wm9713.c 12.2 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481
/*
 * wm9713.c  --  Codec touch driver for Wolfson WM9713 AC97 Codec.
 *
 * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
 * Parts Copyright : Ian Molton <spyro@f2s.com>
 *                   Andrew Zabolotny <zap@homelink.ru>
 *                   Russell King <rmk@arm.linux.org.uk>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/wm97xx.h>

#define TS_NAME			"wm97xx"
#define WM9713_VERSION		"1.00"
#define DEFAULT_PRESSURE	0xb0c0

/*
 * Module parameters
 */

/*
 * Set internal pull up for pen detect.
 *
 * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive)
 * i.e. pull up resistance = 64k Ohms / rpu.
 *
 * Adjust this value if you are having problems with pen detect not
 * detecting any down event.
 */
static int rpu = 8;
module_param(rpu, int, 0);
MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect.");

/*
 * Set current used for pressure measurement.
 *
 * Set pil = 2 to use 400uA
 *     pil = 1 to use 200uA and
 *     pil = 0 to disable pressure measurement.
 *
 * This is used to increase the range of values returned by the adc
 * when measureing touchpanel pressure.
 */
static int pil;
module_param(pil, int, 0);
MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");

/*
 * Set threshold for pressure measurement.
 *
 * Pen down pressure below threshold is ignored.
 */
static int pressure = DEFAULT_PRESSURE & 0xfff;
module_param(pressure, int, 0);
MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");

/*
 * Set adc sample delay.
 *
 * For accurate touchpanel measurements, some settling time may be
 * required between the switch matrix applying a voltage across the
 * touchpanel plate and the ADC sampling the signal.
 *
 * This delay can be set by setting delay = n, where n is the array
 * position of the delay in the array delay_table below.
 * Long delays > 1ms are supported for completeness, but are not
 * recommended.
 */
static int delay = 4;
module_param(delay, int, 0);
MODULE_PARM_DESC(delay, "Set adc sample delay.");

/*
 * Set five_wire = 1 to use a 5 wire touchscreen.
 *
 * NOTE: Five wire mode does not allow for readback of pressure.
 */
static int five_wire;
module_param(five_wire, int, 0);
MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");

/*
 * Set adc mask function.
 *
 * Sources of glitch noise, such as signals driving an LCD display, may feed
 * through to the touch screen plates and affect measurement accuracy. In
 * order to minimise this, a signal may be applied to the MASK pin to delay or
 * synchronise the sampling.
 *
 * 0 = No delay or sync
 * 1 = High on pin stops conversions
 * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
 * 3 = Edge triggered, edge on pin starts conversion after delay param
 */
static int mask;
module_param(mask, int, 0);
MODULE_PARM_DESC(mask, "Set adc mask function.");

/*
 * Coordinate Polling Enable.
 *
 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
 * for every poll.
 */
static int coord;
module_param(coord, int, 0);
MODULE_PARM_DESC(coord, "Polling coordinate mode");

/*
 * ADC sample delay times in uS
 */
static const int delay_table[] = {
	21,    /* 1 AC97 Link frames */
	42,    /* 2 */
	84,    /* 4 */
	167,   /* 8 */
	333,   /* 16 */
	667,   /* 32 */
	1000,  /* 48 */
	1333,  /* 64 */
	2000,  /* 96 */
	2667,  /* 128 */
	3333,  /* 160 */
	4000,  /* 192 */
	4667,  /* 224 */
	5333,  /* 256 */
	6000,  /* 288 */
	0      /* No delay, switch matrix always on */
};

/*
 * Delay after issuing a POLL command.
 *
 * The delay is 3 AC97 link frames + the touchpanel settling delay
 */
static inline void poll_delay(int d)
{
	udelay(3 * AC97_LINK_FRAME + delay_table[d]);
}

/*
 * set up the physical settings of the WM9713
 */
static void wm9713_phy_init(struct wm97xx *wm)
{
	u16 dig1 = 0, dig2, dig3;

	/* default values */
	dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5);
	dig3 = WM9712_RPU(1);

