2 * wm9712.c -- Codec driver for Wolfson WM9712 AC97 Codecs.
4 * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC.
5 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
6 * Parts Copyright : Ian Molton <spyro@f2s.com>
7 * Andrew Zabolotny <zap@homelink.ru>
8 * Russell King <rmk@arm.linux.org.uk>
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.
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
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>
25 #define TS_NAME "wm97xx"
26 #define WM9712_VERSION "1.00"
27 #define DEFAULT_PRESSURE 0xb0c0
34 * Set internal pull up for pen detect.
36 * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive)
37 * i.e. pull up resistance = 64k Ohms / rpu.
39 * Adjust this value if you are having problems with pen detect not
40 * detecting any down event.
43 module_param(rpu, int, 0);
44 MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect.");
47 * Set current used for pressure measurement.
49 * Set pil = 2 to use 400uA
50 * pil = 1 to use 200uA and
51 * pil = 0 to disable pressure measurement.
53 * This is used to increase the range of values returned by the adc
54 * when measureing touchpanel pressure.
57 module_param(pil, int, 0);
58 MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");
61 * Set threshold for pressure measurement.
63 * Pen down pressure below threshold is ignored.
65 static int pressure = DEFAULT_PRESSURE & 0xfff;
66 module_param(pressure, int, 0);
67 MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");
70 * Set adc sample delay.
72 * For accurate touchpanel measurements, some settling time may be
73 * required between the switch matrix applying a voltage across the
74 * touchpanel plate and the ADC sampling the signal.
76 * This delay can be set by setting delay = n, where n is the array
77 * position of the delay in the array delay_table below.
78 * Long delays > 1ms are supported for completeness, but are not
82 module_param(delay, int, 0);
83 MODULE_PARM_DESC(delay, "Set adc sample delay.");
86 * Set five_wire = 1 to use a 5 wire touchscreen.
88 * NOTE: Five wire mode does not allow for readback of pressure.
91 module_param(five_wire, int, 0);
92 MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");
95 * Set adc mask function.
97 * Sources of glitch noise, such as signals driving an LCD display, may feed
98 * through to the touch screen plates and affect measurement accuracy. In
99 * order to minimise this, a signal may be applied to the MASK pin to delay or
100 * synchronise the sampling.
102 * 0 = No delay or sync
103 * 1 = High on pin stops conversions
104 * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
105 * 3 = Edge triggered, edge on pin starts conversion after delay param
108 module_param(mask, int, 0);
109 MODULE_PARM_DESC(mask, "Set adc mask function.");
112 * Coordinate Polling Enable.
114 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
118 module_param(coord, int, 0);
119 MODULE_PARM_DESC(coord, "Polling coordinate mode");
122 * ADC sample delay times in uS
124 static const int delay_table[] = {
125 21, /* 1 AC97 Link frames */
140 0 /* No delay, switch matrix always on */
144 * Delay after issuing a POLL command.
146 * The delay is 3 AC97 link frames + the touchpanel settling delay
148 static inline void poll_delay(int d)
150 udelay(3 * AC97_LINK_FRAME + delay_table[d]);
154 * set up the physical settings of the WM9712
156 static void wm9712_phy_init(struct wm97xx *wm)
159 u16 dig2 = WM97XX_RPR | WM9712_RPU(1);
164 dig2 |= WM9712_RPU(rpu);
165 dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms",
169 /* WM9712 five wire */
172 dev_dbg(wm->dev, "setting 5-wire touchscreen mode.");
175 dev_warn(wm->dev, "pressure measurement is not "
176 "supported in 5-wire mode\n");
181 /* touchpanel pressure current*/
185 "setting pressure measurement current to 400uA.");
188 "setting pressure measurement current to 200uA.");
192 /* polling mode sample settling delay */
193 if (delay < 0 || delay > 15) {
194 dev_dbg(wm->dev, "supplied delay out of range.");
198 dig1 |= WM97XX_DELAY(delay);
199 dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.",
203 dig2 |= ((mask & 0x3) << 6);
206 /* Set GPIO4 as Mask Pin*/
207 reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
208 wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4);
209 reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);
210 wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4);
213 /* wait - coord mode */
217 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
218 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
221 static void wm9712_dig_enable(struct wm97xx *wm, int enable)
223 u16 dig2 = wm->dig[2];
226 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
227 dig2 | WM97XX_PRP_DET_DIG);
228 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
230 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
231 dig2 & ~WM97XX_PRP_DET_DIG);
234 static void wm9712_aux_prepare(struct wm97xx *wm)
236 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
237 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0);
238 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG);
241 static void wm9712_dig_restore(struct wm97xx *wm)
243 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]);
244 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]);
247 static inline int is_pden(struct wm97xx *wm)
249 return wm->dig[2] & WM9712_PDEN;
253 * Read a sample from the WM9712 adc in polling mode.
