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 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 WM9712_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 = 3; 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 WM9712 156 */ 157 static void wm9712_phy_init(struct wm97xx *wm) 158 { 159 u16 dig1 = 0; 160 u16 dig2 = WM97XX_RPR | WM9712_RPU(1); 161 162 /* WM9712 rpu */ 163 if (rpu) { 164 dig2 &= 0xffc0; 165 dig2 |= WM9712_RPU(rpu); 166 dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms", 167 64000 / rpu); 168 } 169 170 /* WM9712 five wire */ 171 if (five_wire) { 172 dig2 |= WM9712_45W; 173 dev_dbg(wm->dev, "setting 5-wire touchscreen mode."); 174 175 if (pil) { 176 dev_warn(wm->dev, "pressure measurement is not " 177 "supported in 5-wire mode\n"); 178 pil = 0; 179 } 180 } 181 182 /* touchpanel pressure current*/ 183 if (pil == 2) { 184 dig2 |= WM9712_PIL; 185 dev_dbg(wm->dev, 186 "setting pressure measurement current to 400uA."); 187 } else if (pil) 188 dev_dbg(wm->dev, 189 "setting pressure measurement current to 200uA."); 190 if (!pil) 191 pressure = 0; 192 193 /* polling mode sample settling delay */ 194 if (delay < 0 || delay > 15) { 195 dev_dbg(wm->dev, "supplied delay out of range."); 196 delay = 4; 197 } 198 dig1 &= 0xff0f; 199 dig1 |= WM97XX_DELAY(delay); 200 dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.", 201 delay_table[delay]); 202 203 /* mask */ 204 dig2 |= ((mask & 0x3) << 6); 205 if (mask) { 206 u16 reg; 207 /* Set GPIO4 as Mask Pin*/ 208 reg = wm97xx_reg_read(wm, AC97_MISC_AFE); 209 wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4); 210 reg = wm97xx_reg_read(wm, AC97_GPIO_CFG); 211 wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4); 212 } 213 214 /* wait - coord mode */ 215 if (coord) 216 dig2 |= WM9712_WAIT; 217 218 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); 219 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); 220 } 221 222 static void wm9712_dig_enable(struct wm97xx *wm, int enable) 223 { 224 u16 dig2 = wm->dig[2]; 225 226 if (enable) { 227 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, 228 dig2 | WM97XX_PRP_DET_DIG); 229 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ 230 } else 231 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, 232 dig2 & ~WM97XX_PRP_DET_DIG); 233 } 234 235 static void wm9712_aux_prepare(struct wm97xx *wm) 236 { 237 memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); 238 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0); 239 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG); 240 } 241 242 static void wm9712_dig_restore(struct wm97xx *wm) 243 { 244 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]); 245 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]); 246 } 247 248 static inline int is_pden(struct wm97xx *wm) 249 { 250 return wm->dig[2] & WM9712_PDEN; 251 } 252 253 /* 254 * Read a sample from the WM9712 adc in polling mode. 255 */ 256 static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample) 257 { 258 int timeout = 5 * delay; 259 260 if (!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 (adcsel & 0x8000) 269 adcsel = ((adcsel & 0x7fff) + 3) << 12; 270 271 if (wm->mach_ops && wm->mach_ops->pre_sample) 272 wm->mach_ops->pre_sample(adcsel); 273 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 274 adcsel | WM97XX_POLL | WM97XX_DELAY(delay)); 275 276 /* wait 3 AC97 time slots + delay for conversion */ 277 poll_delay(delay); 278 279 /* wait for POLL to go low */ 280 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) 281 && timeout) { 282 udelay(AC97_LINK_FRAME); 283 timeout--; 284 } 285 286 if (timeout <= 0) { 287 /* If PDEN is set, we can get a timeout when pen goes up */ 288 if (is_pden(wm)) 289 wm->pen_probably_down = 0; 290 else 291 dev_dbg(wm->dev, "adc sample timeout"); 292 return RC_PENUP; 293 } 294 295 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 296 if (wm->mach_ops && wm->mach_ops->post_sample) 297 wm->mach_ops->post_sample(adcsel); 298 299 /* check we have correct sample */ 300 if ((*sample & WM97XX_ADCSEL_MASK) != adcsel) { 301 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel, 302 *sample & WM97XX_ADCSEL_MASK); 303 return RC_PENUP; 304 } 305 306 if (!