[deliverable/linux.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/mfd/ti_am335x_tscadc.h>

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

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;
	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;
};

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;
	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;
	}

	/* 1 … coordinate_readouts is for X */
	end_step = ts_dev->coordinate_readouts;
	for (i = 0; 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 |
				ts_dev->bit_xn | ts_dev->bit_yp;
		break;
	case 8:
		config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
		break;
	}

	/* coordinate_readouts … coordinate_readouts * 2 is for Y */
	end_step = ts_dev->coordinate_readouts * 2;
	for (i = 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);
	}

	/* Charge step configuration */
	config = ts_dev->bit_xp | ts_dev->bit_yn |
			STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
			STEPCHARGE_INM_AN1 | STEPCHARGE_INP(ts_dev->inp_yp);

	titsc_writel(ts_dev, REG_CHARGECONFIG, config);
	titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);

	/* coordinate_readouts * 2 … coordinate_readouts * 2 + 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 steps1 … end and bit 0 for TS_Charge */
	stepenable = (1 << (end_step + 2)) - 1;
	ts_dev->step_mask = stepenable;
	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
}

static void titsc_read_coordinates(struct titsc *ts_dev,
		u32 *x, u32 *y, u32 *z1, u32 *z2)
{
	unsigned int fifocount = titsc_readl(ts_dev, REG_FIFO0CNT);
	unsigned int prev_val_x = ~0, prev_val_y = ~0;
	unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
	unsigned int read, diff;
	unsigned int i, channel;
	unsigned int creads = ts_dev->coordinate_readouts;

	*z1 = *z2 = 0;
	if (fifocount % (creads * 2 + 2))
		fifocount -= fifocount % (creads * 2 + 2);
	/*
	 * Delta filter is used to remove large variations in sampled
	 * values from ADC. The filter tries to predict where the next
	 * coordinate could be. This is done by taking a previous
	 * coordinate and subtracting it form current one. Further the
	 * algorithm compares the difference with that of a present value,
	 * if true the value is reported to the sub system.
	 */
	for (i = 0; i < fifocount; i++) {
		read = titsc_readl(ts_dev, REG_FIFO0);

		channel = (read & 0xf0000) >> 16;
		read &= 0xfff;
		if (channel < creads) {
			diff = abs(read - prev_val_x);
			if (diff < prev_diff_x) {
				prev_diff_x = diff;
				*x = read;
			}
			prev_val_x = read;

		} else if (channel < creads * 2) {
			diff = abs(read - prev_val_y);
			if (diff < prev_diff_y) {
				prev_diff_y = diff;
				*y = read;
			}
			prev_val_y = read;

		} else if (channel < creads * 2 + 1) {
			*z1 = read;

		} else if (channel < creads * 2 + 2) {
			*z2 = read;
		}
	}
}

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

	status = titsc_readl(ts_dev, REG_IRQSTATUS);
	/*
	 * 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;
	}

	/*
	 * Time for sequencer to settle, to read
	 * correct state of the sequencer.
	 */
	udelay(SEQ_SETTLE);

	status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
	if (status & IRQENB_PENUP) {
		/* Pen up event */
		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);
		} else {
			ts_dev->pen_down = true;
		}
		irqclr |= IRQENB_PENUP;
	}

	if (status & IRQENB_HW_PEN) {

		titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
		titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
	}

	if (irqclr) {
		titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
		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;

	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(struct titsc), 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;

	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;
	}

	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
	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:
	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;

	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;
}

#ifdef CONFIG_PM
static int 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(tscadc_dev->dev)) {
		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 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(tscadc_dev->dev)) {
		titsc_writel(ts_dev, REG_IRQWAKEUP,
				0x00);
		titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
	}
	titsc_step_config(ts_dev);
	titsc_writel(ts_dev, REG_FIFO0THR,
			ts_dev->coordinate_readouts * 2 + 2 - 1);
	return 0;
}

static const struct dev_pm_ops titsc_pm_ops = {
	.suspend = titsc_suspend,
	.resume  = titsc_resume,
};
#define TITSC_PM_OPS (&titsc_pm_ops)
#else
#define TITSC_PM_OPS NULL
#endif

