Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
9448cefc MB |
2 | /* |
3 | * wm9705.c -- Codec driver for Wolfson WM9705 AC97 Codec. | |
4 | * | |
5 | * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC. | |
b8d055a8 | 6 | * Author: Liam Girdwood <lrg@slimlogic.co.uk> |
9448cefc MB |
7 | * Parts Copyright : Ian Molton <spyro@f2s.com> |
8 | * Andrew Zabolotny <zap@homelink.ru> | |
9 | * Russell King <rmk@arm.linux.org.uk> | |
9448cefc MB |
10 | */ |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/moduleparam.h> | |
9448cefc 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 WM9705_VERSION "1.00" | |
22 | #define DEFAULT_PRESSURE 0xb0c0 | |
23 | ||
24 | /* | |
25 | * Module parameters | |
26 | */ | |
27 | ||
28 | /* | |
29 | * Set current used for pressure measurement. | |
30 | * | |
31 | * Set pil = 2 to use 400uA | |
32 | * pil = 1 to use 200uA and | |
33 | * pil = 0 to disable pressure measurement. | |
34 | * | |
35 | * This is used to increase the range of values returned by the adc | |
36 | * when measureing touchpanel pressure. | |
37 | */ | |
38 | static int pil; | |
39 | module_param(pil, int, 0); | |
40 | MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); | |
41 | ||
42 | /* | |
43 | * Set threshold for pressure measurement. | |
44 | * | |
45 | * Pen down pressure below threshold is ignored. | |
46 | */ | |
47 | static int pressure = DEFAULT_PRESSURE & 0xfff; | |
48 | module_param(pressure, int, 0); | |
49 | MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); | |
50 | ||
51 | /* | |
52 | * Set adc sample delay. | |
53 | * | |
54 | * For accurate touchpanel measurements, some settling time may be | |
55 | * required between the switch matrix applying a voltage across the | |
56 | * touchpanel plate and the ADC sampling the signal. | |
57 | * | |
58 | * This delay can be set by setting delay = n, where n is the array | |
59 | * position of the delay in the array delay_table below. | |
60 | * Long delays > 1ms are supported for completeness, but are not | |
61 | * recommended. | |
62 | */ | |
63 | static int delay = 4; | |
64 | module_param(delay, int, 0); | |
65 | MODULE_PARM_DESC(delay, "Set adc sample delay."); | |
66 | ||
67 | /* | |
68 | * Pen detect comparator threshold. | |
69 | * | |
70 | * 0 to Vmid in 15 steps, 0 = use zero power comparator with Vmid threshold | |
71 | * i.e. 1 = Vmid/15 threshold | |
72 | * 15 = Vmid/1 threshold | |
73 | * | |
74 | * Adjust this value if you are having problems with pen detect not | |
75 | * detecting any down events. | |
76 | */ | |
77 | static int pdd = 8; | |
78 | module_param(pdd, int, 0); | |
79 | MODULE_PARM_DESC(pdd, "Set pen detect comparator threshold"); | |
80 | ||
81 | /* | |
82 | * Set adc mask function. | |
83 | * | |
84 | * Sources of glitch noise, such as signals driving an LCD display, may feed | |
85 | * through to the touch screen plates and affect measurement accuracy. In | |
86 | * order to minimise this, a signal may be applied to the MASK pin to delay or | |
87 | * synchronise the sampling. | |
88 | * | |
89 | * 0 = No delay or sync | |
90 | * 1 = High on pin stops conversions | |
91 | * 2 = Edge triggered, edge on pin delays conversion by delay param (above) | |
92 | * 3 = Edge triggered, edge on pin starts conversion after delay param | |
93 | */ | |
94 | static int mask; | |
95 | module_param(mask, int, 0); | |
96 | MODULE_PARM_DESC(mask, "Set adc mask function."); | |
97 | ||
98 | /* | |
99 | * ADC sample delay times in uS | |
100 | */ | |
101 | static const int delay_table[] = { | |
102 | 21, /* 1 AC97 Link frames */ | |
103 | 42, /* 2 */ | |
104 | 84, /* 4 */ | |
105 | 167, /* 8 */ | |
106 | 333, /* 16 */ | |
107 | 667, /* 32 */ | |
108 | 1000, /* 48 */ | |
109 | 1333, /* 64 */ | |
110 | 2000, /* 96 */ | |
111 | 2667, /* 128 */ | |
112 | 3333, /* 160 */ | |
113 | 4000, /* 192 */ | |
114 | 4667, /* 224 */ | |
115 | 5333, /* 256 */ | |
116 | 6000, /* 288 */ | |