(*sample & WM97XX_PEN_DOWN)) { 307 wm->pen_probably_down = 0; 308 return RC_PENUP; 309 } 310 311 return RC_VALID; 312 } 313 314 /* 315 * Read a coord from the WM9712 adc in polling mode. 316 */ 317 static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) 318 { 319 int timeout = 5 * delay; 320 321 if (!wm->pen_probably_down) { 322 u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 323 if (!(data_rd & WM97XX_PEN_DOWN)) 324 return RC_PENUP; 325 wm->pen_probably_down = 1; 326 } 327 328 /* set up digitiser */ 329 if (wm->mach_ops && wm->mach_ops->pre_sample) 330 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 331 332 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 333 WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay)); 334 335 /* wait 3 AC97 time slots + delay for conversion and read x */ 336 poll_delay(delay); 337 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 338 /* wait for POLL to go low */ 339 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) 340 && timeout) { 341 udelay(AC97_LINK_FRAME); 342 timeout--; 343 } 344 345 if (timeout <= 0) { 346 /* If PDEN is set, we can get a timeout when pen goes up */ 347 if (is_pden(wm)) 348 wm->pen_probably_down = 0; 349 else 350 dev_dbg(wm->dev, "adc sample timeout"); 351 return RC_PENUP; 352 } 353 354 /* read back y data */ 355 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 356 if (pil) 357 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 358 else 359 data->p = DEFAULT_PRESSURE; 360 361 if (wm->mach_ops && wm->mach_ops->post_sample) 362 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 363 364 /* check we have correct sample */ 365 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) 366 goto err; 367 if (pil && !(data->p & WM97XX_ADCSEL_PRES)) 368 goto err; 369 370 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { 371 wm->pen_probably_down = 0; 372 return RC_PENUP; 373 } 374 return RC_VALID; 375 err: 376 return 0; 377 } 378 379 /* 380 * Sample the WM9712 touchscreen in polling mode 381 */ 382 static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) 383 { 384 int rc; 385 386 if (coord) { 387 rc = wm9712_poll_coord(wm, data); 388 if (rc != RC_VALID) 389 return rc; 390 } else { 391 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X, &data->x); 392 if (rc != RC_VALID) 393 return rc; 394 395 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y, &data->y); 396 if (rc != RC_VALID) 397 return rc; 398 399 if (pil && !five_wire) { 400 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES, 401 &data->p); 402 if (rc != RC_VALID) 403 return rc; 404 } else 405 data->p = DEFAULT_PRESSURE; 406 } 407 return RC_VALID; 408 } 409 410 /* 411 * Enable WM9712 continuous mode, i.e. touch data is streamed across 412 * an AC97 slot 413 */ 414 static int wm9712_acc_enable(struct wm97xx *wm, int enable) 415 { 416 u16 dig1, dig2; 417 int ret = 0; 418 419 dig1 = wm->dig[1]; 420 dig2 = wm->dig[2]; 421 422 if (enable) { 423 /* continous mode */ 424 if (wm->mach_ops->acc_startup) { 425 ret = wm->mach_ops->acc_startup(wm); 426 if (ret < 0) 427 return ret; 428 } 429 dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK | 430 WM97XX_DELAY_MASK | WM97XX_SLT_MASK); 431 dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN | 432 WM97XX_DELAY(delay) | 433 WM97XX_SLT(wm->acc_slot) | 434 WM97XX_RATE(wm->acc_rate); 435 if (pil) 436 dig1 |= WM97XX_ADCSEL_PRES; 437 dig2 |= WM9712_PDEN; 438 } else { 439 dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN); 440 dig2 &= ~WM9712_PDEN; 441 if (wm->mach_ops->acc_shutdown) 442 wm->mach_ops->acc_shutdown(wm); 443 } 444 445 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); 446 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); 447 448 return 0; 449 } 450 451 struct wm97xx_codec_drv wm9712_codec = { 452 .id = WM9712_ID2, 453 .name = "wm9712", 454 .poll_sample = wm9712_poll_sample, 455 .poll_touch = wm9712_poll_touch, 456 .acc_enable = wm9712_acc_enable, 457 .phy_init = wm9712_phy_init, 458 .dig_enable = wm9712_dig_enable, 459 .dig_restore = wm9712_dig_restore, 460 .aux_prepare = wm9712_aux_prepare, 461 }; 462 EXPORT_SYMBOL_GPL(wm9712_codec); 463 464 /* Module information */ 465 MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>"); 466 MODULE_DESCRIPTION("WM9712 Touch Screen Driver"); 467 MODULE_LICENSE("GPL"); 468