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
1b8be32e RP	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
1b8be32e RP	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>
1b8be32e	26	#include <linux/delay.h>
0396310b PR	27	#include <linux/of.h>
0396310b PR	28	#include <linux/of_device.h>
1b8be32e	29
2b99bafa	30	#include <linux/mfd/ti_am335x_tscadc.h>
33f5cc60 PR	31
33f5cc60 PR	32	#define ADCFSM_STEPID 0x10
1b8be32e	33	#define SEQ_SETTLE 275
1b8be32e	34	#define MAX_12BIT ((1 << 12) - 1)
1b8be32e	35
bb76dc09 PR	36	static const int config_pins[] = {
	37	STEPCONFIG_XPP,
	38	STEPCONFIG_XNN,
	39	STEPCONFIG_YPP,
	40	STEPCONFIG_YNN,
	41	};
	42
55c04de5	43	struct titsc {
1b8be32e	44	struct input_dev *input;
2b99bafa	45	struct ti_tscadc_dev *mfd_tscadc;
1b8be32e RP	46	unsigned int irq;
	47	unsigned int wires;
	48	unsigned int x_plate_resistance;
	49	bool pen_down;
0396310b	50	int coordinate_readouts;
bb76dc09 PR	51	u32 config_inp[4];
	52	u32 bit_xp, bit_xn, bit_yp, bit_yn;
	53	u32 inp_xp, inp_xn, inp_yp, inp_yn;
baee5399	54	u32 step_mask;
1b8be32e RP	55	};
1b8be32e RP	56
55c04de5	57	static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
1b8be32e	58	{
2b99bafa	59	return readl(ts->mfd_tscadc->tscadc_base + reg);
1b8be32e RP	60	}
1b8be32e RP	61
55c04de5	62	static void titsc_writel(struct titsc *tsc, unsigned int reg,
1b8be32e RP	63	unsigned int val)
1b8be32e RP	64	{
2b99bafa	65	writel(val, tsc->mfd_tscadc->tscadc_base + reg);
1b8be32e RP	66	}
1b8be32e RP	67
bb76dc09 PR	68	static int titsc_config_wires(struct titsc *ts_dev)
	69	{
	70	u32 analog_line[4];
	71	u32 wire_order[4];
	72	int i, bit_cfg;
	73
	74	for (i = 0; i < 4; i++) {
	75	/*
	76	* Get the order in which TSC wires are attached
	77	* w.r.t. each of the analog input lines on the EVM.
	78	*/
	79	analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
	80	wire_order[i] = ts_dev->config_inp[i] & 0x0F;
	81	if (WARN_ON(analog_line[i] > 7))
	82	return -EINVAL;
	83	if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
	84	return -EINVAL;
	85	}
	86
	87	for (i = 0; i < 4; i++) {
	88	int an_line;
	89	int wi_order;
	90
	91	an_line = analog_line[i];
	92	wi_order = wire_order[i];
	93	bit_cfg = config_pins[wi_order];
	94	if (bit_cfg == 0)
	95	return -EINVAL;
	96	switch (wi_order) {
	97	case 0:
	98	ts_dev->bit_xp = bit_cfg;
	99	ts_dev->inp_xp = an_line;
	100	break;
	101
	102	case 1:
	103	ts_dev->bit_xn = bit_cfg;
	104	ts_dev->inp_xn = an_line;
	105	break;
	106
	107	case 2:
	108	ts_dev->bit_yp = bit_cfg;
	109	ts_dev->inp_yp = an_line;
	110	break;
	111	case 3:
	112	ts_dev->bit_yn = bit_cfg;
	113	ts_dev->inp_yn = an_line;
	114	break;
	115	}
	116	}
	117	return 0;
	118	}
	119
55c04de5	120	static void titsc_step_config(struct titsc *ts_dev)
1b8be32e RP	121	{
1b8be32e RP	122	unsigned int config;
8c896308 SAS	123	int i;
	124	int end_step;
	125	u32 stepenable;
1b8be32e RP	126
1b8be32e RP	127	config = STEPCONFIG_MODE_HWSYNC \|
bb76dc09	128	STEPCONFIG_AVG_16 \| ts_dev->bit_xp;
1b8be32e RP	129	switch (ts_dev->wires) {
1b8be32e RP	130	case 4:
bb76dc09	131	config \|= STEPCONFIG_INP(ts_dev->inp_yp) \| ts_dev->bit_xn;
1b8be32e RP	132	break;
1b8be32e RP	133	case 5:
bb76dc09 PR	134	config \|= ts_dev->bit_yn \|
	135	STEPCONFIG_INP_AN4 \| ts_dev->bit_xn \|
	136	ts_dev->bit_yp;
1b8be32e RP	137	break;
1b8be32e RP	138	case 8:
