1 /* 2 * wm9712.c -- Codec driver for Wolfson WM9712 AC97 Codecs. 3 * 4 * Copyright 2003, 2004, 2005, 2006, 2007 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 WM9712_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 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 */ 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 = 3; 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 WM9712 155 */ 156 static void wm9712_phy_init(struct wm97xx *wm) 157 { 158 u16 dig1 = 0; 159 u16 dig2 = WM97XX_RPR | WM9712_RPU(1); 160 161 /* WM9712 rpu */ 162 if (rpu) { 163 dig2 &= 0xffc0; 164 dig2 |= WM9712_RPU(rpu); 165 dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms\n", 166 64000 / rpu); 167 } 168 169 /* WM9712 five wire */ 170 if (five_wire) { 171 dig2 |= WM9712_45W; 172 dev_dbg(wm->dev, "setting 5-wire touchscreen mode.\n"); 173 174 if (pil) { 175 dev_warn(wm->dev, "pressure measurement is not " 176 "supported in 5-wire mode\n"); 177 pil = 0; 178 } 179 } 180 181 /* touchpanel pressure current*/ 182 if (pil == 2) { 183 dig2 |= WM9712_PIL; 184 dev_dbg(wm->dev, 185 "setting pressure measurement current to 400uA.\n"); 186 } else if (pil) 187 dev_dbg(wm->dev, 188 "setting pressure measurement current to 200uA.\n"); 189 if (!pil) 190 pressure = 0; 191 192 /* polling mode sample settling delay */ 193 if (delay < 0 || delay > 15) { 194 dev_dbg(wm->dev, "supplied delay out of range.\n"); 195 delay = 4; 196 } 197 dig1 &= 0xff0f; 198 dig1 |= WM97XX_DELAY(delay); 199 dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.\n", 200 delay_table[delay]); 201 202 /* mask */ 203 dig2 |= ((mask & 0x3) << 6); 204 if (mask) { 205 u16 reg; 206 /* Set GPIO4 as Mask Pin*/ 207 reg = wm97xx_reg_read(wm, AC97_MISC_AFE); 208 wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4); 209 reg = wm97xx_reg_read(wm, AC97_GPIO_CFG); 210 wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4); 211 } 212 213 /* wait - coord mode */ 214 if (coord) 215 dig2 |= WM9712_WAIT; 216 217 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); 218 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); 219 } 220 221 static void wm9712_dig_enable(struct wm97xx *wm, int enable) 222 { 223 u16 dig2 = wm->dig[2]; 224 225 if (enable) { 226 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, 227 dig2 | WM97XX_PRP_DET_DIG); 228 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ 229 } else 230 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, 231 dig2 & ~WM97XX_PRP_DET_DIG); 232 } 233 234 static void wm9712_aux_prepare(struct wm97xx *wm) 235 { 236 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); 237 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0); 238 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG); 239 } 240 241 static void wm9712_dig_restore(struct wm97xx *wm) 242 { 243 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]); 244 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]); 245 } 246 247 static inline int is_pden(struct wm97xx *wm) 248 { 249 return wm->dig[2] & WM9712_PDEN; 250 } 251 252 /* 253 * Read a sample from the WM9712 adc in polling mode. 254 */ 255 static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample) 256 { 257 int timeout = 5 * delay; 258 bool wants_pen = adcsel & WM97XX_PEN_DOWN; 259 260 if (wants_pen && !wm->pen_probably_down) { 261 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 262 if (!(data & WM97XX_PEN_DOWN)) 263 return RC_PENUP; 264 wm->pen_probably_down = 1; 265 } 266 267 /* set up digitiser */ 268 if (wm->mach_ops && wm->mach_ops->pre_sample) 269 wm->mach_ops->pre_sample(adcsel); 270 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK) 271 | WM97XX_POLL | WM97XX_DELAY(delay)); 272 273 /* wait 3 AC97 time slots + delay for conversion */ 274 poll_delay(delay); 275 276 /* wait for POLL to go low */ 277 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) 278 && timeout) { 279 udelay(AC97_LINK_FRAME); 280 timeout--; 281 } 282 283 if (timeout <= 0) { 284 /* If PDEN is set, we can get a timeout when pen goes up */ 285 if (is_pden(wm)) 286 wm->pen_probably_down = 0; 287 else 288 dev_dbg(wm->dev, "adc sample timeout\n"); 289 return RC_PENUP; 290 } 291 292 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 293 if (wm->mach_ops && wm->mach_ops->post_sample) 294 wm->mach_ops->post_sample(adcsel); 295 296 /* check we have correct sample */ 297 if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) { 298 dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x\n", 299 adcsel & WM97XX_ADCSEL_MASK, 300 *sample & WM97XX_ADCSEL_MASK); 301 return RC_AGAIN; 302 } 303 304 if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { 305 /* Sometimes it reads a wrong value the first time. */ 306 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 307 if (!