summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/atmel-wm97xx.c
blob: 9140a43cfe20b7f780e7380ed27155e61bc1d6d4 (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
432
433
434
435
436
/*
 * Atmel AT91 and AVR32 continuous touch screen driver for Wolfson WM97xx AC97
 * codecs.
 *
 * Copyright (C) 2008 - 2009 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/wm97xx.h>
#include <linux/timer.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/slab.h>

#define AC97C_ICA		0x10
#define AC97C_CBRHR		0x30
#define AC97C_CBSR		0x38
#define AC97C_CBMR		0x3c
#define AC97C_IER		0x54
#define AC97C_IDR		0x58

#define AC97C_RXRDY		(1 << 4)
#define AC97C_OVRUN		(1 << 5)

#define AC97C_CMR_SIZE_20	(0 << 16)
#define AC97C_CMR_SIZE_18	(1 << 16)
#define AC97C_CMR_SIZE_16	(2 << 16)
#define AC97C_CMR_SIZE_10	(3 << 16)
#define AC97C_CMR_CEM_LITTLE	(1 << 18)
#define AC97C_CMR_CEM_BIG	(0 << 18)
#define AC97C_CMR_CENA		(1 << 21)

#define AC97C_INT_CBEVT		(1 << 4)

#define AC97C_SR_CAEVT		(1 << 3)

#define AC97C_CH_MASK(slot)						\
	(0x7 << (3 * (slot - 3)))
#define AC97C_CH_ASSIGN(slot, channel)					\
	(AC97C_CHANNEL_##channel << (3 * (slot - 3)))
#define AC97C_CHANNEL_NONE	0x0
#define AC97C_CHANNEL_B		0x2

#define ac97c_writel(chip, reg, val)			\
	__raw_writel((val), (chip)->regs + AC97C_##reg)
#define ac97c_readl(chip, reg)				\
	__raw_readl((chip)->regs + AC97C_##reg)

#ifdef CONFIG_CPU_AT32AP700X
#define ATMEL_WM97XX_AC97C_IOMEM	(0xfff02800)
#define ATMEL_WM97XX_AC97C_IRQ		(29)
#define ATMEL_WM97XX_GPIO_DEFAULT	(32+16) /* Pin 16 on port B. */
#else
#error Unknown CPU, this driver only supports AT32AP700X CPUs.
#endif

struct continuous {
	u16 id;    /* codec id */
	u8 code;   /* continuous code */
	u8 reads;  /* number of coord reads per read cycle */
	u32 speed; /* number of coords per second */
};

#define WM_READS(sp) ((sp / HZ) + 1)

static const struct continuous cinfo[] = {
	{WM9705_ID2, 0, WM_READS(94), 94},
	{WM9705_ID2, 1, WM_READS(188), 188},
	{WM9705_ID2, 2, WM_READS(375), 375},
	{WM9705_ID2, 3, WM_READS(750), 750},
	{WM9712_ID2, 0, WM_READS(94), 94},
	{WM9712_ID2, 1, WM_READS(188), 188},
	{WM9712_ID2, 2, WM_READS(375), 375},
	{WM9712_ID2, 3, WM_READS(750), 750},
	{WM9713_ID2, 0, WM_READS(94), 94},
	{WM9713_ID2, 1, WM_READS(120), 120},
	{WM9713_ID2, 2, WM_READS(154), 154},
	{WM9713_ID2, 3, WM_READS(188), 188},
};

/* Continuous speed index. */
static int sp_idx;

/*
 * Pen sampling frequency (Hz) in continuous mode.
 */
static int cont_rate = 188;
module_param(cont_rate, int, 0);
MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");

/*
 * Pen down detection.
 *
 * This driver can either poll or use an interrupt to indicate a pen down
 * event. If the irq request fails then it will fall back to polling mode.
 */
static int pen_int = 1;
module_param(pen_int, int, 0);
MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");

/*
 * Pressure readback.
 *
 * Set to 1 to read back pen down pressure.
 */
static int pressure;
module_param(pressure, int, 0);
MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");

/*
 * AC97 touch data slot.
 *
 * Touch screen readback data ac97 slot.
 */
static int ac97_touch_slot = 5;
module_param(ac97_touch_slot, int, 0);
MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");