bb76dc09	139	config \|= STEPCONFIG_INP(ts_dev->inp_yp) \| ts_dev->bit_xn;
1b8be32e RP	140	break;
	141	}
	142
8c896308 SAS	143	/* 1 … coordinate_readouts is for X */
	144	end_step = ts_dev->coordinate_readouts;
	145	for (i = 0; i < end_step; i++) {
55c04de5 PR	146	titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
55c04de5 PR	147	titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
1b8be32e RP	148	}
	149
	150	config = 0;
	151	config = STEPCONFIG_MODE_HWSYNC \|
bb76dc09	152	STEPCONFIG_AVG_16 \| ts_dev->bit_yn \|
8c896308	153	STEPCONFIG_INM_ADCREFM;
1b8be32e RP	154	switch (ts_dev->wires) {
1b8be32e RP	155	case 4:
bb76dc09	156	config \|= ts_dev->bit_yp \| STEPCONFIG_INP(ts_dev->inp_xp);
1b8be32e RP	157	break;
1b8be32e RP	158	case 5:
bb76dc09 PR	159	config \|= ts_dev->bit_xp \| STEPCONFIG_INP_AN4 \|
bb76dc09 PR	160	ts_dev->bit_xn \| ts_dev->bit_yp;
1b8be32e RP	161	break;
1b8be32e RP	162	case 8:
bb76dc09	163	config \|= ts_dev->bit_yp \| STEPCONFIG_INP(ts_dev->inp_xp);
1b8be32e RP	164	break;
	165	}
	166
8c896308 SAS	167	/* coordinate_readouts … coordinate_readouts * 2 is for Y */
	168	end_step = ts_dev->coordinate_readouts * 2;
	169	for (i = ts_dev->coordinate_readouts; i < end_step; i++) {
55c04de5 PR	170	titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
55c04de5 PR	171	titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
1b8be32e RP	172	}
1b8be32e RP	173
1b8be32e	174	/* Charge step configuration */
bb76dc09	175	config = ts_dev->bit_xp \| ts_dev->bit_yn \|
33f5cc60	176	STEPCHARGE_RFP_XPUL \| STEPCHARGE_RFM_XNUR \|
bb76dc09	177	STEPCHARGE_INM_AN1 \| STEPCHARGE_INP(ts_dev->inp_yp);
1b8be32e	178
55c04de5 PR	179	titsc_writel(ts_dev, REG_CHARGECONFIG, config);
55c04de5 PR	180	titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);
1b8be32e	181
8c896308	182	/* coordinate_readouts * 2 … coordinate_readouts * 2 + 2 is for Z */
1b8be32e	183	config = STEPCONFIG_MODE_HWSYNC \|
bb76dc09 PR	184	STEPCONFIG_AVG_16 \| ts_dev->bit_yp \|
	185	ts_dev->bit_xn \| STEPCONFIG_INM_ADCREFM \|
	186	STEPCONFIG_INP(ts_dev->inp_xp);
8c896308 SAS	187	titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
8c896308 SAS	188	titsc_writel(ts_dev, REG_STEPDELAY(end_step),
d1fb5743	189	STEPCONFIG_OPENDLY);
1b8be32e	190
8c896308 SAS	191	end_step++;
	192	config \|= STEPCONFIG_INP(ts_dev->inp_yn);
	193	titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
	194	titsc_writel(ts_dev, REG_STEPDELAY(end_step),
d1fb5743	195	STEPCONFIG_OPENDLY);
1b8be32e	196
abeccee4	197	/* The steps1 … end and bit 0 for TS_Charge */
8c896308	198	stepenable = (1 << (end_step + 2)) - 1;
baee5399	199	ts_dev->step_mask = stepenable;
7e170c6e	200	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
1b8be32e RP	201	}
1b8be32e RP	202
55c04de5	203	static void titsc_read_coordinates(struct titsc *ts_dev,
8c896308	204	u32 x, u32 y, u32 z1, u32 z2)
1b8be32e	205	{
55c04de5	206	unsigned int fifocount = titsc_readl(ts_dev, REG_FIFO0CNT);
1b8be32e RP	207	unsigned int prev_val_x = ~0, prev_val_y = ~0;
	208	unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
	209	unsigned int read, diff;
2b99bafa	210	unsigned int i, channel;
8c896308	211	unsigned int creads = ts_dev->coordinate_readouts;
1b8be32e	212
8c896308 SAS	213	z1 = z2 = 0;
	214	if (fifocount % (creads * 2 + 2))
	215	fifocount -= fifocount % (creads * 2 + 2);
1b8be32e RP	216	/*
	217	* Delta filter is used to remove large variations in sampled
