1 /* 2 * TI Touch Screen driver 3 * 4 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/ 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation version 2. 9 * 10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 11 * kind, whether express or implied; without even the implied warranty 12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 17 #include <linux/kernel.h> 18 #include <linux/err.h> 19 #include <linux/module.h> 20 #include <linux/input.h> 21 #include <linux/slab.h> 22 #include <linux/interrupt.h> 23 #include <linux/clk.h> 24 #include <linux/platform_device.h> 25 #include <linux/io.h> 26 #include <linux/delay.h> 27 #include <linux/of.h> 28 #include <linux/of_device.h> 29 #include <linux/sort.h> 30 #include <linux/pm_wakeirq.h> 31 32 #include <linux/mfd/ti_am335x_tscadc.h> 33 34 #define ADCFSM_STEPID 0x10 35 #define SEQ_SETTLE 275 36 #define MAX_12BIT ((1 << 12) - 1) 37 38 #define TSC_IRQENB_MASK (IRQENB_FIFO0THRES | IRQENB_EOS | IRQENB_HW_PEN) 39 40 static const int config_pins[] = { 41 STEPCONFIG_XPP, 42 STEPCONFIG_XNN, 43 STEPCONFIG_YPP, 44 STEPCONFIG_YNN, 45 }; 46 47 struct titsc { 48 struct input_dev *input; 49 struct ti_tscadc_dev *mfd_tscadc; 50 struct device *dev; 51 unsigned int irq; 52 unsigned int wires; 53 unsigned int x_plate_resistance; 54 bool pen_down; 55 int coordinate_readouts; 56 u32 config_inp[4]; 57 u32 bit_xp, bit_xn, bit_yp, bit_yn; 58 u32 inp_xp, inp_xn, inp_yp, inp_yn; 59 u32 step_mask; 60 u32 charge_delay; 61 }; 62 63 static unsigned int titsc_readl(struct titsc *ts, unsigned int reg) 64 { 65 return readl(ts->mfd_tscadc->tscadc_base + reg); 66 } 67 68 static void titsc_writel(struct titsc *tsc, unsigned int reg, 69 unsigned int val) 70 { 71 writel(val, tsc->mfd_tscadc->tscadc_base + reg); 72 } 73 74 static int titsc_config_wires(struct titsc *ts_dev) 75 { 76 u32 analog_line[4]; 77 u32 wire_order[4]; 78 int i, bit_cfg; 79 80 for (i = 0; i < 4; i++) { 81 /* 82 * Get the order in which TSC wires are attached 83 * w.r.t. each of the analog input lines on the EVM. 84 */ 85 analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4; 86 wire_order[i] = ts_dev->config_inp[i] & 0x0F; 87 if (WARN_ON(analog_line[i] > 7)) 88 return -EINVAL; 89 if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins))) 90 return -EINVAL; 91 } 92 93 for (i = 0; i < 4; i++) { 94 int an_line; 95 int wi_order; 96 97 an_line = analog_line[i]; 98 wi_order = wire_order[i]; 99 bit_cfg = config_pins[wi_order]; 100 if (bit_cfg == 0) 101 return -EINVAL; 102 switch (wi_order) { 103 case 0: 104 ts_dev->bit_xp = bit_cfg; 105 ts_dev->inp_xp = an_line; 106 break; 107 108 case 1: 109 ts_dev->bit_xn = bit_cfg; 110 ts_dev->inp_xn = an_line; 111 break; 112 113 case 2: 114 ts_dev->bit_yp = bit_cfg; 115 ts_dev->inp_yp = an_line; 116 break; 117 case 3: 118 ts_dev->bit_yn = bit_cfg; 119 ts_dev->inp_yn = an_line; 120 break; 121 } 122 } 123 return 0; 124 } 125 126 static void titsc_step_config(struct titsc *ts_dev) 127 { 128 unsigned int config; 129 int i; 130 int end_step, first_step, tsc_steps; 131 u32 stepenable; 132 133 config = STEPCONFIG_MODE_HWSYNC | 134 STEPCONFIG_AVG_16 | ts_dev->bit_xp; 135 switch (ts_dev->wires) { 136 case 4: 137 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn; 138 break; 139 case 5: 140 config |= ts_dev->bit_yn | 141 STEPCONFIG_INP_AN4 | ts_dev->bit_xn | 142 ts_dev->bit_yp; 143 break; 144 case 8: 145 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn; 146 break; 147 } 148 149 tsc_steps = ts_dev->coordinate_readouts * 2 + 2; 150 first_step = TOTAL_STEPS - tsc_steps; 151 /* Steps 16 to 16-coordinate_readouts is for X */ 152 end_step = first_step + tsc_steps; 153 for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) { 154 titsc_writel(ts_dev, REG_STEPCONFIG(i), config); 155 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY); 