1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * wm9713.c -- Codec touch driver for Wolfson WM9713 AC97 Codec. 4 * 5 * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC. 6 * Author: Liam Girdwood <lrg@slimlogic.co.uk> 7 * Parts Copyright : Ian Molton <spyro@f2s.com> 8 * Andrew Zabolotny <zap@homelink.ru> 9 * Russell King <rmk@arm.linux.org.uk> 10 */ 11 12 #include <linux/export.h> 13 #include <linux/module.h> 14 #include <linux/moduleparam.h> 15 #include <linux/kernel.h> 16 #include <linux/input.h> 17 #include <linux/delay.h> 18 #include <linux/bitops.h> 19 #include <linux/wm97xx.h> 20 21 #define TS_NAME "wm97xx" 22 #define WM9713_VERSION "1.00" 23 #define DEFAULT_PRESSURE 0xb0c0 24 25 /* 26 * Module parameters 27 */ 28 29 /* 30 * Set internal pull up for pen detect. 31 * 32 * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive) 33 * i.e. pull up resistance = 64k Ohms / rpu. 34 * 35 * Adjust this value if you are having problems with pen detect not 36 * detecting any down event. 37 */ 38 static int rpu = 8; 39 module_param(rpu, int, 0); 40 MODULE_PARM_DESC(rpu, "Set internal pull up resistor for pen detect."); 41 42 /* 43 * Set current used for pressure measurement. 44 * 45 * Set pil = 2 to use 400uA 46 * pil = 1 to use 200uA and 47 * pil = 0 to disable pressure measurement. 48 * 49 * This is used to increase the range of values returned by the adc 50 * when measureing touchpanel pressure. 51 */ 52 static int pil; 53 module_param(pil, int, 0); 54 MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); 55 56 /* 57 * Set threshold for pressure measurement. 58 * 59 * Pen down pressure below threshold is ignored. 60 */ 61 static int pressure = DEFAULT_PRESSURE & 0xfff; 62 module_param(pressure, int, 0); 63 MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); 64 65 /* 66 * Set adc sample delay. 67 * 68 * For accurate touchpanel measurements, some settling time may be 69 * required between the switch matrix applying a voltage across the 70 * touchpanel plate and the ADC sampling the signal. 71 * 72 * This delay can be set by setting delay = n, where n is the array 73 * position of the delay in the array delay_table below. 74 * Long delays > 1ms are supported for completeness, but are not 75 * recommended. 76 */ 77 static int delay = 4; 78 module_param(delay, int, 0); 79 MODULE_PARM_DESC(delay, "Set adc sample delay."); 80 81 /* 82 * Set five_wire = 1 to use a 5 wire touchscreen. 83 * 84 * NOTE: Five wire mode does not allow for readback of pressure. 85 */ 86 static int five_wire; 87 module_param(five_wire, int, 0); 88 MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen."); 89 90 /* 91 * Set adc mask function. 92 * 93 * Sources of glitch noise, such as signals driving an LCD display, may feed 94 * through to the touch screen plates and affect measurement accuracy. In 95 * order to minimise this, a signal may be applied to the MASK pin to delay or 96 * synchronise the sampling. 97 * 98 * 0 = No delay or sync 99 * 1 = High on pin stops conversions 100 * 2 = Edge triggered, edge on pin delays conversion by delay param (above) 101 * 3 = Edge triggered, edge on pin starts conversion after delay param 102 */ 103 static int mask; 104 module_param(mask, int, 0); 105 MODULE_PARM_DESC(mask, "Set adc mask function."); 106 107 /* 108 * Coordinate Polling Enable. 109 * 110 * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together 111 * for every poll. 112 */ 113 static int coord; 114 module_param(coord, int, 0); 115 MODULE_PARM_DESC(coord, "Polling coordinate mode"); 116 117 /* 118 * ADC sample delay times in uS 119 */ 120 static const int delay_table[] = { 121 21, /* 1 AC97 Link frames */ 122 42, /* 2 */ 123 84, /* 4 */ 124 167, /* 8 */ 125 333, /* 16 */ 126 667, /* 32 */ 127 1000, /* 48 */ 128 1333, /* 64 */ 129 2000, /* 96 */ 130 2667, /* 128 */ 131 3333, /* 160 */ 132 4000, /* 192 */ 133 4667, /* 224 */ 134 5333, /* 256 */ 135 6000, /* 288 */ 136 0 /* No delay, switch matrix always on */ 137 }; 138 139 /* 140 * Delay after issuing a POLL command. 