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Mark Browndca98e92008-04-02 00:51:30 -04001/*
2 * wm9713.c -- Codec touch driver for Wolfson WM9713 AC97 Codec.
3 *
4 * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
Liam Girdwoodb8d055a2008-10-13 23:00:15 -04005 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
Mark Browndca98e92008-04-02 00:51:30 -04006 * 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>
Mark Browndca98e92008-04-02 00:51:30 -040019#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 */
42static int rpu = 8;
43module_param(rpu, int, 0);
Masanari Iida31b2b162014-09-09 11:23:10 -070044MODULE_PARM_DESC(rpu, "Set internal pull up resistor for pen detect.");
Mark Browndca98e92008-04-02 00:51:30 -040045
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 */
56static int pil;
57module_param(pil, int, 0);
58MODULE_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 */
65static int pressure = DEFAULT_PRESSURE & 0xfff;
66module_param(pressure, int, 0);
67MODULE_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 */
81static int delay = 4;
82module_param(delay, int, 0);
83MODULE_PARM_DESC(delay, "Set adc sample delay.");
84
85/*
Mark Brown43f83a82008-05-27 01:37:26 -040086 * Set five_wire = 1 to use a 5 wire touchscreen.
87 *
88 * NOTE: Five wire mode does not allow for readback of pressure.
89 */
90static int five_wire;
91module_param(five_wire, int, 0);
92MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");
93
94/*
Mark Browndca98e92008-04-02 00:51:30 -040095 * 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 */
107static int mask;
108module_param(mask, int, 0);
109MODULE_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 */
117static int coord;
118module_param(coord, int, 0);
119MODULE_PARM_DESC(coord, "Polling coordinate mode");
120
121/*
122 * ADC sample delay times in uS
123 */
124static 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 */
148static 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 */
156static 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
Mark Brown43f83a82008-05-27 01:37:26 -0400172 /* 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
Mark Browndca98e92008-04-02 00:51:30 -0400185 /* 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
219static 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
237static 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
244static 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
252static 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 */
260static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
261{
262 u16 dig1;
263 int timeout = 5 * delay;
Wolfram Sang77da3832011-07-04 19:22:01 -0700264 bool wants_pen = adcsel & WM97XX_PEN_DOWN;
Mark Browndca98e92008-04-02 00:51:30 -0400265
Wolfram Sang77da3832011-07-04 19:22:01 -0700266 if (wants_pen && !wm->pen_probably_down) {
Mark Browndca98e92008-04-02 00:51:30 -0400267 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
268 if (!(data & WM97XX_PEN_DOWN))
269 return RC_PENUP;
270 wm->pen_probably_down = 1;
271 }
272
273 /* set up digitiser */
Mark Browndca98e92008-04-02 00:51:30 -0400274 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
275 dig1 &= ~WM9713_ADCSEL_MASK;
Wolfram Sangc8f20522011-07-04 19:22:00 -0700276 /* WM97XX_ADCSEL_* channels need to be converted to WM9713 format */
277 dig1 |= 1 << ((adcsel & WM97XX_ADCSEL_MASK) >> 12);
Mark Browndca98e92008-04-02 00:51:30 -0400278
279 if (wm->mach_ops && wm->mach_ops->pre_sample)
280 wm->mach_ops->pre_sample(adcsel);
Wolfram Sangc8f20522011-07-04 19:22:00 -0700281 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | WM9713_POLL);
Mark Browndca98e92008-04-02 00:51:30 -0400282
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 */
Wolfram Sangc8f20522011-07-04 19:22:00 -0700307 if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) {
308 dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x",
309 adcsel & WM97XX_ADCSEL_MASK,
Wolfram Sang24566892011-07-04 19:22:00 -0700310 *sample & WM97XX_ADCSEL_MASK);
Mark Browndca98e92008-04-02 00:51:30 -0400311 return RC_PENUP;
312 }
313
Wolfram Sang77da3832011-07-04 19:22:01 -0700314 if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) {
Mark Browndca98e92008-04-02 00:51:30 -0400315 wm->pen_probably_down = 0;
316 return RC_PENUP;
317 }
318
319 return RC_VALID;
320}
321
322/*
323 * Read a coordinate from the WM9713 adc in polling mode.
