1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // Freescale i.MX6UL touchscreen controller driver 4 // 5 // Copyright (C) 2015 Freescale Semiconductor, Inc. 6 7 #include <linux/errno.h> 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/gpio/consumer.h> 11 #include <linux/input.h> 12 #include <linux/slab.h> 13 #include <linux/completion.h> 14 #include <linux/delay.h> 15 #include <linux/of.h> 16 #include <linux/interrupt.h> 17 #include <linux/platform_device.h> 18 #include <linux/clk.h> 19 #include <linux/io.h> 20 #include <linux/log2.h> 21 22 /* ADC configuration registers field define */ 23 #define ADC_AIEN (0x1 << 7) 24 #define ADC_CONV_DISABLE 0x1F 25 #define ADC_AVGE (0x1 << 5) 26 #define ADC_CAL (0x1 << 7) 27 #define ADC_CALF 0x2 28 #define ADC_12BIT_MODE (0x2 << 2) 29 #define ADC_CONV_MODE_MASK (0x3 << 2) 30 #define ADC_IPG_CLK 0x00 31 #define ADC_INPUT_CLK_MASK 0x3 32 #define ADC_CLK_DIV_8 (0x03 << 5) 33 #define ADC_CLK_DIV_MASK (0x3 << 5) 34 #define ADC_SHORT_SAMPLE_MODE (0x0 << 4) 35 #define ADC_SAMPLE_MODE_MASK (0x1 << 4) 36 #define ADC_HARDWARE_TRIGGER (0x1 << 13) 37 #define ADC_AVGS_SHIFT 14 38 #define ADC_AVGS_MASK (0x3 << 14) 39 #define SELECT_CHANNEL_4 0x04 40 #define SELECT_CHANNEL_1 0x01 41 #define DISABLE_CONVERSION_INT (0x0 << 7) 42 43 /* ADC registers */ 44 #define REG_ADC_HC0 0x00 45 #define REG_ADC_HC1 0x04 46 #define REG_ADC_HC2 0x08 47 #define REG_ADC_HC3 0x0C 48 #define REG_ADC_HC4 0x10 49 #define REG_ADC_HS 0x14 50 #define REG_ADC_R0 0x18 51 #define REG_ADC_CFG 0x2C 52 #define REG_ADC_GC 0x30 53 #define REG_ADC_GS 0x34 54 55 #define ADC_TIMEOUT msecs_to_jiffies(100) 56 57 /* TSC registers */ 58 #define REG_TSC_BASIC_SETING 0x00 59 #define REG_TSC_PRE_CHARGE_TIME 0x10 60 #define REG_TSC_FLOW_CONTROL 0x20 61 #define REG_TSC_MEASURE_VALUE 0x30 62 #define REG_TSC_INT_EN 0x40 63 #define REG_TSC_INT_SIG_EN 0x50 64 #define REG_TSC_INT_STATUS 0x60 65 #define REG_TSC_DEBUG_MODE 0x70 66 #define REG_TSC_DEBUG_MODE2 0x80 67 68 /* TSC configuration registers field define */ 69 #define DETECT_4_WIRE_MODE (0x0 << 4) 70 #define AUTO_MEASURE 0x1 71 #define MEASURE_SIGNAL 0x1 72 #define DETECT_SIGNAL (0x1 << 4) 73 #define VALID_SIGNAL (0x1 << 8) 74 #define MEASURE_INT_EN 0x1 75 #define MEASURE_SIG_EN 0x1 76 #define VALID_SIG_EN (0x1 << 8) 77 #define DE_GLITCH_2 (0x2 << 29) 78 #define START_SENSE (0x1 << 12) 79 #define TSC_DISABLE (0x1 << 16) 80 #define DETECT_MODE 0x2 81 82 struct imx6ul_tsc { 83 struct device *dev; 84 struct input_dev *input; 85 void __iomem *tsc_regs; 86 void __iomem *adc_regs; 87 struct clk *tsc_clk; 88 struct clk *adc_clk; 89 struct gpio_desc *xnur_gpio; 90 91 u32 measure_delay_time; 92 u32 pre_charge_time; 93 bool average_enable; 94 u32 average_select; 95 96 struct completion completion; 97 }; 98 99 /* 100 * TSC module need ADC to get the measure value. So 101 * before config TSC, we should initialize ADC module. 102 */ 103 static int imx6ul_adc_init(struct imx6ul_tsc *tsc) 104 { 105 u32 adc_hc = 0; 106 u32 adc_gc; 107 u32 adc_gs; 108 u32 adc_cfg; 109 unsigned long timeout; 110 111 reinit_completion(&tsc->completion); 112 113 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG); 114 adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK); 115 adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK; 116 adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK); 117 adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE; 118 if (tsc->average_enable) { 119 adc_cfg &= ~ADC_AVGS_MASK; 120 adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT; 121 } 122 adc_cfg &= ~ADC_HARDWARE_TRIGGER; 123 