(*sample & WM97XX_PEN_DOWN)) { 308 wm->pen_probably_down = 0; 309 return RC_PENUP; 310 } 311 } 312 313 return RC_VALID; 314 } 315 316 /* 317 * Read a coord from the WM9712 adc in polling mode. 318 */ 319 static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) 320 { 321 int timeout = 5 * delay; 322 323 if (!wm->pen_probably_down) { 324 u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 325 if (!(data_rd & WM97XX_PEN_DOWN)) 326 return RC_PENUP; 327 wm->pen_probably_down = 1; 328 } 329 330 /* set up digitiser */ 331 if (wm->mach_ops && wm->mach_ops->pre_sample) 332 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 333 334 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 335 WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay)); 336 337 /* wait 3 AC97 time slots + delay for conversion and read x */ 338 poll_delay(delay); 339 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 340 /* wait for POLL to go low */ 341 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) 342 && timeout) { 343 udelay(AC97_LINK_FRAME); 344 timeout--; 345 } 346 347 if (timeout <= 0) { 348 /* If PDEN is set, we can get a timeout when pen goes up */ 349 if (is_pden(wm)) 350 wm->pen_probably_down = 0; 351 else 352 dev_dbg(wm->dev, "adc sample timeout\n"); 353 return RC_PENUP; 354 } 355 356 /* read back y data */ 357 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 358 if (pil) 359 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 360 else 361 data->p = DEFAULT_PRESSURE; 362 363 if (wm->mach_ops && wm->mach_ops->post_sample) 364 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 365 366 /* check we have correct sample */ 367 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) 368 goto err; 369 if (pil && !(data->p & WM97XX_ADCSEL_PRES)) 370 goto err; 371 372 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { 373 wm->pen_probably_down = 0; 374 return RC_PENUP; 375 } 376 return RC_VALID; 377 err: 378 return 0; 379 } 380 381 /* 382 * Sample the WM9712 touchscreen in polling mode 383 */ 384 static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) 385 { 386 int rc; 387 388 if (coord) { 389 rc = wm9712_poll_coord(wm, data); 390 if (rc != RC_VALID) 391 return rc; 392 } else { 393 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, 394 &data->x); 395 if (rc != RC_VALID) 396 return rc; 397 398 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, 399 &data->y); 400 if (rc != RC_VALID) 401 return rc; 402 403 if (pil && !five_wire) { 404 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, 405 &data->p); 406 if (rc != RC_VALID) 407 return rc; 408 } else 409 data->p = DEFAULT_PRESSURE; 410 } 411 return RC_VALID; 412 } 413 414 /* 415 * Enable WM9712 continuous mode, i.e. touch data is streamed across 416 * an AC97 slot 417 */ 418 static int wm9712_acc_enable(struct wm97xx *wm, int enable) 419 { 420 u16 dig1, dig2; 421 int ret = 0; 422 423 dig1 = wm->dig[1]; 424 dig2 = wm->dig[2]; 425 426 if (enable) { 427 /* continuous mode */ 428 if (wm->mach_ops->acc_startup) { 429 ret = wm->mach_ops->acc_startup(wm); 430 if (ret < 0) 431 return ret; 432 } 433 dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK | 434 WM97XX_DELAY_MASK | WM97XX_SLT_MASK); 435 dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN | 436 WM97XX_DELAY(delay) | 437 WM97XX_SLT(wm->acc_slot) | 438 WM97XX_RATE(wm->acc_rate); 439 if (pil) 440 dig1 |= WM97XX_ADCSEL_PRES; 441 dig2 |= WM9712_PDEN; 442 } else { 443 dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN); 444 dig2 &= ~WM9712_PDEN; 445 if (wm->mach_ops->acc_shutdown) 446 wm->mach_ops->acc_shutdown(wm); 447 } 448 449 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); 450 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); 451 452 return 0; 453 } 454 455 struct wm97xx_codec_drv wm9712_codec = { 456 .id = WM9712_ID2, 457 .name = "wm9712", 458 .poll_sample = wm9712_poll_sample, 459 .poll_touch = wm9712_poll_touch, 460 .acc_enable = wm9712_acc_enable, 461 .phy_init = wm9712_phy_init, 462 .dig_enable = wm9712_dig_enable, 463 .dig_restore = wm9712_dig_restore, 464 .aux_prepare = wm9712_aux_prepare, 465 }; 466 EXPORT_SYMBOL_GPL(wm9712_codec); 467 468 /* Module information */ 469 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 470 MODULE_DESCRIPTION("WM9712 Touch Screen Driver"); 471 MODULE_LICENSE("GPL"); 472