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authorMark Brown <broonie@opensource.wolfsonmicro.com>2008-04-02 00:51:26 -0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2008-04-02 00:51:26 -0400
commitde22b9ef1020ffdb9e1ed6f4686e2e62eaeb0958 (patch)
tree053d7a2151ef6ebc3b43a98ac79ee31b84a02b78
parent9448cefc6689aa51f1cd1cfe8b701dc94789c7ee (diff)
Input: WM97xx - add chip driver for WM9712 touchscreen
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com> Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com> Signed-off-by: Mike Arthur <mike.arthur@wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Lars Munch <lars@segv.dk> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
-rw-r--r--drivers/input/touchscreen/Kconfig9
-rw-r--r--drivers/input/touchscreen/Makefile1
-rw-r--r--drivers/input/touchscreen/wm9712.c462
3 files changed, 472 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 4939a96d12b9..240e441c118a 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -208,6 +208,15 @@ config TOUCHSCREEN_WM9705
208 208
209 If unsure, say N. 209 If unsure, say N.
210 210
211config TOUCHSCREEN_WM9712
212 bool "WM9712 Touchscreen interface support"
213 depends on TOUCHSCREEN_WM97XX
214 help
215 Say Y here if you have a Wolfson Microelectronics WM9712
216 touchscreen controller connected to your system.
217
218 If unsure, say N.
219
211config TOUCHSCREEN_USB_COMPOSITE 220config TOUCHSCREEN_USB_COMPOSITE
212 tristate "USB Touchscreen Driver" 221 tristate "USB Touchscreen Driver"
213 depends on USB_ARCH_HAS_HCD 222 depends on USB_ARCH_HAS_HCD
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 5829a435efd1..eb57f66e57f3 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
23obj-$(CONFIG_TOUCHSCREEN_UCB1400) += ucb1400_ts.o 23obj-$(CONFIG_TOUCHSCREEN_UCB1400) += ucb1400_ts.o
24obj-$(CONFIG_TOUCHSCREEN_WM97XX) += wm97xx-ts.o 24obj-$(CONFIG_TOUCHSCREEN_WM97XX) += wm97xx-ts.o
25wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705) += wm9705.o 25wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705) += wm9705.o
26wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9712) += wm9712.o
diff --git a/drivers/input/touchscreen/wm9712.c b/drivers/input/touchscreen/wm9712.c
new file mode 100644
index 000000000000..0b6e4cfa6a21
--- /dev/null
+++ b/drivers/input/touchscreen/wm9712.c
@@ -0,0 +1,462 @@
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 */
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 = 3;
84module_param(delay, int, 0);
85MODULE_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 */
92static int five_wire;
93module_param(five_wire, int, 0);
94MODULE_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 */
109static int mask;
110module_param(mask, int, 0);
111MODULE_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 */
119static int coord;
120module_param(coord, int, 0);
121MODULE_PARM_DESC(coord, "Polling coordinate mode");
122
123/*
124 * ADC sample delay times in uS
125 */
126static 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 */
150static 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 */
158static 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
217static 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
230static 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
237static 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
243static 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 */
251static 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 */
312static 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;
370err:
371 return 0;
372}
373
374/*
375 * Sample the WM9712 touchscreen in polling mode
376 */
377static 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 */
409static 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
446struct 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};
457EXPORT_SYMBOL_GPL(wm9712_codec);
458
459/* Module information */
460MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
461MODULE_DESCRIPTION("WM9712 Touch Screen Driver");
462MODULE_LICENSE("GPL");