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1 | /* |
2 | * wm9705.c -- Codec driver for Wolfson WM9705 AC97 Codec. | |
3 | * | |
4 | * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC. | |
b8d055a8 | 5 | * Author: Liam Girdwood <lrg@slimlogic.co.uk> |
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6 | * 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> | |
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19 | #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 WM9705_VERSION "1.00" | |
27 | #define DEFAULT_PRESSURE 0xb0c0 | |
28 | ||
29 | /* | |
30 | * Module parameters | |
31 | */ | |
32 | ||
33 | /* | |
34 | * Set current used for pressure measurement. | |
35 | * | |
36 | * Set pil = 2 to use 400uA | |
37 | * pil = 1 to use 200uA and | |
38 | * pil = 0 to disable pressure measurement. | |
39 | * | |
40 | * This is used to increase the range of values returned by the adc | |
41 | * when measureing touchpanel pressure. | |
42 | */ | |
43 | static int pil; | |
44 | module_param(pil, int, 0); | |
45 | MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); | |
46 | ||
47 | /* | |
48 | * Set threshold for pressure measurement. | |
49 | * | |
50 | * Pen down pressure below threshold is ignored. | |
51 | */ | |
52 | static int pressure = DEFAULT_PRESSURE & 0xfff; | |
53 | module_param(pressure, int, 0); | |
54 | MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); | |
55 | ||
56 | /* | |
57 | * Set adc sample delay. | |
58 | * | |
59 | * For accurate touchpanel measurements, some settling time may be | |
60 | * required between the switch matrix applying a voltage across the | |
61 | * touchpanel plate and the ADC sampling the signal. | |
62 | * | |
63 | * This delay can be set by setting delay = n, where n is the array | |
64 | * position of the delay in the array delay_table below. | |
65 | * Long delays > 1ms are supported for completeness, but are not | |
66 | * recommended. | |
67 | */ | |
68 | static int delay = 4; | |
69 | module_param(delay, int, 0); | |
70 | MODULE_PARM_DESC(delay, "Set adc sample delay."); | |
71 | ||
72 | /* | |
73 | * Pen detect comparator threshold. | |
74 | * | |
75 | * 0 to Vmid in 15 steps, 0 = use zero power comparator with Vmid threshold | |
76 | * i.e. 1 = Vmid/15 threshold | |
77 | * 15 = Vmid/1 threshold | |
78 | * | |
79 | * Adjust this value if you are having problems with pen detect not | |
80 | * detecting any down events. | |
81 | */ | |
82 | static int pdd = 8; | |
83 | module_param(pdd, int, 0); | |
84 | MODULE_PARM_DESC(pdd, "Set pen detect comparator threshold"); | |
85 | ||
86 | /* | |
87 | * Set adc mask function. | |
88 | * | |
89 | * Sources of glitch noise, such as signals driving an LCD display, may feed | |
90 | * through to the touch screen plates and affect measurement accuracy. In | |
91 | * order to minimise this, a signal may be applied to the MASK pin to delay or | |
92 | * synchronise the sampling. | |
93 | * | |
94 | * 0 = No delay or sync | |
95 | * 1 = High on pin stops conversions | |
96 | * 2 = Edge triggered, edge on pin delays conversion by delay param (above) | |
97 | * 3 = Edge triggered, edge on pin starts conversion after delay param | |
98 | */ | |
99 | static int mask; | |
100 | module_param(mask, int, 0); | |
101 | MODULE_PARM_DESC(mask, "Set adc mask function."); | |
102 | ||
103 | /* | |
104 | * ADC sample delay times in uS | |
105 | */ | |
106 | static const int delay_table[] = { | |
107 | 21, /* 1 AC97 Link frames */ | |
108 | 42, /* 2 */ | |
109 | 84, /* 4 */ | |
110 | 167, /* 8 */ | |
111 | 333, /* 16 */ | |
112 | 667, /* 32 */ | |
113 | 1000, /* 48 */ | |
114 | 1333, /* 64 */ | |
115 | 2000, /* 96 */ | |
116 | 2667, /* 128 */ | |
117 | 3333, /* 160 */ | |
118 | 4000, /* 192 */ | |
119 | 4667, /* 224 */ | |
120 | 5333, /* 256 */ | |
121 | 6000, /* 288 */ | |
122 | 0 /* No delay, switch matrix always on */ | |
123 | }; | |
124 | ||
125 | /* | |
126 | * Delay after issuing a POLL command. | |
127 | * | |
128 | * The delay is 3 AC97 link frames + the touchpanel settling delay | |
