wm9713.c revision 43f83a8f9963a11a9c3f41beecc363da21ae3602
1/* 2 * wm9713.c -- Codec touch driver for Wolfson WM9713 AC97 Codec. 3 * 4 * Copyright 2003, 2004, 2005, 2006, 2007, 2008 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> 10 * 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. 15 * 16 */ 17 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> 26 27#define TS_NAME "wm97xx" 28#define WM9713_VERSION "1.00" 29#define DEFAULT_PRESSURE 0xb0c0 30 31/* 32 * Module parameters 33 */ 34 35/* 36 * Set internal pull up for pen detect. 37 * 38 * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive) 39 * i.e. pull up resistance = 64k Ohms / rpu. 40 * 41 * Adjust this value if you are having problems with pen detect not 42 * detecting any down event. 43 */ 44static int rpu = 8; 45module_param(rpu, int, 0); 46MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect."); 47 48/* 49 * Set current used for pressure measurement. 50 * 51 * Set pil = 2 to use 400uA 52 * pil = 1 to use 200uA and 53 * pil = 0 to disable pressure measurement. 54 * 55 * This is used to increase the range of values returned by the adc 56 * when measureing touchpanel pressure. 57 */ 58static int pil; 59module_param(pil, int, 0); 60MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); 61 62/* 63 * Set threshold for pressure measurement. 64 * 65 * Pen down pressure below threshold is ignored. 66 */ 67static int pressure = DEFAULT_PRESSURE & 0xfff; 68module_param(pressure, int, 0); 69MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); 70 71/* 72 * Set adc sample delay. 73 * 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. 77 * 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 81 * recommended. 82 */ 83static int delay = 4; 84module_param(delay, int, 0); 85MODULE_PARM_DESC(delay, "Set adc sample delay."); 86 87/* 88 * Set five_wire = 1 to use a 5 wire touchscreen. 89 * 90 * NOTE: Five wire mode does not allow for readback of pressure. 91 */ 92static int five_wire; 93module_param(five_wire, int, 0); 94MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen."); 95 96/* 97 * Set adc mask function. 98 * 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. 103 * 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 108 */ 109static int mask; 110module_param(mask, int, 0); 111MODULE_PARM_DESC(mask, "Set adc mask function."); 112 113/* 114 * Coordinate Polling Enable. 115 * 116 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together 117 * for every poll. 118 */ 119static int coord; 120module_param(coord, int, 0); 121MODULE_PARM_DESC(coord, "Polling coordinate mode"); 122 123/* 124 * ADC sample delay times in uS 125 */ 126static const int delay_table[] = { 127 21, /* 1 AC97 Link frames */ 128 42, /* 2 */ 129 84, /* 4 */ 130 167, /* 8 */ 131 333, /* 16 */ 132 667, /* 32 */ 133 1000, /* 48 */ 134 1333, /* 64 */ 135 2000, /* 96 */ 136 2667, /* 128 */ 137 3333, /* 160 */ 138 4000, /* 192 */ 139 4667, /* 224 */ 140 5333, /* 256 */ 141 6000, /* 288 */ 142 0 /* No delay, switch matrix always on */ 143}; 144 145/* 146 * Delay after issuing a POLL command. 147 * 148 * The delay is 3 AC97 link frames + the touchpanel settling delay 149 */ 150static inline void poll_delay(int d) 151{ 152 udelay(3 * AC97_LINK_FRAME + delay_table[d]); 153} 154 155/* 156 * set up the physical settings of the WM9713 157 */ 158static void wm9713_phy_init(struct wm97xx *wm) 159{ 160 u16 dig1 = 0, dig2, dig3; 161 162 /* default values */ 163 dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5); 164 dig3 = WM9712_RPU(1); 165 166 /* rpu */ 167 if (rpu) { 168 dig3 &= 0xffc0; 169 dig3 |= WM9712_RPU(rpu); 170 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n", 171 64000 / rpu); 172 } 173 174 /* Five wire panel? */ 175 if (five_wire) { 176 dig3 |= WM9713_45W; 177 dev_info(wm->dev, "setting 5-wire touchscreen mode."); 178 179 if (pil) { 180 dev_warn(wm->dev, 181 "Pressure measurement not supported in 5 " 182 "wire mode, disabling\n"); 183 pil = 0; 184 } 185 } 186 187 /* touchpanel pressure */ 188 if (pil == 2) { 189 dig3 |= WM9712_PIL; 190 dev_info(wm->dev, 191 "setting pressure measurement