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Merge 3.12-rc6 into staging-next.
[karo-tx-linux.git] / drivers / input / touchscreen / wm9712.c
1 /*
2  * wm9712.c  --  Codec driver for Wolfson WM9712 AC97 Codecs.
3  *
4  * Copyright 2003, 2004, 2005, 2006, 2007 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 WM9712_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 = 3;
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 WM9712
155  */
156 static void wm9712_phy_init(struct wm97xx *wm)
157 {
158         u16 dig1 = 0;
159         u16 dig2 = WM97XX_RPR | WM9712_RPU(1);
160
161         /* WM9712 rpu */
162         if (rpu) {
163                 dig2 &= 0xffc0;
164                 dig2 |= WM9712_RPU(rpu);
165                 dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms\n",
166                         64000 / rpu);
167         }
168
169         /* WM9712 five wire */
170         if (five_wire) {
171                 dig2 |= WM9712_45W;
172                 dev_dbg(wm->dev, "setting 5-wire touchscreen mode.\n");
173
174                 if (pil) {
175                         dev_warn(wm->dev, "pressure measurement is not "
176                                  "supported in 5-wire mode\n");
177                         pil = 0;
178                 }
179         }
180
181         /* touchpanel pressure current*/
182         if (pil == 2) {
183                 dig2 |= WM9712_PIL;
184                 dev_dbg(wm->dev,
185                         "setting pressure measurement current to 400uA.\n");
186         } else if (pil)
187                 dev_dbg(wm->dev,
188                         "setting pressure measurement current to 200uA.\n");
189         if (!pil)
190                 pressure = 0;
191
192         /* polling mode sample settling delay */
193         if (delay < 0 || delay > 15) {
194                 dev_dbg(wm->dev, "supplied delay out of range.\n");
195                 delay = 4;
196         }
197         dig1 &= 0xff0f;
198         dig1 |= WM97XX_DELAY(delay);
199         dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.\n",
200                 delay_table[delay]);
201
202         /* mask */
203         dig2 |= ((mask & 0x3) << 6);
204         if (mask) {
205                 u16 reg;
206                 /* Set GPIO4 as Mask Pin*/
207                 reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
208                 wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4);
209                 reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);
210                 wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4);
211         }
212
213         /* wait - coord mode */
214         if (coord)
215                 dig2 |= WM9712_WAIT;
216
217         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
218         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
219 }
220
221 static void wm9712_dig_enable(struct wm97xx *wm, int enable)
222 {
223         u16 dig2 = wm->dig[2];
224
225         if (enable) {
226                 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
227                                  dig2 | WM97XX_PRP_DET_DIG);
228                 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
229         } else
230                 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
231                                  dig2 & ~WM97XX_PRP_DET_DIG);
232 }
233
234 static void wm9712_aux_prepare(struct wm97xx *wm)
235 {
236         memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
237         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0);
238         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG);
239 }
240
241 static void wm9712_dig_restore(struct wm97xx *wm)
242 {
243         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]);
244         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]);
245 }
246
247 static inline int is_pden(struct wm97xx *wm)
248 {
249         return wm->dig[2] & WM9712_PDEN;
250 }
251
252 /*
253  * Read a sample from the WM9712 adc in polling mode.
254  */
255 static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
256 {
257         int timeout = 5 * delay;
258         bool wants_pen = adcsel & WM97XX_PEN_DOWN;
259
260         if (wants_pen && !wm->pen_probably_down) {
261                 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
262                 if (!(data & WM97XX_PEN_DOWN))
263                         return RC_PENUP;
264                 wm->pen_probably_down = 1;
265         }
266
267         /* set up digitiser */
268         if (wm->mach_ops && wm->mach_ops->pre_sample)
269                 wm->mach_ops->pre_sample(adcsel);
270         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK)
271                                 | WM97XX_POLL | WM97XX_DELAY(delay));
272
273         /* wait 3 AC97 time slots + delay for conversion */
274         poll_delay(delay);
275
276         /* wait for POLL to go low */
277         while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
278                && timeout) {
279                 udelay(AC97_LINK_FRAME);
280                 timeout--;
281         }
282
283         if (timeout <= 0) {
284                 /* If PDEN is set, we can get a timeout when pen goes up */
285                 if (is_pden(wm))
286                         wm->pen_probably_down = 0;
287                 else
288                         dev_dbg(wm->dev, "adc sample timeout\n");
289                 return RC_PENUP;
290         }
291
292         *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
293         if (wm->mach_ops && wm->mach_ops->post_sample)
294                 wm->mach_ops->post_sample(adcsel);
295
296         /* check we have correct sample */
297         if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) {
298                 dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x\n",
299                         adcsel & WM97XX_ADCSEL_MASK,
300                         *sample & WM97XX_ADCSEL_MASK);
301                 return RC_AGAIN;
302         }
303
304         if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) {
305                 /* Sometimes it reads a wrong value the first time. */
306                 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
307                 if (!(*sample & WM97XX_PEN_DOWN)) {
308                         wm->pen_probably_down = 0;
309                         return RC_PENUP;
310                 }
311         }
312
313         return RC_VALID;
314 }
315
316 /*
317  * Read a coord from the WM9712 adc in polling mode.
