2 * wm9713.c -- Codec touch driver for Wolfson WM9713 AC97 Codec.
4 * Copyright 2003, 2004, 2005, 2006, 2007, 2008 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 WM9713_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 WM9713
156 static void wm9713_phy_init(struct wm97xx *wm)
158 u16 dig1 = 0, dig2, dig3;
161 dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5);
162 dig3 = WM9712_RPU(1);
167 dig3 |= WM9712_RPU(rpu);
168 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n",
172 /* Five wire panel? */
175 dev_info(wm->dev, "setting 5-wire touchscreen mode.");
179 "Pressure measurement not supported in 5 "
180 "wire mode, disabling\n");
185 /* touchpanel pressure */
189 "setting pressure measurement current to 400uA.");
192 "setting pressure measurement current to 200uA.");
196 /* sample settling delay */
197 if (delay < 0 || delay > 15) {
198 dev_info(wm->dev, "supplied delay out of range.");
200 dev_info(wm->dev, "setting adc sample delay to %d u Secs.",
204 dig2 |= WM97XX_DELAY(delay);
207 dig3 |= ((mask & 0x3) << 4);
211 wm->misc = wm97xx_reg_read(wm, 0x5a);
213 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
214 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
215 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
216 wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0);
219 static void wm9713_dig_enable(struct wm97xx *wm, int enable)
224 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
225 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff);
226 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] |
228 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
230 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] &
231 ~WM97XX_PRP_DET_DIG);
232 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
233 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000);
237 static void wm9713_dig_restore(struct wm97xx *wm)
239 wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]);
240 wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]);
241 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]);
244 static void wm9713_aux_prepare(struct wm97xx *wm)
246 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
247 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0);
248 wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0);
249 wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG);
252 static inline int is_pden(struct wm97xx *wm)
254 return wm->dig[2] & WM9713_PDEN;
258 * Read a sample from the WM9713 adc in polling mode.
260 static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
263 int timeout = 5 * delay;
265 if (!wm->pen_probably_down) {
266 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
267 if (!(data & WM97XX_PEN_DOWN))
269 wm->pen_probably_down = 1;
272 /* set up digitiser */
274 adcsel = 1 << ((adcsel & 0x7fff) + 3);
276 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
277 dig1 &= ~WM9713_ADCSEL_MASK;
279 if (wm->mach_ops && wm->mach_ops->pre_sample)
280 wm->mach_ops->pre_sample(adcsel);
281 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | adcsel | WM9713_POLL);
283 /* wait 3 AC97 time slots + delay for conversion */
286 /* wait for POLL to go low */
287 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) &&
289 udelay(AC97_LINK_FRAME);
294 /* If PDEN is set, we can get a timeout when pen goes up */
296 wm->pen_probably_down = 0;
298 dev_dbg(wm->dev, "adc sample timeout");
302 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
303 if (wm->mach_ops && wm->mach_ops->post_sample)
304 wm->mach_ops->post_sample(adcsel);
306 /* check we have correct sample */
307 if ((*sample & WM97XX_ADCSRC_MASK) != ffs(adcsel >> 1) << 12) {
308 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,
309 *sample & WM97XX_ADCSRC_MASK);
313 if (!(*sample & WM97XX_PEN_DOWN)) {
314 wm->pen_probably_down = 0;
322 * Read a coordinate from the WM9713 adc in polling mode.
324 static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
327 int timeout = 5 * delay;
329 if (!wm->pen_probably_down) {
330 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
331 if (!(val & WM97XX_PEN_DOWN))
333 wm->pen_probably_down = 1;
336 /* set up digitiser */
337 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
338 dig1 &= ~WM9713_ADCSEL_MASK;
340 dig1 |= WM9713_ADCSEL_PRES;
342 if (wm->mach_ops && wm->mach_ops->pre_sample)
343 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
344 wm97xx_reg_write(wm, AC97_WM9713_DIG1,
345 dig1 | WM9713_POLL | WM9713_COO);
347 /* wait 3 AC97 time slots + delay for conversion */
349 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
350 /* wait for POLL to go low */
351 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL)
353 udelay(AC97_LINK_FRAME);
358 /* If PDEN is set, we can get a timeout when pen goes up */
360 wm->pen_probably_down = 0;
362 dev_dbg(wm->dev, "adc sample timeout");
367 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
369 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
371 data->p = DEFAULT_PRESSURE;
373 if (wm->mach_ops && wm->mach_ops->post_sample)
374 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
376 /* check we have correct sample */
377 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
379 if (pil && !(data->p & WM97XX_ADCSEL_PRES))
382 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
383 wm->pen_probably_down = 0;
392 * Sample the WM9713 touchscreen in polling mode
394 static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
399 rc = wm9713_poll_coord(wm, data);
403 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x);
406 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y);
410 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES,
415 data->p = DEFAULT_PRESSURE;
421 * Enable WM9713 continuous mode, i.e. touch data is streamed across
424 static int wm9713_acc_enable(struct wm97xx *wm, int enable)
426 u16 dig1, dig2, dig3;
435 if (wm->mach_ops->acc_startup &&
436 (ret = wm->mach_ops->acc_startup(wm)) < 0)
439 dig1 &= ~WM9713_ADCSEL_MASK;
440 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X |
443 dig1 |= WM9713_ADCSEL_PRES;
444 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK |
445 WM97XX_CM_RATE_MASK);
446 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) |
447 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate);
450 dig1 &= ~(WM9713_CTC | WM9713_COO);
451 dig2 &= ~WM97XX_SLEN;
452 dig3 &= ~WM9713_PDEN;
453 if (wm->mach_ops->acc_shutdown)
454 wm->mach_ops->acc_shutdown(wm);
457 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
458 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
459 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
464 struct wm97xx_codec_drv wm9713_codec = {
467 .poll_sample = wm9713_poll_sample,
468 .poll_touch = wm9713_poll_touch,
469 .acc_enable = wm9713_acc_enable,
470 .phy_init = wm9713_phy_init,
471 .dig_enable = wm9713_dig_enable,
472 .dig_restore = wm9713_dig_restore,
473 .aux_prepare = wm9713_aux_prepare,
475 EXPORT_SYMBOL_GPL(wm9713_codec);
477 /* Module information */
478 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
479 MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
480 MODULE_LICENSE("GPL");