324 */
325static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
326{
327 u16 dig1;
328 int timeout = 5 * delay;
329
330 if (!wm->pen_probably_down) {
331 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
332 if (!(val & WM97XX_PEN_DOWN))
333 return RC_PENUP;
334 wm->pen_probably_down = 1;
335 }
336
337 /* set up digitiser */
338 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
339 dig1 &= ~WM9713_ADCSEL_MASK;
340 if (pil)
341 dig1 |= WM9713_ADCSEL_PRES;
342
343 if (wm->mach_ops && wm->mach_ops->pre_sample)
344 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
345 wm97xx_reg_write(wm, AC97_WM9713_DIG1,
346 dig1 | WM9713_POLL | WM9713_COO);
347
348 /* wait 3 AC97 time slots + delay for conversion */
349 poll_delay(delay);
350 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
351 /* wait for POLL to go low */
352 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL)
353 && timeout) {
354 udelay(AC97_LINK_FRAME);
355 timeout--;
356 }
357
358 if (timeout <= 0) {
359 /* If PDEN is set, we can get a timeout when pen goes up */
360 if (is_pden(wm))
361 wm->pen_probably_down = 0;
362 else
363 dev_dbg(wm->dev, "adc sample timeout");
364 return RC_PENUP;
365 }
366
367 /* read back data */
368 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
369 if (pil)
370 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
371 else
372 data->p = DEFAULT_PRESSURE;
373
374 if (wm->mach_ops && wm->mach_ops->post_sample)
375 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
376
377 /* check we have correct sample */
378 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
379 goto err;
380 if (pil && !(data->p & WM97XX_ADCSEL_PRES))
381 goto err;
382
383 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
384 wm->pen_probably_down = 0;
385 return RC_PENUP;
386 }
387 return RC_VALID;
388err:
389 return 0;
390}
391
392/*
393 * Sample the WM9713 touchscreen in polling mode
394 */
395static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
396{
397 int rc;
398
399 if (coord) {
400 rc = wm9713_poll_coord(wm, data);
401 if (rc != RC_VALID)
402 return rc;
403 } else {
Wolfram Sang77da3832011-07-04 19:22:01 -0700404 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x);
Mark Browndca98e92008-04-02 00:51:30 -0400405 if (rc != RC_VALID)
406 return rc;
Wolfram Sang77da3832011-07-04 19:22:01 -0700407 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y);
Mark Browndca98e92008-04-02 00:51:30 -0400408 if (rc != RC_VALID)
409 return rc;
410 if (pil) {
Wolfram Sang77da3832011-07-04 19:22:01 -0700411 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN,
Mark Browndca98e92008-04-02 00:51:30 -0400412 &data->p);
413 if (rc != RC_VALID)
414 return rc;
415 } else
416 data->p = DEFAULT_PRESSURE;
417 }
418 return RC_VALID;
419}
420
421/*
422 * Enable WM9713 continuous mode, i.e. touch data is streamed across
423 * an AC97 slot
424 */
425static int wm9713_acc_enable(struct wm97xx *wm, int enable)
426{
427 u16 dig1, dig2, dig3;
428 int ret = 0;
429
430 dig1 = wm->dig[0];
431 dig2 = wm->dig[1];
432 dig3 = wm->dig[2];
433
434 if (enable) {
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300435 /* continuous mode */
Mark Browndca98e92008-04-02 00:51:30 -0400436 if (wm->mach_ops->acc_startup &&
437 (ret = wm->mach_ops->acc_startup(wm)) < 0)
438 return ret;
439
440 dig1 &= ~WM9713_ADCSEL_MASK;
441 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X |
442 WM9713_ADCSEL_Y;
443 if (pil)
444 dig1 |= WM9713_ADCSEL_PRES;
445 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK |
446 WM97XX_CM_RATE_MASK);
447 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) |
448 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate);
449 dig3 |= WM9713_PDEN;
450 } else {
451 dig1 &= ~(WM9713_CTC | WM9713_COO);
452 dig2 &= ~WM97XX_SLEN;
453 dig3 &= ~WM9713_PDEN;
454 if (wm->mach_ops->acc_shutdown)
455 wm->mach_ops->acc_shutdown(wm);
456 }
457
458 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
459 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
460 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
461
462 return ret;
463}
464
465struct wm97xx_codec_drv wm9713_codec = {
466 .id = WM9713_ID2,
467 .name = "wm9713",
468 .poll_sample = wm9713_poll_sample,
469 .poll_touch = wm9713_poll_touch,
470 .acc_enable = wm9713_acc_enable,
471 .phy_init = wm9713_phy_init,
472 .dig_enable = wm9713_dig_enable,
473 .dig_restore = wm9713_dig_restore,
474 .aux_prepare = wm9713_aux_prepare,
475};
476EXPORT_SYMBOL_GPL(wm9713_codec);
477
478/* Module information */
Liam Girdwoodb8d055a2008-10-13 23:00:15 -0400479MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
Mark Browndca98e92008-04-02 00:51:30 -0400480MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
481MODULE_LICENSE("GPL");