
	341	struct titsc *ts_dev)
	342	{
	343	struct device_node *node = pdev->dev.of_node;
	344	int err;
	345
	346	if (!node)
	347	return -EINVAL;
	348
	349	err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
	350	if (err < 0)
	351	return err;
	352	switch (ts_dev->wires) {
	353	case 4:
	354	case 5:
	355	case 8:
	356	break;
	357	default:
	358	return -EINVAL;
	359	}
	360
	361	err = of_property_read_u32(node, "ti,x-plate-resistance",
	362	&ts_dev->x_plate_resistance);
	363	if (err < 0)
	364	return err;
	365
	366	/*
	367	* Try with the new binding first. If it fails, try again with
	368	* bogus, miss-spelled version.
	369	*/
	370	err = of_property_read_u32(node, "ti,coordinate-readouts",
	371	&ts_dev->coordinate_readouts);
	372	if (err < 0) {
	373	dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
	374	err = of_property_read_u32(node, "ti,coordiante-readouts",
	375	&ts_dev->coordinate_readouts);
	376	}
	377
	378	if (err < 0)
	379	return err;
	380
	381	if (ts_dev->coordinate_readouts <= 0) {
	382	dev_warn(&pdev->dev,
	383	"invalid co-ordinate readouts, resetting it to 5\n");
	384	ts_dev->coordinate_readouts = 5;
	385	}
	386
	387	err = of_property_read_u32(node, "ti,charge-delay",
	388	&ts_dev->charge_delay);
	389	/*
	390	* If ti,charge-delay value is not specified, then use
	391	* CHARGEDLY_OPENDLY as the default value.
	392	*/
	393	if (err < 0) {
	394	ts_dev->charge_delay = CHARGEDLY_OPENDLY;
	395	dev_warn(&pdev->dev, "ti,charge-delay not specified\n");
	396	}
	397
	398	return of_property_read_u32_array(node, "ti,wire-config",
	399	ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
	400	}
	401
	402	/*
	403	* The functions for inserting/removing driver as a module.
	404	*/
	405
	406	static int titsc_probe(struct platform_device *pdev)
	407	{
	408	struct titsc *ts_dev;
	409	struct input_dev *input_dev;
	410	struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
	411	int err;
	412
	413	/* Allocate memory for device */
	414	ts_dev = kzalloc(sizeof(*ts_dev), GFP_KERNEL);
	415	input_dev = input_allocate_device();
	416	if (!ts_dev \|\| !input_dev) {
	417	dev_err(&pdev->dev, "failed to allocate memory.\n");
	418	err = -ENOMEM;
	419	goto err_free_mem;
	420	}
	421
	422	tscadc_dev->tsc = ts_dev;
	423	ts_dev->mfd_tscadc = tscadc_dev;
	424	ts_dev->input = input_dev;
	425	ts_dev->irq = tscadc_dev->irq;
	426	ts_dev->dev = &pdev->dev;
	427
	428	err = titsc_parse_dt(pdev, ts_dev);
	429	if (err) {
	430	dev_err(&pdev->dev, "Could not find valid DT data.\n");
	431	goto err_free_mem;
	432	}
	433
	434	err = request_irq(ts_dev->irq, titsc_irq,
	435	IRQF_SHARED, pdev->dev.driver->name, ts_dev);
	436	if (err) {
	437	dev_err(&pdev->dev, "failed to allocate irq.\n");
	438	goto err_free_mem;
	439	}
	440
	441	device_init_wakeup(&pdev->dev, true);
	442
	443	titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
	444	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
	445	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
	446	err = titsc_config_wires(ts_dev);
	447	if (err) {
	448	dev_err(&pdev->dev, "wrong i/p wire configuration\n");
	449	goto err_free_irq;
	450	}
	451	titsc_step_config(ts_dev);
	452	titsc_writel(ts_dev, REG_FIFO0THR,
	453	ts_dev->coordinate_readouts * 2 + 2 - 1);
	454
	455	input_dev->name = "ti-tsc";
	456	input_dev->dev.parent = &pdev->dev;
	457
	458	input_dev->evbit[0] = BIT_MASK(EV_KEY) \| BIT_MASK(EV_ABS);
	459	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
	460
	461	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
	462	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
	463	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
	464
	465	/* register to the input system */
	466	err = input_register_device(input_dev);
	467	if (err)
	468	goto err_free_irq;
	469
	470	platform_set_drvdata(pdev, ts_dev);
	471	return 0;
	472
	473	err_free_irq:
	474	device_init_wakeup(&pdev->dev, false);
	475	free_irq(ts_dev->irq, ts_dev);
	476	err_free_mem:
	477	input_free_device(input_dev);
	478	kfree(ts_dev);
	479	return err;
	480	}
	481
	482	static int titsc_remove(struct platform_device *pdev)
	483	{
	484	struct titsc *ts_dev = platform_get_drvdata(pdev);
	485	u32 steps;
	486
	487	device_init_wakeup(&pdev->dev, false);
	488	free_irq(ts_dev->irq, ts_dev);
	489
	490	/* total steps followed by the enable mask */
	491	steps = 2 * ts_dev->coordinate_readouts + 2;
	492	steps = (1 << steps) - 1;
	493	am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
	494
	495	input_unregister_device(ts_dev->input);
	496
	497	kfree(ts_dev);
	498	return 0;
	499	}
	500
	501	static int __maybe_unused titsc_suspend(struct device *dev)
	502	{
	503	struct titsc *ts_dev = dev_get_drvdata(dev);
	504	struct ti_tscadc_dev *tscadc_dev;
	505	unsigned int idle;
	506
	507	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
	508	if (device_may_wakeup(dev)) {
	509	titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
	510	idle = titsc_readl(ts_dev, REG_IRQENABLE);
	511	titsc_writel(ts_dev, REG_IRQENABLE,
	512	(idle \| IRQENB_HW_PEN));
	513	titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
	514	}
	515	return 0;
	516	}
	517
	518	static int __maybe_unused titsc_resume(struct device *dev)
	519	{
	520	struct titsc *ts_dev = dev_get_drvdata(dev);
	521	struct ti_tscadc_dev *tscadc_dev;
	522
	523	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
	524	if (device_may_wakeup(dev)) {
	525	titsc_writel(ts_dev, REG_IRQWAKEUP,
	526	0x00);
	527	titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
	528	pm_relax(dev);
	529	}
	530	titsc_step_config(ts_dev);
	531	titsc_writel(ts_dev, REG_FIFO0THR,
	532	ts_dev->coordinate_readouts * 2 + 2 - 1);
	533	return 0;
	534	}
	535
	536	static SIMPLE_DEV_PM_OPS(titsc_pm_ops, titsc_suspend, titsc_resume);
	537
	538	static const struct of_device_id ti_tsc_dt_ids[] = {
	539	{ .compatible = "ti,am3359-tsc", },
	540	{ }
	541	};
	542	MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
	543
	544	static struct platform_driver ti_tsc_driver = {
	545	.probe = titsc_probe,
	546	.remove = titsc_remove,
	547	.driver = {
	548	.name = "TI-am335x-tsc",
	549	.pm = &titsc_pm_ops,
	550	.of_match_table = ti_tsc_dt_ids,
	551	},
	552	};
	553	module_platform_driver(ti_tsc_driver);
	554
	555	MODULE_DESCRIPTION("TI touchscreen controller driver");
	556	MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
	557	MODULE_LICENSE("GPL");