Merge branch 'for-2.6.28' of git://linux-nfs.org/~bfields/linux
[pandora-kernel.git] / drivers / input / touchscreen / wm9713.c
1 /*
2  * wm9713.c  --  Codec touch driver for Wolfson WM9713 AC97 Codec.
3  *
4  * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
5  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
6  * Parts Copyright : Ian Molton <spyro@f2s.com>
7  *                   Andrew Zabolotny <zap@homelink.ru>
8  *                   Russell King <rmk@arm.linux.org.uk>
9  *
10  *  This program is free software; you can redistribute  it and/or modify it
11  *  under  the terms of  the GNU General  Public License as published by the
12  *  Free Software Foundation;  either version 2 of the  License, or (at your
13  *  option) any later version.
14  *
15  */
16
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/kernel.h>
20 #include <linux/input.h>
21 #include <linux/delay.h>
22 #include <linux/bitops.h>
23 #include <linux/wm97xx.h>
24
25 #define TS_NAME                 "wm97xx"
26 #define WM9713_VERSION          "1.00"
27 #define DEFAULT_PRESSURE        0xb0c0
28
29 /*
30  * Module parameters
31  */
32
33 /*
34  * Set internal pull up for pen detect.
35  *
36  * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive)
37  * i.e. pull up resistance = 64k Ohms / rpu.
38  *
39  * Adjust this value if you are having problems with pen detect not
40  * detecting any down event.
41  */
42 static int rpu = 8;
43 module_param(rpu, int, 0);
44 MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect.");
45
46 /*
47  * Set current used for pressure measurement.
48  *
49  * Set pil = 2 to use 400uA
50  *     pil = 1 to use 200uA and
51  *     pil = 0 to disable pressure measurement.
52  *
53  * This is used to increase the range of values returned by the adc
54  * when measureing touchpanel pressure.
55  */
56 static int pil;
57 module_param(pil, int, 0);
58 MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");
59
60 /*
61  * Set threshold for pressure measurement.
62  *
63  * Pen down pressure below threshold is ignored.
64  */
65 static int pressure = DEFAULT_PRESSURE & 0xfff;
66 module_param(pressure, int, 0);
67 MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");
68
69 /*
70  * Set adc sample delay.
71  *
72  * For accurate touchpanel measurements, some settling time may be
73  * required between the switch matrix applying a voltage across the
74  * touchpanel plate and the ADC sampling the signal.
75  *
76  * This delay can be set by setting delay = n, where n is the array
77  * position of the delay in the array delay_table below.
78  * Long delays > 1ms are supported for completeness, but are not
79  * recommended.
80  */
81 static int delay = 4;
82 module_param(delay, int, 0);
83 MODULE_PARM_DESC(delay, "Set adc sample delay.");
84
85 /*
86  * Set five_wire = 1 to use a 5 wire touchscreen.
87  *
88  * NOTE: Five wire mode does not allow for readback of pressure.
89  */
90 static int five_wire;
91 module_param(five_wire, int, 0);
92 MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");
93
94 /*
95  * Set adc mask function.
96  *
97  * Sources of glitch noise, such as signals driving an LCD display, may feed
98  * through to the touch screen plates and affect measurement accuracy. In
99  * order to minimise this, a signal may be applied to the MASK pin to delay or
100  * synchronise the sampling.
101  *
102  * 0 = No delay or sync
103  * 1 = High on pin stops conversions
104  * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
105  * 3 = Edge triggered, edge on pin starts conversion after delay param
106  */
107 static int mask;
108 module_param(mask, int, 0);
109 MODULE_PARM_DESC(mask, "Set adc mask function.");
110
111 /*
112  * Coordinate Polling Enable.
113  *
114  * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
115  * for every poll.
116  */
117 static int coord;
118 module_param(coord, int, 0);
119 MODULE_PARM_DESC(coord, "Polling coordinate mode");
120
121 /*
122  * ADC sample delay times in uS
123  */
124 static const int delay_table[] = {
125         21,    /* 1 AC97 Link frames */
126         42,    /* 2 */
127         84,    /* 4 */
128         167,   /* 8 */
129         333,   /* 16 */
130         667,   /* 32 */
131         1000,  /* 48 */
132         1333,  /* 64 */
133         2000,  /* 96 */
134         2667,  /* 128 */
135         3333,  /* 160 */
136         4000,  /* 192 */
137         4667,  /* 224 */
138         5333,  /* 256 */
139         6000,  /* 288 */
140         0      /* No delay, switch matrix always on */
141 };
142
143 /*
144  * Delay after issuing a POLL command.