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG); 124 125 /* enable calibration interrupt */ 126 adc_hc |= ADC_AIEN; 127 adc_hc |= ADC_CONV_DISABLE; 128 writel(adc_hc, tsc->adc_regs + REG_ADC_HC0); 129 130 /* start ADC calibration */ 131 adc_gc = readl(tsc->adc_regs + REG_ADC_GC); 132 adc_gc |= ADC_CAL; 133 if (tsc->average_enable) 134 adc_gc |= ADC_AVGE; 135 writel(adc_gc, tsc->adc_regs + REG_ADC_GC); 136 137 timeout = wait_for_completion_timeout 138 (&tsc->completion, ADC_TIMEOUT); 139 if (timeout == 0) { 140 dev_err(tsc->dev, "Timeout for adc calibration\n"); 141 return -ETIMEDOUT; 142 } 143 144 adc_gs = readl(tsc->adc_regs + REG_ADC_GS); 145 if (adc_gs & ADC_CALF) { 146 dev_err(tsc->dev, "ADC calibration failed\n"); 147 return -EINVAL; 148 } 149 150 /* TSC need the ADC work in hardware trigger */ 151 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG); 152 adc_cfg |= ADC_HARDWARE_TRIGGER; 153 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG); 154 155 return 0; 156 } 157 158 /* 159 * This is a TSC workaround. Currently TSC misconnect two 160 * ADC channels, this function remap channel configure for 161 * hardware trigger. 162 */ 163 static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc) 164 { 165 u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4; 166 167 adc_hc0 = DISABLE_CONVERSION_INT; 168 writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0); 169 170 adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4; 171 writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1); 172 173 adc_hc2 = DISABLE_CONVERSION_INT; 174 writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2); 175 176 adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1; 177 writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3); 178 179 adc_hc4 = DISABLE_CONVERSION_INT; 180 writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4); 181 } 182 183 /* 184 * TSC setting, confige the pre-charge time and measure delay time. 185 * different touch screen may need different pre-charge time and 186 * measure delay time. 187 */ 188 static void imx6ul_tsc_set(struct imx6ul_tsc *tsc) 189 { 190 u32 basic_setting = 0; 191 u32 start; 192 193 basic_setting |= tsc->measure_delay_time << 8; 194 basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE; 195 writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING); 196 197 writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2); 198 199 writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME); 200 writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN); 201 writel(MEASURE_SIG_EN | VALID_SIG_EN, 202 tsc->tsc_regs + REG_TSC_INT_SIG_EN); 203 204 /* start sense detection */ 205 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 206 start |= START_SENSE; 207 start &= ~TSC_DISABLE; 208 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 209 } 210 211 static int imx6ul_tsc_init(struct imx6ul_tsc *tsc) 212 { 213 int err; 214 215 err = imx6ul_adc_init(tsc); 216 if (err) 217 return err; 218 imx6ul_tsc_channel_config(tsc); 219 imx6ul_tsc_set(tsc); 220 221 return 0; 222 } 223 224 static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc) 225 { 226 u32 tsc_flow; 227 u32 adc_cfg; 228 229 /* TSC controller enters to idle status */ 230 tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 231 tsc_flow |= TSC_DISABLE; 232 writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 233 234 /* ADC controller enters to stop mode */ 235 adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0); 236 adc_cfg |= ADC_CONV_DISABLE; 237 writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0); 238 } 239 