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 #include <linux/slab.h>
23
24 #define AC97C_ICA 0x10
25 #define AC97C_CBRHR 0x30
26 #define AC97C_CBSR 0x38
27 #define AC97C_CBMR 0x3c
28 #define AC97C_IER 0x54
29 #define AC97C_IDR 0x58
30
31 #define AC97C_RXRDY (1 << 4)
32 #define AC97C_OVRUN (1 << 5)
33
34 #define AC97C_CMR_SIZE_20 (0 << 16)
35 #define AC97C_CMR_SIZE_18 (1 << 16)
36 #define AC97C_CMR_SIZE_16 (2 << 16)
37 #define AC97C_CMR_SIZE_10 (3 << 16)
38 #define AC97C_CMR_CEM_LITTLE (1 << 18)
39 #define AC97C_CMR_CEM_BIG (0 << 18)
40 #define AC97C_CMR_CENA (1 << 21)
41
42 #define AC97C_INT_CBEVT (1 << 4)
43
44 #define AC97C_SR_CAEVT (1 << 3)
45
46 #define AC97C_CH_MASK(slot) \
47 (0x7 << (3 * (slot - 3)))
48 #define AC97C_CH_ASSIGN(slot, channel) \
49 (AC97C_CHANNEL_##channel << (3 * (slot - 3)))
50 #define AC97C_CHANNEL_NONE 0x0
51 #define AC97C_CHANNEL_B 0x2
52
53 #define ac97c_writel(chip, reg, val) \
54 __raw_writel((val), (chip)->regs + AC97C_##reg)
55 #define ac97c_readl(chip, reg) \
56 __raw_readl((chip)->regs + AC97C_##reg)
57
58 #ifdef CONFIG_CPU_AT32AP700X
59 #define ATMEL_WM97XX_AC97C_IOMEM (0xfff02800)
60 #define ATMEL_WM97XX_AC97C_IRQ (29)
61 #define ATMEL_WM97XX_GPIO_DEFAULT (32+16) /* Pin 16 on port B. */
62 #else
63 #error Unknown CPU, this driver only supports AT32AP700X CPUs.
64 #endif
65
66 struct continuous {
67 u16 id; /* codec id */
68 u8 code; /* continuous code */
69 u8 reads; /* number of coord reads per read cycle */
70 u32 speed; /* number of coords per second */
71 };
72
73 #define WM_READS(sp) ((sp / HZ) + 1)
74
75 static const struct continuous cinfo[] = {
76 {WM9705_ID2, 0, WM_READS(94), 94},
77 {WM9705_ID2, 1, WM_READS(188), 188},
78 {WM9705_ID2, 2, WM_READS(375), 375},
79 {WM9705_ID2, 3, WM_READS(750), 750},
80 {WM9712_ID2, 0, WM_READS(94), 94},
81 {WM9712_ID2, 1, WM_READS(188), 188},
82 {WM9712_ID2, 2, WM_READS(375), 375},
83 {WM9712_ID2, 3, WM_READS(750), 750},
84 {WM9713_ID2, 0, WM_READS(94), 94},
85 {WM9713_ID2, 1, WM_READS(120), 120},
86 {WM9713_ID2, 2, WM_READS(154), 154},
87 {WM9713_ID2, 3, WM_READS(188), 188},
88 };
89
90 /* Continuous speed index. */
91 static int sp_idx;
92
93 /*
94 * Pen sampling frequency (Hz) in continuous mode.
95 */
96 static int cont_rate = 188;
97 module_param(cont_rate, int, 0);
98 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
99
100 /*
101 * Pen down detection.
102 *
103 * This driver can either poll or use an interrupt to indicate a pen down
104 * event. If the irq request fails then it will fall back to polling mode.
105 */
106 static int pen_int = 1;
107 module_param(pen_int, int, 0);
108 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
109
110 /*
111 * Pressure readback.
112 *
113 * Set to 1 to read back pen down pressure.
114 */
115 static int pressure;
116 module_param(pressure, int, 0);
117 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
118
119 /*
120 * AC97 touch data slot.
121 *
122 * Touch screen readback data ac97 slot.
123 */
124 static int ac97_touch_slot = 5;
125 module_param(ac97_touch_slot, int, 0);
126 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
127
128 /*
129 * GPIO line number.
