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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
de22b9ef MB |
2 | /* |
3 | * wm9712.c -- Codec driver for Wolfson WM9712 AC97 Codecs. | |
4 | * | |
5 | * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC. | |
b8d055a8 | 6 | * Author: Liam Girdwood <lrg@slimlogic.co.uk> |
de22b9ef MB |
7 | * Parts Copyright : Ian Molton <spyro@f2s.com> |
8 | * Andrew Zabolotny <zap@homelink.ru> | |
9 | * Russell King <rmk@arm.linux.org.uk> | |
de22b9ef MB |
10 | */ |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/moduleparam.h> | |
de22b9ef MB |
14 | #include <linux/kernel.h> |
15 | #include <linux/input.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/bitops.h> | |
18 | #include <linux/wm97xx.h> | |
19 | ||
20 | #define TS_NAME "wm97xx" | |
21 | #define WM9712_VERSION "1.00" | |
22 | #define DEFAULT_PRESSURE 0xb0c0 | |
23 | ||
24 | /* | |
25 | * Module parameters | |
26 | */ | |
27 | ||
28 | /* | |
29 | * Set internal pull up for pen detect. | |
30 | * | |
31 | * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive) | |
32 | * i.e. pull up resistance = 64k Ohms / rpu. | |
33 | * | |
34 | * Adjust this value if you are having problems with pen detect not | |
35 | * detecting any down event. | |
36 | */ | |
37 | static int rpu = 8; | |
38 | module_param(rpu, int, 0); | |
31b2b16d | 39 | MODULE_PARM_DESC(rpu, "Set internal pull up resistor for pen detect."); |
de22b9ef MB |
40 | |
41 | /* | |
42 | * Set current used for pressure measurement. | |
43 | * | |
44 | * Set pil = 2 to use 400uA | |
45 | * pil = 1 to use 200uA and | |
46 | * pil = 0 to disable pressure measurement. | |
47 | * | |
48 | * This is used to increase the range of values returned by the adc | |
49 | * when measureing touchpanel pressure. | |
50 | */ | |
51 | static int pil; | |
52 | module_param(pil, int, 0); | |
53 | MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); | |
54 | ||
55 | /* | |
56 | * Set threshold for pressure measurement. | |
57 | * | |
58 | * Pen down pressure below threshold is ignored. | |
59 | */ | |
60 | static int pressure = DEFAULT_PRESSURE & 0xfff; | |
61 | module_param(pressure, int, 0); | |
62 | MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); | |
63 | ||
64 | /* | |
65 | * Set adc sample delay. | |
66 | * | |
67 | * For accurate touchpanel measurements, some settling time may be | |
68 | * required between the switch matrix applying a voltage across the | |
69 | * touchpanel plate and the ADC sampling the signal. | |
70 | * | |
71 | * This delay can be set by setting delay = n, where n is the array | |
72 | * position of the delay in the array delay_table below. | |
73 | * Long delays > 1ms are supported for completeness, but are not | |
74 | * recommended. | |
75 | */ | |
76 | static int delay = 3; | |
77 | module_param(delay, int, 0); | |
78 | MODULE_PARM_DESC(delay, "Set adc sample delay."); | |
79 | ||
80 | /* | |
81 | * Set five_wire = 1 to use a 5 wire touchscreen. | |
82 | * | |
83 | * NOTE: Five wire mode does not allow for readback of pressure. | |
84 | */ | |
85 | static int five_wire; | |
86 | module_param(five_wire, int, 0); | |
87 | MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen."); | |
88 | ||
89 | /* | |
90 | * Set adc mask function. | |
91 | * | |
92 | * Sources of glitch noise, such as signals driving an LCD display, may feed | |
93 | * through to the touch screen plates and affect measurement accuracy. In | |
94 | * order to minimise this, a signal may be applied to the MASK pin to delay or | |
95 | * synchronise the sampling. | |
96 | * | |
97 | * 0 = No delay or sync | |
98 | * 1 = High on pin stops conversions | |
99 | * 2 = Edge triggered, edge on pin delays conversion by delay param (above) | |
100 | * 3 = Edge triggered, edge on pin starts conversion after delay param | |
101 | */ | |
102 | static int mask; | |
103 | module_param(mask, int, 0); | |
104 | MODULE_PARM_DESC(mask, "Set adc mask function."); | |
105 | ||
106 | /* | |
107 | * Coordinate Polling Enable. | |
