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 <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> 9 * 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. 14 * 15 */ 16 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> 24 25#define TS_NAME "wm97xx" 26#define WM9713_VERSION "1.00" 27#define DEFAULT_PRESSURE 0xb0c0 28 29/* 30 * Module parameters 31 */ 32 33/* 34 * Set internal pull up for pen detect. 35 * 36 * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive) 37 * i.e. pull up resistance = 64k Ohms / rpu. 38 * 39 * Adjust this value if you are having problems with pen detect not 40 * detecting any down event. 41 */ 42static int rpu = 8; 43module_param(rpu, int, 0); 44MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect."); 45 46/* 47 * Set current used for pressure measurement. 48 * 49 * Set pil = 2 to use 400uA 50 * pil = 1 to use 200uA and 51 * pil = 0 to disable pressure measurement. 52 * 53 * This is used to increase the range of values returned by the adc 54 * when measureing touchpanel pressure. 55 */ 56static int pil; 57module_param(pil, int, 0); 58MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); 59 60/* 61 * Set threshold for pressure measurement. 62 * 63 * Pen down pressure below threshold is ignored. 64 */ 65static int pressure = DEFAULT_PRESSURE & 0xfff; 66module_param(pressure, int, 0); 67MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); 68 69/* 70 * Set adc sample delay. 71 * 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. 75 * 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 79 * recommended. 80 */ 81static int delay = 4; 82module_param(delay, int, 0); 83MODULE_PARM_DESC(delay, "Set adc sample delay."); 84 85/* 86 * Set five_wire = 1 to use a 5 wire touchscreen. 87 * 88 * NOTE: Five wire mode does not allow for readback of pressure. 89 */ 90static int five_wire; 91module_param(five_wire, int, 0); 92MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen."); 93 94/* 95 * Set adc mask function. 96 * 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. 101 * 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 106 */ 107static int mask; 108module_param(mask, int, 0); 109MODULE_PARM_DESC(mask, "Set adc mask function."); 110 111/* 112 * Coordinate Polling Enable. 113 * 114 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together 115 * for every poll. 116 */ 117static int coord; 118module_param(coord, int, 0); 119MODULE_PARM_DESC(coord, "Polling coordinate mode"); 120 121/* 122 * ADC sample delay times in uS 123 */ 124static const int delay_table[] = { 125 21, /* 1 AC97 Link frames */ 126 42, /* 2 */ 127 84, /* 4 */ 128 167, /* 8 */ 129 333, /* 16 */ 130 667, /* 32 */ 131 1000, /* 48 */ 132 1333, /* 64 */ 133 2000, /* 96 */ 134 2667, /* 128 */ 135 3333, /* 160 */ 136 4000, /* 192 */ 137 4667, /* 224 */ 138 5333, /* 256 */ 139 6000, /* 288 */ 140 0 /* No delay, switch matrix always on */ 141}; 142 143/* 144 * Delay after issuing a POLL command. 145 * 146 * The delay is 3 AC97 link frames + the touchpanel settling delay 147 */ 148static inline void poll_delay(int d) 149{ 150 udelay(3 * AC97_LINK_FRAME + delay_table[d]); 151} 152 153/* 154 * set up the physical settings of the WM9713 155 */ 156static void wm9713_phy_init(struct wm97xx *wm) 157{ 158 u16 dig1 = 0, dig2, dig3; 159 160 /* default values */ 161 dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5); 162 dig3 = WM9712_RPU(1); 163 164 /* rpu */ 165 if (rpu) { 166 dig3 &= 0xffc0; 167 dig3 |= WM9712_RPU(rpu); 168 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n", 169 64000 / rpu); 170 } 171 172 /* Five wire panel? */ 173 if (five_wire) { 174 dig3 |= WM9713_45W; 175 dev_info(wm->dev, "setting 5-wire touchscreen mode."); 176 177 if (pil) { 178 dev_warn(wm->dev, 179 "Pressure measurement not supported in 5 " 180 "wire mode, disabling\n"); 181 pil = 0; 182 } 183 } 184 185 /* touchpanel pressure */ 186 if (pil == 2) { 187 dig3 |= WM9712_PIL; 188 dev_info(wm->dev, 189 "setting pressure measurement current to 400uA."); 190 } else if (pil) 191 dev_info(wm->dev, 192 "setting pressure measurement current to 200uA."); 193 if (!pil) 194 pressure = 0; 195 196 /* sample settling delay */ 197 if (delay < 0 || delay > 15) { 198 dev_info(wm->dev, "supplied delay out of range."); 199 delay = 4; 200 dev_info(wm->dev, "setting adc sample delay to %d u Secs.", 201 delay_table[delay]); 202 } 203 dig2 &= 0xff0f; 204 dig2 |= WM97XX_DELAY(delay); 205 206 /* mask */ 207 dig3 |= ((mask & 0x3) << 4); 208 if (coord) 209 dig3 |= WM9713_WAIT; 210 211 wm->misc = wm97xx_reg_read(wm, 0x5a); 212 213 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); 217} 218 219static void wm9713_dig_enable(struct wm97xx *wm, int enable) 220{ 221 u16 val; 222 223 if (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] | 227 WM97XX_PRP_DET_DIG); 228 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ 229 } else { 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); 234 } 235} 236 237static void wm9713_dig_restore(struct wm97xx *wm) 238{ 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]); 242} 243 244static void wm9713_aux_prepare(struct wm97xx *wm) 245{ 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); 250} 251 252static inline int is_pden(struct wm97xx *wm) 253{ 254 return wm->dig[2] & WM9713_PDEN; 255} 256 257/* 258 * Read a sample from the WM9713 adc in polling mode. 259 */ 260static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample) 261{ 262 u16 dig1; 263 int timeout = 5 * delay; 264 265 if (!wm->pen_probably_down) { 266 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 267 if (!