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