atmel-wm97xx.c revision 864fe73c312ca8e177da01207ce86fb1b80b3e54 
1/*
2 * Atmel AT91 and AVR32 continuous touch screen driver for Wolfson WM97xx AC97
3 * codecs.
4 *
5 * Copyright (C) 2008 - 2009 Atmel Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 */
11#include <linux/module.h>
12#include <linux/moduleparam.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/delay.h>
16#include <linux/irq.h>
17#include <linux/interrupt.h>
18#include <linux/wm97xx.h>
19#include <linux/timer.h>
20#include <linux/gpio.h>
21#include <linux/io.h>
22
23#define AC97C_ICA		0x10
24#define AC97C_CBRHR		0x30
25#define AC97C_CBSR		0x38
26#define AC97C_CBMR		0x3c
27#define AC97C_IER		0x54
28#define AC97C_IDR		0x58
29
30#define AC97C_RXRDY		(1 << 4)
31#define AC97C_OVRUN		(1 << 5)
32
33#define AC97C_CMR_SIZE_20	(0 << 16)
34#define AC97C_CMR_SIZE_18	(1 << 16)
35#define AC97C_CMR_SIZE_16	(2 << 16)
36#define AC97C_CMR_SIZE_10	(3 << 16)
37#define AC97C_CMR_CEM_LITTLE	(1 << 18)
38#define AC97C_CMR_CEM_BIG	(0 << 18)
39#define AC97C_CMR_CENA		(1 << 21)
40
41#define AC97C_INT_CBEVT		(1 << 4)
42
43#define AC97C_SR_CAEVT		(1 << 3)
44
45#define AC97C_CH_MASK(slot)						\
46	(0x7 << (3 * (slot - 3)))
47#define AC97C_CH_ASSIGN(slot, channel)					\
48	(AC97C_CHANNEL_##channel << (3 * (slot - 3)))
49#define AC97C_CHANNEL_NONE	0x0
50#define AC97C_CHANNEL_B		0x2
51
52#define ac97c_writel(chip, reg, val)			\
53	__raw_writel((val), (chip)->regs + AC97C_##reg)
54#define ac97c_readl(chip, reg)				\
55	__raw_readl((chip)->regs + AC97C_##reg)
56
57#ifdef CONFIG_CPU_AT32AP700X
58#define ATMEL_WM97XX_AC97C_IOMEM	(0xfff02800)
59#define ATMEL_WM97XX_AC97C_IRQ		(29)
60#define ATMEL_WM97XX_GPIO_DEFAULT	(32+16) /* Pin 16 on port B. */
61#else
62#error Unkown CPU, this driver only supports AT32AP700X CPUs.
63#endif
64
65struct continuous {
66	u16 id;    /* codec id */
67	u8 code;   /* continuous code */
68	u8 reads;  /* number of coord reads per read cycle */
69	u32 speed; /* number of coords per second */
70};
71
72#define WM_READS(sp) ((sp / HZ) + 1)
73
74static const struct continuous cinfo[] = {
75	{WM9705_ID2, 0, WM_READS(94), 94},
76	{WM9705_ID2, 1, WM_READS(188), 188},
77	{WM9705_ID2, 2, WM_READS(375), 375},
78	{WM9705_ID2, 3, WM_READS(750), 750},
79	{WM9712_ID2, 0, WM_READS(94), 94},
80	{WM9712_ID2, 1, WM_READS(188), 188},
81	{WM9712_ID2, 2, WM_READS(375), 375},
82	{WM9712_ID2, 3, WM_READS(750), 750},
83	{WM9713_ID2, 0, WM_READS(94), 94},
84	{WM9713_ID2, 1, WM_READS(120), 120},
85	{WM9713_ID2, 2, WM_READS(154), 154},
86	{WM9713_ID2, 3, WM_READS(188), 188},
87};
88
89/* Continuous speed index. */
90static int sp_idx;
91
92/*
93 * Pen sampling frequency (Hz) in continuous mode.
94 */
95static int cont_rate = 188;
96module_param(cont_rate, int, 0);
97MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
98
99/*
100 * Pen down detection.
