Merge branch 'eseries' into pxa
[linux-2.6] / 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
6  *         liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
7  * Parts Copyright : Ian Molton <spyro@f2s.com>
8  *                   Andrew Zabolotny <zap@homelink.ru>
9  *                   Russell King <rmk@arm.linux.org.uk>
10  *
11  *  This program is free software; you can redistribute  it and/or modify it
12  *  under  the terms of  the GNU General  Public License as published by the
13  *  Free Software Foundation;  either version 2 of the  License, or (at your
14  *  option) any later version.
15  *
16  */
17
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/version.h>
21 #include <linux/kernel.h>
22 #include <linux/input.h>
23 #include <linux/delay.h>
24 #include <linux/bitops.h>
25 #include <linux/wm97xx.h>
26
27 #define TS_NAME                 "wm97xx"
28 #define WM9712_VERSION          "1.00"
29 #define DEFAULT_PRESSURE        0xb0c0
30
31 /*
32  * Module parameters
33  */
34
35 /*
36  * Set internal pull up for pen detect.
37  *
38  * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive)
39  * i.e. pull up resistance = 64k Ohms / rpu.
40  *
41  * Adjust this value if you are having problems with pen detect not
42  * detecting any down event.
43  */
44 static int rpu = 8;
45 module_param(rpu, int, 0);
46 MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect.");
47
48 /*
49  * Set current used for pressure measurement.
50  *
51  * Set pil = 2 to use 400uA
52  *     pil = 1 to use 200uA and
53  *     pil = 0 to disable pressure measurement.
54  *
55  * This is used to increase the range of values returned by the adc
56  * when measureing touchpanel pressure.
57  */
58 static int pil;
59 module_param(pil, int, 0);
60 MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");
61
62 /*
63  * Set threshold for pressure measurement.
64  *
65  * Pen down pressure below threshold is ignored.
66  */
67 static int pressure = DEFAULT_PRESSURE & 0xfff;
68 module_param(pressure, int, 0);
69 MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");
70
71 /*
72  * Set adc sample delay.
73  *
74  * For accurate touchpanel measurements, some settling time may be
75  * required between the switch matrix applying a voltage across the
76  * touchpanel plate and the ADC sampling the signal.
77  *
78  * This delay can be set by setting delay = n, where n is the array
79  * position of the delay in the array delay_table below.
80  * Long delays > 1ms are supported for completeness, but are not
81  * recommended.
82  */
83 static int delay = 3;
84 module_param(delay, int, 0);
85 MODULE_PARM_DESC(delay, "Set adc sample delay.");
86
87 /*
88  * Set five_wire = 1 to use a 5 wire touchscreen.
89  *
90  * NOTE: Five wire mode does not allow for readback of pressure.
91  */
92 static int five_wire;
93 module_param(five_wire, int, 0);
94 MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");
95
96 /*
97  * Set adc mask function.
98  *
99  * Sources of glitch noise, such as signals driving an LCD display, may feed
100  * through to the touch screen plates and affect measurement accuracy. In
101  * order to minimise this, a signal may be applied to the MASK pin to delay or
102  * synchronise the sampling.
103  *
104  * 0 = No delay or sync
105  * 1 = High on pin stops conversions
106  * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
107  * 3 = Edge triggered, edge on pin starts conversion after delay param
108  */
109 static int mask;
110 module_param(mask, int, 0);
111 MODULE_PARM_DESC(mask, "Set adc mask function.");
112
113 /*
114  * Coordinate Polling Enable.
115  *
116  * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
117  * for every poll.
118  */
119 static int coord;
120 module_param(coord, int, 0);
121 MODULE_PARM_DESC(coord, "Polling coordinate mode");
122
123 /*
124  * ADC sample delay times in uS
125  */
126 static const int delay_table[] = {
127         21,    /* 1 AC97 Link frames */
128         42,    /* 2 */
129         84,    /* 4 */
130         167,   /* 8 */
131         333,   /* 16 */
132         667,   /* 32 */
133         1000,  /* 48 */
134         1333,  /* 64 */
135         2000,  /* 96 */
136         2667,  /* 128 */
137         3333,  /* 160 */
138         4000,  /* 192 */
139         4667,  /* 224 */
140         5333,  /* 256 */
141         6000,  /* 288 */
142         0      /* No delay, switch matrix always on */
143 };
144
145 /*
146  * Delay after issuing a POLL command.