318  */
319 static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
320 {
321         int timeout = 5 * delay;
322
323         if (!wm->pen_probably_down) {
324                 u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
325                 if (!(data_rd & WM97XX_PEN_DOWN))
326                         return RC_PENUP;
327                 wm->pen_probably_down = 1;
328         }
329
330         /* set up digitiser */
331         if (wm->mach_ops && wm->mach_ops->pre_sample)
332                 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
333
334         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,
335                 WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay));
336
337         /* wait 3 AC97 time slots + delay for conversion and read x */
338         poll_delay(delay);
339         data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
340         /* wait for POLL to go low */
341         while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
342                && timeout) {
343                 udelay(AC97_LINK_FRAME);
344                 timeout--;
345         }
346
347         if (timeout <= 0) {
348                 /* If PDEN is set, we can get a timeout when pen goes up */
349                 if (is_pden(wm))
350                         wm->pen_probably_down = 0;
351                 else
352                         dev_dbg(wm->dev, "adc sample timeout\n");
353                 return RC_PENUP;
354         }
355
356         /* read back y data */
357         data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
358         if (pil)
359                 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
360         else
361                 data->p = DEFAULT_PRESSURE;
362
363         if (wm->mach_ops && wm->mach_ops->post_sample)
364                 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
365
366         /* check we have correct sample */
367         if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
368                 goto err;
369         if (pil && !(data->p & WM97XX_ADCSEL_PRES))
370                 goto err;
371
372         if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
373                 wm->pen_probably_down = 0;
374                 return RC_PENUP;
375         }
376         return RC_VALID;
377 err:
378         return 0;
379 }
380
381 /*
382  * Sample the WM9712 touchscreen in polling mode
383  */
384 static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
385 {
386         int rc;
387
388         if (coord) {
389                 rc = wm9712_poll_coord(wm, data);
390                 if (rc != RC_VALID)
391                         return rc;
392         } else {
393                 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN,
394                                         &data->x);
395                 if (rc != RC_VALID)
396                         return rc;
397
398                 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN,
399                                         &data->y);
400                 if (rc != RC_VALID)
401                         return rc;
402
403                 if (pil && !five_wire) {
404                         rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN,
405                                                 &data->p);
406                         if (rc != RC_VALID)
407                                 return rc;
408                 } else
409                         data->p = DEFAULT_PRESSURE;
410         }
411         return RC_VALID;
412 }
413
414 /*
415  * Enable WM9712 continuous mode, i.e. touch data is streamed across
416  * an AC97 slot
417  */
418 static int wm9712_acc_enable(struct wm97xx *wm, int enable)
419 {
420         u16 dig1, dig2;
421         int ret = 0;
422
423         dig1 = wm->dig[1];
424         dig2 = wm->dig[2];
425
426         if (enable) {
427                 /* continuous mode */
428                 if (wm->mach_ops->acc_startup) {
429                         ret = wm->mach_ops->acc_startup(wm);
430                         if (ret < 0)
431                                 return ret;
432                 }
433                 dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK |
434                         WM97XX_DELAY_MASK | WM97XX_SLT_MASK);
435                 dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN |
436                         WM97XX_DELAY(delay) |
437                         WM97XX_SLT(wm->acc_slot) |
438                         WM97XX_RATE(wm->acc_rate);
439                 if (pil)
440                         dig1 |= WM97XX_ADCSEL_PRES;
441                 dig2 |= WM9712_PDEN;
442         } else {
443                 dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN);
444                 dig2 &= ~WM9712_PDEN;
445                 if (wm->mach_ops->acc_shutdown)
446                         wm->mach_ops->acc_shutdown(wm);
447         }
448
449         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
450         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
451
452         return 0;
453 }
454
455 struct wm97xx_codec_drv wm9712_codec = {
456         .id = WM9712_ID2,
457         .name = "wm9712",
458         .poll_sample = wm9712_poll_sample,
459         .poll_touch = wm9712_poll_touch,
460         .acc_enable = wm9712_acc_enable,
461         .phy_init = wm9712_phy_init,
462         .dig_enable = wm9712_dig_enable,
463         .dig_restore = wm9712_dig_restore,
464         .aux_prepare = wm9712_aux_prepare,
465 };
466 EXPORT_SYMBOL_GPL(wm9712_codec);
467
468 /* Module information */
469 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
470 MODULE_DESCRIPTION("WM9712 Touch Screen Driver");
471 MODULE_LICENSE("GPL");