117 | 0 /* No delay, switch matrix always on */ | |
118 | }; | |
119 | ||
120 | /* | |
121 | * Delay after issuing a POLL command. | |
122 | * | |
123 | * The delay is 3 AC97 link frames + the touchpanel settling delay | |
124 | */ | |
125 | static inline void poll_delay(int d) | |
126 | { | |
127 | udelay(3 * AC97_LINK_FRAME + delay_table[d]); | |
128 | } | |
129 | ||
130 | /* | |
131 | * set up the physical settings of the WM9705 | |
132 | */ | |
133 | static void wm9705_phy_init(struct wm97xx *wm) | |
134 | { | |
135 | u16 dig1 = 0, dig2 = WM97XX_RPR; | |
136 | ||
137 | /* | |
138 | * mute VIDEO and AUX as they share X and Y touchscreen | |
139 | * inputs on the WM9705 | |
140 | */ | |
141 | wm97xx_reg_write(wm, AC97_AUX, 0x8000); | |
142 | wm97xx_reg_write(wm, AC97_VIDEO, 0x8000); | |
143 | ||
144 | /* touchpanel pressure current*/ | |
145 | if (pil == 2) { | |
146 | dig2 |= WM9705_PIL; | |
147 | dev_dbg(wm->dev, | |
148 | "setting pressure measurement current to 400uA."); | |
149 | } else if (pil) | |
150 | dev_dbg(wm->dev, | |
151 | "setting pressure measurement current to 200uA."); | |
152 | if (!pil) | |
153 | pressure = 0; | |
154 | ||
155 | /* polling mode sample settling delay */ | |
156 | if (delay != 4) { | |
157 | if (delay < 0 || delay > 15) { | |
158 | dev_dbg(wm->dev, "supplied delay out of range."); | |
159 | delay = 4; | |
160 | } | |
161 | } | |
162 | dig1 &= 0xff0f; | |
163 | dig1 |= WM97XX_DELAY(delay); | |
164 | dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.", | |
165 | delay_table[delay]); | |
166 | ||
167 | /* WM9705 pdd */ | |
168 | dig2 |= (pdd & 0x000f); | |
169 | dev_dbg(wm->dev, "setting pdd to Vmid/%d", 1 - (pdd & 0x000f)); | |
170 | ||
171 | /* mask */ | |
172 | dig2 |= ((mask & 0x3) << 4); | |
173 | ||
174 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); | |
175 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); | |
176 | } | |
177 | ||
178 | static void wm9705_dig_enable(struct wm97xx *wm, int enable) | |
179 | { | |
180 | if (enable) { | |
181 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, | |
182 | wm->dig[2] | WM97XX_PRP_DET_DIG); | |
183 | wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ | |
184 | } else | |
185 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, | |
186 | wm->dig[2] & ~WM97XX_PRP_DET_DIG); | |
187 | } | |
188 | ||
189 | static void wm9705_aux_prepare(struct wm97xx *wm) | |
190 | { | |
191 | memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); | |
192 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0); | |
193 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG); | |
194 | } | |
195 | ||
196 | static void wm9705_dig_restore(struct wm97xx *wm) | |
197 | { | |
198 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]); | |
199 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]); | |
200 | } | |
201 | ||
202 | static inline int is_pden(struct wm97xx *wm) | |
203 | { | |
204 | return wm->dig[2] & WM9705_PDEN; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Read a sample from the WM9705 adc in polling mode. | |
209 | */ | |
210 | static int wm9705_poll_sample(struct wm97xx *wm, int adcsel, int *sample) | |
211 | { | |
212 | int timeout = 5 * delay; | |
77da3838 | 213 | bool wants_pen = adcsel & WM97XX_PEN_DOWN; |
9448cefc | 214 | |
77da3838 | 215 | if (wants_pen && !wm->pen_probably_down) { |
9448cefc MB |
216 | u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); |
217 | if (!(data & WM97XX_PEN_DOWN)) | |
218 | return RC_PENUP; | |
219 | wm->pen_probably_down = 1; | |
220 | } | |
221 | ||
222 | /* set up digitiser */ | |
9448cefc MB |
223 | if (wm->mach_ops && wm->mach_ops->pre_sample) |
224 | wm->mach_ops->pre_sample(adcsel); | |
c8f20525 WS |
225 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK) |
226 | | WM97XX_POLL | WM97XX_DELAY(delay)); | |
9448cefc MB |
227 | |
228 | /* wait 3 AC97 time slots + delay for conversion */ | |
229 | poll_delay(delay); | |
230 | ||
231 | /* wait for POLL to go low */ | |