(data & WM97XX_PEN_DOWN)) 268 return RC_PENUP; 269 wm->pen_probably_down = 1; 270 } 271 272 /* set up digitiser */ 273 if (adcsel & 0x8000) 274 adcsel = 1 << ((adcsel & 0x7fff) + 3); 275 276 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 277 dig1 &= ~WM9713_ADCSEL_MASK; 278 279 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); 282 283 /* wait 3 AC97 time slots + delay for conversion */ 284 poll_delay(delay); 285 286 /* wait for POLL to go low */ 287 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) && 288 timeout) { 289 udelay(AC97_LINK_FRAME); 290 timeout--; 291 } 292 293 if (timeout <= 0) { 294 /* If PDEN is set, we can get a timeout when pen goes up */ 295 if (is_pden(wm)) 296 wm->pen_probably_down = 0; 297 else 298 dev_dbg(wm->dev, "adc sample timeout"); 299 return RC_PENUP; 300 } 301 302 *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); 305 306 /* 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); 310 return RC_PENUP; 311 } 312 313 if (!(*sample & WM97XX_PEN_DOWN)) { 314 wm->pen_probably_down = 0; 315 return RC_PENUP; 316 } 317 318 return RC_VALID; 319} 320 321/* 322 * Read a coordinate from the WM9713 adc in polling mode. 323 */ 324static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) 325{ 326 u16 dig1; 327 int timeout = 5 * delay; 328 329 if (!wm->pen_probably_down) { 330 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 331 if (!(val & WM97XX_PEN_DOWN)) 332 return RC_PENUP; 333 wm->pen_probably_down = 1; 334 } 335 336 /* set up digitiser */ 337 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 338 dig1 &= ~WM9713_ADCSEL_MASK; 339 if (pil) 340 dig1 |= WM9713_ADCSEL_PRES; 341 342 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); 346 347 /* wait 3 AC97 time slots + delay for conversion */ 348 poll_delay(delay); 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) 352 && timeout) { 353 udelay(AC97_LINK_FRAME); 354 timeout--; 355 } 356 357 if (timeout <= 0) { 358 /* If PDEN is set, we can get a timeout when pen goes up */ 359 if (is_pden(wm)) 360 wm->pen_probably_down = 0; 361 else 362 dev_dbg(wm->dev, "adc sample timeout"); 363 return RC_PENUP; 364 } 365 366 /* read back data */ 367 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 368 if (pil) 369 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 370 else 371 data->p = DEFAULT_PRESSURE; 372 373 if (wm->mach_ops && wm->mach_ops->post_sample) 374 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 375 376 /* check we have correct sample */ 377 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) 378 goto err; 379 if (pil && !(data->p & WM97XX_ADCSEL_PRES)) 380 goto err; 381 382 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { 383 wm->pen_probably_down = 0; 384 return RC_PENUP; 385 } 386 return RC_VALID; 387err: 388 return 0; 389} 390 391/* 392 * Sample the WM9713 touchscreen in polling mode 393 */ 394static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) 395{ 396 int rc; 397 398 if (coord) { 399 rc = wm9713_poll_coord(wm, data); 400 if (rc != RC_VALID) 401 return rc; 402 } else { 403 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x); 404 if (rc != RC_VALID) 405 return rc; 406 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y); 407 if (rc != RC_VALID) 408 return rc; 409 if (pil) { 410 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES, 411 &data->p); 412 if (rc != RC_VALID) 413 return rc; 414 } else 415 data->p = DEFAULT_PRESSURE; 416 } 417 return RC_VALID; 418} 419 420/* 421 * Enable WM9713 continuous mode, i.e. touch data is streamed across 422 * an AC97 slot 423 */ 424static int wm9713_acc_enable(struct wm97xx *wm, int enable) 425{ 426 u16 dig1, dig2, dig3; 427 int ret = 0; 428 429 dig1 = wm->dig[0]; 430 dig2 = wm->dig[1]; 431 dig3 = wm->dig[2]; 432 433 if (enable) { 434 /* continous mode */ 435 if (wm->mach_ops->acc_startup && 436 (ret = wm->mach_ops->acc_startup(wm)) < 0) 437 return ret; 438 439 dig1 &= ~WM9713_ADCSEL_MASK; 440 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X | 441 WM9713_ADCSEL_Y; 442 if (pil) 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); 448 dig3 |= WM9713_PDEN; 449 } else { 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); 455 } 456 457 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); 460 461 return ret; 462} 463 464struct wm97xx_codec_drv wm9713_codec = { 465 .id = WM9713_ID2, 466 .name = "wm9713", 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, 474}; 475EXPORT_SYMBOL_GPL(wm9713_codec); 476 477/* Module information */ 478MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 479MODULE_DESCRIPTION("WM9713 Touch Screen Driver"); 480MODULE_LICENSE("GPL"); 481