summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/s3c2410_ts.c
blob: 82920ff46f72fc66decdcb790a12c3c17d31771c (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
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Samsung S3C24XX touchscreen driver
 *
 * Copyright 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
 * Copyright 2008 Ben Dooks <ben-linux@fluff.org>
 * Copyright 2009 Simtec Electronics <linux@simtec.co.uk>
 *
 * Additional work by Herbert Pötzl <herbert@13thfloor.at> and
 * Harald Welte <laforge@openmoko.org>
 */

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

#include <plat/adc.h>
#include <plat/regs-adc.h>
#include <linux/platform_data/touchscreen-s3c2410.h>

#define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))

#define INT_DOWN	(0)
#define INT_UP		(1 << 8)

#define WAIT4INT	(S3C2410_ADCTSC_YM_SEN | \
			 S3C2410_ADCTSC_YP_SEN | \
			 S3C2410_ADCTSC_XP_SEN | \
			 S3C2410_ADCTSC_XY_PST(3))

#define AUTOPST		(S3C2410_ADCTSC_YM_SEN | \
			 S3C2410_ADCTSC_YP_SEN | \
			 S3C2410_ADCTSC_XP_SEN | \
			 S3C2410_ADCTSC_AUTO_PST | \
			 S3C2410_ADCTSC_XY_PST(0))

#define FEAT_PEN_IRQ	(1 << 0)	/* HAS ADCCLRINTPNDNUP */

/* Per-touchscreen data. */

/**
 * struct s3c2410ts - driver touchscreen state.
 * @client: The ADC client we registered with the core driver.
 * @dev: The device we are bound to.
 * @input: The input device we registered with the input subsystem.
 * @clock: The clock for the adc.
 * @io: Pointer to the IO base.
 * @xp: The accumulated X position data.
 * @yp: The accumulated Y position data.
 * @irq_tc: The interrupt number for pen up/down interrupt
 * @count: The number of samples collected.
 * @shift: The log2 of the maximum count to read in one go.
 * @features: The features supported by the TSADC MOdule.
 */
struct s3c2410ts {
	struct s3c_adc_client *client;
	struct device *dev;
	struct input_dev *input;
	struct clk *clock;
	void __iomem *io;
	unsigned long xp;
	unsigned long yp;
	int irq_tc;
	int count;
	int shift;
	int features;
};

static struct s3c2410ts ts;

/**
 * get_down - return the down state of the pen
 * @data0: The data read from ADCDAT0 register.
 * @data1: The data read from ADCDAT1 register.
 *
 * Return non-zero if both readings show that the pen is down.
 */
static inline bool get_down(unsigned long data0, unsigned long data1)
{
	/* returns true if both data values show stylus down */
	return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
		!(data1 & S3C2410_ADCDAT0_UPDOWN));
}

static void touch_timer_fire(struct timer_list *unused)
{
	unsigned long data0;
	unsigned long data1;
	bool down;

	data0 = readl(ts.io + S3C2410_ADCDAT0);
	data1 = readl(ts.io + S3C2410_ADCDAT1);

	down = get_down(data0, data1);

	if (down) {
		if (ts.count == (1 << ts.shift)) {
			ts.xp >>= ts.shift;
			ts.yp >>= ts.shift;

			dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
				__func__, ts.xp, ts.yp, ts.count);

			input_report_abs(ts.input, ABS_X, ts.xp);
			input_report_abs(ts.input, ABS_Y, ts.yp);

			input_report_key(ts.input, BTN_TOUCH, 1);
			input_sync(ts.input);

			ts.xp = 0;
			ts.yp = 0;
			ts.count = 0;
		}

		s3c_adc_start(ts.client, 0, 1 << ts.shift);
	} else {
		ts.xp = 0;
		ts.yp = 0;
		ts.count = 0;

		input_report_key(ts.input, BTN_TOUCH, 0);
		input_sync(ts.input);

		writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
	}
}

static DEFINE_TIMER(touch_timer, touch_timer_fire);