/*
 * GPIO line number.
 *
 * Set to GPIO number where the signal from the WM97xx device is hooked up.
 */
static int atmel_gpio_line = ATMEL_WM97XX_GPIO_DEFAULT;
module_param(atmel_gpio_line, int, 0);
MODULE_PARM_DESC(atmel_gpio_line, "GPIO line number connected to WM97xx");

struct atmel_wm97xx {
	struct wm97xx		*wm;
	struct timer_list	pen_timer;
	void __iomem		*regs;
	unsigned long		ac97c_irq;
	unsigned long		gpio_pen;
	unsigned long		gpio_irq;
	unsigned short		x;
	unsigned short		y;
};

static irqreturn_t atmel_wm97xx_channel_b_interrupt(int irq, void *dev_id)
{
	struct atmel_wm97xx *atmel_wm97xx = dev_id;
	struct wm97xx *wm = atmel_wm97xx->wm;
	int status = ac97c_readl(atmel_wm97xx, CBSR);
	irqreturn_t retval = IRQ_NONE;

	if (status & AC97C_OVRUN) {
		dev_dbg(&wm->touch_dev->dev, "AC97C overrun\n");
		ac97c_readl(atmel_wm97xx, CBRHR);
		retval = IRQ_HANDLED;
	} else if (status & AC97C_RXRDY) {
		u16 data;
		u16 value;
		u16 source;
		u16 pen_down;

		data = ac97c_readl(atmel_wm97xx, CBRHR);
		value = data & 0x0fff;
		source = data & WM97XX_ADCSEL_MASK;
		pen_down = (data & WM97XX_PEN_DOWN) >> 8;

		if (source == WM97XX_ADCSEL_X)
			atmel_wm97xx->x = value;
		if (source == WM97XX_ADCSEL_Y)
			atmel_wm97xx->y = value;

		if (!pressure && source == WM97XX_ADCSEL_Y) {
			input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
			input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
			input_report_key(wm->input_dev, BTN_TOUCH, pen_down);
			input_sync(wm->input_dev);
		} else if (pressure && source == WM97XX_ADCSEL_PRES) {
			input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
			input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
			input_report_abs(wm->input_dev, ABS_PRESSURE, value);
			input_report_key(wm->input_dev, BTN_TOUCH, value);
			input_sync(wm->input_dev);
		}

		retval = IRQ_HANDLED;
	}

	return retval;
}

static void atmel_wm97xx_acc_pen_up(struct wm97xx *wm)
{
	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
	struct input_dev *input_dev = wm->input_dev;
	int pen_down = gpio_get_value(atmel_wm97xx->gpio_pen);

	if (pen_down != 0) {
		mod_timer(&atmel_wm97xx->pen_timer,
			  jiffies + msecs_to_jiffies(1));
	} else {
		if (pressure)
			input_report_abs(input_dev, ABS_PRESSURE, 0);
		input_report_key(input_dev, BTN_TOUCH, 0);
		input_sync(input_dev);
	}
}

static void atmel_wm97xx_pen_timer(struct timer_list *t)
{
	struct atmel_wm97xx *atmel_wm97xx = from_timer(atmel_wm97xx, t,
						       pen_timer);

	atmel_wm97xx_acc_pen_up(atmel_wm97xx->wm);
}

static int atmel_wm97xx_acc_startup(struct wm97xx *wm)
{
	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
	int idx = 0;

	if (wm->ac97 == NULL)
		return -ENODEV;

	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
		if (wm->id != cinfo[idx].id)
			continue;

		sp_idx = idx;

		if (cont_rate <= cinfo[idx].speed)
			break;
	}

	wm->acc_rate = cinfo[sp_idx].code;
	wm->acc_slot = ac97_touch_slot;
	dev_info(&wm->touch_dev->dev, "atmel accelerated touchscreen driver, "
			"%d samples/sec\n", cinfo[sp_idx].speed);

	if (pen_int) {
		unsigned long reg;

		wm->pen_irq = atmel_wm97xx->gpio_irq;

		switch (wm->id) {
		case WM9712_ID2: /* Fall through. */
		case WM9713_ID2:
			/*
			 * Use GPIO 13 (PEN_DOWN) to assert GPIO line 3
			 * (PENDOWN).
			 */
			wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
					WM97XX_GPIO_POL_HIGH,
					WM97XX_GPIO_STICKY,
					WM97XX_GPIO_WAKE);
			wm97xx_config_gpio(wm, WM97XX_GPIO_3, WM97XX_GPIO_OUT,
					WM97XX_GPIO_POL_HIGH,
					WM97XX_GPIO_NOTSTICKY,
					WM97XX_GPIO_NOWAKE);
		case WM9705_ID2: /* Fall through. */
			/*
			 * Enable touch data slot in AC97 controller channel B.
			 */
			reg = ac97c_readl(atmel_wm97xx, ICA);
			reg &= ~AC97C_CH_MASK(wm->acc_slot);
			reg |= AC97C_CH_ASSIGN(wm->acc_slot, B);
			ac97c_writel(atmel_wm97xx, ICA, reg);