	218	* values from ADC. The filter tries to predict where the next
	219	* coordinate could be. This is done by taking a previous
	220	* coordinate and subtracting it form current one. Further the
	221	* algorithm compares the difference with that of a present value,
	222	* if true the value is reported to the sub system.
	223	*/
8c896308	224	for (i = 0; i < fifocount; i++) {
2b99bafa	225	read = titsc_readl(ts_dev, REG_FIFO0);
8c896308 SAS	226
	227	channel = (read & 0xf0000) >> 16;
	228	read &= 0xfff;
	229	if (channel < creads) {
2b99bafa PR	230	diff = abs(read - prev_val_x);
	231	if (diff < prev_diff_x) {
	232	prev_diff_x = diff;
	233	*x = read;
	234	}
	235	prev_val_x = read;
1b8be32e	236
8c896308	237	} else if (channel < creads * 2) {
2b99bafa PR	238	diff = abs(read - prev_val_y);
	239	if (diff < prev_diff_y) {
	240	prev_diff_y = diff;
	241	*y = read;
	242	}
	243	prev_val_y = read;
8c896308 SAS	244
	245	} else if (channel < creads * 2 + 1) {
	246	*z1 = read;
	247
	248	} else if (channel < creads * 2 + 2) {
	249	*z2 = read;
1b8be32e	250	}
1b8be32e RP	251	}
	252	}
	253
55c04de5	254	static irqreturn_t titsc_irq(int irq, void *dev)
1b8be32e	255	{
55c04de5	256	struct titsc *ts_dev = dev;
1b8be32e RP	257	struct input_dev *input_dev = ts_dev->input;
	258	unsigned int status, irqclr = 0;
	259	unsigned int x = 0, y = 0;
	260	unsigned int z1, z2, z;
	261	unsigned int fsm;
	262
55c04de5	263	status = titsc_readl(ts_dev, REG_IRQSTATUS);
baee5399 ZL	264	/*
	265	* ADC and touchscreen share the IRQ line.
	266	* FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
	267	*/
30af55f9	268	if (status & IRQENB_FIFO0THRES) {
1b8be32e	269
8c896308	270	titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
2b99bafa	271
1b8be32e RP	272	if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
	273	/*
	274	* Calculate pressure using formula
	275	* Resistance(touch) = x plate resistance *
	276	* x postion/4096 * ((z2 / z1) - 1)
	277	*/
8c896308	278	z = z1 - z2;
1b8be32e RP	279	z *= x;
1b8be32e RP	280	z *= ts_dev->x_plate_resistance;
8c896308	281	z /= z2;
1b8be32e RP	282	z = (z + 2047) >> 12;
	283
	284	if (z <= MAX_12BIT) {
	285	input_report_abs(input_dev, ABS_X, x);
	286	input_report_abs(input_dev, ABS_Y, y);
	287	input_report_abs(input_dev, ABS_PRESSURE, z);
	288	input_report_key(input_dev, BTN_TOUCH, 1);
	289	input_sync(input_dev);
	290	}
	291	}
30af55f9	292	irqclr \|= IRQENB_FIFO0THRES;
1b8be32e RP	293	}
	294
	295	/*
	296	* Time for sequencer to settle, to read
	297	* correct state of the sequencer.
	298	*/
	299	udelay(SEQ_SETTLE);
	300
55c04de5	301	status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
1b8be32e RP	302	if (status & IRQENB_PENUP) {
1b8be32e RP	303	/* Pen up event */
55c04de5	304	fsm = titsc_readl(ts_dev, REG_ADCFSM);
1b8be32e RP	305	if (fsm == ADCFSM_STEPID) {
	306	ts_dev->pen_down = false;
	307	input_report_key(input_dev, BTN_TOUCH, 0);
	308	input_report_abs(input_dev, ABS_PRESSURE, 0);
	309	input_sync(input_dev);
	310	} else {
	311	ts_dev->pen_down = true;
	312	}
	313	irqclr \|= IRQENB_PENUP;
	314	}
	315
00789e5d SAS	316	if (status & IRQENB_HW_PEN) {
	317
	318	titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
	319	titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
	320	}
1b8be32e	321
9a28b883 SAS	322	if (irqclr) {
9a28b883 SAS	323	titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
