1 /* 2 * Freescale i.MX6UL touchscreen controller driver 3 * 4 * Copyright (C) 2015 Freescale Semiconductor, Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/errno.h> 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/gpio/consumer.h> 15 #include <linux/input.h> 16 #include <linux/slab.h> 17 #include <linux/completion.h> 18 #include <linux/delay.h> 19 #include <linux/of.h> 20 #include <linux/interrupt.h> 21 #include <linux/platform_device.h> 22 #include <linux/clk.h> 23 #include <linux/io.h> 24 #include <linux/log2.h> 25 26 /* ADC configuration registers field define */ 27 #define ADC_AIEN (0x1 << 7) 28 #define ADC_CONV_DISABLE 0x1F 29 #define ADC_AVGE (0x1 << 5) 30 #define ADC_CAL (0x1 << 7) 31 #define ADC_CALF 0x2 32 #define ADC_12BIT_MODE (0x2 << 2) 33 #define ADC_CONV_MODE_MASK (0x3 << 2) 34 #define ADC_IPG_CLK 0x00 35 #define ADC_INPUT_CLK_MASK 0x3 36 #define ADC_CLK_DIV_8 (0x03 << 5) 37 #define ADC_CLK_DIV_MASK (0x3 << 5) 38 #define ADC_SHORT_SAMPLE_MODE (0x0 << 4) 39 #define ADC_SAMPLE_MODE_MASK (0x1 << 4) 40 #define ADC_HARDWARE_TRIGGER (0x1 << 13) 41 #define ADC_AVGS_SHIFT 14 42 #define ADC_AVGS_MASK (0x3 << 14) 43 #define SELECT_CHANNEL_4 0x04 44 #define SELECT_CHANNEL_1 0x01 45 #define DISABLE_CONVERSION_INT (0x0 << 7) 46 47 /* ADC registers */ 48 #define REG_ADC_HC0 0x00 49 #define REG_ADC_HC1 0x04 50 #define REG_ADC_HC2 0x08 51 #define REG_ADC_HC3 0x0C 52 #define REG_ADC_HC4 0x10 53 #define REG_ADC_HS 0x14 54 #define REG_ADC_R0 0x18 55 #define REG_ADC_CFG 0x2C 56 #define REG_ADC_GC 0x30 57 #define REG_ADC_GS 0x34 58 59 #define ADC_TIMEOUT msecs_to_jiffies(100) 60 61 /* TSC registers */ 62 #define REG_TSC_BASIC_SETING 0x00 63 #define REG_TSC_PRE_CHARGE_TIME 0x10 64 #define REG_TSC_FLOW_CONTROL 0x20 65 #define REG_TSC_MEASURE_VALUE 0x30 66 #define REG_TSC_INT_EN 0x40 67 #define REG_TSC_INT_SIG_EN 0x50 68 #define REG_TSC_INT_STATUS 0x60 69 #define REG_TSC_DEBUG_MODE 0x70 70 #define REG_TSC_DEBUG_MODE2 0x80 71 72 /* TSC configuration registers field define */ 73 #define DETECT_4_WIRE_MODE (0x0 << 4) 74 #define AUTO_MEASURE 0x1 75 #define MEASURE_SIGNAL 0x1 76 #define DETECT_SIGNAL (0x1 << 4) 77 #define VALID_SIGNAL (0x1 << 8) 78 #define MEASURE_INT_EN 0x1 79 #define MEASURE_SIG_EN 0x1 80 #define VALID_SIG_EN (0x1 << 8) 81 #define DE_GLITCH_2 (0x2 << 29) 82 #define START_SENSE (0x1 << 12) 83 #define TSC_DISABLE (0x1 << 16) 84 #define DETECT_MODE 0x2 85 86 struct imx6ul_tsc { 87 struct device *dev; 88 struct input_dev *input; 89 void __iomem *tsc_regs; 90 void __iomem *adc_regs; 91 struct clk *tsc_clk; 92 struct clk *adc_clk; 93 struct gpio_desc *xnur_gpio; 94 95 u32 measure_delay_time; 96 u32 pre_charge_time; 97 bool average_enable; 98 u32 average_select; 99 100 struct completion completion; 101 }; 102 103 /* 104 * TSC module need ADC to get the measure value. So 105 * before config TSC, we should initialize ADC module. 106 */ 107 static int imx6ul_adc_init(struct imx6ul_tsc *tsc) 108 { 109 u32 adc_hc = 0; 110 u32 adc_gc; 111 u32 adc_gs; 112 u32 adc_cfg; 113 unsigned long timeout; 114 115 reinit_completion(&tsc->completion); 116 117 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG); 118 adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK); 119 adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK; 120 adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK); 121 adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE; 122 if (tsc->average_enable) { 123 adc_cfg &= ~ADC_AVGS_MASK; 124 adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT; 125 } 126 adc_cfg &= ~ADC_HARDWARE_TRIGGER; 127 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG); 128 129 /* enable calibration interrupt */ 130 adc_hc |= ADC_AIEN; 131 adc_hc |= ADC_CONV_DISABLE; 132 writel(adc_hc, tsc->adc_regs + REG_ADC_HC0); 133 134 /* start ADC calibration */ 135 adc_gc = readl(tsc->adc_regs + REG_ADC_GC); 136 adc_gc |= ADC_CAL; 137 if (tsc->average_enable) 138 adc_gc |= ADC_AVGE; 139 writel(adc_gc, tsc->adc_regs + REG_ADC_GC); 140 141 timeout = wait_for_completion_timeout 