summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/w90p910_ts.c
blob: 003d0c3b5d08f091a32f97e401e83b59550de9a6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
/*
 * Copyright (c) 2008 Nuvoton technology corporation.
 *
 * Wan ZongShun <mcuos.com@gmail.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 of the License.
 *
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

/* ADC controller bit defines */
#define ADC_DELAY	0xf00
#define ADC_DOWN	0x01
#define ADC_TSC_Y	(0x01 << 8)
#define ADC_TSC_X	(0x00 << 8)
#define TSC_FOURWIRE	(~(0x03 << 1))
#define ADC_CLK_EN	(0x01 << 28)	/* ADC clock enable */
#define ADC_READ_CON	(0x01 << 12)
#define ADC_CONV	(0x01 << 13)
#define ADC_SEMIAUTO	(0x01 << 14)
#define ADC_WAITTRIG	(0x03 << 14)
#define ADC_RST1	(0x01 << 16)
#define ADC_RST0	(0x00 << 16)
#define ADC_EN		(0x01 << 17)
#define ADC_INT		(0x01 << 18)
#define WT_INT		(0x01 << 20)
#define ADC_INT_EN	(0x01 << 21)
#define LVD_INT_EN	(0x01 << 22)
#define WT_INT_EN	(0x01 << 23)
#define ADC_DIV		(0x04 << 1)	/* div = 6 */

enum ts_state {
	TS_WAIT_NEW_PACKET,	/* We are waiting next touch report */
	TS_WAIT_X_COORD,	/* We are waiting for ADC to report X coord */
	TS_WAIT_Y_COORD,	/* We are waiting for ADC to report Y coord */
	TS_IDLE,		/* Input device is closed, don't do anything */
};

struct w90p910_ts {
	struct input_dev *input;
	struct timer_list timer;
	struct clk *clk;
	int irq_num;
	void __iomem *ts_reg;
	spinlock_t lock;
	enum ts_state state;
};

static void w90p910_report_event(struct w90p910_ts *w90p910_ts, bool down)
{
	struct input_dev *dev = w90p910_ts->input;

	if (down) {
		input_report_abs(dev, ABS_X,
				 __raw_readl(w90p910_ts->ts_reg + 0x0c));
		input_report_abs(dev, ABS_Y,
				 __raw_readl(w90p910_ts->ts_reg + 0x10));
	}

	input_report_key(dev, BTN_TOUCH, down);
	input_sync(dev);
}

static void w90p910_prepare_x_reading(struct w90p910_ts *w90p910_ts)
{
	unsigned long ctlreg;

	__raw_writel(ADC_TSC_X, w90p910_ts->ts_reg + 0x04);
	ctlreg = __raw_readl(w90p910_ts->ts_reg);
	ctlreg &= ~(ADC_WAITTRIG | WT_INT | WT_INT_EN);
	ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
	__raw_writel(ctlreg, w90p910_ts->ts_reg);

	w90p910_ts->state = TS_WAIT_X_COORD;
}

static void w90p910_prepare_y_reading(struct w90p910_ts *w90p910_ts)
{
	unsigned long ctlreg;

	__raw_writel(ADC_TSC_Y, w90p910_ts->ts_reg + 0x04);
	ctlreg = __raw_readl(w90p910_ts->ts_reg);
	ctlreg &= ~(ADC_WAITTRIG | ADC_INT | WT_INT_EN);
	ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
	__raw_writel(ctlreg, w90p910_ts->ts_reg);

	w90p910_ts->state = TS_WAIT_Y_COORD;
}

static void w90p910_prepare_next_packet(struct w90p910_ts *w90p910_ts)
{
	unsigned long ctlreg;

	ctlreg = __raw_readl(w90p910_ts->ts_reg);
	ctlreg &= ~(ADC_INT | ADC_INT_EN | ADC_SEMIAUTO | ADC_CONV);
	ctlreg |= ADC_WAITTRIG | WT_INT_EN;
	__raw_writel(ctlreg, w90p910_ts->ts_reg);

	w90p910_ts->state = TS_WAIT_NEW_PACKET;
}

static irqreturn_t w90p910_ts_interrupt(int irq, void *dev_id)
{
	struct w90p910_ts *w90p910_ts = dev_id;
	unsigned long flags;

	spin_lock_irqsave(&w90p910_ts->lock, flags);

	switch (w90p910_ts->state) {
	case TS_WAIT_NEW_PACKET:
		/*
		 * The controller only generates interrupts when pen
		 * is down.
		 */
		del_timer(&w90p910_ts->timer);
		w90p910_prepare_x_reading(w90p910_ts);
		break;


	case TS_WAIT_X_COORD:
		w90p910_prepare_y_reading(w90p910_ts);
		break;

	case TS_WAIT_Y_COORD:
		w90p910_report_event(w90p910_ts, true);
		w90p910_prepare_next_packet(w90p910_ts);
		mod_timer(&w90p910_ts->timer, jiffies + msecs_to_jiffies(100));
		break;

	case TS_IDLE:
		break;
	}

	spin_unlock_irqrestore(&w90p910_ts->lock, flags);

	return IRQ_HANDLED;
}

static void w90p910_check_pen_up(unsigned long data)
{
	struct w90p910_ts *w90p910_ts = (struct w90p910_ts *) data;
	unsigned long flags;

	spin_lock_irqsave(&w90p910_ts->lock, flags);

	if (w90p910_ts->state == TS_WAIT_NEW_PACKET &&
	    !(__raw_readl(w90p910_ts->ts_reg + 0x04) & ADC_DOWN)) {

		w90p910_report_event(w90p910_ts, false);
	}

	spin_unlock_irqrestore(&w90p910_ts->lock, flags);
}

static int w90p910_open(struct input_dev *dev)
{
	struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
	unsigned long val;