141 * 142 * The delay is 3 AC97 link frames + the touchpanel settling delay 143 */ 144 static inline void poll_delay(int d) 145 { 146 udelay(3 * AC97_LINK_FRAME + delay_table[d]); 147 } 148 149 /* 150 * set up the physical settings of the WM9713 151 */ 152 static void wm9713_phy_init(struct wm97xx *wm) 153 { 154 u16 dig1 = 0, dig2, dig3; 155 156 /* default values */ 157 dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5); 158 dig3 = WM9712_RPU(1); 159 160 /* rpu */ 161 if (rpu) { 162 dig3 &= 0xffc0; 163 dig3 |= WM9712_RPU(rpu); 164 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n", 165 64000 / rpu); 166 } 167 168 /* Five wire panel? */ 169 if (five_wire) { 170 dig3 |= WM9713_45W; 171 dev_info(wm->dev, "setting 5-wire touchscreen mode."); 172 173 if (pil) { 174 dev_warn(wm->dev, 175 "Pressure measurement not supported in 5 " 176 "wire mode, disabling\n"); 177 pil = 0; 178 } 179 } 180 181 /* touchpanel pressure */ 182 if (pil == 2) { 183 dig3 |= WM9712_PIL; 184 dev_info(wm->dev, 185 "setting pressure measurement current to 400uA."); 186 } else if (pil) 187 dev_info(wm->dev, 188 "setting pressure measurement current to 200uA."); 189 if (!pil) 190 pressure = 0; 191 192 /* sample settling delay */ 193 if (delay < 0 || delay > 15) { 194 dev_info(wm->dev, "supplied delay out of range."); 195 delay = 4; 196 dev_info(wm->dev, "setting adc sample delay to %d u Secs.", 197 delay_table[delay]); 198 } 199 dig2 &= 0xff0f; 200 dig2 |= WM97XX_DELAY(delay); 201 202 /* mask */ 203 dig3 |= ((mask & 0x3) << 4); 204 if (coord) 205 dig3 |= WM9713_WAIT; 206 207 wm->misc = wm97xx_reg_read(wm, 0x5a); 208 209 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1); 210 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2); 211 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3); 212 wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0); 213 } 214 215 static void wm9713_dig_enable(struct wm97xx *wm, int enable) 216 { 217 u16 val; 218 219 if (enable) { 220 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID); 221 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff); 222 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] | 223 WM97XX_PRP_DET_DIG); 224 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ 225 } else { 226 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] & 227 ~WM97XX_PRP_DET_DIG); 228 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID); 229 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000); 230 } 231 } 232 233 static void wm9713_dig_restore(struct wm97xx *wm) 234 { 235 wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]); 236 wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]); 237 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]); 238 } 239 240 static void wm9713_aux_prepare(struct wm97xx *wm) 241 { 242 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); 243 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0); 244 wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0); 245 wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG); 246 } 247 248 static inline int is_pden(struct wm97xx *wm) 249 { 250 return wm->dig[2] & WM9713_PDEN; 251 } 252 253 /* 254 * Read a sample from the WM9713 adc in polling mode. 255 */ 256 static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample) 257 { 258 u16 dig1; 259 int timeout = 5 * delay; 260 bool wants_pen = adcsel & WM97XX_PEN_DOWN; 261 262 if (wants_pen && !wm->pen_probably_down) { 263 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 264 if (!(data & WM97XX_PEN_DOWN)) 265 return RC_PENUP; 266 wm->pen_probably_down = 1; 267 } 268 269 /* set up digitiser */ 270 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 271 dig1 &= ~WM9713_ADCSEL_MASK; 272 /* WM97XX_ADCSEL_* channels need to be converted to WM9713 format */ 273 dig1 |= 1 << ((adcsel & WM97XX_ADCSEL_MASK) >> 12); 274 275 if (wm->mach_ops && wm->mach_ops->pre_sample) 276 wm->mach_ops->pre_sample(adcsel); 277 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | WM9713_POLL); 278 279 /* wait 3 AC97 time slots + delay for conversion */ 280 poll_delay(delay); 281 282 /* wait for POLL to go low */ 283 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) && 284 timeout) { 285 udelay(AC97_LINK_FRAME); 286 timeout--; 287 } 288 289 if (timeout <= 0) { 290 /* If PDEN is set, we can get a timeout when pen goes up */ 291 if (is_pden(wm)) 292 wm->pen_probably_down = 0; 293 else 294 dev_dbg(wm->dev, "adc sample timeout"); 295 return RC_PENUP; 296 } 297 298 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 299 if (wm->mach_ops && wm->mach_ops->post_sample) 300 wm->mach_ops->post_sample(adcsel); 301 302 /* check we have correct sample */ 303 if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) { 304 dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x", 305 adcsel & WM97XX_ADCSEL_MASK, 306 *sample & WM97XX_ADCSEL_MASK); 307 return RC_PENUP; 308 } 309 310 if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { 311 wm->pen_probably_down = 0; 312 return RC_PENUP; 313 } 314 315 return RC_VALID; 316 } 317 318 /* 319 * Read a coordinate from the WM9713 adc in polling mode. 320 */ 321 static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) 322 { 323 u16 dig1; 324 int timeout = 5 * delay; 325 326 if (!wm->pen_probably_down) { 327 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 328 if (!