142 (&tsc->completion, ADC_TIMEOUT); 143 if (timeout == 0) { 144 dev_err(tsc->dev, "Timeout for adc calibration\n"); 145 return -ETIMEDOUT; 146 } 147 148 adc_gs = readl(tsc->adc_regs + REG_ADC_GS); 149 if (adc_gs & ADC_CALF) { 150 dev_err(tsc->dev, "ADC calibration failed\n"); 151 return -EINVAL; 152 } 153 154 /* TSC need the ADC work in hardware trigger */ 155 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG); 156 adc_cfg |= ADC_HARDWARE_TRIGGER; 157 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG); 158 159 return 0; 160 } 161 162 /* 163 * This is a TSC workaround. Currently TSC misconnect two 164 * ADC channels, this function remap channel configure for 165 * hardware trigger. 166 */ 167 static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc) 168 { 169 u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4; 170 171 adc_hc0 = DISABLE_CONVERSION_INT; 172 writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0); 173 174 adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4; 175 writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1); 176 177 adc_hc2 = DISABLE_CONVERSION_INT; 178 writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2); 179 180 adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1; 181 writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3); 182 183 adc_hc4 = DISABLE_CONVERSION_INT; 184 writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4); 185 } 186 187 /* 188 * TSC setting, confige the pre-charge time and measure delay time. 189 * different touch screen may need different pre-charge time and 190 * measure delay time. 191 */ 192 static void imx6ul_tsc_set(struct imx6ul_tsc *tsc) 193 { 194 u32 basic_setting = 0; 195 u32 start; 196 197 basic_setting |= tsc->measure_delay_time << 8; 198 basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE; 199 writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING); 200 201 writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2); 202 203 writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME); 204 writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN); 205 writel(MEASURE_SIG_EN | VALID_SIG_EN, 206 tsc->tsc_regs + REG_TSC_INT_SIG_EN); 207 208 /* start sense detection */ 209 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 210 start |= START_SENSE; 211 start &= ~TSC_DISABLE; 212 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 213 } 214 215 static int imx6ul_tsc_init(struct imx6ul_tsc *tsc) 216 { 217 int err; 218 219 err = imx6ul_adc_init(tsc); 220 if (err) 221 return err; 222 imx6ul_tsc_channel_config(tsc); 223 imx6ul_tsc_set(tsc); 224 225 return 0; 226 } 227 228 static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc) 229 { 230 u32 tsc_flow; 231 u32 adc_cfg; 232 233 /* TSC controller enters to idle status */ 234 tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 235 tsc_flow |= TSC_DISABLE; 236 writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 237 238 /* ADC controller enters to stop mode */ 239 adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0); 240 adc_cfg |= ADC_CONV_DISABLE; 241 writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0); 242 } 243 244 /* Delay some time (max 2ms), wait the pre-charge done. */ 245 static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc) 246 { 247 unsigned long timeout = jiffies + msecs_to_jiffies(2); 248 u32 state_machine; 249 u32 debug_mode2; 250 251 do { 252 if (time_after(jiffies, timeout)) 253 return false; 254 255 usleep_range(200, 400); 256 debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2); 257 state_machine = (debug_mode2 >> 20) & 0x7; 258 } while (state_machine != DETECT_MODE); 259 260 usleep_range(200, 400); 261 return true; 262 } 263 264 static irqreturn_t tsc_irq_fn(int irq, void *dev_id) 265 { 266 struct imx6ul_tsc *tsc = dev_id; 267 u32 status; 268 u32 value; 269 u32 x, y; 270 u32 start; 271 272 status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS); 273 274 /* write 1 to clear the bit measure-signal */ 275 writel(MEASURE_SIGNAL | DETECT_SIGNAL, 276 tsc->tsc_regs + REG_TSC_INT_STATUS); 277 278 /* It's a HW self-clean bit. Set this bit and start sense detection */ 279 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 280 start |= START_SENSE; 281 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 282 283 if (status & MEASURE_SIGNAL) { 284 value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE); 285 x = (value >> 16) & 0x0fff; 286 y = value & 0x0fff; 287 288 /* 289 * In detect mode, we can get the xnur gpio value, 290 * otherwise assume contact is stiull active. 