101 *
102 * This driver can either poll or use an interrupt to indicate a pen down
103 * event. If the irq request fails then it will fall back to polling mode.
104 */
105static int pen_int = 1;
106module_param(pen_int, int, 0);
107MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
108
109/*
110 * Pressure readback.
111 *
112 * Set to 1 to read back pen down pressure.
113 */
114static int pressure;
115module_param(pressure, int, 0);
116MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
117
118/*
119 * AC97 touch data slot.
120 *
121 * Touch screen readback data ac97 slot.
122 */
123static int ac97_touch_slot = 5;
124module_param(ac97_touch_slot, int, 0);
125MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
126
127/*
128 * GPIO line number.
129 *
130 * Set to GPIO number where the signal from the WM97xx device is hooked up.
131 */
132static int atmel_gpio_line = ATMEL_WM97XX_GPIO_DEFAULT;
133module_param(atmel_gpio_line, int, 0);
134MODULE_PARM_DESC(atmel_gpio_line, "GPIO line number connected to WM97xx");
135
136struct atmel_wm97xx {
137	struct wm97xx		*wm;
138	struct timer_list	pen_timer;
139	void __iomem		*regs;
140	unsigned long		ac97c_irq;
141	unsigned long		gpio_pen;
142	unsigned long		gpio_irq;
143	unsigned short		x;
144	unsigned short		y;
145};
146
147static irqreturn_t atmel_wm97xx_channel_b_interrupt(int irq, void *dev_id)
148{
149	struct atmel_wm97xx *atmel_wm97xx = dev_id;
150	struct wm97xx *wm = atmel_wm97xx->wm;
151	int status = ac97c_readl(atmel_wm97xx, CBSR);
152	irqreturn_t retval = IRQ_NONE;
153
154	if (status & AC97C_OVRUN) {
155		dev_dbg(&wm->touch_dev->dev, "AC97C overrun\n");
156		ac97c_readl(atmel_wm97xx, CBRHR);
157		retval = IRQ_HANDLED;
158	} else if (status & AC97C_RXRDY) {
159		u16 data;
160		u16 value;
161		u16 source;
162		u16 pen_down;
163
164		data = ac97c_readl(atmel_wm97xx, CBRHR);
165		value = data & 0x0fff;
166		source = data & WM97XX_ADCSRC_MASK;
167		pen_down = (data & WM97XX_PEN_DOWN) >> 8;
168
169		if (source == WM97XX_ADCSEL_X)
170			atmel_wm97xx->x = value;
171		if (source == WM97XX_ADCSEL_Y)
172			atmel_wm97xx->y = value;
173
174		if (!pressure && source == WM97XX_ADCSEL_Y) {
175			input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
176			input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
177			input_report_key(wm->input_dev, BTN_TOUCH, pen_down);
178			input_sync(wm->input_dev);
179		} else if (pressure && source == WM97XX_ADCSEL_PRES) {
180			input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
181			input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
182			input_report_abs(wm->input_dev, ABS_PRESSURE, value);
183			input_report_key(wm->input_dev, BTN_TOUCH, value);
184			input_sync(wm->input_dev);
185		}
186
187		retval = IRQ_HANDLED;
188	}
189
190	return retval;
191}
192
193static void atmel_wm97xx_acc_pen_up(struct wm97xx *wm)
194{
195	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
196	struct input_dev *input_dev = wm->input_dev;
197	int pen_down = gpio_get_value(atmel_wm97xx->gpio_pen);
198
199	if (pen_down != 0) {
200		mod_timer(&atmel_wm97xx->pen_timer,
201			  jiffies + msecs_to_jiffies(1));
202	} else {
203		if (pressure)
204			input_report_abs(input_dev, ABS_PRESSURE, 0);
205		input_report_key(input_dev, BTN_TOUCH, 0);
206		input_sync(input_dev);
207	}
208}
209
210static void atmel_wm97xx_pen_timer(unsigned long data)
211{
212	atmel_wm97xx_acc_pen_up((struct wm97xx *)data);
213}
214
215static int atmel_wm97xx_acc_startup(struct wm97xx *wm)
216{
217	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
218	int idx = 0;
219
220	if (wm->ac97 == NULL)
221		return -ENODEV;
222
223	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
224		if (wm->id != cinfo[idx].id)
225			continue;
226
227		sp_idx = idx;
228
229		if (cont_rate <= cinfo[idx].speed)
230			break;
231	}
232
233	wm->acc_rate = cinfo[sp_idx].code;
234	wm->acc_slot = ac97_touch_slot;
235	dev_info(&wm->touch_dev->dev, "atmel accelerated touchscreen driver, "
236			"%d samples/sec\n", cinfo[sp_idx].speed);
237
238	if (pen_int) {
239		unsigned long reg;
240
241		wm->pen_irq = atmel_wm97xx->gpio_irq;
242
243		switch (wm->id) {
244		case WM9712_ID2: /* Fall through. */
245		case WM9713_ID2:
246			/*
247			 * Use GPIO 13 (PEN_DOWN) to assert GPIO line 3
248			 * (PENDOWN).
