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-rw-r--r--drivers/input/touchscreen/wm9713.c460
1 files changed, 460 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/wm9713.c b/drivers/input/touchscreen/wm9713.c
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index 000000000000..01278bd7e65c
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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
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 WM9713_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 */
44static int rpu = 8;
45module_param(rpu, int, 0);
46MODULE_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 */
58static int pil;
59module_param(pil, int, 0);
60MODULE_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 */
67static int pressure = DEFAULT_PRESSURE & 0xfff;
68module_param(pressure, int, 0);
69MODULE_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 */
83static int delay = 4;
84module_param(delay, int, 0);
85MODULE_PARM_DESC(delay, "Set adc sample delay.");
86
87/*
88 * Set adc mask function.
89 *
90 * Sources of glitch noise, such as signals driving an LCD display, may feed
91 * through to the touch screen plates and affect measurement accuracy. In
92 * order to minimise this, a signal may be applied to the MASK pin to delay or
93 * synchronise the sampling.
94 *
95 * 0 = No delay or sync
96 * 1 = High on pin stops conversions
97 * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
98 * 3 = Edge triggered, edge on pin starts conversion after delay param
99 */
100static int mask;
101module_param(mask, int, 0);
102MODULE_PARM_DESC(mask, "Set adc mask function.");
103
104/*
105 * Coordinate Polling Enable.
106 *
107 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
108 * for every poll.
109 */
110static int coord;
111module_param(coord, int, 0);
112MODULE_PARM_DESC(coord, "Polling coordinate mode");
113
114/*
115 * ADC sample delay times in uS
116 */
117static const int delay_table[] = {
118 21, /* 1 AC97 Link frames */
119 42, /* 2 */
120 84, /* 4 */
121 167, /* 8 */
122 333, /* 16 */
123 667, /* 32 */
124 1000, /* 48 */
125 1333, /* 64 */
126 2000, /* 96 */
127 2667, /* 128 */
128 3333, /* 160 */
129 4000, /* 192 */
130 4667, /* 224 */
131 5333, /* 256 */
132 6000, /* 288 */
133 0 /* No delay, switch matrix always on */
134};
135
136/*
137 * Delay after issuing a POLL command.
138 *
139 * The delay is 3 AC97 link frames + the touchpanel settling delay
140 */
141static inline void poll_delay(int d)
142{
143 udelay(3 * AC97_LINK_FRAME + delay_table[d]);
144}
145
146/*
147 * set up the physical settings of the WM9713
148 */
149static void wm9713_phy_init(struct wm97xx *wm)
150{
151 u16 dig1 = 0, dig2, dig3;
152
153 /* default values */
154 dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5);
155 dig3 = WM9712_RPU(1);
156
157 /* rpu */
158 if (rpu) {
159 dig3 &= 0xffc0;
160 dig3 |= WM9712_RPU(rpu);
161 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n",
162 64000 / rpu);
163 }
164
165 /* touchpanel pressure */
166 if (pil == 2) {
167 dig3 |= WM9712_PIL;
168 dev_info(wm->dev,
169 "setting pressure measurement current to 400uA.");
170 } else if (pil)
171 dev_info(wm->dev,
172 "setting pressure measurement current to 200uA.");
173 if (!pil)
174 pressure = 0;
175
176 /* sample settling delay */
177 if (delay < 0 || delay > 15) {
178 dev_info(wm->dev, "supplied delay out of range.");
179 delay = 4;
180 dev_info(wm->dev, "setting adc sample delay to %d u Secs.",
181 delay_table[delay]);
182 }
183 dig2 &= 0xff0f;
184 dig2 |= WM97XX_DELAY(delay);
185
186 /* mask */
187 dig3 |= ((mask & 0x3) << 4);
188 if (coord)
189 dig3 |= WM9713_WAIT;
190
191 wm->misc = wm97xx_reg_read(wm, 0x5a);
192
193 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
194 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
195 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
196 wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0);
197}
198
199static void wm9713_dig_enable(struct wm97xx *wm, int enable)
200{
201 u16 val;
202
203 if (enable) {
204 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
205 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff);
206 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] |
207 WM97XX_PRP_DET_DIG);
208 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
209 } else {
210 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] &
211 ~WM97XX_PRP_DET_DIG);
212 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
213 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000);
214 }
215}
216
217static void wm9713_dig_restore(struct wm97xx *wm)
218{
219 wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]);
220 wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]);
221 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]);
222}
223
224static void wm9713_aux_prepare(struct wm97xx *wm)
225{
226 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
227 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0);
228 wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0);
229 wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG);
230}
231
232static inline int is_pden(struct wm97xx *wm)
233{
234 return wm->dig[2] & WM9713_PDEN;
235}
236
237/*
238 * Read a sample from the WM9713 adc in polling mode.