291 */ 292 if (!tsc_wait_detect_mode(tsc) || 293 gpiod_get_value_cansleep(tsc->xnur_gpio)) { 294 input_report_key(tsc->input, BTN_TOUCH, 1); 295 input_report_abs(tsc->input, ABS_X, x); 296 input_report_abs(tsc->input, ABS_Y, y); 297 } else { 298 input_report_key(tsc->input, BTN_TOUCH, 0); 299 } 300 301 input_sync(tsc->input); 302 } 303 304 return IRQ_HANDLED; 305 } 306 307 static irqreturn_t adc_irq_fn(int irq, void *dev_id) 308 { 309 struct imx6ul_tsc *tsc = dev_id; 310 u32 coco; 311 u32 value; 312 313 coco = readl(tsc->adc_regs + REG_ADC_HS); 314 if (coco & 0x01) { 315 value = readl(tsc->adc_regs + REG_ADC_R0); 316 complete(&tsc->completion); 317 } 318 319 return IRQ_HANDLED; 320 } 321 322 static int imx6ul_tsc_open(struct input_dev *input_dev) 323 { 324 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); 325 int err; 326 327 err = clk_prepare_enable(tsc->adc_clk); 328 if (err) { 329 dev_err(tsc->dev, 330 "Could not prepare or enable the adc clock: %d\n", 331 err); 332 return err; 333 } 334 335 err = clk_prepare_enable(tsc->tsc_clk); 336 if (err) { 337 dev_err(tsc->dev, 338 "Could not prepare or enable the tsc clock: %d\n", 339 err); 340 clk_disable_unprepare(tsc->adc_clk); 341 return err; 342 } 343 344 return imx6ul_tsc_init(tsc); 345 } 346 347 static void imx6ul_tsc_close(struct input_dev *input_dev) 348 { 349 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); 350 351 imx6ul_tsc_disable(tsc); 352 353 clk_disable_unprepare(tsc->tsc_clk); 354 clk_disable_unprepare(tsc->adc_clk); 355 } 356 357 static int imx6ul_tsc_probe(struct platform_device *pdev) 358 { 359 struct device_node *np = pdev->dev.of_node; 360 struct imx6ul_tsc *tsc; 361 struct input_dev *input_dev; 362 struct resource *tsc_mem; 363 struct resource *adc_mem; 364 int err; 365 int tsc_irq; 366 int adc_irq; 367 u32 average_samples; 368 369 tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL); 370 if (!tsc) 371 return -ENOMEM; 372 373 input_dev = devm_input_allocate_device(&pdev->dev); 374 if (!input_dev) 375 return -ENOMEM; 376 377 input_dev->name = "iMX6UL Touchscreen Controller"; 378 input_dev->id.bustype = BUS_HOST; 379 380 input_dev->open = imx6ul_tsc_open; 381 input_dev->close = imx6ul_tsc_close; 382 383 input_set_capability(input_dev, EV_KEY, BTN_TOUCH); 384 input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0); 385 input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0); 386 387 input_set_drvdata(input_dev, tsc); 388 389 tsc->dev = &pdev->dev; 390 tsc->input = input_dev; 391 init_completion(&tsc->completion); 392 393 tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN); 394 if (IS_ERR(tsc->xnur_gpio)) { 395 err = PTR_ERR(tsc->xnur_gpio); 396 dev_err(&pdev->dev, 397 "failed to request GPIO tsc_X- (xnur): %d\n", err); 398 return err; 399 } 400 401 tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 402 tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem); 403 if (IS_ERR(tsc->tsc_regs)) { 404 err = PTR_ERR(tsc->tsc_regs); 405 dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err); 406 return err; 407 } 408 409 adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1); 410 tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem); 411 if (IS_ERR(tsc->adc_regs)) { 412 err = PTR_ERR(tsc->adc_regs); 413 dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err); 414 return err; 415 } 416 417 tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc"); 418 if (IS_ERR(tsc->tsc_clk)) { 419 err = PTR_ERR(tsc->tsc_clk); 420 dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err); 421 return err; 422 } 423 424 tsc->adc_clk = devm_clk_get(&pdev->dev, "adc"); 425 if (IS_ERR(tsc->adc_clk)) { 426 err = PTR_ERR(tsc->adc_clk); 427 dev_err(&pdev->dev, "failed getting adc clock: %d\n", err); 428 return err; 429 } 430 431 tsc_irq = platform_get_irq(pdev, 0); 432 if (tsc_irq < 0) { 433 dev_err(&pdev->dev, "no tsc irq resource?