130 *
131 * Set to GPIO number where the signal from the WM97xx device is hooked up.
132 */
133 static int atmel_gpio_line = ATMEL_WM97XX_GPIO_DEFAULT;
134 module_param(atmel_gpio_line, int, 0);
135 MODULE_PARM_DESC(atmel_gpio_line, "GPIO line number connected to WM97xx");
136
137 struct atmel_wm97xx {
138 struct wm97xx *wm;
139 struct timer_list pen_timer;
140 void __iomem *regs;
141 unsigned long ac97c_irq;
142 unsigned long gpio_pen;
143 unsigned long gpio_irq;
144 unsigned short x;
145 unsigned short y;
146 };
147
atmel_wm97xx_channel_b_interrupt(int irq,void * dev_id)148 static irqreturn_t atmel_wm97xx_channel_b_interrupt(int irq, void *dev_id)
149 {
150 struct atmel_wm97xx *atmel_wm97xx = dev_id;
151 struct wm97xx *wm = atmel_wm97xx->wm;
152 int status = ac97c_readl(atmel_wm97xx, CBSR);
153 irqreturn_t retval = IRQ_NONE;
154
155 if (status & AC97C_OVRUN) {
156 dev_dbg(&wm->touch_dev->dev, "AC97C overrun\n");
157 ac97c_readl(atmel_wm97xx, CBRHR);
158 retval = IRQ_HANDLED;
159 } else if (status & AC97C_RXRDY) {
160 u16 data;
161 u16 value;
162 u16 source;
163 u16 pen_down;
164
165 data = ac97c_readl(atmel_wm97xx, CBRHR);
166 value = data & 0x0fff;
167 source = data & WM97XX_ADCSEL_MASK;
168 pen_down = (data & WM97XX_PEN_DOWN) >> 8;
169
170 if (source == WM97XX_ADCSEL_X)
171 atmel_wm97xx->x = value;
172 if (source == WM97XX_ADCSEL_Y)
173 atmel_wm97xx->y = value;
174
175 if (!pressure && source == WM97XX_ADCSEL_Y) {
176 input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
177 input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
178 input_report_key(wm->input_dev, BTN_TOUCH, pen_down);
179 input_sync(wm->input_dev);
180 } else if (pressure && source == WM97XX_ADCSEL_PRES) {
181 input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
182 input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
183 input_report_abs(wm->input_dev, ABS_PRESSURE, value);
184 input_report_key(wm->input_dev, BTN_TOUCH, value);
185 input_sync(wm->input_dev);
186 }
187
188 retval = IRQ_HANDLED;
189 }
190
191 return retval;
192 }
193
atmel_wm97xx_acc_pen_up(struct wm97xx * wm)194 static void atmel_wm97xx_acc_pen_up(struct wm97xx *wm)
195 {
196 struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
197 struct input_dev *input_dev = wm->input_dev;
198 int pen_down = gpio_get_value(atmel_wm97xx->gpio_pen);
199
200 if (pen_down != 0) {
201 mod_timer(&atmel_wm97xx->pen_timer,
202 jiffies + msecs_to_jiffies(1));
203 } else {
204 if (pressure)
205 input_report_abs(input_dev, ABS_PRESSURE, 0);
206 input_report_key(input_dev, BTN_TOUCH, 0);
207 input_sync(input_dev);
208 }
209 }
210
atmel_wm97xx_pen_timer(unsigned long data)211 static void atmel_wm97xx_pen_timer(unsigned long data)
212 {
213 atmel_wm97xx_acc_pen_up((struct wm97xx *)data);
214 }
215
atmel_wm97xx_acc_startup(struct wm97xx * wm)216 static int atmel_wm97xx_acc_startup(struct wm97xx *wm)
217 {
218 struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
219 int idx = 0;
220
221 if (wm->ac97 == NULL)
222 return -ENODEV;
223
224 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
225 if (wm->id != cinfo[idx].id)
226 continue;
227
228 sp_idx = idx;
229
230 if (cont_rate <= cinfo[idx].speed)
231 break;
232 }
233
234 wm->acc_rate = cinfo[sp_idx].code;
235 wm->acc_slot = ac97_touch_slot;
236 dev_info(&wm->touch_dev->dev, "atmel accelerated touchscreen driver, "
237 "%d samples/sec\n", cinfo[sp_idx].speed);
238
239 if (pen_int) {
240 unsigned long reg;
241
242 wm->pen_irq = atmel_wm97xx->gpio_irq;
243
244 switch (wm->id) {
245 case WM9712_ID2: /* Fall through. */
246 case WM9713_ID2:
247 /*
248 * Use GPIO 13 (PEN_DOWN) to assert GPIO line 3
249 * (PENDOWN).