129 | */ | |
130 | static inline void poll_delay(int d) | |
131 | { | |
132 | udelay(3 * AC97_LINK_FRAME + delay_table[d]); | |
133 | } | |
134 | ||
135 | /* | |
136 | * set up the physical settings of the WM9705 | |
137 | */ | |
138 | static void wm9705_phy_init(struct wm97xx *wm) | |
139 | { | |
140 | u16 dig1 = 0, dig2 = WM97XX_RPR; | |
141 | ||
142 | /* | |
143 | * mute VIDEO and AUX as they share X and Y touchscreen | |
144 | * inputs on the WM9705 | |
145 | */ | |
146 | wm97xx_reg_write(wm, AC97_AUX, 0x8000); | |
147 | wm97xx_reg_write(wm, AC97_VIDEO, 0x8000); | |
148 | ||
149 | /* touchpanel pressure current*/ | |
150 | if (pil == 2) { | |
151 | dig2 |= WM9705_PIL; | |
152 | dev_dbg(wm->dev, | |
153 | "setting pressure measurement current to 400uA."); | |
154 | } else if (pil) | |
155 | dev_dbg(wm->dev, | |
156 | "setting pressure measurement current to 200uA."); | |
157 | if (!pil) | |
158 | pressure = 0; | |
159 | ||
160 | /* polling mode sample settling delay */ | |
161 | if (delay != 4) { | |
162 | if (delay < 0 || delay > 15) { | |
163 | dev_dbg(wm->dev, "supplied delay out of range."); | |
164 | delay = 4; | |
165 | } | |
166 | } | |
167 | dig1 &= 0xff0f; | |
168 | dig1 |= WM97XX_DELAY(delay); | |
169 | dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.", | |
170 | delay_table[delay]); | |
171 | ||
172 | /* WM9705 pdd */ | |
173 | dig2 |= (pdd & 0x000f); | |
174 | dev_dbg(wm->dev, "setting pdd to Vmid/%d", 1 - (pdd & 0x000f)); | |
175 | ||
176 | /* mask */ | |
177 | dig2 |= ((mask & 0x3) << 4); | |
178 | ||
179 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); | |
180 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); | |
181 | } | |
182 | ||
183 | static void wm9705_dig_enable(struct wm97xx *wm, int enable) | |
184 | { | |
185 | if (enable) { | |
186 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, | |
187 | wm->dig[2] | WM97XX_PRP_DET_DIG); | |
188 | wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ | |
189 | } else | |
190 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, | |
191 | wm->dig[2] & ~WM97XX_PRP_DET_DIG); | |
192 | } | |
193 | ||
194 | static void wm9705_aux_prepare(struct wm97xx *wm) | |
195 | { | |
196 | memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); | |
197 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0); | |
198 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG); | |
199 | } | |
200 | ||
201 | static void wm9705_dig_restore(struct wm97xx *wm) | |
202 | { | |
203 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]); | |
204 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]); | |
205 | } | |
206 | ||
207 | static inline int is_pden(struct wm97xx *wm) | |
208 | { | |
209 | return wm->dig[2] & WM9705_PDEN; | |
210 | } | |
211 | ||
212 | /* | |
213 | * Read a sample from the WM9705 adc in polling mode. | |
214 | */ | |
215 | static int wm9705_poll_sample(struct wm97xx *wm, int adcsel, int *sample) | |
216 | { | |
217 | int timeout = 5 * delay; | |
77da3838 | 218 | bool wants_pen = adcsel & WM97XX_PEN_DOWN; |
9448cefc | 219 | |
77da3838 | 220 | if (wants_pen && !wm->pen_probably_down) { |
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221 | u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); |
222 | if (!(data & WM97XX_PEN_DOWN)) | |
223 | return RC_PENUP; | |
224 | wm->pen_probably_down = 1; | |
225 | } | |
226 | ||
227 | /* set up digitiser */ | |
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228 | if (wm->mach_ops && wm->mach_ops->pre_sample) |
229 | wm->mach_ops->pre_sample(adcsel); | |
c8f20525 WS |
230 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK) |
231 | | WM97XX_POLL | WM97XX_DELAY(delay)); | |
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232 | |
233 | /* wait 3 AC97 time slots + delay for conversion */ | |
234 | poll_delay(delay); | |
235 | ||
236 | /* wait for POLL to go low */ | |
237 | while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) | |
238 | && timeout) { | |
239 | udelay(AC97_LINK_FRAME); | |
240 | timeout--; | |
241 | } | |
242 | ||
