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Hans-Christian Egtvedt864fe732009-04-18 18:45:06 -07001/*
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
André Goddard Rosaaf901ca2009-11-14 13:09:05 -020062#error Unknown CPU, this driver only supports AT32AP700X CPUs.
Hans-Christian Egtvedt864fe732009-04-18 18:45:06 -070063#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");