156 } 157 158 config = 0; 159 config = STEPCONFIG_MODE_HWSYNC | 160 STEPCONFIG_AVG_16 | ts_dev->bit_yn | 161 STEPCONFIG_INM_ADCREFM; 162 switch (ts_dev->wires) { 163 case 4: 164 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp); 165 break; 166 case 5: 167 config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 | 168 STEPCONFIG_XNP | STEPCONFIG_YPN; 169 break; 170 case 8: 171 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp); 172 break; 173 } 174 175 /* 1 ... coordinate_readouts is for Y */ 176 end_step = first_step + ts_dev->coordinate_readouts; 177 for (i = first_step; i < end_step; i++) { 178 titsc_writel(ts_dev, REG_STEPCONFIG(i), config); 179 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY); 180 } 181 182 /* Make CHARGECONFIG same as IDLECONFIG */ 183 184 config = titsc_readl(ts_dev, REG_IDLECONFIG); 185 titsc_writel(ts_dev, REG_CHARGECONFIG, config); 186 titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay); 187 188 /* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */ 189 config = STEPCONFIG_MODE_HWSYNC | 190 STEPCONFIG_AVG_16 | ts_dev->bit_yp | 191 ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM | 192 STEPCONFIG_INP(ts_dev->inp_xp); 193 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config); 194 titsc_writel(ts_dev, REG_STEPDELAY(end_step), 195 STEPCONFIG_OPENDLY); 196 197 end_step++; 198 config |= STEPCONFIG_INP(ts_dev->inp_yn); 199 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config); 200 titsc_writel(ts_dev, REG_STEPDELAY(end_step), 201 STEPCONFIG_OPENDLY); 202 203 /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */ 204 stepenable = 1; 205 for (i = 0; i < tsc_steps; i++) 206 stepenable |= 1 << (first_step + i + 1); 207 208 ts_dev->step_mask = stepenable; 209 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask); 210 } 211 212 static int titsc_cmp_coord(const void *a, const void *b) 213 { 214 return *(int *)a - *(int *)b; 215 } 216 217 static void titsc_read_coordinates(struct titsc *ts_dev, 218 u32 *x, u32 *y, u32 *z1, u32 *z2) 219 { 220 unsigned int yvals[7], xvals[7]; 221 unsigned int i, xsum = 0, ysum = 0; 222 unsigned int creads = ts_dev->coordinate_readouts; 223 224 for (i = 0; i < creads; i++) { 225 yvals[i] = titsc_readl(ts_dev, REG_FIFO0); 226 yvals[i] &= 0xfff; 227 } 228 229 *z1 = titsc_readl(ts_dev, REG_FIFO0); 230 *z1 &= 0xfff; 231 *z2 = titsc_readl(ts_dev, REG_FIFO0); 232 *z2 &= 0xfff; 233 234 for (i = 0; i < creads; i++) { 235 xvals[i] = titsc_readl(ts_dev, REG_FIFO0); 236 xvals[i] &= 0xfff; 237 } 238 239 /* 240 * If co-ordinates readouts is less than 4 then 241 * report the average. In case of 4 or more 242 * readouts, sort the co-ordinate samples, drop 243 * min and max values and report the average of 244 * remaining values. 245 */ 246 if (creads <= 3) { 247 for (i = 0; i < creads; i++) { 248 ysum += yvals[i]; 249 xsum += xvals[i]; 250 } 251 ysum /= creads; 252 xsum /= creads; 253 } else { 254 sort(yvals, creads, sizeof(unsigned int), 255 titsc_cmp_coord, NULL); 256 sort(xvals, creads, sizeof(unsigned int), 257 titsc_cmp_coord, NULL); 258 for (i = 1; i < creads - 1; i++) { 259 ysum += yvals[i]; 260 xsum += xvals[i]; 261 } 262 ysum /= creads - 2; 263 xsum /= creads - 2; 264 } 265 *y = ysum; 266 *x = xsum; 267 } 268 269 static irqreturn_t titsc_irq(int irq, void *dev) 270 { 271 struct titsc *ts_dev = dev; 272 struct input_dev *input_dev = ts_dev->input; 273 unsigned int fsm, status, irqclr = 0; 274 unsigned int x = 0, y = 0; 275 unsigned int z1, z2, z; 276 277 status = titsc_readl(ts_dev, REG_RAWIRQSTATUS); 278 if (status & IRQENB_HW_PEN) { 279 ts_dev->pen_down = true; 280 irqclr |= IRQENB_HW_PEN; 281 pm_stay_awake(ts_dev->dev); 282 } 283 284 if (status & IRQENB_PENUP) { 285 fsm = titsc_readl(ts_dev, REG_ADCFSM); 286 if (fsm == ADCFSM_STEPID) { 