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 */ 42 static int rpu = 8; 43 module_param(rpu, int, 0); 44 MODULE_PARM_DESC(rpu, "Set internal pull up resistor 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 */ 56 static int pil; 57 module_param(pil, int, 0); 58 MODULE_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 */ 65 static int pressure = DEFAULT_PRESSURE & 0xfff; 66 module_param(pressure, int, 0); 67 MODULE_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 */ 81 static int delay = 4; 82 module_param(delay, int, 0); 83 MODULE_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 */ 90 static int five_wire; 91 module_param(five_wire, int, 0); 92 MODULE_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 */ 107 static int mask; 108 module_param(mask, int, 0); 109 MODULE_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 */ 117 static int coord; 118 module_param(coord, int, 0); 119 MODULE_PARM_DESC(coord, "Polling coordinate mode"); 120 121 /* 122 * ADC sample delay times in uS 123 */ 124 static 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 */ 148 static 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 */ 156 static 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 } 218 219 static 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 } 236 237 static 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 } 243 244 static 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 } 251 252 static 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 */ 260 static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample) 261 { 262 u16 dig1; 263 int timeout = 5 * delay; 264 bool wants_pen = adcsel & WM97XX_PEN_DOWN; 265 266 if (wants_pen && !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 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 275 dig1 &= ~WM9713_ADCSEL_MASK; 276 /* WM97XX_ADCSEL_* channels need to be converted to WM9713 format */ 277 dig1 |= 1 << ((adcsel & WM97XX_ADCSEL_MASK) >> 12); 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 | 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 ^ adcsel) & WM97XX_ADCSEL_MASK) { 308 dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x", 309 adcsel & WM97XX_ADCSEL_MASK, 310 *sample & WM97XX_ADCSEL_MASK); 311 return RC_PENUP; 312 } 313 314 if (wants_pen && !(*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, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x); 405 if (rc != RC_VALID) 406 return rc; 407 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y); 408 if (rc != RC_VALID) 409 return rc; 410 if (pil) { 411 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, 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 /* continuous 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 <lrg@slimlogic.co.uk>"); 480 MODULE_DESCRIPTION("WM9713 Touch Screen Driver"); 481 MODULE_LICENSE("GPL"); 482