249			 */
250			wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
251					WM97XX_GPIO_POL_HIGH,
252					WM97XX_GPIO_STICKY,
253					WM97XX_GPIO_WAKE);
254			wm97xx_config_gpio(wm, WM97XX_GPIO_3, WM97XX_GPIO_OUT,
255					WM97XX_GPIO_POL_HIGH,
256					WM97XX_GPIO_NOTSTICKY,
257					WM97XX_GPIO_NOWAKE);
258		case WM9705_ID2: /* Fall through. */
259			/*
260			 * Enable touch data slot in AC97 controller channel B.
261			 */
262			reg = ac97c_readl(atmel_wm97xx, ICA);
263			reg &= ~AC97C_CH_MASK(wm->acc_slot);
264			reg |= AC97C_CH_ASSIGN(wm->acc_slot, B);
265			ac97c_writel(atmel_wm97xx, ICA, reg);
266
267			/*
268			 * Enable channel and interrupt for RXRDY and OVERRUN.
269			 */
270			ac97c_writel(atmel_wm97xx, CBMR, AC97C_CMR_CENA
271					| AC97C_CMR_CEM_BIG
272					| AC97C_CMR_SIZE_16
273					| AC97C_OVRUN
274					| AC97C_RXRDY);
275			/* Dummy read to empty RXRHR. */
276			ac97c_readl(atmel_wm97xx, CBRHR);
277			/*
278			 * Enable interrupt for channel B in the AC97
279			 * controller.
280			 */
281			ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
282			break;
283		default:
284			dev_err(&wm->touch_dev->dev, "pen down irq not "
285					"supported on this device\n");
286			pen_int = 0;
287			break;
288		}
289	}
290
291	return 0;
292}
293
294static void atmel_wm97xx_acc_shutdown(struct wm97xx *wm)
295{
296	if (pen_int) {
297		struct atmel_wm97xx *atmel_wm97xx =
298			platform_get_drvdata(wm->touch_dev);
299		unsigned long ica;
300
301		switch (wm->id & 0xffff) {
302		case WM9705_ID2: /* Fall through. */
303		case WM9712_ID2: /* Fall through. */
304		case WM9713_ID2:
305			/* Disable slot and turn off channel B interrupts. */
306			ica = ac97c_readl(atmel_wm97xx, ICA);
307			ica &= ~AC97C_CH_MASK(wm->acc_slot);
308			ac97c_writel(atmel_wm97xx, ICA, ica);
309			ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
310			ac97c_writel(atmel_wm97xx, CBMR, 0);
311			wm->pen_irq = 0;
312			break;
313		default:
314			dev_err(&wm->touch_dev->dev, "unknown codec\n");
315			break;
316		}
317	}
318}
319
320static void atmel_wm97xx_irq_enable(struct wm97xx *wm, int enable)
321{
322	/* Intentionally left empty. */
323}
324
325static struct wm97xx_mach_ops atmel_mach_ops = {
326	.acc_enabled	= 1,
327	.acc_pen_up	= atmel_wm97xx_acc_pen_up,
328	.acc_startup	= atmel_wm97xx_acc_startup,
329	.acc_shutdown	= atmel_wm97xx_acc_shutdown,
330	.irq_enable	= atmel_wm97xx_irq_enable,
331	.irq_gpio	= WM97XX_GPIO_3,
332};
333
334static int __init atmel_wm97xx_probe(struct platform_device *pdev)
335{
336	struct wm97xx *wm = platform_get_drvdata(pdev);
337	struct atmel_wm97xx *atmel_wm97xx;
338	int ret;
339
340	atmel_wm97xx = kzalloc(sizeof(struct atmel_wm97xx), GFP_KERNEL);
341	if (!atmel_wm97xx) {
342		dev_dbg(&pdev->dev, "out of memory\n");
343		return -ENOMEM;
344	}
345
346	atmel_wm97xx->wm	= wm;
