2 * wm9712.c -- Codec driver for Wolfson WM9712 AC97 Codecs.
4 * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC.
5 * Author: Liam Girdwood
6 * liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
7 * Parts Copyright : Ian Molton <spyro@f2s.com>
8 * Andrew Zabolotny <zap@homelink.ru>
9 * Russell King <rmk@arm.linux.org.uk>
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/version.h>
21 #include <linux/kernel.h>
22 #include <linux/input.h>
23 #include <linux/delay.h>
24 #include <linux/bitops.h>
25 #include <linux/wm97xx.h>
27 #define TS_NAME "wm97xx"
28 #define WM9712_VERSION "1.00"
29 #define DEFAULT_PRESSURE 0xb0c0
36 * Set internal pull up for pen detect.
38 * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive)
39 * i.e. pull up resistance = 64k Ohms / rpu.
41 * Adjust this value if you are having problems with pen detect not
42 * detecting any down event.
45 module_param(rpu
, int, 0);
46 MODULE_PARM_DESC(rpu
, "Set internal pull up resitor for pen detect.");
49 * Set current used for pressure measurement.
51 * Set pil = 2 to use 400uA
52 * pil = 1 to use 200uA and
53 * pil = 0 to disable pressure measurement.
55 * This is used to increase the range of values returned by the adc
56 * when measureing touchpanel pressure.
59 module_param(pil
, int, 0);
60 MODULE_PARM_DESC(pil
, "Set current used for pressure measurement.");
63 * Set threshold for pressure measurement.
65 * Pen down pressure below threshold is ignored.
67 static int pressure
= DEFAULT_PRESSURE
& 0xfff;
68 module_param(pressure
, int, 0);
69 MODULE_PARM_DESC(pressure
, "Set threshold for pressure measurement.");
72 * Set adc sample delay.
74 * For accurate touchpanel measurements, some settling time may be
75 * required between the switch matrix applying a voltage across the
76 * touchpanel plate and the ADC sampling the signal.
78 * This delay can be set by setting delay = n, where n is the array
79 * position of the delay in the array delay_table below.
80 * Long delays > 1ms are supported for completeness, but are not
84 module_param(delay
, int, 0);
85 MODULE_PARM_DESC(delay
, "Set adc sample delay.");
88 * Set five_wire = 1 to use a 5 wire touchscreen.
90 * NOTE: Five wire mode does not allow for readback of pressure.
93 module_param(five_wire
, int, 0);
94 MODULE_PARM_DESC(five_wire
, "Set to '1' to use 5-wire touchscreen.");
97 * Set adc mask function.
99 * Sources of glitch noise, such as signals driving an LCD display, may feed
100 * through to the touch screen plates and affect measurement accuracy. In
101 * order to minimise this, a signal may be applied to the MASK pin to delay or
102 * synchronise the sampling.
104 * 0 = No delay or sync
105 * 1 = High on pin stops conversions
106 * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
107 * 3 = Edge triggered, edge on pin starts conversion after delay param
110 module_param(mask
, int, 0);
111 MODULE_PARM_DESC(mask
, "Set adc mask function.");
114 * Coordinate Polling Enable.
116 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
120 module_param(coord
, int, 0);
121 MODULE_PARM_DESC(coord
, "Polling coordinate mode");
124 * ADC sample delay times in uS
126 static const int delay_table
[] = {
127 21, /* 1 AC97 Link frames */
142 0 /* No delay, switch matrix always on */
146 * Delay after issuing a POLL command.
