summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/wm831x-ts.c
blob: 607d1aeb595d7fcf765725bd20508bf56529aad0 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Touchscreen driver for WM831x PMICs
 *
 * Copyright 2011 Wolfson Microelectronics plc.
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/irq.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>

/*
 * R16424 (0x4028) - Touch Control 1
 */
#define WM831X_TCH_ENA                          0x8000  /* TCH_ENA */
#define WM831X_TCH_CVT_ENA                      0x4000  /* TCH_CVT_ENA */
#define WM831X_TCH_SLPENA                       0x1000  /* TCH_SLPENA */
#define WM831X_TCH_Z_ENA                        0x0400  /* TCH_Z_ENA */
#define WM831X_TCH_Y_ENA                        0x0200  /* TCH_Y_ENA */
#define WM831X_TCH_X_ENA                        0x0100  /* TCH_X_ENA */
#define WM831X_TCH_DELAY_MASK                   0x00E0  /* TCH_DELAY - [7:5] */
#define WM831X_TCH_DELAY_SHIFT                       5  /* TCH_DELAY - [7:5] */
#define WM831X_TCH_DELAY_WIDTH                       3  /* TCH_DELAY - [7:5] */
#define WM831X_TCH_RATE_MASK                    0x001F  /* TCH_RATE - [4:0] */
#define WM831X_TCH_RATE_SHIFT                        0  /* TCH_RATE - [4:0] */
#define WM831X_TCH_RATE_WIDTH                        5  /* TCH_RATE - [4:0] */

/*
 * R16425 (0x4029) - Touch Control 2
 */
#define WM831X_TCH_PD_WK                        0x2000  /* TCH_PD_WK */
#define WM831X_TCH_5WIRE                        0x1000  /* TCH_5WIRE */
#define WM831X_TCH_PDONLY                       0x0800  /* TCH_PDONLY */
#define WM831X_TCH_ISEL                         0x0100  /* TCH_ISEL */
#define WM831X_TCH_RPU_MASK                     0x000F  /* TCH_RPU - [3:0] */
#define WM831X_TCH_RPU_SHIFT                         0  /* TCH_RPU - [3:0] */
#define WM831X_TCH_RPU_WIDTH                         4  /* TCH_RPU - [3:0] */

/*
 * R16426-8 (0x402A-C) - Touch Data X/Y/X
 */
#define WM831X_TCH_PD                           0x8000  /* TCH_PD1 */
#define WM831X_TCH_DATA_MASK                    0x0FFF  /* TCH_DATA - [11:0] */
#define WM831X_TCH_DATA_SHIFT                        0  /* TCH_DATA - [11:0] */
#define WM831X_TCH_DATA_WIDTH                       12  /* TCH_DATA - [11:0] */

struct wm831x_ts {
	struct input_dev *input_dev;
	struct wm831x *wm831x;
	unsigned int data_irq;
	unsigned int pd_irq;
	bool pressure;
	bool pen_down;
	struct work_struct pd_data_work;
};

static void wm831x_pd_data_work(struct work_struct *work)
{
	struct wm831x_ts *wm831x_ts =
		container_of(work, struct wm831x_ts, pd_data_work);

	if (wm831x_ts->pen_down) {
		enable_irq(wm831x_ts->data_irq);
		dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
	} else {
		enable_irq(wm831x_ts->pd_irq);
		dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
	}
}

static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
{
	struct wm831x_ts *wm831x_ts = irq_data;
	struct wm831x *wm831x = wm831x_ts->wm831x;
	static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
	u16 data[3];
	int count;
	int i, ret;

	if (wm831x_ts->pressure)
		count = 3;
	else
		count = 2;

	wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
			WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);

	ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
			       data);
	if (ret != 0) {
		dev_err(wm831x->dev, "Failed to read touch data: %d\n",
			ret);
		return IRQ_NONE;
	}