145  *
146  * The delay is 3 AC97 link frames + the touchpanel settling delay
147  */
148 static inline void poll_delay(int d)
149 {
150         udelay(3 * AC97_LINK_FRAME + delay_table[d]);
151 }
152
153 /*
154  * set up the physical settings of the WM9713
155  */
156 static void wm9713_phy_init(struct wm97xx *wm)
157 {
158         u16 dig1 = 0, dig2, dig3;
159
160         /* default values */
161         dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5);
162         dig3 = WM9712_RPU(1);
163
164         /* rpu */
165         if (rpu) {
166                 dig3 &= 0xffc0;
167                 dig3 |= WM9712_RPU(rpu);
168                 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n",
169                          64000 / rpu);
170         }
171
172         /* Five wire panel? */
173         if (five_wire) {
174                 dig3 |= WM9713_45W;
175                 dev_info(wm->dev, "setting 5-wire touchscreen mode.");
176
177                 if (pil) {
178                         dev_warn(wm->dev,
179                                  "Pressure measurement not supported in 5 "
180                                  "wire mode, disabling\n");
181                         pil = 0;
182                 }
183         }
184
185         /* touchpanel pressure */
186         if (pil == 2) {
187                 dig3 |= WM9712_PIL;
188                 dev_info(wm->dev,
189                          "setting pressure measurement current to 400uA.");
190         } else if (pil)
191                 dev_info(wm->dev,
192                          "setting pressure measurement current to 200uA.");
193         if (!pil)
194                 pressure = 0;
195
196         /* sample settling delay */
197         if (delay < 0 || delay > 15) {
198                 dev_info(wm->dev, "supplied delay out of range.");
199                 delay = 4;
200                 dev_info(wm->dev, "setting adc sample delay to %d u Secs.",
201                          delay_table[delay]);
202         }
203         dig2 &= 0xff0f;
204         dig2 |= WM97XX_DELAY(delay);
205
206         /* mask */
207         dig3 |= ((mask & 0x3) << 4);
208         if (coord)
209                 dig3 |= WM9713_WAIT;
210
211         wm->misc = wm97xx_reg_read(wm, 0x5a);
212
213         wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
214         wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
215         wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
216         wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0);
217 }
218
219 static void wm9713_dig_enable(struct wm97xx *wm, int enable)
220 {
221         u16 val;
222
223         if (enable) {
224                 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
225                 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff);
226                 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] |
227                                  WM97XX_PRP_DET_DIG);
228                 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
229         } else {
230                 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] &
231                                         ~WM97XX_PRP_DET_DIG);
232                 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
233                 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000);
234         }
235 }
236
237 static void wm9713_dig_restore(struct wm97xx *wm)
238 {
239         wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]);
240         wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]);
241         wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]);
242 }
243
244 static void wm9713_aux_prepare(struct wm97xx *wm)
245 {
246         memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
247         wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0);
248         wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0);
249         wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG);
250 }
251
252 static inline int is_pden(struct wm97xx *wm)
253 {
254         return wm->dig[2] & WM9713_PDEN;
255 }
256
257 /*
258  * Read a sample from the WM9713 adc in polling mode.
259  */
260 static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
261 {
262         u16 dig1;
263         int timeout = 5 * delay;
264
265         if (!wm->pen_probably_down) {
266                 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
267                 if (!(data & WM97XX_PEN_DOWN))
268                         return RC_PENUP;
269                 wm->pen_probably_down = 1;
270         }
271
272         /* set up digitiser */
273         if (adcsel & 0x8000)
274                 adcsel = 1 << ((adcsel & 0x7fff) + 3);
275
276         dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
277         dig1 &= ~WM9713_ADCSEL_MASK;
278
279         if (wm->mach_ops && wm->mach_ops->pre_sample)
280                 wm->mach_ops->pre_sample(adcsel);
281         wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | adcsel | WM9713_POLL);
282
283         /* wait 3 AC97 time slots + delay for conversion */
284         poll_delay(delay);
285
286         /* wait for POLL to go low */
287         while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) &&
288                 timeout) {
289                 udelay(AC97_LINK_FRAME);
290                 timeout--;
291         }
292
293         if (timeout <= 0) {
294                 /* If PDEN is set, we can get a timeout when pen goes up */
295                 if (is_pden(wm))
296                         wm->pen_probably_down = 0;
297                 else
298                         dev_dbg(wm->dev, "adc sample timeout");
299                 return RC_PENUP;
300         }
301
302         *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
303         if (wm->mach_ops && wm->mach_ops->post_sample)
304                 wm->mach_ops->post_sample(adcsel);
305
306         /* check we have correct sample */
307         if ((*sample & WM97XX_ADCSRC_MASK) != ffs(adcsel >> 1) << 12) {
308                 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,
309                         *sample & WM97XX_ADCSRC_MASK);
310                 return RC_PENUP;
311         }
312
313         if (!(*sample & WM97XX_PEN_DOWN)) {
314                 wm->pen_probably_down = 0;
315                 return RC_PENUP;
316         }
317
318         return RC_VALID;
319 }
320
321 /*
322  * Read a coordinate from the WM9713 adc in polling mode.
