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/kernel.h> 21 #include <linux/input.h> 22 #include <linux/delay.h> 23 #include <linux/bitops.h> 24 #include <linux/wm97xx.h> 25 26 #define TS_NAME "wm97xx" 27 #define WM9713_VERSION "1.00" 28 #define DEFAULT_PRESSURE 0xb0c0 29 30 /* 31 * Module parameters 32 */ 33 34 /* 35 * Set internal pull up for pen detect. 36 * 37 * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive) 38 * i.e. pull up resistance = 64k Ohms / rpu. 39 * 40 * Adjust this value if you are having problems with pen detect not 41 * detecting any down event. 42 */ 43 static int rpu = 8; 44 module_param(rpu, int, 0); 45 MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect."); 46 47 /* 48 * Set current used for pressure measurement. 49 * 50 * Set pil = 2 to use 400uA 51 * pil = 1 to use 200uA and 52 * pil = 0 to disable pressure measurement. 53 * 54 * This is used to increase the range of values returned by the adc 55 * when measureing touchpanel pressure. 56 */ 57 static int pil; 58 module_param(pil, int, 0); 59 MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); 60 61 /* 62 * Set threshold for pressure measurement. 63 * 64 * Pen down pressure below threshold is ignored. 65 */ 66 static int pressure = DEFAULT_PRESSURE & 0xfff; 67 module_param(pressure, int, 0); 68 MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); 69 70 /* 71 * Set adc sample delay. 72 * 73 * For accurate touchpanel measurements, some settling time may be 74 * required between the switch matrix applying a voltage across the 75 * touchpanel plate and the ADC sampling the signal. 76 * 77 * This delay can be set by setting delay = n, where n is the array 78 * position of the delay in the array delay_table below. 79 * Long delays > 1ms are supported for completeness, but are not 80 * recommended. 81 */ 82 static int delay = 4; 83 module_param(delay, int, 0); 84 MODULE_PARM_DESC(delay, "Set adc sample delay."); 85 86 /* 87 * Set five_wire = 1 to use a 5 wire touchscreen. 88 * 89 * NOTE: Five wire mode does not allow for readback of pressure. 90 */ 91 static int five_wire; 92 module_param(five_wire, int, 0); 93 MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen."); 94 95 /* 96 * Set adc mask function. 97 * 98 * Sources of glitch noise, such as signals driving an LCD display, may feed 99 * through to the touch screen plates and affect measurement accuracy. In 100 * order to minimise this, a signal may be applied to the MASK pin to delay or 101 * synchronise the sampling. 102 * 103 * 0 = No delay or sync 104 * 1 = High on pin stops conversions 105 * 2 = Edge triggered, edge on pin delays conversion by delay param (above) 106 * 3 = Edge triggered, edge on pin starts conversion after delay param 107 */ 108 static int mask; 109 module_param(mask, int, 0); 110 MODULE_PARM_DESC(mask, "Set adc mask function."); 111 112 /* 113 * Coordinate Polling Enable. 114 * 115 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together 116 * for every poll. 117 */ 118 static int coord; 119 module_param(coord, int, 0); 120 MODULE_PARM_DESC(coord, "Polling coordinate mode"); 121 122 /* 123 * ADC sample delay times in uS 124 */ 125 static const int delay_table[] = { 126 21, /* 1 AC97 Link frames */ 127 42, /* 2 */ 128 84, /* 4 */ 129 167, /* 8 */ 130 333, /* 16 */ 131 667, /* 32 */ 132 1000, /* 48 */ 133 1333, /* 64 */ 134 2000, /* 96 */ 135 2667, /* 128 */ 136 3333, /* 160 */ 137 4000, /* 192 */ 138 4667, /* 224 */ 139 5333, /* 256 */ 140 6000, /* 288 */ 141 0 /* No delay, switch matrix always on */ 142 }; 143 144 /* 145 * Delay after issuing a POLL command. 146 * 147 * The delay is 3 AC97 link frames + the touchpanel settling delay 148 */ 149 static inline void poll_delay(int d) 150 { 151 udelay(3 * AC97_LINK_FRAME + delay_table[d]); 152 } 153 154 /* 155 * set up the physical settings of the WM9713 156 */ 157 static void wm9713_phy_init(struct wm97xx *wm) 158 { 159 u16 dig1 = 0, dig2, dig3; 160 161 /* default values */ 162 dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5); 163 dig3 = WM9712_RPU(1); 164 165 /* rpu */ 166 if (rpu) { 167 dig3 &= 0xffc0; 168 dig3 |= WM9712_RPU(rpu); 169 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n", 170 64000 / rpu); 171 } 172 173 /* Five wire panel? */ 174 if (five_wire) { 175 dig3 |= WM9713_45W; 176 