			/*
			 * Enable channel and interrupt for RXRDY and OVERRUN.
			 */
			ac97c_writel(atmel_wm97xx, CBMR, AC97C_CMR_CENA
					| AC97C_CMR_CEM_BIG
					| AC97C_CMR_SIZE_16
					| AC97C_OVRUN
					| AC97C_RXRDY);
			/* Dummy read to empty RXRHR. */
			ac97c_readl(atmel_wm97xx, CBRHR);
			/*
			 * Enable interrupt for channel B in the AC97
			 * controller.
			 */
			ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
			break;
		default:
			dev_err(&wm->touch_dev->dev, "pen down irq not "
					"supported on this device\n");
			pen_int = 0;
			break;
		}
	}

	return 0;
}

static void atmel_wm97xx_acc_shutdown(struct wm97xx *wm)
{
	if (pen_int) {
		struct atmel_wm97xx *atmel_wm97xx =
			platform_get_drvdata(wm->touch_dev);
		unsigned long ica;

		switch (wm->id & 0xffff) {
		case WM9705_ID2: /* Fall through. */
		case WM9712_ID2: /* Fall through. */
		case WM9713_ID2:
			/* Disable slot and turn off channel B interrupts. */
			ica = ac97c_readl(atmel_wm97xx, ICA);
			ica &= ~AC97C_CH_MASK(wm->acc_slot);
			ac97c_writel(atmel_wm97xx, ICA, ica);
			ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
			ac97c_writel(atmel_wm97xx, CBMR, 0);
			wm->pen_irq = 0;
			break;
		default:
			dev_err(&wm->touch_dev->dev, "unknown codec\n");
			break;
		}
	}
}

static void atmel_wm97xx_irq_enable(struct wm97xx *wm, int enable)
{
	/* Intentionally left empty. */
}

static struct wm97xx_mach_ops atmel_mach_ops = {
	.acc_enabled	= 1,
	.acc_pen_up	= atmel_wm97xx_acc_pen_up,
	.acc_startup	= atmel_wm97xx_acc_startup,
	.acc_shutdown	= atmel_wm97xx_acc_shutdown,
	.irq_enable	= atmel_wm97xx_irq_enable,
	.irq_gpio	= WM97XX_GPIO_3,
};

static int __init atmel_wm97xx_probe(struct platform_device *pdev)
{
	struct wm97xx *wm = platform_get_drvdata(pdev);
	struct atmel_wm97xx *atmel_wm97xx;
	int ret;

	atmel_wm97xx = kzalloc(sizeof(struct atmel_wm97xx), GFP_KERNEL);
	if (!atmel_wm97xx)
		return -ENOMEM;

	atmel_wm97xx->wm	= wm;
	atmel_wm97xx->regs	= (void *)ATMEL_WM97XX_AC97C_IOMEM;
	atmel_wm97xx->ac97c_irq	= ATMEL_WM97XX_AC97C_IRQ;
	atmel_wm97xx->gpio_pen	= atmel_gpio_line;
	atmel_wm97xx->gpio_irq	= gpio_to_irq(atmel_wm97xx->gpio_pen);

	timer_setup(&atmel_wm97xx->pen_timer, atmel_wm97xx_pen_timer, 0);

	ret = request_irq(atmel_wm97xx->ac97c_irq,
			  atmel_wm97xx_channel_b_interrupt,
			  IRQF_SHARED, "atmel-wm97xx-ch-b", atmel_wm97xx);
	if (ret) {
		dev_dbg(&pdev->dev, "could not request ac97c irq\n");
		goto err;
	}

	platform_set_drvdata(pdev, atmel_wm97xx);

	ret = wm97xx_register_mach_ops(wm, &atmel_mach_ops);
	if (ret)
		goto err_irq;

	return ret;

err_irq:
	free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
err:
	kfree(atmel_wm97xx);
	return ret;
}

static int __exit atmel_wm97xx_remove(struct platform_device *pdev)
{
	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
	struct wm97xx *wm = atmel_wm97xx->wm;

	ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
	free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
	del_timer_sync(&atmel_wm97xx->pen_timer);
	wm97xx_unregister_mach_ops(wm);
	kfree(atmel_wm97xx);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int atmel_wm97xx_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);

	ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
	disable_irq(atmel_wm97xx->gpio_irq);
	del_timer_sync(&atmel_wm97xx->pen_timer);

	return 0;
}

static int atmel_wm97xx_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
	struct wm97xx *wm = atmel_wm97xx->wm;

	if (wm->input_dev->users) {
		enable_irq(atmel_wm97xx->gpio_irq);
		ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
	}

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(atmel_wm97xx_pm_ops,
			 atmel_wm97xx_suspend, atmel_wm97xx_resume);

static struct platform_driver atmel_wm97xx_driver = {
	.remove		= __exit_p(atmel_wm97xx_remove),
	.driver		= {
		.name	= "wm97xx-touch",
		.pm	= &atmel_wm97xx_pm_ops,
	},
};

module_platform_driver_probe(atmel_wm97xx_driver, atmel_wm97xx_probe);

MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
MODULE_DESCRIPTION("wm97xx continuous touch driver for Atmel AT91 and AVR32");
MODULE_LICENSE("GPL");