1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * wm9712.c -- Codec driver for Wolfson WM9712 AC97 Codecs. |
4 | * |
5 | * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC. |
6 | * Author: Liam Girdwood <lrg@slimlogic.co.uk> |
7 | * Parts Copyright : Ian Molton <spyro@f2s.com> |
8 | * Andrew Zabolotny <zap@homelink.ru> |
9 | * Russell King <rmk@arm.linux.org.uk> |
10 | */ |
11 | |
12 | #include <linux/module.h> |
13 | #include <linux/moduleparam.h> |
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); |
39 | MODULE_PARM_DESC(rpu, "Set internal pull up resistor for pen detect." ); |
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); |
160 | dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms\n" , |
161 | 64000 / rpu); |
162 | } |
163 | |
164 | /* WM9712 five wire */ |
165 | if (five_wire) { |
166 | dig2 |= WM9712_45W; |
167 | dev_dbg(wm->dev, "setting 5-wire touchscreen mode.\n" ); |
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 | |
176 | /* touchpanel pressure current*/ |
177 | if (pil == 2) { |
178 | dig2 |= WM9712_PIL; |
179 | dev_dbg(wm->dev, |
180 | "setting pressure measurement current to 400uA.\n" ); |
181 | } else if (pil) |
182 | dev_dbg(wm->dev, |
183 | "setting pressure measurement current to 200uA.\n" ); |
184 | if (!pil) |
185 | pressure = 0; |
186 | |
187 | /* polling mode sample settling delay */ |
188 | if (delay < 0 || delay > 15) { |
189 | dev_dbg(wm->dev, "supplied delay out of range.\n" ); |
190 | delay = 4; |
191 | } |
192 | dig1 &= 0xff0f; |
193 | dig1 |= WM97XX_DELAY(delay); |
194 | dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.\n" , |
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, val: reg | WM97XX_GPIO_4); |
204 | reg = wm97xx_reg_read(wm, AC97_GPIO_CFG); |
205 | wm97xx_reg_write(wm, AC97_GPIO_CFG, val: 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, val: dig1); |
213 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, val: 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 | val: 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 | val: 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, val: 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, val: wm->dig_save[1]); |
239 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, val: 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; |
253 | bool wants_pen = adcsel & WM97XX_PEN_DOWN; |
254 | |
255 | if (wants_pen && !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 (wm->mach_ops && wm->mach_ops->pre_sample) |
264 | wm->mach_ops->pre_sample(adcsel); |
265 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, val: (adcsel & WM97XX_ADCSEL_MASK) |
266 | | WM97XX_POLL | WM97XX_DELAY(delay)); |
267 | |
268 | /* wait 3 AC97 time slots + delay for conversion */ |
269 | poll_delay(d: 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 |
283 | dev_dbg(wm->dev, "adc sample timeout\n" ); |
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 */ |
292 | if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) { |
293 | dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x\n" , |
294 | adcsel & WM97XX_ADCSEL_MASK, |
295 | *sample & WM97XX_ADCSEL_MASK); |
296 | return RC_AGAIN; |
297 | } |
298 | |
299 | if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { |
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 | } |
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(d: 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 |
347 | dev_dbg(wm->dev, "adc sample timeout\n" ); |
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 { |
388 | rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, |
389 | sample: &data->x); |
390 | if (rc != RC_VALID) |
391 | return rc; |
392 | |
393 | rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, |
394 | sample: &data->y); |
395 | if (rc != RC_VALID) |
396 | return rc; |
397 | |
398 | if (pil && !five_wire) { |
399 | rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, |
400 | sample: &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) { |
422 | /* continuous mode */ |
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, val: dig1); |
445 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, val: 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 */ |
464 | MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>" ); |
465 | MODULE_DESCRIPTION("WM9712 Touch Screen Driver" ); |
466 | MODULE_LICENSE("GPL" ); |
467 | |