250 */
251 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
252 WM97XX_GPIO_POL_HIGH,
253 WM97XX_GPIO_STICKY,
254 WM97XX_GPIO_WAKE);
255 wm97xx_config_gpio(wm, WM97XX_GPIO_3, WM97XX_GPIO_OUT,
256 WM97XX_GPIO_POL_HIGH,
257 WM97XX_GPIO_NOTSTICKY,
258 WM97XX_GPIO_NOWAKE);
259 case WM9705_ID2: /* Fall through. */
260 /*
261 * Enable touch data slot in AC97 controller channel B.
262 */
263 reg = ac97c_readl(atmel_wm97xx, ICA);
264 reg &= ~AC97C_CH_MASK(wm->acc_slot);
265 reg |= AC97C_CH_ASSIGN(wm->acc_slot, B);
266 ac97c_writel(atmel_wm97xx, ICA, reg);
267
268 /*
269 * Enable channel and interrupt for RXRDY and OVERRUN.
270 */
271 ac97c_writel(atmel_wm97xx, CBMR, AC97C_CMR_CENA
272 | AC97C_CMR_CEM_BIG
273 | AC97C_CMR_SIZE_16
274 | AC97C_OVRUN
275 | AC97C_RXRDY);
276 /* Dummy read to empty RXRHR. */
277 ac97c_readl(atmel_wm97xx, CBRHR);
278 /*
279 * Enable interrupt for channel B in the AC97
280 * controller.
281 */
282 ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
283 break;
284 default:
285 dev_err(&wm->touch_dev->dev, "pen down irq not "
286 "supported on this device\n");
287 pen_int = 0;
288 break;
289 }
290 }
291
292 return 0;
293 }
294
atmel_wm97xx_acc_shutdown(struct wm97xx * wm)295 static void atmel_wm97xx_acc_shutdown(struct wm97xx *wm)
296 {
297 if (pen_int) {
298 struct atmel_wm97xx *atmel_wm97xx =
299 platform_get_drvdata(wm->touch_dev);
300 unsigned long ica;
301
302 switch (wm->id & 0xffff) {
303 case WM9705_ID2: /* Fall through. */
304 case WM9712_ID2: /* Fall through. */
305 case WM9713_ID2:
306 /* Disable slot and turn off channel B interrupts. */
307 ica = ac97c_readl(atmel_wm97xx, ICA);
308 ica &= ~AC97C_CH_MASK(wm->acc_slot);
309 ac97c_writel(atmel_wm97xx, ICA, ica);
310 ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
311 ac97c_writel(atmel_wm97xx, CBMR, 0);
312 wm->pen_irq = 0;
313 break;
314 default:
315 dev_err(&wm->touch_dev->dev, "unknown codec\n");
316 break;
317 }
318 }
319 }
320
atmel_wm97xx_irq_enable(struct wm97xx * wm,int enable)321 static void atmel_wm97xx_irq_enable(struct wm97xx *wm, int enable)
322 {
323 /* Intentionally left empty. */
324 }
325
326 static struct wm97xx_mach_ops atmel_mach_ops = {
327 .acc_enabled = 1,
328 .acc_pen_up = atmel_wm97xx_acc_pen_up,
329 .acc_startup = atmel_wm97xx_acc_startup,
330 .acc_shutdown = atmel_wm97xx_acc_shutdown,
331 .irq_enable = atmel_wm97xx_irq_enable,
332 .irq_gpio = WM97XX_GPIO_3,
333 };
334
atmel_wm97xx_probe(struct platform_device * pdev)335 static int __init atmel_wm97xx_probe(struct platform_device *pdev)
336 {
337 struct wm97xx *wm = platform_get_drvdata(pdev);
338 struct atmel_wm97xx *atmel_wm97xx;
339 int ret;
340
341 atmel_wm97xx = kzalloc(sizeof(struct atmel_wm97xx), GFP_KERNEL);
342 if (!atmel_wm97xx) {
343 dev_dbg(&pdev->dev, "out of memory\n");
344 return -ENOMEM;
345 }
346
347 atmel_wm97xx->wm = wm;
348 atmel_wm97xx->regs = (void *)ATMEL_WM97XX_AC97C_IOMEM;
349 atmel_wm97xx->ac97c_irq = ATMEL_WM97XX_AC97C_IRQ;
350 atmel_wm97xx->gpio_pen = atmel_gpio_line;