287 ts_dev->pen_down = false; 288 input_report_key(input_dev, BTN_TOUCH, 0); 289 input_report_abs(input_dev, ABS_PRESSURE, 0); 290 input_sync(input_dev); 291 pm_relax(ts_dev->dev); 292 } else { 293 ts_dev->pen_down = true; 294 } 295 irqclr |= IRQENB_PENUP; 296 } 297 298 if (status & IRQENB_EOS) 299 irqclr |= IRQENB_EOS; 300 301 /* 302 * ADC and touchscreen share the IRQ line. 303 * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only 304 */ 305 if (status & IRQENB_FIFO0THRES) { 306 307 titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2); 308 309 if (ts_dev->pen_down && z1 != 0 && z2 != 0) { 310 /* 311 * Calculate pressure using formula 312 * Resistance(touch) = x plate resistance * 313 * x postion/4096 * ((z2 / z1) - 1) 314 */ 315 z = z1 - z2; 316 z *= x; 317 z *= ts_dev->x_plate_resistance; 318 z /= z2; 319 z = (z + 2047) >> 12; 320 321 if (z <= MAX_12BIT) { 322 input_report_abs(input_dev, ABS_X, x); 323 input_report_abs(input_dev, ABS_Y, y); 324 input_report_abs(input_dev, ABS_PRESSURE, z); 325 input_report_key(input_dev, BTN_TOUCH, 1); 326 input_sync(input_dev); 327 } 328 } 329 irqclr |= IRQENB_FIFO0THRES; 330 } 331 if (irqclr) { 332 titsc_writel(ts_dev, REG_IRQSTATUS, irqclr); 333 if (status & IRQENB_EOS) 334 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, 335 ts_dev->step_mask); 336 return IRQ_HANDLED; 337 } 338 return IRQ_NONE; 339 } 340 341 static int titsc_parse_dt(struct platform_device *pdev, 342 struct titsc *ts_dev) 343 { 344 struct device_node *node = pdev->dev.of_node; 345 int err; 346 347 if (!node) 348 return -EINVAL; 349 350 err = of_property_read_u32(node, "ti,wires", &ts_dev->wires); 351 if (err < 0) 352 return err; 353 switch (ts_dev->wires) { 354 case 4: 355 case 5: 356 case 8: 357 break; 358 default: 359 return -EINVAL; 360 } 361 362 err = of_property_read_u32(node, "ti,x-plate-resistance", 363 &ts_dev->x_plate_resistance); 364 if (err < 0) 365 return err; 366 367 /* 368 * Try with the new binding first. If it fails, try again with 369 * bogus, miss-spelled version. 370 */ 371 err = of_property_read_u32(node, "ti,coordinate-readouts", 372 &ts_dev->coordinate_readouts); 373 if (err < 0) { 374 dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n"); 375 err = of_property_read_u32(node, "ti,coordiante-readouts", 376 &ts_dev->coordinate_readouts); 377 } 378 379 if (err < 0) 380 return err; 381 382 if (ts_dev->coordinate_readouts <= 0) { 383 dev_warn(&pdev->dev, 384 "invalid co-ordinate readouts, resetting it to 5\n"); 385 ts_dev->coordinate_readouts = 5; 386 } 387 388 err = of_property_read_u32(node, "ti,charge-delay", 389 &ts_dev->charge_delay); 390 /* 391 * If ti,charge-delay value is not specified, then use 392 * CHARGEDLY_OPENDLY as the default value. 393 */ 394 if (err < 0) { 395 ts_dev->charge_delay = CHARGEDLY_OPENDLY; 396 dev_warn(&pdev->dev, "ti,charge-delay not specified\n"); 397 } 398 399 return of_property_read_u32_array(node, "ti,wire-config", 400 ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp)); 401 } 402 403 /* 404 * The functions for inserting/removing driver as a module. 405 */ 406 407 static int titsc_probe(struct platform_device *pdev) 408 { 409 struct titsc *ts_dev; 410 struct input_dev *input_dev; 411 struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev); 412 int err; 413 414 /* Allocate memory for device */ 415 ts_dev = kzalloc(sizeof(*ts_dev), GFP_KERNEL); 416 input_dev = input_allocate_device(); 417 if (!ts_dev || !input_dev) { 418 dev_err(&pdev->dev, "failed to allocate memory.\n"); 419 err = -ENOMEM; 420 goto err_free_mem; 421 } 422 423 tscadc_dev->tsc = ts_dev; 424 ts_dev->mfd_tscadc = tscadc_dev; 425 ts_dev->input = input_dev; 426 ts_dev->irq = tscadc_dev->irq; 427 ts_dev->dev = &pdev->dev; 428 429 err = titsc_parse_dt(pdev, ts_dev); 430 if (err) { 431 dev_err(&pdev->dev, "Could not find valid DT data.