\n"); 434 return tsc_irq; 435 } 436 437 adc_irq = platform_get_irq(pdev, 1); 438 if (adc_irq < 0) { 439 dev_err(&pdev->dev, "no adc irq resource?\n"); 440 return adc_irq; 441 } 442 443 err = devm_request_threaded_irq(tsc->dev, tsc_irq, 444 NULL, tsc_irq_fn, IRQF_ONESHOT, 445 dev_name(&pdev->dev), tsc); 446 if (err) { 447 dev_err(&pdev->dev, 448 "failed requesting tsc irq %d: %d\n", 449 tsc_irq, err); 450 return err; 451 } 452 453 err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0, 454 dev_name(&pdev->dev), tsc); 455 if (err) { 456 dev_err(&pdev->dev, 457 "failed requesting adc irq %d: %d\n", 458 adc_irq, err); 459 return err; 460 } 461 462 err = of_property_read_u32(np, "measure-delay-time", 463 &tsc->measure_delay_time); 464 if (err) 465 tsc->measure_delay_time = 0xffff; 466 467 err = of_property_read_u32(np, "pre-charge-time", 468 &tsc->pre_charge_time); 469 if (err) 470 tsc->pre_charge_time = 0xfff; 471 472 err = of_property_read_u32(np, "touchscreen-average-samples", 473 &average_samples); 474 if (err) 475 average_samples = 1; 476 477 switch (average_samples) { 478 case 1: 479 tsc->average_enable = false; 480 tsc->average_select = 0; /* value unused; initialize anyway */ 481 break; 482 case 4: 483 case 8: 484 case 16: 485 case 32: 486 tsc->average_enable = true; 487 tsc->average_select = ilog2(average_samples) - 2; 488 break; 489 default: 490 dev_err(&pdev->dev, 491 "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n", 492 average_samples); 493 return -EINVAL; 494 } 495 496 err = input_register_device(tsc->input); 497 if (err) { 498 dev_err(&pdev->dev, 499 "failed to register input device: %d\n", err); 500 return err; 501 } 502 503 platform_set_drvdata(pdev, tsc); 504 return 0; 505 } 506 507 static int __maybe_unused imx6ul_tsc_suspend(struct device *dev) 508 { 509 struct platform_device *pdev = to_platform_device(dev); 510 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); 511 struct input_dev *input_dev = tsc->input; 512 513 mutex_lock(&input_dev->mutex); 514 515 if (input_dev->users) { 516 imx6ul_tsc_disable(tsc); 517 518 clk_disable_unprepare(tsc->tsc_clk); 519 clk_disable_unprepare(tsc->adc_clk); 520 } 521 522 mutex_unlock(&input_dev->mutex); 523 524 return 0; 525 } 526 527 static int __maybe_unused imx6ul_tsc_resume(struct device *dev) 528 { 529 struct platform_device *pdev = to_platform_device(dev); 530 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); 531 struct input_dev *input_dev = tsc->input; 532 int retval = 0; 533 534 mutex_lock(&input_dev->mutex); 535 536 if (input_dev->users) { 537 retval = clk_prepare_enable(tsc->adc_clk); 538 if (retval) 539 goto out; 540 541 retval = clk_prepare_enable(tsc->tsc_clk); 542 if (retval) { 543 clk_disable_unprepare(tsc->adc_clk); 544 goto out; 545 } 546 547 retval = imx6ul_tsc_init(tsc); 548 } 549 550 out: 551 mutex_unlock(&input_dev->mutex); 552 return retval; 553 } 554 555 static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops, 556 imx6ul_tsc_suspend, imx6ul_tsc_resume); 557 558 static const struct of_device_id imx6ul_tsc_match[] = { 559 { .compatible = "fsl,imx6ul-tsc", }, 560 { /* sentinel */ } 561 }; 562 MODULE_DEVICE_TABLE(of, imx6ul_tsc_match); 563 564 static struct platform_driver imx6ul_tsc_driver = { 565 .driver = { 566 .name = "imx6ul-tsc", 567 .of_match_table = imx6ul_tsc_match, 568 .pm = &imx6ul_tsc_pm_ops, 569 }, 570 .probe = imx6ul_tsc_probe, 571 }; 572 module_platform_driver(imx6ul_tsc_driver); 573 574 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>"); 575 MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver"); 576 MODULE_LICENSE("GPL v2"); 577