243 | if (timeout == 0) { | |
244 | /* If PDEN is set, we can get a timeout when pen goes up */ | |
245 | if (is_pden(wm)) | |
246 | wm->pen_probably_down = 0; | |
247 | else | |
248 | dev_dbg(wm->dev, "adc sample timeout"); | |
249 | return RC_PENUP; | |
250 | } | |
251 | ||
252 | *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); | |
253 | if (wm->mach_ops && wm->mach_ops->post_sample) | |
254 | wm->mach_ops->post_sample(adcsel); | |
255 | ||
256 | /* check we have correct sample */ | |
c8f20525 WS |
257 | if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) { |
258 | dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x", | |
259 | adcsel & WM97XX_ADCSEL_MASK, | |
260 | *sample & WM97XX_ADCSEL_MASK); | |
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261 | return RC_PENUP; |
262 | } | |
263 | ||
77da3838 | 264 | if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { |
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265 | wm->pen_probably_down = 0; |
266 | return RC_PENUP; | |
267 | } | |
268 | ||
269 | return RC_VALID; | |
270 | } | |
271 | ||
272 | /* | |
273 | * Sample the WM9705 touchscreen in polling mode | |
274 | */ | |
275 | static int wm9705_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) | |
276 | { | |
277 | int rc; | |
278 | ||
77da3838 | 279 | rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x); |
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280 | if (rc != RC_VALID) |
281 | return rc; | |
77da3838 | 282 | rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y); |
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283 | if (rc != RC_VALID) |
284 | return rc; | |
285 | if (pil) { | |
77da3838 | 286 | rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, &data->p); |
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287 | if (rc != RC_VALID) |
288 | return rc; | |
289 | } else | |
290 | data->p = DEFAULT_PRESSURE; | |
291 | ||
292 | return RC_VALID; | |
293 | } | |
294 | ||
295 | /* | |
296 | * Enable WM9705 continuous mode, i.e. touch data is streamed across | |
297 | * an AC97 slot | |
298 | */ | |
299 | static int wm9705_acc_enable(struct wm97xx *wm, int enable) | |
300 | { | |
301 | u16 dig1, dig2; | |
302 | int ret = 0; | |
303 | ||
304 | dig1 = wm->dig[1]; | |
305 | dig2 = wm->dig[2]; | |
306 | ||
307 | if (enable) { | |
25985edc | 308 | /* continuous mode */ |
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309 | if (wm->mach_ops->acc_startup && |
310 | (ret = wm->mach_ops->acc_startup(wm)) < 0) | |
311 | return ret; | |
312 | dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK | | |
313 | WM97XX_DELAY_MASK | WM97XX_SLT_MASK); | |
314 | dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN | | |
315 | WM97XX_DELAY(delay) | | |
316 | WM97XX_SLT(wm->acc_slot) | | |
317 | WM97XX_RATE(wm->acc_rate); | |
318 | if (pil) | |
319 | dig1 |= WM97XX_ADCSEL_PRES; | |
320 | dig2 |= WM9705_PDEN; | |
321 | } else { | |
322 | dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN); | |
323 | dig2 &= ~WM9705_PDEN; | |
324 | if (wm->mach_ops->acc_shutdown) | |
325 | wm->mach_ops->acc_shutdown(wm); | |
326 | } | |
327 | ||
328 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); | |
329 | wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); | |
330 | ||
331 | return ret; | |
332 | } | |
333 | ||
334 | struct wm97xx_codec_drv wm9705_codec = { | |
335 | .id = WM9705_ID2, | |
336 | .name = "wm9705", | |
337 | .poll_sample = wm9705_poll_sample, | |
338 | .poll_touch = wm9705_poll_touch, | |
339 | .acc_enable = wm9705_acc_enable, | |
340 | .phy_init = wm9705_phy_init, | |
341 | .dig_enable = wm9705_dig_enable, | |
342 | .dig_restore = wm9705_dig_restore, | |
343 | .aux_prepare = wm9705_aux_prepare, | |
344 | }; | |
345 | EXPORT_SYMBOL_GPL(wm9705_codec); | |
346 | ||
347 | /* Module information */ | |
b8d055a8 | 348 | MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); |
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349 | MODULE_DESCRIPTION("WM9705 Touch Screen Driver"); |
350 | MODULE_LICENSE("GPL"); |