\n"); 432 goto err_free_mem; 433 } 434 435 err = request_irq(ts_dev->irq, titsc_irq, 436 IRQF_SHARED, pdev->dev.driver->name, ts_dev); 437 if (err) { 438 dev_err(&pdev->dev, "failed to allocate irq.\n"); 439 goto err_free_mem; 440 } 441 442 device_init_wakeup(&pdev->dev, true); 443 err = dev_pm_set_wake_irq(&pdev->dev, ts_dev->irq); 444 if (err) 445 dev_err(&pdev->dev, "irq wake enable failed.\n"); 446 447 titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK); 448 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES); 449 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS); 450 err = titsc_config_wires(ts_dev); 451 if (err) { 452 dev_err(&pdev->dev, "wrong i/p wire configuration\n"); 453 goto err_free_irq; 454 } 455 titsc_step_config(ts_dev); 456 titsc_writel(ts_dev, REG_FIFO0THR, 457 ts_dev->coordinate_readouts * 2 + 2 - 1); 458 459 input_dev->name = "ti-tsc"; 460 input_dev->dev.parent = &pdev->dev; 461 462 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 463 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 464 465 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0); 466 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0); 467 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0); 468 469 /* register to the input system */ 470 err = input_register_device(input_dev); 471 if (err) 472 goto err_free_irq; 473 474 platform_set_drvdata(pdev, ts_dev); 475 return 0; 476 477 err_free_irq: 478 dev_pm_clear_wake_irq(&pdev->dev); 479 device_init_wakeup(&pdev->dev, false); 480 free_irq(ts_dev->irq, ts_dev); 481 err_free_mem: 482 input_free_device(input_dev); 483 kfree(ts_dev); 484 return err; 485 } 486 487 static int titsc_remove(struct platform_device *pdev) 488 { 489 struct titsc *ts_dev = platform_get_drvdata(pdev); 490 u32 steps; 491 492 dev_pm_clear_wake_irq(&pdev->dev); 493 device_init_wakeup(&pdev->dev, false); 494 free_irq(ts_dev->irq, ts_dev); 495 496 /* total steps followed by the enable mask */ 497 steps = 2 * ts_dev->coordinate_readouts + 2; 498 steps = (1 << steps) - 1; 499 am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps); 500 501 input_unregister_device(ts_dev->input); 502 503 kfree(ts_dev); 504 return 0; 505 } 506 507 static int __maybe_unused titsc_suspend(struct device *dev) 508 { 509 struct titsc *ts_dev = dev_get_drvdata(dev); 510 unsigned int idle; 511 512 if (device_may_wakeup(dev)) { 513 titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK); 514 idle = titsc_readl(ts_dev, REG_IRQENABLE); 515 titsc_writel(ts_dev, REG_IRQENABLE, 516 (idle | IRQENB_HW_PEN)); 517 titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB); 518 } 519 return 0; 520 } 521 522 static int __maybe_unused titsc_resume(struct device *dev) 523 { 524 struct titsc *ts_dev = dev_get_drvdata(dev); 525 526 if (device_may_wakeup(dev)) { 527 titsc_writel(ts_dev, REG_IRQWAKEUP, 528 0x00); 529 titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN); 530 pm_relax(dev); 531 } 532 titsc_step_config(ts_dev); 533 titsc_writel(ts_dev, REG_FIFO0THR, 534 ts_dev->coordinate_readouts * 2 + 2 - 1); 535 return 0; 536 } 537 538 static SIMPLE_DEV_PM_OPS(titsc_pm_ops, titsc_suspend, titsc_resume); 539 540 static const struct of_device_id ti_tsc_dt_ids[] = { 541 { .compatible = "ti,am3359-tsc", }, 542 { } 543 }; 544 MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids); 545 546 static struct platform_driver ti_tsc_driver = { 547 .probe = titsc_probe, 548 .remove = titsc_remove, 549 .driver = { 550 .name = "TI-am335x-tsc", 551 .pm = &titsc_pm_ops, 552 .of_match_table = ti_tsc_dt_ids, 553 }, 554 }; 555 module_platform_driver(ti_tsc_driver); 556 557 MODULE_DESCRIPTION("TI touchscreen controller driver"); 558 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>"); 559 MODULE_LICENSE("GPL"); 560