dev_info(wm->dev, "setting 5-wire touchscreen mode."); 177 178 if (pil) { 179 dev_warn(wm->dev, 180 "Pressure measurement not supported in 5 " 181 "wire mode, disabling\n"); 182 pil = 0; 183 } 184 } 185 186 /* touchpanel pressure */ 187 if (pil == 2) { 188 dig3 |= WM9712_PIL; 189 dev_info(wm->dev, 190 "setting pressure measurement current to 400uA."); 191 } else if (pil) 192 dev_info(wm->dev, 193 "setting pressure measurement current to 200uA."); 194 if (!pil) 195 pressure = 0; 196 197 /* sample settling delay */ 198 if (delay < 0 || delay > 15) { 199 dev_info(wm->dev, "supplied delay out of range."); 200 delay = 4; 201 dev_info(wm->dev, "setting adc sample delay to %d u Secs.", 202 delay_table[delay]); 203 } 204 dig2 &= 0xff0f; 205 dig2 |= WM97XX_DELAY(delay); 206 207 /* mask */ 208 dig3 |= ((mask & 0x3) << 4); 209 if (coord) 210 dig3 |= WM9713_WAIT; 211 212 wm->misc = wm97xx_reg_read(wm, 0x5a); 213 214 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1); 215 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2); 216 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3); 217 wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0); 218 } 219 220 static void wm9713_dig_enable(struct wm97xx *wm, int enable) 221 { 222 u16 val; 223 224 if (enable) { 225 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID); 226 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff); 227 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] | 228 WM97XX_PRP_DET_DIG); 229 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ 230 } else { 231 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] & 232 ~WM97XX_PRP_DET_DIG); 233 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID); 234 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000); 235 } 236 } 237 238 static void wm9713_dig_restore(struct wm97xx *wm) 239 { 240 wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]); 241 wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]); 242 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]); 243 } 244 245 static void wm9713_aux_prepare(struct wm97xx *wm) 246 { 247 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); 248 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0); 249 wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0); 250 wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG); 251 } 252 253 static inline int is_pden(struct wm97xx *wm) 254 { 255 return wm->dig[2] & WM9713_PDEN; 256 } 257 258 /* 259 * Read a sample from the WM9713 adc in polling mode. 260 */ 261 static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample) 262 { 263 u16 dig1; 264 int timeout = 5 * delay; 265 266 if (!wm->pen_probably_down) { 267 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 268 if (!(data & WM97XX_PEN_DOWN)) 269 return RC_PENUP; 270 wm->pen_probably_down = 1; 271 } 272 273 /* set up digitiser */ 274 if (adcsel & 0x8000) 275 adcsel = 1 << ((adcsel & 0x7fff) + 3); 276 277 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 278 dig1 &= ~WM9713_ADCSEL_MASK; 279 280 if (wm->mach_ops && wm->mach_ops->pre_sample) 281 wm->mach_ops->pre_sample(adcsel); 282 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | adcsel | WM9713_POLL); 283 284 /* wait 3 AC97 time slots + delay for conversion */ 285 poll_delay(delay); 286 287 /* wait for POLL to go low */ 288 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) && 289 timeout) { 290 udelay(AC97_LINK_FRAME); 291 timeout--; 292 } 293 294 if (timeout <= 0) { 295 /* If PDEN is set, we can get a timeout when pen goes up */ 296 if (is_pden(wm)) 297 wm->pen_probably_down = 0; 298 else 299 dev_dbg(wm->dev, "adc sample timeout"); 300 return RC_PENUP; 301 } 302 303 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 304 if (wm->mach_ops && wm->mach_ops->post_sample) 305 wm->mach_ops->post_sample(adcsel); 306 307 /* check we have correct sample */ 308 if ((*sample & WM97XX_ADCSRC_MASK) != ffs(adcsel >> 1) << 12) { 309 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel, 310 *sample & WM97XX_ADCSRC_MASK); 311 return RC_PENUP; 312 } 313 314 if (!(*sample & WM97XX_PEN_DOWN)) { 315 wm->pen_probably_down = 0; 316 return RC_PENUP; 317 } 318 319 return RC_VALID; 320 } 321 322 /* 323 * Read a coordinate from the WM9713 adc in polling mode. 324 */ 325 static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) 326 { 327 u16 dig1; 328 int timeout = 5 * delay; 329 330 if (!wm->pen_probably_down) { 331 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 332 if (!