108 | * | |
109 | * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together | |
110 | * for every poll. | |
111 | */ | |
112 | static int coord; | |
113 | module_param(coord, int, 0); | |
114 | MODULE_PARM_DESC(coord, "Polling coordinate mode"); | |
115 | ||
116 | /* | |
117 | * ADC sample delay times in uS | |
118 | */ | |
119 | static const int delay_table[] = { | |
120 | 21, /* 1 AC97 Link frames */ | |
121 | 42, /* 2 */ | |
122 | 84, /* 4 */ | |
123 | 167, /* 8 */ | |
124 | 333, /* 16 */ | |
125 | 667, /* 32 */ | |
126 | 1000, /* 48 */ | |
127 | 1333, /* 64 */ | |
128 | 2000, /* 96 */ | |
129 | 2667, /* 128 */ | |
130 | 3333, /* 160 */ | |
131 | 4000, /* 192 */ | |
132 | 4667, /* 224 */ | |
133 | 5333, /* 256 */ | |
134 | 6000, /* 288 */ | |
135 | 0 /* No delay, switch matrix always on */ | |
136 | }; | |
137 | ||
138 | /* | |
139 | * Delay after issuing a POLL command. | |
140 | * | |
141 | * The delay is 3 AC97 link frames + the touchpanel settling delay | |
142 | */ | |
143 | static inline void poll_delay(int d) | |
144 | { | |
145 | udelay(3 * AC97_LINK_FRAME + delay_table[d]); | |
146 | } | |
147 | ||
148 | /* | |
149 | * set up the physical settings of the WM9712 | |
150 | */ | |
151 | static void wm9712_phy_init(struct wm97xx *wm) | |
152 | { | |
153 | u16 dig1 = 0; | |
154 | u16 dig2 = WM97XX_RPR | WM9712_RPU(1); | |
155 | ||
156 | /* WM9712 rpu */ | |
157 | if (rpu) { | |
158 | dig2 &= 0xffc0; | |
159 | dig2 |= WM9712_RPU(rpu); | |
d73a17e6 | 160 | dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms\n", |
de22b9ef MB |
161 | 64000 / rpu); |
162 | } | |
163 | ||
8a65c02f MB |
164 | /* WM9712 five wire */ |
165 | if (five_wire) { | |
166 | dig2 |= WM9712_45W; | |
d73a17e6 | 167 | dev_dbg(wm->dev, "setting 5-wire touchscreen mode.\n"); |
8a65c02f MB |
168 | |
169 | if (pil) { | |
170 | dev_warn(wm->dev, "pressure measurement is not " | |
171 | "supported in 5-wire mode\n"); | |
172 | pil = 0; | |
173 | } | |
174 | } | |
175 | ||
de22b9ef MB |
176 | /* touchpanel pressure current*/ |
177 | if (pil == 2) { | |
178 | dig2 |= WM9712_PIL; | |
179 | dev_dbg(wm->dev, | |
d73a17e6 | 180 | "setting pressure measurement current to 400uA.\n"); |
de22b9ef MB |
181 | } else if (pil) |
182 | dev_dbg(wm->dev, | |
d73a17e6 | 183 | "setting pressure measurement current to 200uA.\n"); |
de22b9ef MB |
184 | if (!pil) |
185 | pressure = 0; | |
186 | ||
de22b9ef MB |
187 | /* polling mode sample settling delay */ |
188 | if (delay < 0 || delay > 15) { | |
d73a17e6 | 189 | dev_dbg(wm->dev, "supplied delay out of range.\n"); |
de22b9ef MB |
190 | delay = 4; |
191 | } | |
192 | dig1 &= 0xff0f; | |
193 | dig1 |= WM97XX_DELAY(delay); | |
d73a17e6 | 194 | dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.\n", |
de22b9ef MB |
195 | delay_table[delay]); |
196 | ||
197 | /* mask */ | |
198 | dig2 |= ((mask & 0x3) << 6); | |
199 | if (mask) { | |
200 | u16 reg; | |
201 | /* Set GPIO4 as Mask Pin*/ | |
202 | reg = wm97xx_reg_read(wm, AC97_MISC_AFE); | |
203 | wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4); | |
204 | reg = wm97xx_reg_read(wm, AC97_GPIO_CFG); | |
205 | wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4); | |
206 | } | |
207 | ||
208 | /* wait - coord mode */ | |
209 | if (coord) | |
210 | dig2 |= WM9712_WAIT; | |
211 | ||
212 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); | |
213 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); | |
214 | } | |
215 | ||
216 | static void wm9712_dig_enable(struct wm97xx *wm, int enable) | |
217 | { | |
218 | u16 dig2 = wm->dig[2]; | |
219 | ||
220 | if (enable) { | |
221 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, | |
222 | dig2 | WM97XX_PRP_DET_DIG); | |
223 | wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ | |
224 | } else | |
225 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, | |
226 | dig2 & ~WM97XX_PRP_DET_DIG); | |
227 | } | |
228 | ||
229 | static void wm9712_aux_prepare(struct wm97xx *wm) | |
230 | { | |