7e170c6e	324	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
9a28b883 SAS	325	return IRQ_HANDLED;
	326	}
	327	return IRQ_NONE;
1b8be32e RP	328	}
1b8be32e RP	329
0396310b PR	330	static int titsc_parse_dt(struct platform_device *pdev,
	331	struct titsc *ts_dev)
	332	{
	333	struct device_node *node = pdev->dev.of_node;
	334	int err;
	335
	336	if (!node)
	337	return -EINVAL;
	338
	339	err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
	340	if (err < 0)
	341	return err;
	342	switch (ts_dev->wires) {
	343	case 4:
	344	case 5:
	345	case 8:
	346	break;
	347	default:
	348	return -EINVAL;
	349	}
	350
	351	err = of_property_read_u32(node, "ti,x-plate-resistance",
	352	&ts_dev->x_plate_resistance);
	353	if (err < 0)
	354	return err;
	355
c9aeb249 FB	356	/*
	357	* Try with the new binding first. If it fails, try again with
	358	* bogus, miss-spelled version.
	359	*/
	360	err = of_property_read_u32(node, "ti,coordinate-readouts",
0396310b	361	&ts_dev->coordinate_readouts);
31972f6e FB	362	if (err < 0) {
31972f6e FB	363	dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
c9aeb249 FB	364	err = of_property_read_u32(node, "ti,coordiante-readouts",
c9aeb249 FB	365	&ts_dev->coordinate_readouts);
31972f6e FB	366	}
31972f6e FB	367
0396310b PR	368	if (err < 0)
	369	return err;
	370
	371	return of_property_read_u32_array(node, "ti,wire-config",
	372	ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
1b8be32e RP	373	}
	374
	375	/*
	376	* The functions for inserting/removing driver as a module.
	377	*/
	378
31564cbd	379	static int titsc_probe(struct platform_device *pdev)
1b8be32e	380	{
55c04de5	381	struct titsc *ts_dev;
1b8be32e	382	struct input_dev *input_dev;
a9bce1b0	383	struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
1b8be32e	384	int err;
1b8be32e	385
1b8be32e	386	/* Allocate memory for device */
55c04de5	387	ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);
1b8be32e RP	388	input_dev = input_allocate_device();
	389	if (!ts_dev \|\| !input_dev) {
	390	dev_err(&pdev->dev, "failed to allocate memory.\n");
	391	err = -ENOMEM;
	392	goto err_free_mem;
	393	}
	394
2b99bafa PR	395	tscadc_dev->tsc = ts_dev;
2b99bafa PR	396	ts_dev->mfd_tscadc = tscadc_dev;
1b8be32e	397	ts_dev->input = input_dev;
2b99bafa	398	ts_dev->irq = tscadc_dev->irq;
0396310b	399
b9194fdf	400	err = titsc_parse_dt(pdev, ts_dev);
0396310b PR	401	if (err) {
	402	dev_err(&pdev->dev, "Could not find valid DT data.\n");
	403	goto err_free_mem;
	404	}
1b8be32e	405
55c04de5	406	err = request_irq(ts_dev->irq, titsc_irq,
baee5399	407	IRQF_SHARED, pdev->dev.driver->name, ts_dev);
1b8be32e RP	408	if (err) {
1b8be32e RP	409	dev_err(&pdev->dev, "failed to allocate irq.\n");
2b99bafa	410	goto err_free_mem;
1b8be32e	411	}
1b8be32e	412
55c04de5	413	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
bb76dc09 PR	414	err = titsc_config_wires(ts_dev);
	415	if (err) {
	416	dev_err(&pdev->dev, "wrong i/p wire configuration\n");
	417	goto err_free_irq;
	418	}
55c04de5	419	titsc_step_config(ts_dev);
8c896308 SAS	420	titsc_writel(ts_dev, REG_FIFO0THR,
8c896308 SAS	421	ts_dev->coordinate_readouts * 2 + 2 - 1);
1b8be32e	422
2b99bafa	423	input_dev->name = "ti-tsc";
1b8be32e RP	424	input_dev->dev.parent = &pdev->dev;
	425
	426	input_dev->evbit[0] = BIT_MASK(EV_KEY) \| BIT_MASK(EV_ABS);
	427	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