current to 400uA."); 192 } else if (pil) 193 dev_info(wm->dev, 194 "setting pressure measurement current to 200uA."); 195 if (!pil) 196 pressure = 0; 197 198 /* sample settling delay */ 199 if (delay < 0 || delay > 15) { 200 dev_info(wm->dev, "supplied delay out of range."); 201 delay = 4; 202 dev_info(wm->dev, "setting adc sample delay to %d u Secs.", 203 delay_table[delay]); 204 } 205 dig2 &= 0xff0f; 206 dig2 |= WM97XX_DELAY(delay); 207 208 /* mask */ 209 dig3 |= ((mask & 0x3) << 4); 210 if (coord) 211 dig3 |= WM9713_WAIT; 212 213 wm->misc = wm97xx_reg_read(wm, 0x5a); 214 215 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1); 216 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2); 217 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3); 218 wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0); 219} 220 221static void wm9713_dig_enable(struct wm97xx *wm, int enable) 222{ 223 u16 val; 224 225 if (enable) { 226 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID); 227 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff); 228 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] | 229 WM97XX_PRP_DET_DIG); 230 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ 231 } else { 232 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] & 233 ~WM97XX_PRP_DET_DIG); 234 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID); 235 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000); 236 } 237} 238 239static void wm9713_dig_restore(struct wm97xx *wm) 240{ 241 wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]); 242 wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]); 243 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]); 244} 245 246static void wm9713_aux_prepare(struct wm97xx *wm) 247{ 248 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); 249 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0); 250 wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0); 251 wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG); 252} 253 254static inline int is_pden(struct wm97xx *wm) 255{ 256 return wm->dig[2] & WM9713_PDEN; 257} 258 259/* 260 * Read a sample from the WM9713 adc in polling mode. 261 */ 262static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample) 263{ 264 u16 dig1; 265 int timeout = 5 * delay; 266 267 if (!wm->pen_probably_down) { 268 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 269 if (!(data & WM97XX_PEN_DOWN)) 270 return RC_PENUP; 271 wm->pen_probably_down = 1; 272 } 273 274 /* set up digitiser */ 275 if (adcsel & 0x8000) 276 adcsel = 1 << ((adcsel & 0x7fff) + 3); 277 278 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 279 dig1 &= ~WM9713_ADCSEL_MASK; 280 281 if (wm->mach_ops && wm->mach_ops->pre_sample) 282 wm->mach_ops->pre_sample(adcsel); 283 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | adcsel | WM9713_POLL); 284 285 /* wait 3 AC97 time slots + delay for conversion */ 286 poll_delay(delay); 287 288 /* wait for POLL to go low */ 289 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) && 290 timeout) { 291 udelay(AC97_LINK_FRAME); 292 timeout--; 293 } 294 295 if (timeout <= 0) { 296 /* If PDEN is set, we can get a timeout when pen goes up */ 297 if (is_pden(wm)) 298 wm->pen_probably_down = 0; 299 else 300 dev_dbg(wm->dev, "adc sample timeout"); 301 return RC_PENUP; 302 } 303 304 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 305 if (wm->mach_ops && wm->mach_ops->post_sample) 306 wm->mach_ops->post_sample(adcsel); 307 308 /* check we have correct sample */ 309 if ((*sample & WM97XX_ADCSRC_MASK) != ffs(adcsel >> 1) << 12) { 310 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel, 311 *sample & WM97XX_ADCSRC_MASK); 312 return RC_PENUP; 313 } 314 315 if (!(*sample & WM97XX_PEN_DOWN)) { 316 wm->pen_probably_down = 0; 317 return RC_PENUP; 318 } 319 320 return RC_VALID; 321} 322 323/* 324 * Read a coordinate from the WM9713 adc in polling mode. 325 */ 326static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) 327{ 328 u16 dig1; 329 int timeout = 5 * delay; 330 331 if (!wm->pen_probably_down) { 332 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 333 if (!