231 | memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); | |
232 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0); | |
233 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG); | |
234 | } | |
235 | ||
236 | static void wm9712_dig_restore(struct wm97xx *wm) | |
237 | { | |
238 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]); | |
239 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]); | |
240 | } | |
241 | ||
242 | static inline int is_pden(struct wm97xx *wm) | |
243 | { | |
244 | return wm->dig[2] & WM9712_PDEN; | |
245 | } | |
246 | ||
247 | /* | |
248 | * Read a sample from the WM9712 adc in polling mode. | |
249 | */ | |
250 | static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample) | |
251 | { | |
252 | int timeout = 5 * delay; | |
77da3838 | 253 | bool wants_pen = adcsel & WM97XX_PEN_DOWN; |
de22b9ef | 254 | |
77da3838 | 255 | if (wants_pen && !wm->pen_probably_down) { |
de22b9ef MB |
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 */ | |
de22b9ef MB |
263 | if (wm->mach_ops && wm->mach_ops->pre_sample) |
264 | wm->mach_ops->pre_sample(adcsel); | |
c8f20525 WS |
265 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK) |
266 | | WM97XX_POLL | WM97XX_DELAY(delay)); | |
de22b9ef MB |
267 | |
268 | /* wait 3 AC97 time slots + delay for conversion */ | |
269 | poll_delay(delay); | |
270 | ||
271 | /* wait for POLL to go low */ | |
272 | while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) | |
273 | && timeout) { | |
274 | udelay(AC97_LINK_FRAME); | |
275 | timeout--; | |
276 | } | |
277 | ||
278 | if (timeout <= 0) { | |
279 | /* If PDEN is set, we can get a timeout when pen goes up */ | |
280 | if (is_pden(wm)) | |
281 | wm->pen_probably_down = 0; | |
282 | else | |
d73a17e6 | 283 | dev_dbg(wm->dev, "adc sample timeout\n"); |
de22b9ef MB |
284 | return RC_PENUP; |
285 | } | |
286 | ||
287 | *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
288 | if (wm->mach_ops && wm->mach_ops->post_sample) | |
289 | wm->mach_ops->post_sample(adcsel); | |
290 | ||
291 | /* check we have correct sample */ | |
c8f20525 | 292 | if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) { |
d73a17e6 | 293 | dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x\n", |
c8f20525 WS |
294 | adcsel & WM97XX_ADCSEL_MASK, |
295 | *sample & WM97XX_ADCSEL_MASK); | |
fa45255e | 296 | return RC_AGAIN; |
de22b9ef MB |
297 | } |
298 | ||
77da3838 | 299 | if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { |
54079275 MP |
300 | /* Sometimes it reads a wrong value the first time. */ |
301 | *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
302 | if (!(*sample & WM97XX_PEN_DOWN)) { | |
303 | wm->pen_probably_down = 0; | |
304 | return RC_PENUP; | |
305 | } | |
de22b9ef MB |
306 | } |
307 | ||
308 | return RC_VALID; | |
309 | } | |
310 | ||
311 | /* | |
312 | * Read a coord from the WM9712 adc in polling mode. | |
313 | */ | |
314 | static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) | |
315 | { | |
316 | int timeout = 5 * delay; | |
317 | ||
318 | if (!wm->pen_probably_down) { | |
319 | u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
320 | if (!(data_rd & WM97XX_PEN_DOWN)) | |
321 | return RC_PENUP; | |
322 | wm->pen_probably_down = 1; | |
323 | } | |
324 | ||
325 | /* set up digitiser */ | |
326 | if (wm->mach_ops && wm->mach_ops->pre_sample) | |
327 | wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); | |
328 | ||
329 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, | |
330 | WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay)); | |
331 | ||
332 | /* wait 3 AC97 time slots + delay for conversion and read x */ | |
333 | poll_delay(delay); | |
334 | data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
335 | /* wait for POLL to go low */ | |
336 | while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) | |
337 | && timeout) { | |
338 | udelay(AC97_LINK_FRAME); | |
339 | timeout--; | |
340 | } | |
341 | ||
342 | if (timeout <= 0) { | |
343 | /* If PDEN is set, we can get a timeout when pen goes up */ | |