(val & WM97XX_PEN_DOWN)) 333 return RC_PENUP; 334 wm->pen_probably_down = 1; 335 } 336 337 /* set up digitiser */ 338 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 339 dig1 &= ~WM9713_ADCSEL_MASK; 340 if (pil) 341 dig1 |= WM9713_ADCSEL_PRES; 342 343 if (wm->mach_ops && wm->mach_ops->pre_sample) 344 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 345 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 346 dig1 | WM9713_POLL | WM9713_COO); 347 348 /* wait 3 AC97 time slots + delay for conversion */ 349 poll_delay(delay); 350 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 351 /* wait for POLL to go low */ 352 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) 353 && timeout) { 354 udelay(AC97_LINK_FRAME); 355 timeout--; 356 } 357 358 if (timeout <= 0) { 359 /* If PDEN is set, we can get a timeout when pen goes up */ 360 if (is_pden(wm)) 361 wm->pen_probably_down = 0; 362 else 363 dev_dbg(wm->dev, "adc sample timeout"); 364 return RC_PENUP; 365 } 366 367 /* read back data */ 368 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 369 if (pil) 370 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 371 else 372 data->p = DEFAULT_PRESSURE; 373 374 if (wm->mach_ops && wm->mach_ops->post_sample) 375 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 376 377 /* check we have correct sample */ 378 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) 379 goto err; 380 if (pil && !(data->p & WM97XX_ADCSEL_PRES)) 381 goto err; 382 383 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { 384 wm->pen_probably_down = 0; 385 return RC_PENUP; 386 } 387 return RC_VALID; 388 err: 389 return 0; 390 } 391 392 /* 393 * Sample the WM9713 touchscreen in polling mode 394 */ 395 static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) 396 { 397 int rc; 398 399 if (coord) { 400 rc = wm9713_poll_coord(wm, data); 401 if (rc != RC_VALID) 402 return rc; 403 } else { 404 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x); 405 if (rc != RC_VALID) 406 return rc; 407 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y); 408 if (rc != RC_VALID) 409 return rc; 410 if (pil) { 411 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES, 412 &data->p); 413 if (rc != RC_VALID) 414 return rc; 415 } else 416 data->p = DEFAULT_PRESSURE; 417 } 418 return RC_VALID; 419 } 420 421 /* 422 * Enable WM9713 continuous mode, i.e. touch data is streamed across 423 * an AC97 slot 424 */ 425 static int wm9713_acc_enable(struct wm97xx *wm, int enable) 426 { 427 u16 dig1, dig2, dig3; 428 int ret = 0; 429 430 dig1 = wm->dig[0]; 431 dig2 = wm->dig[1]; 432 dig3 = wm->dig[2]; 433 434 if (enable) { 435 /* continous mode */ 436 if (wm->mach_ops->acc_startup && 437 (ret = wm->mach_ops->acc_startup(wm)) < 0) 438 return ret; 439 440 dig1 &= ~WM9713_ADCSEL_MASK; 441 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X | 442 WM9713_ADCSEL_Y; 443 if (pil) 444 dig1 |= WM9713_ADCSEL_PRES; 445 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK | 446 WM97XX_CM_RATE_MASK); 447 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) | 448 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate); 449 dig3 |= WM9713_PDEN; 450 } else { 451 dig1 &= ~(WM9713_CTC | WM9713_COO); 452 dig2 &= ~WM97XX_SLEN; 453 dig3 &= ~WM9713_PDEN; 454 if (wm->mach_ops->acc_shutdown) 455 wm->mach_ops->acc_shutdown(wm); 456 } 457 458 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1); 459 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2); 460 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3); 461 462 return ret; 463 } 464 465 struct wm97xx_codec_drv wm9713_codec = { 466 .id = WM9713_ID2, 467 .name = "wm9713", 468 .poll_sample = wm9713_poll_sample, 469 .poll_touch = wm9713_poll_touch, 470 .acc_enable = wm9713_acc_enable, 471 .phy_init = wm9713_phy_init, 472 .dig_enable = wm9713_dig_enable, 473 .dig_restore = wm9713_dig_restore, 474 .aux_prepare = wm9713_aux_prepare, 475 }; 476 EXPORT_SYMBOL_GPL(wm9713_codec); 477 478 /* Module information */ 479 MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>"); 480 MODULE_DESCRIPTION("WM9713 Touch Screen Driver"); 481 MODULE_LICENSE("GPL"); 482