148 * The delay is 3 AC97 link frames + the touchpanel settling delay
150 static inline void poll_delay(int d
)
152 udelay(3 * AC97_LINK_FRAME
+ delay_table
[d
]);
156 * set up the physical settings of the WM9712
158 static void wm9712_phy_init(struct wm97xx
*wm
)
161 u16 dig2
= WM97XX_RPR
| WM9712_RPU(1);
166 dig2
|= WM9712_RPU(rpu
);
167 dev_dbg(wm
->dev
, "setting pen detect pull-up to %d Ohms",
171 /* touchpanel pressure current*/
175 "setting pressure measurement current to 400uA.");
178 "setting pressure measurement current to 200uA.");
182 /* WM9712 five wire */
185 dev_dbg(wm
->dev
, "setting 5-wire touchscreen mode.");
188 /* polling mode sample settling delay */
189 if (delay
< 0 || delay
> 15) {
190 dev_dbg(wm
->dev
, "supplied delay out of range.");
194 dig1
|= WM97XX_DELAY(delay
);
195 dev_dbg(wm
->dev
, "setting adc sample delay to %d u Secs.",
199 dig2
|= ((mask
& 0x3) << 6);
202 /* Set GPIO4 as Mask Pin*/
203 reg
= wm97xx_reg_read(wm
, AC97_MISC_AFE
);
204 wm97xx_reg_write(wm
, AC97_MISC_AFE
, reg
| WM97XX_GPIO_4
);
205 reg
= wm97xx_reg_read(wm
, AC97_GPIO_CFG
);
206 wm97xx_reg_write(wm
, AC97_GPIO_CFG
, reg
| WM97XX_GPIO_4
);
209 /* wait - coord mode */
213 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER1
, dig1
);
214 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER2
, dig2
);
217 static void wm9712_dig_enable(struct wm97xx
*wm
, int enable
)
219 u16 dig2
= wm
->dig
[2];
222 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER2
,
223 dig2
| WM97XX_PRP_DET_DIG
);
224 wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER_RD
); /* dummy read */
226 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER2
,
227 dig2
& ~WM97XX_PRP_DET_DIG
);
230 static void wm9712_aux_prepare(struct wm97xx
*wm
)
232 memcpy(wm
->dig_save
, wm
->dig
, sizeof(wm
->dig
));
233 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER1
, 0);
234 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER2
, WM97XX_PRP_DET_DIG
);
237 static void wm9712_dig_restore(struct wm97xx
*wm
)
239 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER1
, wm
->dig_save
[1]);
240 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER2
, wm
->dig_save
[2]);
243 static inline int is_pden(struct wm97xx
*wm
)
245 return wm
->dig
[2] & WM9712_PDEN
;
249 * Read a sample from the WM9712 adc in polling mode.
251 static int wm9712_poll_sample(struct wm97xx
*wm
, int adcsel
, int *sample
)
253 int timeout
= 5 * delay
;
255 if (!wm
->pen_probably_down
) {
256 u16 data
= wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER_RD
);
257 if (!(data
& WM97XX_PEN_DOWN
))
259 wm
->pen_probably_down
= 1;
262 /* set up digitiser */
264 adcsel
= ((adcsel
& 0x7fff) + 3) << 12;
266 if (wm
->mach_ops
&& wm
->mach_ops
->pre_sample
)
267 wm
->mach_ops
->pre_sample(adcsel
);
268 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER1
,
269 adcsel
| WM97XX_POLL
| WM97XX_DELAY(delay
));
271 /* wait 3 AC97 time slots + delay for conversion */
274 /* wait for POLL to go low */
275 while ((wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER1
) & WM97XX_POLL
)
277 udelay(AC97_LINK_FRAME
);
282 /* If PDEN is set, we can get a timeout when pen goes up */
284 wm
->pen_probably_down
= 0;
286 dev_dbg(wm
->dev
, "adc sample timeout");
290 *sample
= wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER_RD
);
291 if (wm
->mach_ops
&& wm
->mach_ops
->post_sample
)
292 wm
->mach_ops
->post_sample(adcsel
);
294 /* check we have correct sample */
295 if ((*sample
& WM97XX_ADCSEL_MASK
) != adcsel
) {
296 dev_dbg(wm
->dev
, "adc wrong sample, read %x got %x", adcsel
,
297 *sample
& WM97XX_ADCSEL_MASK
);
301 if (!(*sample
& WM97XX_PEN_DOWN
)) {
302 wm
->pen_probably_down
= 0;
310 * Read a coord from the WM9712 adc in polling mode.