/**
 * stylus_irq - touchscreen stylus event interrupt
 * @irq: The interrupt number
 * @dev_id: The device ID.
 *
 * Called when the IRQ_TC is fired for a pen up or down event.
 */
static irqreturn_t stylus_irq(int irq, void *dev_id)
{
	unsigned long data0;
	unsigned long data1;
	bool down;

	data0 = readl(ts.io + S3C2410_ADCDAT0);
	data1 = readl(ts.io + S3C2410_ADCDAT1);

	down = get_down(data0, data1);

	/* TODO we should never get an interrupt with down set while
	 * the timer is running, but maybe we ought to verify that the
	 * timer isn't running anyways. */

	if (down)
		s3c_adc_start(ts.client, 0, 1 << ts.shift);
	else
		dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);

	if (ts.features & FEAT_PEN_IRQ) {
		/* Clear pen down/up interrupt */
		writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
	}

	return IRQ_HANDLED;
}

/**
 * s3c24xx_ts_conversion - ADC conversion callback
 * @client: The client that was registered with the ADC core.
 * @data0: The reading from ADCDAT0.
 * @data1: The reading from ADCDAT1.
 * @left: The number of samples left.
 *
 * Called when a conversion has finished.
 */
static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
				  unsigned data0, unsigned data1,
				  unsigned *left)
{
	dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);

	ts.xp += data0;
	ts.yp += data1;

	ts.count++;

	/* From tests, it seems that it is unlikely to get a pen-up
	 * event during the conversion process which means we can
	 * ignore any pen-up events with less than the requisite
	 * count done.
	 *
	 * In several thousand conversions, no pen-ups where detected
	 * before count completed.
	 */
}

/**
 * s3c24xx_ts_select - ADC selection callback.
 * @client: The client that was registered with the ADC core.
 * @select: The reason for select.
 *
 * Called when the ADC core selects (or deslects) us as a client.
 */
static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
{
	if (select) {
		writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
		       ts.io + S3C2410_ADCTSC);
	} else {
		mod_timer(&touch_timer, jiffies+1);
		writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
	}
}

/**
 * s3c2410ts_probe - device core probe entry point
 * @pdev: The device we are being bound to.
 *
 * Initialise, find and allocate any resources we need to run and then
 * register with the ADC and input systems.
 */
static int s3c2410ts_probe(struct platform_device *pdev)
{
	struct s3c2410_ts_mach_info *info;
	struct device *dev = &pdev->dev;
	struct input_dev *input_dev;
	struct resource *res;
	int ret = -EINVAL;

	/* Initialise input stuff */
	memset(&ts, 0, sizeof(struct s3c2410ts));

	ts.dev = dev;

	info = dev_get_platdata(dev);
	if (!info) {
		dev_err(dev, "no platform data, cannot attach\n");
		return -EINVAL;
	}

	dev_dbg(dev, "initialising touchscreen\n");

	ts.clock = clk_get(dev, "adc");
	if (IS_ERR(ts.clock)) {
		dev_err(dev, "cannot get adc clock source\n");
		return -ENOENT;
	}

	ret = clk_prepare_enable(ts.clock);
	if (ret) {
		dev_err(dev, "Failed! to enabled clocks\n");
		goto err_clk_get;
	}
	dev_dbg(dev, "got and enabled clocks\n");

	ts.irq_tc = ret = platform_get_irq(pdev, 0);
	if (ret < 0) {
		dev_err(dev, "no resource for interrupt\n");
		goto err_clk;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(dev, "no resource for registers\n");
		ret = -ENOENT;
		goto err_clk;
	}

	ts.io = ioremap(res->start, resource_size(res));
	if (ts.io == NULL) {
		dev_err(dev, "cannot map registers\n");
		ret = -ENOMEM;
		goto err_clk;
	}

	/* inititalise the gpio */
	if (info->cfg_gpio)
		info->cfg_gpio(to_platform_device(ts.dev));

	ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
				     s3c24xx_ts_conversion, 1);
	if (IS_ERR(ts.client)) {
		dev_err(dev, "failed to register adc client\n");
		ret = PTR_ERR(ts.client);
		goto err_iomap;
	}

	/* Initialise registers */
	if ((info->delay & 0xffff) > 0)
		writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);

	writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);

	input_dev = input_allocate_device();
	if (!input_dev) {
		dev_err(dev, "Unable to allocate the input device !!\n");
		ret = -ENOMEM;
		goto err_iomap;
	}

	ts.input = input_dev;
	ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
	input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
	input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);

	ts.input->name = "S3C24XX TouchScreen";
	ts.input->id.bustype = BUS_HOST;
	ts.input->id.vendor = 0xDEAD;
	ts.input->id.product = 0xBEEF;
	ts.input->id.version = 0x0102;

	ts.shift = info->oversampling_shift;
	ts.features = platform_get_device_id(pdev)->driver_data;

	ret = request_irq(ts.irq_tc, stylus_irq, 0,
			  "s3c2410_ts_pen", ts.input);
	if (ret) {
		dev_err(dev, "cannot get TC interrupt\n");
		goto err_inputdev;
	}

	dev_info(dev, "driver attached, registering input device\n");

	/* All went ok, so register to the input system */
	ret = input_register_device(ts.input);
	if (ret < 0) {
		dev_err(dev, "failed to register input device\n");
		ret = -EIO;
		goto err_tcirq;
	}

	return 0;

 err_tcirq:
	free_irq(ts.irq_tc, ts.input);
 err_inputdev:
	input_free_device(ts.input);
 err_iomap:
	iounmap(ts.io);
 err_clk:
	clk_disable_unprepare(ts.clock);
	del_timer_sync(&touch_timer);
 err_clk_get:
	clk_put(ts.clock);
	return ret;
}

/**
 * s3c2410ts_remove - device core removal entry point
 * @pdev: The device we are being removed from.
 *
 * Free up our state ready to be removed.
 */
static int s3c2410ts_remove(struct platform_device *pdev)
{
	free_irq(ts.irq_tc, ts.input);
	del_timer_sync(&touch_timer);

	clk_disable_unprepare(ts.clock);
	clk_put(ts.clock);

	input_unregister_device(ts.input);
	iounmap(ts.io);

	return 0;
}

#ifdef CONFIG_PM
static int s3c2410ts_suspend(struct device *dev)
{
	writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
	disable_irq(ts.irq_tc);
	clk_disable(ts.clock);

	return 0;
}

static int s3c2410ts_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct s3c2410_ts_mach_info *info = dev_get_platdata(&pdev->dev);

	clk_enable(ts.clock);
	enable_irq(ts.irq_tc);

	/* Initialise registers */
	if ((info->delay & 0xffff) > 0)
		writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);

	writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);

	return 0;
}

static const struct dev_pm_ops s3c_ts_pmops = {
	.suspend	= s3c2410ts_suspend,
	.resume		= s3c2410ts_resume,
};
#endif

static const struct platform_device_id s3cts_driver_ids[] = {
	{ "s3c2410-ts", 0 },
	{ "s3c2440-ts", 0 },
	{ "s3c64xx-ts", FEAT_PEN_IRQ },
	{ }
};
MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);

static struct platform_driver s3c_ts_driver = {
	.driver         = {
		.name   = "samsung-ts",
#ifdef CONFIG_PM
		.pm	= &s3c_ts_pmops,
#endif
	},
	.id_table	= s3cts_driver_ids,
	.probe		= s3c2410ts_probe,
	.remove		= s3c2410ts_remove,
};
module_platform_driver(s3c_ts_driver);

MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
	      "Ben Dooks <ben@simtec.co.uk>, "
	      "Simtec Electronics <linux@simtec.co.uk>");
MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
MODULE_LICENSE("GPL v2");