239 */
240static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
241{
242 u16 dig1;
243 int timeout = 5 * delay;
244
245 if (!wm->pen_probably_down) {
246 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
247 if (!(data & WM97XX_PEN_DOWN))
248 return RC_PENUP;
249 wm->pen_probably_down = 1;
250 }
251
252 /* set up digitiser */
253 if (adcsel & 0x8000)
254 adcsel = 1 << ((adcsel & 0x7fff) + 3);
255
256 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
257 dig1 &= ~WM9713_ADCSEL_MASK;
258
259 if (wm->mach_ops && wm->mach_ops->pre_sample)
260 wm->mach_ops->pre_sample(adcsel);
261 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | adcsel | WM9713_POLL);
262
263 /* wait 3 AC97 time slots + delay for conversion */
264 poll_delay(delay);
265
266 /* wait for POLL to go low */
267 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) &&
268 timeout) {
269 udelay(AC97_LINK_FRAME);
270 timeout--;
271 }
272
273 if (timeout <= 0) {
274 /* If PDEN is set, we can get a timeout when pen goes up */
275 if (is_pden(wm))
276 wm->pen_probably_down = 0;
277 else
278 dev_dbg(wm->dev, "adc sample timeout");
279 return RC_PENUP;
280 }
281
282 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
283 if (wm->mach_ops && wm->mach_ops->post_sample)
284 wm->mach_ops->post_sample(adcsel);
285
286 /* check we have correct sample */
287 if ((*sample & WM97XX_ADCSRC_MASK) != ffs(adcsel >> 1) << 12) {
288 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,
289 *sample & WM97XX_ADCSRC_MASK);
290 return RC_PENUP;
291 }
292
293 if (!(*sample & WM97XX_PEN_DOWN)) {
294 wm->pen_probably_down = 0;
295 return RC_PENUP;
296 }
297
298 return RC_VALID;
299}
300
301/*
302 * Read a coordinate from the WM9713 adc in polling mode.
303 */
304static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
305{
306 u16 dig1;
307 int timeout = 5 * delay;
308
309 if (!wm->pen_probably_down) {
310 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
311 if (!(val & WM97XX_PEN_DOWN))
312 return RC_PENUP;
313 wm->pen_probably_down = 1;
314 }
315
316 /* set up digitiser */
317 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
318 dig1 &= ~WM9713_ADCSEL_MASK;
319 if (pil)
320 dig1 |= WM9713_ADCSEL_PRES;
321
322 if (wm->mach_ops && wm->mach_ops->pre_sample)
323 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
324 wm97xx_reg_write(wm, AC97_WM9713_DIG1,
325 dig1 | WM9713_POLL | WM9713_COO);
326
327 /* wait 3 AC97 time slots + delay for conversion */
328 poll_delay(delay);
329 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
330 /* wait for POLL to go low */
331 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL)
332 && timeout) {
333 udelay(AC97_LINK_FRAME);
334 timeout--;
335 }
336
337 if (timeout <= 0) {
338 /* If PDEN is set, we can get a timeout when pen goes up */
339 if (is_pden(wm))
340 wm->pen_probably_down = 0;
341 else
342 dev_dbg(wm->dev, "adc sample timeout");
343 return RC_PENUP;
344 }
345
346 /* read back data */
347 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
348 if (pil)
349 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
350 else
351 data->p = DEFAULT_PRESSURE;
352
353 if (wm->mach_ops && wm->mach_ops->post_sample)
354 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
355
356 /* check we have correct sample */
357 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
358 goto err;
359 if (pil && !(data->p & WM97XX_ADCSEL_PRES))
360 goto err;
361
362 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
363 wm->pen_probably_down = 0;
364 return RC_PENUP;
365 }
366 return RC_VALID;
367err:
368 return 0;
369}
370
371/*
372 * Sample the WM9713 touchscreen in polling mode
373 */
374static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
375{
376 int rc;
377
378 if (coord) {
379 rc = wm9713_poll_coord(wm, data);
380 if (rc != RC_VALID)
381 return rc;
382 } else {
383 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x);
384 if (rc != RC_VALID)
385 return rc;
386 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y);
387 if (rc != RC_VALID)
388 return rc;
389 if (pil) {
390 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES,
391 &data->p);
392 if (rc != RC_VALID)
393 return rc;
394 } else
395 data->p = DEFAULT_PRESSURE;
396 }
397 return RC_VALID;
398}
399
400/*
401 * Enable WM9713 continuous mode, i.e. touch data is streamed across
402 * an AC97 slot
403 */
404static int wm9713_acc_enable(struct wm97xx *wm, int enable)
405{
406 u16 dig1, dig2, dig3;
407 int ret = 0;
408
409 dig1 = wm->dig[0];
410 dig2 = wm->dig[1];
411 dig3 = wm->dig[2];
412
413 if (enable) {
414 /* continous mode */
415 if (wm->mach_ops->acc_startup &&
416 (ret = wm->mach_ops->acc_startup(wm)) < 0)
417 return ret;
418
419 dig1 &= ~WM9713_ADCSEL_MASK;
420 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X |
421 WM9713_ADCSEL_Y;
422 if (pil)
423 dig1 |= WM9713_ADCSEL_PRES;
424 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK |
425 WM97XX_CM_RATE_MASK);
426 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) |
427 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate);
428 dig3 |= WM9713_PDEN;
429 } else {
430 dig1 &= ~(WM9713_CTC | WM9713_COO);
431 dig2 &= ~WM97XX_SLEN;
432 dig3 &= ~WM9713_PDEN;
433 if (wm->mach_ops->acc_shutdown)
434 wm->mach_ops->acc_shutdown(wm);
435 }
436
437 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
438 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
439 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
440
441 return ret;
442}
443
444struct wm97xx_codec_drv wm9713_codec = {
445 .id = WM9713_ID2,
446 .name = "wm9713",
447 .poll_sample = wm9713_poll_sample,
448 .poll_touch = wm9713_poll_touch,
449 .acc_enable = wm9713_acc_enable,
450 .phy_init = wm9713_phy_init,
451 .dig_enable = wm9713_dig_enable,
452 .dig_restore = wm9713_dig_restore,
453 .aux_prepare = wm9713_aux_prepare,
454};
455EXPORT_SYMBOL_GPL(wm9713_codec);
456
457/* Module information */
458MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
459MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
460MODULE_LICENSE("GPL");