255 static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
257 int timeout = 5 * delay;
258 bool wants_pen = adcsel & WM97XX_PEN_DOWN;
260 if (wants_pen && !wm->pen_probably_down) {
261 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
262 if (!(data & WM97XX_PEN_DOWN))
264 wm->pen_probably_down = 1;
267 /* set up digitiser */
268 if (wm->mach_ops && wm->mach_ops->pre_sample)
269 wm->mach_ops->pre_sample(adcsel);
270 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK)
271 | WM97XX_POLL | WM97XX_DELAY(delay));
273 /* wait 3 AC97 time slots + delay for conversion */
276 /* wait for POLL to go low */
277 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
279 udelay(AC97_LINK_FRAME);
284 /* If PDEN is set, we can get a timeout when pen goes up */
286 wm->pen_probably_down = 0;
288 dev_dbg(wm->dev, "adc sample timeout");
292 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
293 if (wm->mach_ops && wm->mach_ops->post_sample)
294 wm->mach_ops->post_sample(adcsel);
296 /* check we have correct sample */
297 if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) {
298 dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x",
299 adcsel & WM97XX_ADCSEL_MASK,
300 *sample & WM97XX_ADCSEL_MASK);
304 if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) {
305 wm->pen_probably_down = 0;
313 * Read a coord from the WM9712 adc in polling mode.
315 static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
317 int timeout = 5 * delay;
319 if (!wm->pen_probably_down) {
320 u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
321 if (!(data_rd & WM97XX_PEN_DOWN))
323 wm->pen_probably_down = 1;
326 /* set up digitiser */
327 if (wm->mach_ops && wm->mach_ops->pre_sample)
328 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
330 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,
331 WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay));
333 /* wait 3 AC97 time slots + delay for conversion and read x */
335 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
336 /* wait for POLL to go low */
337 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
339 udelay(AC97_LINK_FRAME);
344 /* If PDEN is set, we can get a timeout when pen goes up */
346 wm->pen_probably_down = 0;
348 dev_dbg(wm->dev, "adc sample timeout");
352 /* read back y data */
353 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
355 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
357 data->p = DEFAULT_PRESSURE;
359 if (wm->mach_ops && wm->mach_ops->post_sample)
360 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
362 /* check we have correct sample */
363 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
365 if (pil && !(data->p & WM97XX_ADCSEL_PRES))
368 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
369 wm->pen_probably_down = 0;
378 * Sample the WM9712 touchscreen in polling mode
380 static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
385 rc = wm9712_poll_coord(wm, data);
389 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN,
394 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN,
399 if (pil && !five_wire) {
400 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN,
405 data->p = DEFAULT_PRESSURE;
411 * Enable WM9712 continuous mode, i.e. touch data is streamed across
414 static int wm9712_acc_enable(struct wm97xx *wm, int enable)
423 /* continuous mode */
424 if (wm->mach_ops->acc_startup) {
425 ret = wm->mach_ops->acc_startup(wm);
429 dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK |
430 WM97XX_DELAY_MASK | WM97XX_SLT_MASK);
431 dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN |
432 WM97XX_DELAY(delay) |
433 WM97XX_SLT(wm->acc_slot) |
434 WM97XX_RATE(wm->acc_rate);
436 dig1 |= WM97XX_ADCSEL_PRES;
439 dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN);
440 dig2 &= ~WM9712_PDEN;
441 if (wm->mach_ops->acc_shutdown)
442 wm->mach_ops->acc_shutdown(wm);
445 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
446 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
451 struct wm97xx_codec_drv wm9712_codec = {
454 .poll_sample = wm9712_poll_sample,
455 .poll_touch = wm9712_poll_touch,
456 .acc_enable = wm9712_acc_enable,
457 .phy_init = wm9712_phy_init,
458 .dig_enable = wm9712_dig_enable,
459 .dig_restore = wm9712_dig_restore,
460 .aux_prepare = wm9712_aux_prepare,
462 EXPORT_SYMBOL_GPL(wm9712_codec);
464 /* Module information */
465 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
466 MODULE_DESCRIPTION("WM9712 Touch Screen Driver");
467 MODULE_LICENSE("GPL");