351 atmel_wm97xx->gpio_irq = gpio_to_irq(atmel_wm97xx->gpio_pen);
352
353 setup_timer(&atmel_wm97xx->pen_timer, atmel_wm97xx_pen_timer,
354 (unsigned long)wm);
355
356 ret = request_irq(atmel_wm97xx->ac97c_irq,
357 atmel_wm97xx_channel_b_interrupt,
358 IRQF_SHARED, "atmel-wm97xx-ch-b", atmel_wm97xx);
359 if (ret) {
360 dev_dbg(&pdev->dev, "could not request ac97c irq\n");
361 goto err;
362 }
363
364 platform_set_drvdata(pdev, atmel_wm97xx);
365
366 ret = wm97xx_register_mach_ops(wm, &atmel_mach_ops);
367 if (ret)
368 goto err_irq;
369
370 return ret;
371
372 err_irq:
373 free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
374 err:
375 platform_set_drvdata(pdev, NULL);
376 kfree(atmel_wm97xx);
377 return ret;
378 }
379
atmel_wm97xx_remove(struct platform_device * pdev)380 static int __exit atmel_wm97xx_remove(struct platform_device *pdev)
381 {
382 struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
383 struct wm97xx *wm = atmel_wm97xx->wm;
384
385 ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
386 free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
387 del_timer_sync(&atmel_wm97xx->pen_timer);
388 wm97xx_unregister_mach_ops(wm);
389 platform_set_drvdata(pdev, NULL);
390 kfree(atmel_wm97xx);
391
392 return 0;
393 }
394
395 #ifdef CONFIG_PM_SLEEP
atmel_wm97xx_suspend(struct * dev)396 static int atmel_wm97xx_suspend(struct *dev)
397 {
398 struct platform_device *pdev = to_platform_device(dev);
399 struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
400
401 ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
402 disable_irq(atmel_wm97xx->gpio_irq);
403 del_timer_sync(&atmel_wm97xx->pen_timer);
404
405 return 0;
406 }
407
atmel_wm97xx_resume(struct device * dev)408 static int atmel_wm97xx_resume(struct device *dev)
409 {
410 struct platform_device *pdev = to_platform_device(dev);
411 struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
412 struct wm97xx *wm = atmel_wm97xx->wm;
413
414 if (wm->input_dev->users) {
415 enable_irq(atmel_wm97xx->gpio_irq);
416 ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
417 }
418
419 return 0;
420 }
421 #endif
422
423 static SIMPLE_DEV_PM_OPS(atmel_wm97xx_pm_ops,
424 atmel_wm97xx_suspend, atmel_wm97xx_resume);
425
426 static struct platform_driver atmel_wm97xx_driver = {
427 .remove = __exit_p(atmel_wm97xx_remove),
428 .driver = {
429 .name = "wm97xx-touch",
430 .owner = THIS_MODULE,
431 .pm = &atmel_wm97xx_pm_ops,
432 },
433 };
434
atmel_wm97xx_init(void)435 static int __init atmel_wm97xx_init(void)
436 {
437 return platform_driver_probe(&atmel_wm97xx_driver, atmel_wm97xx_probe);
438 }
439 module_init(atmel_wm97xx_init);
440
atmel_wm97xx_exit(void)441 static void __exit atmel_wm97xx_exit(void)
442 {
443 platform_driver_unregister(&atmel_wm97xx_driver);
444 }
445 module_exit(atmel_wm97xx_exit);
446
447 MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
448 MODULE_DESCRIPTION("wm97xx continuous touch driver for Atmel AT91 and AVR32");
449 MODULE_LICENSE("GPL");
450