344 | if (is_pden(wm)) | |
345 | wm->pen_probably_down = 0; | |
346 | else | |
d73a17e6 | 347 | dev_dbg(wm->dev, "adc sample timeout\n"); |
de22b9ef MB |
348 | return RC_PENUP; |
349 | } | |
350 | ||
351 | /* read back y data */ | |
352 | data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
353 | if (pil) | |
354 | data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
355 | else | |
356 | data->p = DEFAULT_PRESSURE; | |
357 | ||
358 | if (wm->mach_ops && wm->mach_ops->post_sample) | |
359 | wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); | |
360 | ||
361 | /* check we have correct sample */ | |
362 | if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) | |
363 | goto err; | |
364 | if (pil && !(data->p & WM97XX_ADCSEL_PRES)) | |
365 | goto err; | |
366 | ||
367 | if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { | |
368 | wm->pen_probably_down = 0; | |
369 | return RC_PENUP; | |
370 | } | |
371 | return RC_VALID; | |
372 | err: | |
373 | return 0; | |
374 | } | |
375 | ||
376 | /* | |
377 | * Sample the WM9712 touchscreen in polling mode | |
378 | */ | |
379 | static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) | |
380 | { | |
381 | int rc; | |
382 | ||
383 | if (coord) { | |
384 | rc = wm9712_poll_coord(wm, data); | |
385 | if (rc != RC_VALID) | |
386 | return rc; | |
387 | } else { | |
77da3838 WS |
388 | rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, |
389 | &data->x); | |
de22b9ef MB |
390 | if (rc != RC_VALID) |
391 | return rc; | |
392 | ||
77da3838 WS |
393 | rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, |
394 | &data->y); | |
de22b9ef MB |
395 | if (rc != RC_VALID) |
396 | return rc; | |
397 | ||
398 | if (pil && !five_wire) { | |
77da3838 | 399 | rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, |
de22b9ef MB |
400 | &data->p); |
401 | if (rc != RC_VALID) | |
402 | return rc; | |
403 | } else | |
404 | data->p = DEFAULT_PRESSURE; | |
405 | } | |
406 | return RC_VALID; | |
407 | } | |
408 | ||
409 | /* | |
410 | * Enable WM9712 continuous mode, i.e. touch data is streamed across | |
411 | * an AC97 slot | |
412 | */ | |
413 | static int wm9712_acc_enable(struct wm97xx *wm, int enable) | |
414 | { | |
415 | u16 dig1, dig2; | |
416 | int ret = 0; | |
417 | ||
418 | dig1 = wm->dig[1]; | |
419 | dig2 = wm->dig[2]; | |
420 | ||
421 | if (enable) { | |
25985edc | 422 | /* continuous mode */ |
de22b9ef MB |
423 | if (wm->mach_ops->acc_startup) { |
424 | ret = wm->mach_ops->acc_startup(wm); | |
425 | if (ret < 0) | |
426 | return ret; | |
427 | } | |
428 | dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK | | |
429 | WM97XX_DELAY_MASK | WM97XX_SLT_MASK); | |
430 | dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN | | |
431 | WM97XX_DELAY(delay) | | |
432 | WM97XX_SLT(wm->acc_slot) | | |
433 | WM97XX_RATE(wm->acc_rate); | |
434 | if (pil) | |
435 | dig1 |= WM97XX_ADCSEL_PRES; | |
436 | dig2 |= WM9712_PDEN; | |
437 | } else { | |
438 | dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN); | |
439 | dig2 &= ~WM9712_PDEN; | |
440 | if (wm->mach_ops->acc_shutdown) | |
441 | wm->mach_ops->acc_shutdown(wm); | |
442 | } | |
443 | ||
444 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); | |
445 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); | |
446 | ||
447 | return 0; | |
448 | } | |
449 | ||
450 | struct wm97xx_codec_drv wm9712_codec = { | |
451 | .id = WM9712_ID2, | |
452 | .name = "wm9712", | |
453 | .poll_sample = wm9712_poll_sample, | |
454 | .poll_touch = wm9712_poll_touch, | |
455 | .acc_enable = wm9712_acc_enable, | |
456 | .phy_init = wm9712_phy_init, | |
457 | .dig_enable = wm9712_dig_enable, | |
458 | .dig_restore = wm9712_dig_restore, | |
459 | .aux_prepare = wm9712_aux_prepare, | |
460 | }; | |
461 | EXPORT_SYMBOL_GPL(wm9712_codec); | |
462 | ||
463 | /* Module information */ | |
b8d055a8 | 464 | MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); |
de22b9ef MB |
465 | MODULE_DESCRIPTION("WM9712 Touch Screen Driver"); |
466 | MODULE_LICENSE("GPL"); |