	/* enable the ADC clock */
	clk_enable(w90p910_ts->clk);

	__raw_writel(ADC_RST1, w90p910_ts->ts_reg);
	msleep(1);
	__raw_writel(ADC_RST0, w90p910_ts->ts_reg);
	msleep(1);

	/* set delay and screen type */
	val = __raw_readl(w90p910_ts->ts_reg + 0x04);
	__raw_writel(val & TSC_FOURWIRE, w90p910_ts->ts_reg + 0x04);
	__raw_writel(ADC_DELAY, w90p910_ts->ts_reg + 0x08);

	w90p910_ts->state = TS_WAIT_NEW_PACKET;
	wmb();

	/* set trigger mode */
	val = __raw_readl(w90p910_ts->ts_reg);
	val |= ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN;
	__raw_writel(val, w90p910_ts->ts_reg);

	return 0;
}

static void w90p910_close(struct input_dev *dev)
{
	struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
	unsigned long val;

	/* disable trigger mode */

	spin_lock_irq(&w90p910_ts->lock);

	w90p910_ts->state = TS_IDLE;

	val = __raw_readl(w90p910_ts->ts_reg);
	val &= ~(ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN | ADC_INT_EN);
	__raw_writel(val, w90p910_ts->ts_reg);

	spin_unlock_irq(&w90p910_ts->lock);

	/* Now that interrupts are shut off we can safely delete timer */
	del_timer_sync(&w90p910_ts->timer);

	/* stop the ADC clock */
	clk_disable(w90p910_ts->clk);
}

static int w90x900ts_probe(struct platform_device *pdev)
{
	struct w90p910_ts *w90p910_ts;
	struct input_dev *input_dev;
	struct resource *res;
	int err;

	w90p910_ts = kzalloc(sizeof(struct w90p910_ts), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!w90p910_ts || !input_dev) {
		err = -ENOMEM;
		goto fail1;
	}

	w90p910_ts->input = input_dev;
	w90p910_ts->state = TS_IDLE;
	spin_lock_init(&w90p910_ts->lock);
	setup_timer(&w90p910_ts->timer, w90p910_check_pen_up,
		    (unsigned long)w90p910_ts);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		err = -ENXIO;
		goto fail1;
	}

	if (!request_mem_region(res->start, resource_size(res),
				pdev->name)) {
		err = -EBUSY;
		goto fail1;
	}

	w90p910_ts->ts_reg = ioremap(res->start, resource_size(res));
	if (!w90p910_ts->ts_reg) {
		err = -ENOMEM;
		goto fail2;
	}

	w90p910_ts->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(w90p910_ts->clk)) {
		err = PTR_ERR(w90p910_ts->clk);
		goto fail3;
	}

	input_dev->name = "W90P910 TouchScreen";
	input_dev->phys = "w90p910ts/event0";
	input_dev->id.bustype = BUS_HOST;
	input_dev->id.vendor  = 0x0005;
	input_dev->id.product = 0x0001;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &pdev->dev;
	input_dev->open = w90p910_open;
	input_dev->close = w90p910_close;

	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, 0x400, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, 0x400, 0, 0);

	input_set_drvdata(input_dev, w90p910_ts);

	w90p910_ts->irq_num = platform_get_irq(pdev, 0);
	if (request_irq(w90p910_ts->irq_num, w90p910_ts_interrupt,
			0, "w90p910ts", w90p910_ts)) {
		err = -EBUSY;
		goto fail4;
	}

	err = input_register_device(w90p910_ts->input);
	if (err)
		goto fail5;

	platform_set_drvdata(pdev, w90p910_ts);

	return 0;

fail5:	free_irq(w90p910_ts->irq_num, w90p910_ts);
fail4:	clk_put(w90p910_ts->clk);
fail3:	iounmap(w90p910_ts->ts_reg);
fail2:	release_mem_region(res->start, resource_size(res));
fail1:	input_free_device(input_dev);
	kfree(w90p910_ts);
	return err;
}

static int w90x900ts_remove(struct platform_device *pdev)
{
	struct w90p910_ts *w90p910_ts = platform_get_drvdata(pdev);
	struct resource *res;

	free_irq(w90p910_ts->irq_num, w90p910_ts);
	del_timer_sync(&w90p910_ts->timer);
	iounmap(w90p910_ts->ts_reg);

	clk_put(w90p910_ts->clk);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(res->start, resource_size(res));

	input_unregister_device(w90p910_ts->input);
	kfree(w90p910_ts);

	return 0;
}

static struct platform_driver w90x900ts_driver = {
	.probe		= w90x900ts_probe,
	.remove		= w90x900ts_remove,
	.driver		= {
		.name	= "nuc900-ts",
		.owner	= THIS_MODULE,
	},
};
module_platform_driver(w90x900ts_driver);

MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
MODULE_DESCRIPTION("w90p910 touch screen driver!");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:nuc900-ts");