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", 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."); 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."); 186 } else if (pil) 187 dev_dbg(wm->dev, 188 "setting pressure measurement current to 200uA."); 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."); 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.", 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; 258 259 if (!wm->pen_probably_down) { 260 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 261 if (!(data & WM97XX_PEN_DOWN)) 262 return RC_PENUP; 263 wm->pen_probably_down = 1; 264 } 265 266 /* set up digitiser */ 267 if (adcsel & 0x8000) 268 adcsel = ((adcsel & 0x7fff) + 3) << 12; 269 270 if (wm->mach_ops && wm->mach_ops->pre_sample) 271 wm->mach_ops->pre_sample(adcsel); 272 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 273 adcsel | WM97XX_POLL | WM97XX_DELAY(delay)); 274 275 /* wait 3 AC97 time slots + delay for conversion */ 276 poll_delay(delay); 277 278 /* wait for POLL to go low */ 279 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) 280 && timeout) { 281 udelay(AC97_LINK_FRAME); 282 timeout--; 283 } 284 285 if (timeout <= 0) { 286 /* If PDEN is set, we can get a timeout when pen goes up */ 287 if (is_pden(wm)) 288 wm->pen_probably_down = 0; 289 else 290 dev_dbg(wm->dev, "adc sample timeout"); 291 return RC_PENUP; 292 } 293 294 *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 295 if (wm->mach_ops && wm->mach_ops->post_sample) 296 wm->mach_ops->post_sample(adcsel); 297 298 /* check we have correct sample */ 299 if ((*sample & WM97XX_ADCSEL_MASK) != adcsel) { 300 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel, 301 *sample & WM97XX_ADCSEL_MASK); 302 return RC_PENUP; 303 } 304 305 if (!(*sample & WM97XX_PEN_DOWN)) { 306 wm->pen_probably_down = 0; 307 return RC_PENUP; 308 } 309 310 return RC_VALID; 311 } 312 313 /* 314 * Read a coord from the WM9712 adc in polling mode. 315 */ 316 static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data) 317 { 318 int timeout = 5 * delay; 319 320 if (!wm->pen_probably_down) { 321 u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 322 if (!(data_rd & WM97XX_PEN_DOWN)) 323 return RC_PENUP; 324 wm->pen_probably_down = 1; 325 } 326 327 /* set up digitiser */ 328 if (wm->mach_ops && wm->mach_ops->pre_sample) 329 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 330 331 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 332 WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay)); 333 334 /* wait 3 AC97 time slots + delay for conversion and read x */ 335 poll_delay(delay); 336 data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 337 /* wait for POLL to go low */ 338 while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) 339 && timeout) { 340 udelay(AC97_LINK_FRAME); 341 timeout--; 342 } 343 344 if (timeout <= 0) { 345 /* If PDEN is set, we can get a timeout when pen goes up */ 346 if (is_pden(wm)) 347 wm->pen_probably_down = 0; 348 else 349 dev_dbg(wm->dev, "adc sample timeout"); 350 return RC_PENUP; 351 } 352 353 /* read back y data */ 354 data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 355 if (pil) 356 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); 357 else 358 data->p = DEFAULT_PRESSURE; 359 360 if (wm->mach_ops && wm->mach_ops->post_sample) 361 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y); 362 363 /* check we have correct sample */ 364 if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y)) 365 goto err; 366 if (pil && !(data->p & WM97XX_ADCSEL_PRES)) 367 goto err; 368 369 if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) { 370 wm->pen_probably_down = 0; 371 return RC_PENUP; 372 } 373 return RC_VALID; 374 err: 375 return 0; 376 } 377 378 /* 379 * Sample the WM9712 touchscreen in polling mode 380 */ 381 static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) 382 { 383 int rc; 384 385 if (coord) { 386 rc = wm9712_poll_coord(wm, data); 387 if (rc != RC_VALID) 388 return rc; 389 } else { 390 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X, &data->x); 391 if (rc != RC_VALID) 392 return rc; 393 394 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y, &data->y); 395 if (rc != RC_VALID) 396 return rc; 397 398 if (pil && !five_wire) { 399 rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES, 400 &data->p); 401 if (rc != RC_VALID) 402 return rc; 403 } else 404 data->p = DEFAULT_PRESSURE; 405 } 406 return RC_VALID; 407 } 408 409 /* 410 * Enable WM9712 continuous mode, i.e. touch data is streamed across 411 * an AC97 slot 412 */ 413 static int wm9712_acc_enable(struct wm97xx *wm, int enable) 414 { 415 u16 dig1, dig2; 416 int ret = 0; 417 418 dig1 = wm->dig[1]; 419 dig2 = wm->dig[2]; 420 421 if (enable) { 422 /* continous mode */ 423 if (wm->mach_ops->acc_startup) { 424 ret = wm->mach_ops->acc_startup(wm); 425 if (ret < 0) 426 return ret; 427 } 428 dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK | 429 WM97XX_DELAY_MASK | WM97XX_SLT_MASK); 430 dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN | 431 WM97XX_DELAY(delay) | 432 WM97XX_SLT(wm->acc_slot) | 433 WM97XX_RATE(wm->acc_rate); 434 if (pil) 435 dig1 |= WM97XX_ADCSEL_PRES; 436 dig2 |= WM9712_PDEN; 437 } else { 438 dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN); 439 dig2 &= ~WM9712_PDEN; 440 if (wm->mach_ops->acc_shutdown) 441 wm->mach_ops->acc_shutdown(wm); 442 } 443 444 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); 445 wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); 446 447 return 0; 448 } 449 450 struct wm97xx_codec_drv wm9712_codec = { 451 .id = WM9712_ID2, 452 .name = "wm9712", 453 .poll_sample = wm9712_poll_sample, 454 .poll_touch = wm9712_poll_touch, 455 .acc_enable = wm9712_acc_enable, 456 .phy_init = wm9712_phy_init, 457 .dig_enable = wm9712_dig_enable, 458 .dig_restore = wm9712_dig_restore, 459 .aux_prepare = wm9712_aux_prepare, 460 }; 461 EXPORT_SYMBOL_GPL(wm9712_codec); 462 463 /* Module information */ 464 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 465 MODULE_DESCRIPTION("WM9712 Touch Screen Driver"); 466 MODULE_LICENSE("GPL"); 467