	/*
	 * We get a pen down reading on every reading, report pen up if any
	 * individual reading does so.
	 */
	wm831x_ts->pen_down = true;
	for (i = 0; i < count; i++) {
		if (!(data[i] & WM831X_TCH_PD)) {
			wm831x_ts->pen_down = false;
			continue;
		}
		input_report_abs(wm831x_ts->input_dev, data_types[i],
				 data[i] & WM831X_TCH_DATA_MASK);
	}

	if (!wm831x_ts->pen_down) {
		/* Switch from data to pen down */
		dev_dbg(wm831x->dev, "IRQ DATA->PD\n");

		disable_irq_nosync(wm831x_ts->data_irq);

		/* Don't need data any more */
		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
				WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
				WM831X_TCH_Z_ENA, 0);

		/* Flush any final samples that arrived while reading */
		wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
				WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);

		wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);

		if (wm831x_ts->pressure)
			input_report_abs(wm831x_ts->input_dev,
					 ABS_PRESSURE, 0);

		input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);

		schedule_work(&wm831x_ts->pd_data_work);
	} else {
		input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
	}

	input_sync(wm831x_ts->input_dev);

	return IRQ_HANDLED;
}

static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
{
	struct wm831x_ts *wm831x_ts = irq_data;
	struct wm831x *wm831x = wm831x_ts->wm831x;
	int ena = 0;

	if (wm831x_ts->pen_down)
		return IRQ_HANDLED;

	disable_irq_nosync(wm831x_ts->pd_irq);

	/* Start collecting data */
	if (wm831x_ts->pressure)
		ena |= WM831X_TCH_Z_ENA;

	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);

	wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
			WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);

	wm831x_ts->pen_down = true;

	/* Switch from pen down to data */
	dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
	schedule_work(&wm831x_ts->pd_data_work);

	return IRQ_HANDLED;
}

static int wm831x_ts_input_open(struct input_dev *idev)
{
	struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
	struct wm831x *wm831x = wm831x_ts->wm831x;

	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
			WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
			WM831X_TCH_Z_ENA, WM831X_TCH_ENA);

	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
			WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);

	return 0;
}

static void wm831x_ts_input_close(struct input_dev *idev)
{
	struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
	struct wm831x *wm831x = wm831x_ts->wm831x;

	/* Shut the controller down, disabling all other functionality too */
	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
			WM831X_TCH_ENA | WM831X_TCH_X_ENA |
			WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);

	/* Make sure any pending IRQs are done, the above will prevent
	 * new ones firing.
	 */
	synchronize_irq(wm831x_ts->data_irq);
	synchronize_irq(wm831x_ts->pd_irq);

	/* Make sure the IRQ completion work is quiesced */
	flush_work(&wm831x_ts->pd_data_work);

	/* If we ended up with the pen down then make sure we revert back
	 * to pen detection state for the next time we start up.
	 */
	if (wm831x_ts->pen_down) {
		disable_irq(wm831x_ts->data_irq);
		enable_irq(wm831x_ts->pd_irq);
		wm831x_ts->pen_down = false;
	}
}

static int wm831x_ts_probe(struct platform_device *pdev)
{
	struct wm831x_ts *wm831x_ts;
	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
	struct wm831x_touch_pdata *pdata = NULL;
	struct input_dev *input_dev;
	int error, irqf;

	if (core_pdata)
		pdata = core_pdata->touch;

	wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
				 GFP_KERNEL);
	input_dev = devm_input_allocate_device(&pdev->dev);
	if (!wm831x_ts || !input_dev) {
		error = -ENOMEM;
		goto err_alloc;
	}

	wm831x_ts->wm831x = wm831x;
	wm831x_ts->input_dev = input_dev;
	INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);