(val & WM97XX_PEN_DOWN)) 329 return RC_PENUP; 330 wm->pen_probably_down = 1; 331 } 332 333 /* set up digitiser */ 334 dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1); 335 dig1 &= ~WM9713_ADCSEL_MASK; 336 if (pil) 337 dig1 |= WM9713_ADCSEL_PRES; 338 339 if (wm->mach_ops && wm->mach_ops->pre_sample) 340 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 341 wm97xx_reg_write(wm, AC97_WM9713_DIG1, 342 dig1 | WM9713_POLL | WM9713_COO); 343 344 /* wait 3 AC97 time slots + delay for conversion */ 345 poll_delay(delay); 346 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 347 /* wait for POLL to go low */ 348 while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) 349 && timeout) { 350 udelay(AC97_LINK_FRAME); 351 timeout--; 352 } 353 354 if (timeout <= 0) { 355 /* If PDEN is set, we can get a timeout when pen goes up */ 356 if (is_pden(wm)) 357 wm->pen_probably_down = 0; 358 else 359 dev_dbg(wm->dev, "adc sample timeout"); 360 return RC_PENUP; 361 } 362 363 /* read back data */ 364 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 365 if (pil) 366 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 367 else 368 data->p = DEFAULT_PRESSURE; 369 370 if (wm->mach_ops && wm->mach_ops->post_sample) 371 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 372 373 /* check we have correct sample */ 374 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) 375 goto err; 376 if (pil && !(data->p & WM97XX_ADCSEL_PRES)) 377 goto err; 378 379 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { 380 wm->pen_probably_down = 0; 381 return RC_PENUP; 382 } 383 return RC_VALID; 384 err: 385 return 0; 386 } 387 388 /* 389 * Sample the WM9713 touchscreen in polling mode 390 */ 391 static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) 392 { 393 int rc; 394 395 if (coord) { 396 rc = wm9713_poll_coord(wm, data); 397 if (rc != RC_VALID) 398 return rc; 399 } else { 400 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x); 401 if (rc != RC_VALID) 402 return rc; 403 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y); 404 if (rc != RC_VALID) 405 return rc; 406 if (pil) { 407 rc = wm9713_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, 408 &data->p); 409 if (rc != RC_VALID) 410 return rc; 411 } else 412 data->p = DEFAULT_PRESSURE; 413 } 414 return RC_VALID; 415 } 416 417 /* 418 * Enable WM9713 continuous mode, i.e. touch data is streamed across 419 * an AC97 slot 420 */ 421 static int wm9713_acc_enable(struct wm97xx *wm, int enable) 422 { 423 u16 dig1, dig2, dig3; 424 int ret = 0; 425 426 dig1 = wm->dig[0]; 427 dig2 = wm->dig[1]; 428 dig3 = wm->dig[2]; 429 430 if (enable) { 431 /* continuous mode */ 432 if (wm->mach_ops->acc_startup && 433 (ret = wm->mach_ops->acc_startup(wm)) < 0) 434 return ret; 435 436 dig1 &= ~WM9713_ADCSEL_MASK; 437 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X | 438 WM9713_ADCSEL_Y; 439 if (pil) 440 dig1 |= WM9713_ADCSEL_PRES; 441 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK | 442 WM97XX_CM_RATE_MASK); 443 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) | 444 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate); 445 dig3 |= WM9713_PDEN; 446 } else { 447 dig1 &= ~(WM9713_CTC | WM9713_COO); 448 dig2 &= ~WM97XX_SLEN; 449 dig3 &= ~WM9713_PDEN; 450 if (wm->mach_ops->acc_shutdown) 451 wm->mach_ops->acc_shutdown(wm); 452 } 453 454 wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1); 455 wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2); 456 wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3); 457 458 return ret; 459 } 460 461 struct wm97xx_codec_drv wm9713_codec = { 462 .id = WM9713_ID2, 463 .name = "wm9713", 464 .poll_sample = wm9713_poll_sample, 465 .poll_touch = wm9713_poll_touch, 466 .acc_enable = wm9713_acc_enable, 467 .phy_init = wm9713_phy_init, 468 .dig_enable = wm9713_dig_enable, 469 .dig_restore = wm9713_dig_restore, 470 .aux_prepare = wm9713_aux_prepare, 471 }; 472 EXPORT_SYMBOL_GPL(wm9713_codec); 473 474 /* Module information */ 475 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 476 MODULE_DESCRIPTION("WM9713 Touch Screen Driver"); 477 MODULE_LICENSE("GPL"); 478