(val & WM97XX_PEN_DOWN)) 334 return RC_PENUP; 335 wm->pen_probably_down = 1; 336 } 337 338 /* set up digitiser */ 339 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 340 dig1 &= ~WM9713_ADCSEL_MASK; 341 if (pil) 342 dig1 |= WM9713_ADCSEL_PRES; 343 344 if (wm->mach_ops && wm->mach_ops->pre_sample) 345 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 346 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 347 dig1 | WM9713_POLL | WM9713_COO); 348 349 /* wait 3 AC97 time slots + delay for conversion */ 350 poll_delay(delay); 351 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 352 /* wait for POLL to go low */ 353 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) 354 && timeout) { 355 udelay(AC97_LINK_FRAME); 356 timeout--; 357 } 358 359 if (timeout <= 0) { 360 /* If PDEN is set, we can get a timeout when pen goes up */ 361 if (is_pden(wm)) 362 wm->pen_probably_down = 0; 363 else 364 dev_dbg(wm->dev, "adc sample timeout"); 365 return RC_PENUP; 366 } 367 368 /* read back data */ 369 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 370 if (pil) 371 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 372 else 373 data->p = DEFAULT_PRESSURE; 374 375 if (wm->mach_ops && wm->mach_ops->post_sample) 376 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 377 378 /* check we have correct sample */ 379 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) 380 goto err; 381 if (pil && !(data->p & WM97XX_ADCSEL_PRES)) 382 goto err; 383 384 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { 385 wm->pen_probably_down = 0; 386 return RC_PENUP; 387 } 388 return RC_VALID; 389err: 390 return 0; 391} 392 393/* 394 * Sample the WM9713 touchscreen in polling mode 395 */ 396static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) 397{ 398 int rc; 399 400 if (coord) { 401 rc = wm9713_poll_coord(wm, data); 402 if (rc != RC_VALID) 403 return rc; 404 } else { 405 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x); 406 if (rc != RC_VALID) 407 return rc; 408 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y); 409 if (rc != RC_VALID) 410 return rc; 411 if (pil) { 412 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES, 413 &data->p); 414 if (rc != RC_VALID) 415 return rc; 416 } else 417 data->p = DEFAULT_PRESSURE; 418 } 419 return RC_VALID; 420} 421 422/* 423 * Enable WM9713 continuous mode, i.e. touch data is streamed across 424 * an AC97 slot 425 */ 426static int wm9713_acc_enable(struct wm97xx *wm, int enable) 427{ 428 u16 dig1, dig2, dig3; 429 int ret = 0; 430 431 dig1 = wm->dig[0]; 432 dig2 = wm->dig[1]; 433 dig3 = wm->dig[2]; 434 435 if (enable) { 436 /* continous mode */ 437 if (wm->mach_ops->acc_startup && 438 (ret = wm->mach_ops->acc_startup(wm)) < 0) 439 return ret; 440 441 dig1 &= ~WM9713_ADCSEL_MASK; 442 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X | 443 WM9713_ADCSEL_Y; 444 if (pil) 445 dig1 |= WM9713_ADCSEL_PRES; 446 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK | 447 WM97XX_CM_RATE_MASK); 448 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) | 449 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate); 450 dig3 |= WM9713_PDEN; 451 } else { 452 dig1 &= ~(WM9713_CTC | WM9713_COO); 453 dig2 &= ~WM97XX_SLEN; 454 dig3 &= ~WM9713_PDEN; 455 if (wm->mach_ops->acc_shutdown) 456 wm->mach_ops->acc_shutdown(wm); 457 } 458 459 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1); 460 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2); 461 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3); 462 463 return ret; 464} 465 466struct wm97xx_codec_drv wm9713_codec = { 467 .id = WM9713_ID2, 468 .name = "wm9713", 469 .poll_sample = wm9713_poll_sample, 470 .poll_touch = wm9713_poll_touch, 471 .acc_enable = wm9713_acc_enable, 472 .phy_init = wm9713_phy_init, 473 .dig_enable = wm9713_dig_enable, 474 .dig_restore = wm9713_dig_restore, 475 .aux_prepare = wm9713_aux_prepare, 476}; 477EXPORT_SYMBOL_GPL(wm9713_codec); 478 479/* Module information */ 480MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>"); 481MODULE_DESCRIPTION("WM9713 Touch Screen Driver"); 482MODULE_LICENSE("GPL"); 483