312 static int wm9712_poll_coord(struct wm97xx
*wm
, struct wm97xx_data
*data
)
314 int timeout
= 5 * delay
;
316 if (!wm
->pen_probably_down
) {
317 u16 data_rd
= wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER_RD
);
318 if (!(data_rd
& WM97XX_PEN_DOWN
))
320 wm
->pen_probably_down
= 1;
323 /* set up digitiser */
324 if (wm
->mach_ops
&& wm
->mach_ops
->pre_sample
)
325 wm
->mach_ops
->pre_sample(WM97XX_ADCSEL_X
| WM97XX_ADCSEL_Y
);
327 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER1
,
328 WM97XX_COO
| WM97XX_POLL
| WM97XX_DELAY(delay
));
330 /* wait 3 AC97 time slots + delay for conversion and read x */
332 data
->x
= wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER_RD
);
333 /* wait for POLL to go low */
334 while ((wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER1
) & WM97XX_POLL
)
336 udelay(AC97_LINK_FRAME
);
341 /* If PDEN is set, we can get a timeout when pen goes up */
343 wm
->pen_probably_down
= 0;
345 dev_dbg(wm
->dev
, "adc sample timeout");
349 /* read back y data */
350 data
->y
= wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER_RD
);
352 data
->p
= wm97xx_reg_read(wm
, AC97_WM97XX_DIGITISER_RD
);
354 data
->p
= DEFAULT_PRESSURE
;
356 if (wm
->mach_ops
&& wm
->mach_ops
->post_sample
)
357 wm
->mach_ops
->post_sample(WM97XX_ADCSEL_X
| WM97XX_ADCSEL_Y
);
359 /* check we have correct sample */
360 if (!(data
->x
& WM97XX_ADCSEL_X
) || !(data
->y
& WM97XX_ADCSEL_Y
))
362 if (pil
&& !(data
->p
& WM97XX_ADCSEL_PRES
))
365 if (!(data
->x
& WM97XX_PEN_DOWN
) || !(data
->y
& WM97XX_PEN_DOWN
)) {
366 wm
->pen_probably_down
= 0;
375 * Sample the WM9712 touchscreen in polling mode
377 static int wm9712_poll_touch(struct wm97xx
*wm
, struct wm97xx_data
*data
)
382 rc
= wm9712_poll_coord(wm
, data
);
386 rc
= wm9712_poll_sample(wm
, WM97XX_ADCSEL_X
, &data
->x
);
390 rc
= wm9712_poll_sample(wm
, WM97XX_ADCSEL_Y
, &data
->y
);
394 if (pil
&& !five_wire
) {
395 rc
= wm9712_poll_sample(wm
, WM97XX_ADCSEL_PRES
,
400 data
->p
= DEFAULT_PRESSURE
;
406 * Enable WM9712 continuous mode, i.e. touch data is streamed across
409 static int wm9712_acc_enable(struct wm97xx
*wm
, int enable
)
419 if (wm
->mach_ops
->acc_startup
) {
420 ret
= wm
->mach_ops
->acc_startup(wm
);
424 dig1
&= ~(WM97XX_CM_RATE_MASK
| WM97XX_ADCSEL_MASK
|
425 WM97XX_DELAY_MASK
| WM97XX_SLT_MASK
);
426 dig1
|= WM97XX_CTC
| WM97XX_COO
| WM97XX_SLEN
|
427 WM97XX_DELAY(delay
) |
428 WM97XX_SLT(wm
->acc_slot
) |
429 WM97XX_RATE(wm
->acc_rate
);
431 dig1
|= WM97XX_ADCSEL_PRES
;
434 dig1
&= ~(WM97XX_CTC
| WM97XX_COO
| WM97XX_SLEN
);
435 dig2
&= ~WM9712_PDEN
;
436 if (wm
->mach_ops
->acc_shutdown
)
437 wm
->mach_ops
->acc_shutdown(wm
);
440 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER1
, dig1
);
441 wm97xx_reg_write(wm
, AC97_WM97XX_DIGITISER2
, dig2
);
446 struct wm97xx_codec_drv wm9712_codec
= {
449 .poll_sample
= wm9712_poll_sample
,
450 .poll_touch
= wm9712_poll_touch
,
451 .acc_enable
= wm9712_acc_enable
,
452 .phy_init
= wm9712_phy_init
,
453 .dig_enable
= wm9712_dig_enable
,
454 .dig_restore
= wm9712_dig_restore
,
455 .aux_prepare
= wm9712_aux_prepare
,
457 EXPORT_SYMBOL_GPL(wm9712_codec
);
459 /* Module information */
460 MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
461 MODULE_DESCRIPTION("WM9712 Touch Screen Driver");
462 MODULE_LICENSE("GPL");