	/*
	 * If we have a direct IRQ use it, otherwise use the interrupt
	 * from the WM831x IRQ controller.
	 */
	wm831x_ts->data_irq = wm831x_irq(wm831x,
					 platform_get_irq_byname(pdev,
								 "TCHDATA"));
	if (pdata && pdata->data_irq)
		wm831x_ts->data_irq = pdata->data_irq;

	wm831x_ts->pd_irq = wm831x_irq(wm831x,
				       platform_get_irq_byname(pdev, "TCHPD"));
	if (pdata && pdata->pd_irq)
		wm831x_ts->pd_irq = pdata->pd_irq;

	if (pdata)
		wm831x_ts->pressure = pdata->pressure;
	else
		wm831x_ts->pressure = true;

	/* Five wire touchscreens can't report pressure */
	if (pdata && pdata->fivewire) {
		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
				WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);

		/* Pressure measurements are not possible for five wire mode */
		WARN_ON(pdata->pressure && pdata->fivewire);
		wm831x_ts->pressure = false;
	} else {
		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
				WM831X_TCH_5WIRE, 0);
	}

	if (pdata) {
		switch (pdata->isel) {
		default:
			dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
				pdata->isel);
			/* Fall through */
		case 200:
		case 0:
			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
					WM831X_TCH_ISEL, 0);
			break;
		case 400:
			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
					WM831X_TCH_ISEL, WM831X_TCH_ISEL);
			break;
		}
	}

	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
			WM831X_TCH_PDONLY, 0);

	/* Default to 96 samples/sec */
	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
			WM831X_TCH_RATE_MASK, 6);

	if (pdata && pdata->data_irqf)
		irqf = pdata->data_irqf;
	else
		irqf = IRQF_TRIGGER_HIGH;

	error = request_threaded_irq(wm831x_ts->data_irq,
				     NULL, wm831x_ts_data_irq,
				     irqf | IRQF_ONESHOT,
				     "Touchscreen data", wm831x_ts);
	if (error) {
		dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
			wm831x_ts->data_irq, error);
		goto err_alloc;
	}
	disable_irq(wm831x_ts->data_irq);

	if (pdata && pdata->pd_irqf)
		irqf = pdata->pd_irqf;
	else
		irqf = IRQF_TRIGGER_HIGH;

	error = request_threaded_irq(wm831x_ts->pd_irq,
				     NULL, wm831x_ts_pen_down_irq,
				     irqf | IRQF_ONESHOT,
				     "Touchscreen pen down", wm831x_ts);
	if (error) {
		dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
			wm831x_ts->pd_irq, error);
		goto err_data_irq;
	}

	/* set up touch configuration */
	input_dev->name = "WM831x touchscreen";
	input_dev->phys = "wm831x";
	input_dev->open = wm831x_ts_input_open;
	input_dev->close = wm831x_ts_input_close;

	__set_bit(EV_ABS, input_dev->evbit);
	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(BTN_TOUCH, input_dev->keybit);

	input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
	if (wm831x_ts->pressure)
		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);

	input_set_drvdata(input_dev, wm831x_ts);
	input_dev->dev.parent = &pdev->dev;

	error = input_register_device(input_dev);
	if (error)
		goto err_pd_irq;

	platform_set_drvdata(pdev, wm831x_ts);
	return 0;

err_pd_irq:
	free_irq(wm831x_ts->pd_irq, wm831x_ts);
err_data_irq:
	free_irq(wm831x_ts->data_irq, wm831x_ts);
err_alloc:

	return error;
}

static int wm831x_ts_remove(struct platform_device *pdev)
{
	struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);

	free_irq(wm831x_ts->pd_irq, wm831x_ts);
	free_irq(wm831x_ts->data_irq, wm831x_ts);

	return 0;
}

static struct platform_driver wm831x_ts_driver = {
	.driver = {
		.name = "wm831x-touch",
	},
	.probe = wm831x_ts_probe,
	.remove = wm831x_ts_remove,
};
module_platform_driver(wm831x_ts_driver);

/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-touch");