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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);
44MODULE_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 */
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;
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 */
324static 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;
387err:
388 return 0;
389}
390
391/*
392 * Sample the WM9713 touchscreen in polling mode
393 */
394static 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 */
424static 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
464struct 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};
475EXPORT_SYMBOL_GPL(wm9713_codec);
476
477/* Module information */
Liam Girdwoodb8d055a2008-10-13 23:00:15 -0400478MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
Mark Browndca98e92008-04-02 00:51:30 -0400479MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
480MODULE_LICENSE("GPL");