	428
	429	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
	430	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
	431	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
	432
	433	/* register to the input system */
	434	err = input_register_device(input_dev);
	435	if (err)
2b99bafa	436	goto err_free_irq;
1b8be32e RP	437
	438	platform_set_drvdata(pdev, ts_dev);
	439	return 0;
	440
1b8be32e RP	441	err_free_irq:
1b8be32e RP	442	free_irq(ts_dev->irq, ts_dev);
1b8be32e RP	443	err_free_mem:
	444	input_free_device(input_dev);
	445	kfree(ts_dev);
	446	return err;
	447	}
	448
31564cbd	449	static int titsc_remove(struct platform_device *pdev)
1b8be32e	450	{
a9bce1b0 SAS	451	struct titsc *ts_dev = platform_get_drvdata(pdev);
a9bce1b0 SAS	452	u32 steps;
1b8be32e RP	453
	454	free_irq(ts_dev->irq, ts_dev);
	455
abeccee4	456	/* total steps followed by the enable mask */
0396310b	457	steps = 2 * ts_dev->coordinate_readouts + 2;
abeccee4 PR	458	steps = (1 << steps) - 1;
	459	am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
	460
1b8be32e RP	461	input_unregister_device(ts_dev->input);
1b8be32e RP	462
2b99bafa PR	463	kfree(ts_dev);
	464	return 0;
	465	}
1b8be32e	466
2b99bafa PR	467	#ifdef CONFIG_PM
	468	static int titsc_suspend(struct device *dev)
	469	{
a9bce1b0 SAS	470	struct titsc *ts_dev = dev_get_drvdata(dev);
a9bce1b0 SAS	471	struct ti_tscadc_dev *tscadc_dev;
2b99bafa PR	472	unsigned int idle;
2b99bafa PR	473
a9bce1b0	474	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
2b99bafa PR	475	if (device_may_wakeup(tscadc_dev->dev)) {
	476	idle = titsc_readl(ts_dev, REG_IRQENABLE);
	477	titsc_writel(ts_dev, REG_IRQENABLE,
	478	(idle \| IRQENB_HW_PEN));
	479	titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
	480	}
	481	return 0;
	482	}
1b8be32e	483
2b99bafa PR	484	static int titsc_resume(struct device *dev)
2b99bafa PR	485	{
a9bce1b0 SAS	486	struct titsc *ts_dev = dev_get_drvdata(dev);
a9bce1b0 SAS	487	struct ti_tscadc_dev *tscadc_dev;
1b8be32e	488
a9bce1b0	489	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
2b99bafa PR	490	if (device_may_wakeup(tscadc_dev->dev)) {
	491	titsc_writel(ts_dev, REG_IRQWAKEUP,
	492	0x00);
	493	titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
	494	}
	495	titsc_step_config(ts_dev);
	496	titsc_writel(ts_dev, REG_FIFO0THR,
8c896308	497	ts_dev->coordinate_readouts * 2 + 2 - 1);
1b8be32e RP	498	return 0;
	499	}
	500
2b99bafa PR	501	static const struct dev_pm_ops titsc_pm_ops = {
	502	.suspend = titsc_suspend,
	503	.resume = titsc_resume,
	504	};
	505	#define TITSC_PM_OPS (&titsc_pm_ops)
	506	#else
	507	#define TITSC_PM_OPS NULL
	508	#endif
	509
0396310b PR	510	static const struct of_device_id ti_tsc_dt_ids[] = {
	511	{ .compatible = "ti,am3359-tsc", },
	512	{ }
	513	};
	514	MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
	515
1b8be32e	516	static struct platform_driver ti_tsc_driver = {
55c04de5	517	.probe = titsc_probe,
31564cbd	518	.remove = titsc_remove,
1b8be32e	519	.driver = {
5f184e63	520	.name = "TI-am335x-tsc",
2b99bafa	521	.pm = TITSC_PM_OPS,
8e6146bf	522	.of_match_table = ti_tsc_dt_ids,
1b8be32e RP	523	},
	524	};
	525	module_platform_driver(ti_tsc_driver);
	526
	527	MODULE_DESCRIPTION("TI touchscreen controller driver");
	528	MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
	529	MODULE_LICENSE("GPL");