347	atmel_wm97xx->regs	= (void *)ATMEL_WM97XX_AC97C_IOMEM;
348	atmel_wm97xx->ac97c_irq	= ATMEL_WM97XX_AC97C_IRQ;
349	atmel_wm97xx->gpio_pen	= atmel_gpio_line;
350	atmel_wm97xx->gpio_irq	= gpio_to_irq(atmel_wm97xx->gpio_pen);
351
352	setup_timer(&atmel_wm97xx->pen_timer, atmel_wm97xx_pen_timer,
353			(unsigned long)wm);
354
355	ret = request_irq(atmel_wm97xx->ac97c_irq,
356			  atmel_wm97xx_channel_b_interrupt,
357			  IRQF_SHARED, "atmel-wm97xx-ch-b", atmel_wm97xx);
358	if (ret) {
359		dev_dbg(&pdev->dev, "could not request ac97c irq\n");
360		goto err;
361	}
362
363	platform_set_drvdata(pdev, atmel_wm97xx);
364
365	ret = wm97xx_register_mach_ops(wm, &atmel_mach_ops);
366	if (ret)
367		goto err_irq;
368
369	return ret;
370
371err_irq:
372	free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
373err:
374	platform_set_drvdata(pdev, NULL);
375	kfree(atmel_wm97xx);
376	return ret;
377}
378
379static int __exit atmel_wm97xx_remove(struct platform_device *pdev)
380{
381	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
382	struct wm97xx *wm = atmel_wm97xx->wm;
383
384	ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
385	free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
386	del_timer_sync(&atmel_wm97xx->pen_timer);
387	wm97xx_unregister_mach_ops(wm);
388	platform_set_drvdata(pdev, NULL);
389	kfree(atmel_wm97xx);
390
391	return 0;
392}
393
394#ifdef CONFIG_PM
395static int atmel_wm97xx_suspend(struct platform_device *pdev, pm_message_t msg)
396{
397	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
398
399	ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
400	disable_irq(atmel_wm97xx->gpio_irq);
401	del_timer_sync(&atmel_wm97xx->pen_timer);
402
403	return 0;
404}
405
406static int atmel_wm97xx_resume(struct platform_device *pdev)
407{
408	struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
409	struct wm97xx *wm = atmel_wm97xx->wm;
410
411	if (wm->input_dev->users) {
412		enable_irq(atmel_wm97xx->gpio_irq);
413		ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
414	}
415
416	return 0;
417}
418#else
419#define atmel_wm97xx_suspend	NULL
420#define atmel_wm97xx_resume	NULL
421#endif
422
423static struct platform_driver atmel_wm97xx_driver = {
424	.remove		= __exit_p(atmel_wm97xx_remove),
425	.driver		= {
426		.name = "wm97xx-touch",
427	},
428	.suspend	= atmel_wm97xx_suspend,
429	.resume		= atmel_wm97xx_resume,
430};
431
432static int __init atmel_wm97xx_init(void)
433{
434	return platform_driver_probe(&atmel_wm97xx_driver, atmel_wm97xx_probe);
435}
436module_init(atmel_wm97xx_init);
437
438static void __exit atmel_wm97xx_exit(void)
439{
440	platform_driver_unregister(&atmel_wm97xx_driver);
441}
442module_exit(atmel_wm97xx_exit);
443
444MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>");
445MODULE_DESCRIPTION("wm97xx continuous touch driver for Atmel AT91 and AVR32");
446MODULE_LICENSE("GPL");
447