147  *
148  * The delay is 3 AC97 link frames + the touchpanel settling delay
149  */
150 static inline void poll_delay(int d)
151 {
152         udelay(3 * AC97_LINK_FRAME + delay_table[d]);
153 }
154
155 /*
156  * set up the physical settings of the WM9712
157  */
158 static void wm9712_phy_init(struct wm97xx *wm)
159 {
160         u16 dig1 = 0;
161         u16 dig2 = WM97XX_RPR | WM9712_RPU(1);
162
163         /* WM9712 rpu */
164         if (rpu) {
165                 dig2 &= 0xffc0;
166                 dig2 |= WM9712_RPU(rpu);
167                 dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms",
168                         64000 / rpu);
169         }
170
171         /* touchpanel pressure current*/
172         if (pil == 2) {
173                 dig2 |= WM9712_PIL;
174                 dev_dbg(wm->dev,
175                         "setting pressure measurement current to 400uA.");
176         } else if (pil)
177                 dev_dbg(wm->dev,
178                         "setting pressure measurement current to 200uA.");
179         if (!pil)
180                 pressure = 0;
181
182         /* WM9712 five wire */
183         if (five_wire) {
184                 dig2 |= WM9712_45W;
185                 dev_dbg(wm->dev, "setting 5-wire touchscreen mode.");
186         }
187
188         /* polling mode sample settling delay */
189         if (delay < 0 || delay > 15) {
190                 dev_dbg(wm->dev, "supplied delay out of range.");
191                 delay = 4;
192         }
193         dig1 &= 0xff0f;
194         dig1 |= WM97XX_DELAY(delay);
195         dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.",
196                 delay_table[delay]);
197
198         /* mask */
199         dig2 |= ((mask & 0x3) << 6);
200         if (mask) {
201                 u16 reg;
202                 /* Set GPIO4 as Mask Pin*/
203                 reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
204                 wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4);
205                 reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);
206                 wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4);
207         }
208
209         /* wait - coord mode */
210         if (coord)
211                 dig2 |= WM9712_WAIT;
212
213         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
214         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
215 }
216
217 static void wm9712_dig_enable(struct wm97xx *wm, int enable)
218 {
219         u16 dig2 = wm->dig[2];
220
221         if (enable) {
222                 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
223                                  dig2 | WM97XX_PRP_DET_DIG);
224                 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
225         } else
226                 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
227                                  dig2 & ~WM97XX_PRP_DET_DIG);
228 }
229
230 static void wm9712_aux_prepare(struct wm97xx *wm)
231 {
232         memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
233         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0);
234         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG);
235 }
236
237 static void wm9712_dig_restore(struct wm97xx *wm)
238 {
239         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]);
240         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]);
241 }
242
243 static inline int is_pden(struct wm97xx *wm)
244 {
245         return wm->dig[2] & WM9712_PDEN;
246 }
247
248 /*
249  * Read a sample from the WM9712 adc in polling mode.
250  */
251 static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
252 {
253         int timeout = 5 * delay;
254
255         if (!wm->pen_probably_down) {
256                 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
257                 if (!(data & WM97XX_PEN_DOWN))
258                         return RC_PENUP;
259                 wm->pen_probably_down = 1;
260         }
261
262         /* set up digitiser */
263         if (adcsel & 0x8000)
264                 adcsel = ((adcsel & 0x7fff) + 3) << 12;
265
266         if (wm->mach_ops && wm->mach_ops->pre_sample)
267                 wm->mach_ops->pre_sample(adcsel);
268         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,
269                          adcsel | WM97XX_POLL | WM97XX_DELAY(delay));
270
271         /* wait 3 AC97 time slots + delay for conversion */
272         poll_delay(delay);
273
274         /* wait for POLL to go low */
275         while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
276                && timeout) {
277                 udelay(AC97_LINK_FRAME);
278                 timeout--;
279         }
280
281         if (timeout <= 0) {
282                 /* If PDEN is set, we can get a timeout when pen goes up */
283                 if (is_pden(wm))
284                         wm->pen_probably_down = 0;
285                 else
286                         dev_dbg(wm->dev, "adc sample timeout");
287                 return RC_PENUP;
288         }
289
290         *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
291         if (wm->mach_ops && wm->mach_ops->post_sample)
292                 wm->mach_ops->post_sample(adcsel);
293
294         /* check we have correct sample */
295         if ((*sample & WM97XX_ADCSEL_MASK) != adcsel) {
296                 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,
297                 *sample & WM97XX_ADCSEL_MASK);
298                 return RC_PENUP;
299         }
300
301         if (!(*sample & WM97XX_PEN_DOWN)) {
302                 wm->pen_probably_down = 0;
303                 return RC_PENUP;
304         }
305
306         return RC_VALID;
307 }
308
309 /*
310  * Read a coord from the WM9712 adc in polling mode.