240 /* Delay some time (max 2ms), wait the pre-charge done. */ 241 static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc) 242 { 243 unsigned long timeout = jiffies + msecs_to_jiffies(2); 244 u32 state_machine; 245 u32 debug_mode2; 246 247 do { 248 if (time_after(jiffies, timeout)) 249 return false; 250 251 usleep_range(200, 400); 252 debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2); 253 state_machine = (debug_mode2 >> 20) & 0x7; 254 } while (state_machine != DETECT_MODE); 255 256 usleep_range(200, 400); 257 return true; 258 } 259 260 static irqreturn_t tsc_irq_fn(int irq, void *dev_id) 261 { 262 struct imx6ul_tsc *tsc = dev_id; 263 u32 status; 264 u32 value; 265 u32 x, y; 266 u32 start; 267 268 status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS); 269 270 /* write 1 to clear the bit measure-signal */ 271 writel(MEASURE_SIGNAL | DETECT_SIGNAL, 272 tsc->tsc_regs + REG_TSC_INT_STATUS); 273 274 /* It's a HW self-clean bit. Set this bit and start sense detection */ 275 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 276 start |= START_SENSE; 277 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); 278 279 if (status & MEASURE_SIGNAL) { 280 value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE); 281 x = (value >> 16) & 0x0fff; 282 y = value & 0x0fff; 283 284 /* 285 * In detect mode, we can get the xnur gpio value, 286 * otherwise assume contact is stiull active. 287 */ 288 if (!tsc_wait_detect_mode(tsc) || 289 gpiod_get_value_cansleep(tsc->xnur_gpio)) { 290 input_report_key(tsc->input, BTN_TOUCH, 1); 291 input_report_abs(tsc->input, ABS_X, x); 292 input_report_abs(tsc->input, ABS_Y, y); 293 } else { 294 input_report_key(tsc->input, BTN_TOUCH, 0); 295 } 296 297 input_sync(tsc->input); 298 } 299 300 return IRQ_HANDLED; 301 } 302 303 static irqreturn_t adc_irq_fn(int irq, void *dev_id) 304 { 305 struct imx6ul_tsc *tsc = dev_id; 306 u32 coco; 307 u32 value; 308 309 coco = readl(tsc->adc_regs + REG_ADC_HS); 310 if (coco & 0x01) { 311 value = readl(tsc->adc_regs + REG_ADC_R0); 312 complete(&tsc->completion); 313 } 314 315 return IRQ_HANDLED; 316 } 317 318 static int imx6ul_tsc_open(struct input_dev *input_dev) 319 { 320 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); 321 int err; 322 323 err = clk_prepare_enable(tsc->adc_clk); 324 if (err) { 325 dev_err(tsc->dev, 326 "Could not prepare or enable the adc clock: %d\n", 327 err); 328 return err; 329 } 330 331 err = clk_prepare_enable(tsc->tsc_clk); 332 if (err) { 333 dev_err(tsc->dev, 334 "Could not prepare or enable the tsc clock: %d\n", 335 err); 336 goto disable_adc_clk; 337 } 338 339 err = imx6ul_tsc_init(tsc); 340 if (err) 341 goto disable_tsc_clk; 342 343 return 0; 344 345 disable_tsc_clk: 346 clk_disable_unprepare(tsc->tsc_clk); 347 disable_adc_clk: 348 clk_disable_unprepare(tsc->adc_clk); 349 return err; 350 } 351 352 static void imx6ul_tsc_close(struct input_dev *input_dev) 353 { 354 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); 355 356 imx6ul_tsc_disable(tsc); 357 358 clk_disable_unprepare(tsc->tsc_clk); 359 clk_disable_unprepare(tsc->adc_clk); 360 } 361 362 static int imx6ul_tsc_probe(struct platform_device *pdev) 363 { 364 struct device_node *np = pdev->dev.of_node; 365 struct imx6ul_tsc *tsc; 366 struct input_dev *input_dev; 367 int err; 368 int tsc_irq; 369 int adc_irq; 370 u32 average_samples; 371 372 tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL); 373 if (!tsc) 374 return -ENOMEM; 375 376 input_dev = devm_input_allocate_device(&pdev->dev); 377 if (!input_dev) 378 return -ENOMEM; 379 380 input_dev->name = "iMX6UL Touchscreen