	/* rpu */
	if (rpu) {
		dig3 &= 0xffc0;
		dig3 |= WM9712_RPU(rpu);
		dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n",
			 64000 / rpu);
	}

	/* Five wire panel? */
	if (five_wire) {
		dig3 |= WM9713_45W;
		dev_info(wm->dev, "setting 5-wire touchscreen mode.");

		if (pil) {
			dev_warn(wm->dev,
				 "Pressure measurement not supported in 5 "
				 "wire mode, disabling\n");
			pil = 0;
		}
	}

	/* touchpanel pressure */
	if (pil == 2) {
		dig3 |= WM9712_PIL;
		dev_info(wm->dev,
			 "setting pressure measurement current to 400uA.");
	} else if (pil)
		dev_info(wm->dev,
			 "setting pressure measurement current to 200uA.");
	if (!pil)
		pressure = 0;

	/* sample settling delay */
	if (delay < 0 || delay > 15) {
		dev_info(wm->dev, "supplied delay out of range.");
		delay = 4;
		dev_info(wm->dev, "setting adc sample delay to %d u Secs.",
			 delay_table[delay]);
	}
	dig2 &= 0xff0f;
	dig2 |= WM97XX_DELAY(delay);

	/* mask */
	dig3 |= ((mask & 0x3) << 4);
	if (coord)
		dig3 |= WM9713_WAIT;

	wm->misc = wm97xx_reg_read(wm, 0x5a);

	wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
	wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
	wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
	wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0);
}

static void wm9713_dig_enable(struct wm97xx *wm, int enable)
{
	u16 val;

	if (enable) {
		val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
		wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff);
		wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] |
				 WM97XX_PRP_DET_DIG);
		wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
	} else {
		wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] &
					~WM97XX_PRP_DET_DIG);
		val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
		wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000);
	}
}

static void wm9713_dig_restore(struct wm97xx *wm)
{
	wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]);
	wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]);
	wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]);
}

static void wm9713_aux_prepare(struct wm97xx *wm)
{
	memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
	wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0);
	wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0);
	wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG);
}

static inline int is_pden(struct wm97xx *wm)
{
	return wm->dig[2] & WM9713_PDEN;
}

/*
 * Read a sample from the WM9713 adc in polling mode.
 */
static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
{
	u16 dig1;
	int timeout = 5 * delay;
	bool wants_pen = adcsel & WM97XX_PEN_DOWN;

	if (wants_pen && !wm->pen_probably_down) {
		u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
		if (!(data & WM97XX_PEN_DOWN))
			return RC_PENUP;
		wm->pen_probably_down = 1;
	}

	/* set up digitiser */
	dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
	dig1 &= ~WM9713_ADCSEL_MASK;
	/* WM97XX_ADCSEL_* channels need to be converted to WM9713 format */
	dig1 |= 1 << ((adcsel & WM97XX_ADCSEL_MASK) >> 12);

	if (wm->mach_ops && wm->mach_ops->pre_sample)
		wm->mach_ops->pre_sample(adcsel);
	wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | WM9713_POLL);

	/* wait 3 AC97 time slots + delay for conversion */
	poll_delay(delay);

	/* wait for POLL to go low */
	while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) &&
		timeout) {
		udelay(AC97_LINK_FRAME);
		timeout--;
	}

	if (timeout <= 0) {
		/* If PDEN is set, we can get a timeout when pen goes up */
		if (is_pden(wm))
			wm->pen_probably_down = 0;
		else
			dev_dbg(wm->dev, "adc sample timeout");
		return RC_PENUP;
	}

	*sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
	if (wm->mach_ops && wm->mach_ops->post_sample)
		wm->mach_ops->post_sample(adcsel);

	/* check we have correct sample */
	if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) {
		dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x",
			adcsel & WM97XX_ADCSEL_MASK,
			*sample & WM97XX_ADCSEL_MASK);
		return RC_PENUP;
	}

	if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) {
		wm->pen_probably_down = 0;
		return RC_PENUP;
	}

	return RC_VALID;
}

/*
 * Read a coordinate from the WM9713 adc in polling mode.
 */
static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
{
	u16 dig1;
	int timeout = 5 * delay;

	if (!wm->pen_probably_down) {
		u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
		if (!(val & WM97XX_PEN_DOWN))
			return RC_PENUP;
		wm->pen_probably_down = 1;
	}