232 | while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) | |
233 | && timeout) { | |
234 | udelay(AC97_LINK_FRAME); | |
235 | timeout--; | |
236 | } | |
237 | ||
238 | if (timeout == 0) { | |
239 | /* If PDEN is set, we can get a timeout when pen goes up */ | |
240 | if (is_pden(wm)) | |
241 | wm->pen_probably_down = 0; | |
242 | else | |
243 | dev_dbg(wm->dev, "adc sample timeout"); | |
244 | return RC_PENUP; | |
245 | } | |
246 | ||
247 | *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
248 | if (wm->mach_ops && wm->mach_ops->post_sample) | |
249 | wm->mach_ops->post_sample(adcsel); | |
250 | ||
251 | /* check we have correct sample */ | |
c8f20525 WS |
252 | if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) { |
253 | dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x", | |
254 | adcsel & WM97XX_ADCSEL_MASK, | |
255 | *sample & WM97XX_ADCSEL_MASK); | |
9448cefc MB |
256 | return RC_PENUP; |
257 | } | |
258 | ||
77da3838 | 259 | if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { |
9448cefc MB |
260 | wm->pen_probably_down = 0; |
261 | return RC_PENUP; | |
262 | } | |
263 | ||
264 | return RC_VALID; | |
265 | } | |
266 | ||
267 | /* | |
268 | * Sample the WM9705 touchscreen in polling mode | |
269 | */ | |
270 | static int wm9705_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) | |
271 | { | |
272 | int rc; | |
273 | ||
77da3838 | 274 | rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x); |
9448cefc MB |
275 | if (rc != RC_VALID) |
276 | return rc; | |
77da3838 | 277 | rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y); |
9448cefc MB |
278 | if (rc != RC_VALID) |
279 | return rc; | |
280 | if (pil) { | |
77da3838 | 281 | rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, &data->p); |
9448cefc MB |
282 | if (rc != RC_VALID) |
283 | return rc; | |
284 | } else | |
285 | data->p = DEFAULT_PRESSURE; | |
286 | ||
287 | return RC_VALID; | |
288 | } | |
289 | ||
290 | /* | |
291 | * Enable WM9705 continuous mode, i.e. touch data is streamed across | |
292 | * an AC97 slot | |
293 | */ | |
294 | static int wm9705_acc_enable(struct wm97xx *wm, int enable) | |
295 | { | |
296 | u16 dig1, dig2; | |
297 | int ret = 0; | |
298 | ||
299 | dig1 = wm->dig[1]; | |
300 | dig2 = wm->dig[2]; | |
301 | ||
302 | if (enable) { | |
25985edc | 303 | /* continuous mode */ |
9448cefc MB |
304 | if (wm->mach_ops->acc_startup && |
305 | (ret = wm->mach_ops->acc_startup(wm)) < 0) | |
306 | return ret; | |
307 | dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK | | |
308 | WM97XX_DELAY_MASK | WM97XX_SLT_MASK); | |
309 | dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN | | |
310 | WM97XX_DELAY(delay) | | |
311 | WM97XX_SLT(wm->acc_slot) | | |
312 | WM97XX_RATE(wm->acc_rate); | |
313 | if (pil) | |
314 | dig1 |= WM97XX_ADCSEL_PRES; | |
315 | dig2 |= WM9705_PDEN; | |
316 | } else { | |
317 | dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN); | |
318 | dig2 &= ~WM9705_PDEN; | |
319 | if (wm->mach_ops->acc_shutdown) | |
320 | wm->mach_ops->acc_shutdown(wm); | |
321 | } | |
322 | ||
323 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); | |
324 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); | |
325 | ||
326 | return ret; | |
327 | } | |
328 | ||
329 | struct wm97xx_codec_drv wm9705_codec = { | |
330 | .id = WM9705_ID2, | |
331 | .name = "wm9705", | |
332 | .poll_sample = wm9705_poll_sample, | |
333 | .poll_touch = wm9705_poll_touch, | |
334 | .acc_enable = wm9705_acc_enable, | |
335 | .phy_init = wm9705_phy_init, | |
336 | .dig_enable = wm9705_dig_enable, | |
337 | .dig_restore = wm9705_dig_restore, | |
338 | .aux_prepare = wm9705_aux_prepare, | |
339 | }; | |
340 | EXPORT_SYMBOL_GPL(wm9705_codec); | |
341 | ||
342 | /* Module information */ | |
b8d055a8 | 343 | MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); |
9448cefc MB |
344 | MODULE_DESCRIPTION("WM9705 Touch Screen Driver"); |
345 | MODULE_LICENSE("GPL"); |