323  */
324 static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
325 {
326         u16 dig1;
327         int timeout = 5 * delay;
328
329         if (!wm->pen_probably_down) {
330                 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
331                 if (!(val & WM97XX_PEN_DOWN))
332                         return RC_PENUP;
333                 wm->pen_probably_down = 1;
334         }
335
336         /* set up digitiser */
337         dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
338         dig1 &= ~WM9713_ADCSEL_MASK;
339         if (pil)
340                 dig1 |= WM9713_ADCSEL_PRES;
341
342         if (wm->mach_ops && wm->mach_ops->pre_sample)
343                 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
344         wm97xx_reg_write(wm, AC97_WM9713_DIG1,
345                          dig1 | WM9713_POLL | WM9713_COO);
346
347         /* wait 3 AC97 time slots + delay for conversion */
348         poll_delay(delay);
349         data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
350         /* wait for POLL to go low */
351         while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL)
352                && timeout) {
353                 udelay(AC97_LINK_FRAME);
354                 timeout--;
355         }
356
357         if (timeout <= 0) {
358                 /* If PDEN is set, we can get a timeout when pen goes up */
359                 if (is_pden(wm))
360                         wm->pen_probably_down = 0;
361                 else
362                         dev_dbg(wm->dev, "adc sample timeout");
363                 return RC_PENUP;
364         }
365
366         /* read back data */
367         data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
368         if (pil)
369                 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
370         else
371                 data->p = DEFAULT_PRESSURE;
372
373         if (wm->mach_ops && wm->mach_ops->post_sample)
374                 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
375
376         /* check we have correct sample */
377         if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
378                 goto err;
379         if (pil && !(data->p & WM97XX_ADCSEL_PRES))
380                 goto err;
381
382         if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
383                 wm->pen_probably_down = 0;
384                 return RC_PENUP;
385         }
386         return RC_VALID;
387 err:
388         return 0;
389 }
390
391 /*
392  * Sample the WM9713 touchscreen in polling mode
393  */
394 static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
395 {
396         int rc;
397
398         if (coord) {
399                 rc = wm9713_poll_coord(wm, data);
400                 if (rc != RC_VALID)
401                         return rc;
402         } else {
403                 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x);
404                 if (rc != RC_VALID)
405                         return rc;
406                 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y);
407                 if (rc != RC_VALID)
408                         return rc;
409                 if (pil) {
410                         rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES,
411                                                 &data->p);
412                         if (rc != RC_VALID)
413                                 return rc;
414                 } else
415                         data->p = DEFAULT_PRESSURE;
416         }
417         return RC_VALID;
418 }
419
420 /*
421  * Enable WM9713 continuous mode, i.e. touch data is streamed across
422  * an AC97 slot
423  */
424 static int wm9713_acc_enable(struct wm97xx *wm, int enable)
425 {
426         u16 dig1, dig2, dig3;
427         int ret = 0;
428
429         dig1 = wm->dig[0];
430         dig2 = wm->dig[1];
431         dig3 = wm->dig[2];
432
433         if (enable) {
434                 /* continous mode */
435                 if (wm->mach_ops->acc_startup &&
436                         (ret = wm->mach_ops->acc_startup(wm)) < 0)
437                         return ret;
438
439                 dig1 &= ~WM9713_ADCSEL_MASK;
440                 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X |
441                         WM9713_ADCSEL_Y;
442                 if (pil)
443                         dig1 |= WM9713_ADCSEL_PRES;
444                 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK  |
445                         WM97XX_CM_RATE_MASK);
446                 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) |
447                 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate);
448                 dig3 |= WM9713_PDEN;
449         } else {
450                 dig1 &= ~(WM9713_CTC | WM9713_COO);
451                 dig2 &= ~WM97XX_SLEN;
452                 dig3 &= ~WM9713_PDEN;
453                 if (wm->mach_ops->acc_shutdown)
454                         wm->mach_ops->acc_shutdown(wm);
455         }
456
457         wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
458         wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
459         wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
460
461         return ret;
462 }
463
464 struct wm97xx_codec_drv wm9713_codec = {
465         .id = WM9713_ID2,
466         .name = "wm9713",
467         .poll_sample = wm9713_poll_sample,
468         .poll_touch = wm9713_poll_touch,
469         .acc_enable = wm9713_acc_enable,
470         .phy_init = wm9713_phy_init,
471         .dig_enable = wm9713_dig_enable,
472         .dig_restore = wm9713_dig_restore,
473         .aux_prepare = wm9713_aux_prepare,
474 };
475 EXPORT_SYMBOL_GPL(wm9713_codec);
476
477 /* Module information */
478 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
479 MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
480 MODULE_LICENSE("GPL");