	/* set up digitiser */
	dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
	dig1 &= ~WM9713_ADCSEL_MASK;
	if (pil)
		dig1 |= WM9713_ADCSEL_PRES;

	if (wm->mach_ops && wm->mach_ops->pre_sample)
		wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
	wm97xx_reg_write(wm, AC97_WM9713_DIG1,
			 dig1 | WM9713_POLL | WM9713_COO);

	/* wait 3 AC97 time slots + delay for conversion */
	poll_delay(delay);
	data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
	/* wait for POLL to go low */
	while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL)
	       && timeout) {
		udelay(AC97_LINK_FRAME);
		timeout--;
	}

	if (timeout <= 0) {
		/* If PDEN is set, we can get a timeout when pen goes up */
		if (is_pden(wm))
			wm->pen_probably_down = 0;
		else
			dev_dbg(wm->dev, "adc sample timeout");
		return RC_PENUP;
	}

	/* read back data */
	data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
	if (pil)
		data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
	else
		data->p = DEFAULT_PRESSURE;

	if (wm->mach_ops && wm->mach_ops->post_sample)
		wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);

	/* check we have correct sample */
	if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
		goto err;
	if (pil && !(data->p & WM97XX_ADCSEL_PRES))
		goto err;

	if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
		wm->pen_probably_down = 0;
		return RC_PENUP;
	}
	return RC_VALID;
err:
	return 0;
}

/*
 * Sample the WM9713 touchscreen in polling mode
 */
static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
{
	int rc;

	if (coord) {
		rc = wm9713_poll_coord(wm, data);
		if (rc != RC_VALID)
			return rc;
	} else {
		rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x);
		if (rc != RC_VALID)
			return rc;
		rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y);
		if (rc != RC_VALID)
			return rc;
		if (pil) {
			rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN,
						&data->p);
			if (rc != RC_VALID)
				return rc;
		} else
			data->p = DEFAULT_PRESSURE;
	}
	return RC_VALID;
}

/*
 * Enable WM9713 continuous mode, i.e. touch data is streamed across
 * an AC97 slot
 */
static int wm9713_acc_enable(struct wm97xx *wm, int enable)
{
	u16 dig1, dig2, dig3;
	int ret = 0;

	dig1 = wm->dig[0];
	dig2 = wm->dig[1];
	dig3 = wm->dig[2];

	if (enable) {
		/* continuous mode */
		if (wm->mach_ops->acc_startup &&
			(ret = wm->mach_ops->acc_startup(wm)) < 0)
			return ret;

		dig1 &= ~WM9713_ADCSEL_MASK;
		dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X |
			WM9713_ADCSEL_Y;
		if (pil)
			dig1 |= WM9713_ADCSEL_PRES;
		dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK  |
			WM97XX_CM_RATE_MASK);
		dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) |
		WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate);
		dig3 |= WM9713_PDEN;
	} else {
		dig1 &= ~(WM9713_CTC | WM9713_COO);
		dig2 &= ~WM97XX_SLEN;
		dig3 &= ~WM9713_PDEN;
		if (wm->mach_ops->acc_shutdown)
			wm->mach_ops->acc_shutdown(wm);
	}

	wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
	wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
	wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);

	return ret;
}

struct wm97xx_codec_drv wm9713_codec = {
	.id = WM9713_ID2,
	.name = "wm9713",
	.poll_sample = wm9713_poll_sample,
	.poll_touch = wm9713_poll_touch,
	.acc_enable = wm9713_acc_enable,
	.phy_init = wm9713_phy_init,
	.dig_enable = wm9713_dig_enable,
	.dig_restore = wm9713_dig_restore,
	.aux_prepare = wm9713_aux_prepare,
};
EXPORT_SYMBOL_GPL(wm9713_codec);

/* Module information */
MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
MODULE_LICENSE("GPL");