311  */
312 static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
313 {
314         int timeout = 5 * delay;
315
316         if (!wm->pen_probably_down) {
317                 u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
318                 if (!(data_rd & WM97XX_PEN_DOWN))
319                         return RC_PENUP;
320                 wm->pen_probably_down = 1;
321         }
322
323         /* set up digitiser */
324         if (wm->mach_ops && wm->mach_ops->pre_sample)
325                 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
326
327         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,
328                 WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay));
329
330         /* wait 3 AC97 time slots + delay for conversion and read x */
331         poll_delay(delay);
332         data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
333         /* wait for POLL to go low */
334         while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
335                && timeout) {
336                 udelay(AC97_LINK_FRAME);
337                 timeout--;
338         }
339
340         if (timeout <= 0) {
341                 /* If PDEN is set, we can get a timeout when pen goes up */
342                 if (is_pden(wm))
343                         wm->pen_probably_down = 0;
344                 else
345                         dev_dbg(wm->dev, "adc sample timeout");
346                 return RC_PENUP;
347         }
348
349         /* read back y data */
350         data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
351         if (pil)
352                 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
353         else
354                 data->p = DEFAULT_PRESSURE;
355
356         if (wm->mach_ops && wm->mach_ops->post_sample)
357                 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
358
359         /* check we have correct sample */
360         if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
361                 goto err;
362         if (pil && !(data->p & WM97XX_ADCSEL_PRES))
363                 goto err;
364
365         if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
366                 wm->pen_probably_down = 0;
367                 return RC_PENUP;
368         }
369         return RC_VALID;
370 err:
371         return 0;
372 }
373
374 /*
375  * Sample the WM9712 touchscreen in polling mode
376  */
377 static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
378 {
379         int rc;
380
381         if (coord) {
382                 rc = wm9712_poll_coord(wm, data);
383                 if (rc != RC_VALID)
384                         return rc;
385         } else {
386                 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X, &data->x);
387                 if (rc != RC_VALID)
388                         return rc;
389
390                 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y, &data->y);
391                 if (rc != RC_VALID)
392                         return rc;
393
394                 if (pil && !five_wire) {
395                         rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES,
396                                                 &data->p);
397                         if (rc != RC_VALID)
398                                 return rc;
399                 } else
400                         data->p = DEFAULT_PRESSURE;
401         }
402         return RC_VALID;
403 }
404
405 /*
406  * Enable WM9712 continuous mode, i.e. touch data is streamed across
407  * an AC97 slot
408  */
409 static int wm9712_acc_enable(struct wm97xx *wm, int enable)
410 {
411         u16 dig1, dig2;
412         int ret = 0;
413
414         dig1 = wm->dig[1];
415         dig2 = wm->dig[2];
416
417         if (enable) {
418                 /* continous mode */
419                 if (wm->mach_ops->acc_startup) {
420                         ret = wm->mach_ops->acc_startup(wm);
421                         if (ret < 0)
422                                 return ret;
423                 }
424                 dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK |
425                         WM97XX_DELAY_MASK | WM97XX_SLT_MASK);
426                 dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN |
427                         WM97XX_DELAY(delay) |
428                         WM97XX_SLT(wm->acc_slot) |
429                         WM97XX_RATE(wm->acc_rate);
430                 if (pil)
431                         dig1 |= WM97XX_ADCSEL_PRES;
432                 dig2 |= WM9712_PDEN;
433         } else {
434                 dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN);
435                 dig2 &= ~WM9712_PDEN;
436                 if (wm->mach_ops->acc_shutdown)
437                         wm->mach_ops->acc_shutdown(wm);
438         }
439
440         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
441         wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
442
443         return 0;
444 }
445
446 struct wm97xx_codec_drv wm9712_codec = {
447         .id = WM9712_ID2,
448         .name = "wm9712",
449         .poll_sample = wm9712_poll_sample,
450         .poll_touch = wm9712_poll_touch,
451         .acc_enable = wm9712_acc_enable,
452         .phy_init = wm9712_phy_init,
453         .dig_enable = wm9712_dig_enable,
454         .dig_restore = wm9712_dig_restore,
455         .aux_prepare = wm9712_aux_prepare,
456 };
457 EXPORT_SYMBOL_GPL(wm9712_codec);
458
459 /* Module information */
460 MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
461 MODULE_DESCRIPTION("WM9712 Touch Screen Driver");
462 MODULE_LICENSE("GPL");