Controller"; 381 input_dev->id.bustype = BUS_HOST; 382 383 input_dev->open = imx6ul_tsc_open; 384 input_dev->close = imx6ul_tsc_close; 385 386 input_set_capability(input_dev, EV_KEY, BTN_TOUCH); 387 input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0); 388 input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0); 389 390 input_set_drvdata(input_dev, tsc); 391 392 tsc->dev = &pdev->dev; 393 tsc->input = input_dev; 394 init_completion(&tsc->completion); 395 396 tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN); 397 if (IS_ERR(tsc->xnur_gpio)) { 398 err = PTR_ERR(tsc->xnur_gpio); 399 dev_err(&pdev->dev, 400 "failed to request GPIO tsc_X- (xnur): %d\n", err); 401 return err; 402 } 403 404 tsc->tsc_regs = devm_platform_ioremap_resource(pdev, 0); 405 if (IS_ERR(tsc->tsc_regs)) { 406 err = PTR_ERR(tsc->tsc_regs); 407 dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err); 408 return err; 409 } 410 411 tsc->adc_regs = devm_platform_ioremap_resource(pdev, 1); 412 if (IS_ERR(tsc->adc_regs)) { 413 err = PTR_ERR(tsc->adc_regs); 414 dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err); 415 return err; 416 } 417 418 tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc"); 419 if (IS_ERR(tsc->tsc_clk)) { 420 err = PTR_ERR(tsc->tsc_clk); 421 dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err); 422 return err; 423 } 424 425 tsc->adc_clk = devm_clk_get(&pdev->dev, "adc"); 426 if (IS_ERR(tsc->adc_clk)) { 427 err = PTR_ERR(tsc->adc_clk); 428 dev_err(&pdev->dev, "failed getting adc clock: %d\n", err); 429 return err; 430 } 431 432 tsc_irq = platform_get_irq(pdev, 0); 433 if (tsc_irq < 0) 434 return tsc_irq; 435 436 adc_irq = platform_get_irq(pdev, 1); 437 if (adc_irq < 0) 438 return adc_irq; 439 440 err = devm_request_threaded_irq(tsc->dev, tsc_irq, 441 NULL, tsc_irq_fn, IRQF_ONESHOT, 442 dev_name(&pdev->dev), tsc); 443 if (err) { 444 dev_err(&pdev->dev, 445 "failed requesting tsc irq %d: %d\n", 446 tsc_irq, err); 447 return err; 448 } 449 450 err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0, 451 dev_name(&pdev->dev), tsc); 452 if (err) { 453 dev_err(&pdev->dev, 454 "failed requesting adc irq %d: %d\n", 455 adc_irq, err); 456 return err; 457 } 458 459 err = of_property_read_u32(np, "measure-delay-time", 460 &tsc->measure_delay_time); 461 if (err) 462 tsc->measure_delay_time = 0xffff; 463 464 err = of_property_read_u32(np, "pre-charge-time", 465 &tsc->pre_charge_time); 466 if (err) 467 tsc->pre_charge_time = 0xfff; 468 469 err = of_property_read_u32(np, "touchscreen-average-samples", 470 &average_samples); 471 if (err) 472 average_samples = 1; 473 474 switch (average_samples) { 475 case 1: 476 tsc->average_enable = false; 477 tsc->average_select = 0; /* value unused; initialize anyway */ 478 break; 479 case 4: 480 case 8: 481 case 16: 482 case 32: 483 tsc->average_enable = true; 484 tsc->average_select = ilog2(average_samples) - 2; 485 break; 486 default: 487 dev_err(&pdev->dev, 488 "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n", 489 average_samples); 490 return -EINVAL; 491 } 492 493 err = input_register_device(tsc->input); 494 if (err) { 495 dev_err(&pdev->dev, 496 "failed to register input device: %d\n", err); 497 return err; 498 } 499 500 platform_set_drvdata(pdev, tsc); 501 return 0; 502 } 503 504 static int __maybe_unused imx6ul_tsc_suspend(struct device *dev) 505 { 506 struct platform_device *pdev = to_platform_device(dev); 507 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); 508 struct input_dev *input_dev = tsc->input; 509 510 mutex_lock(&input_dev->mutex); 511 512 if (input_dev->users) { 513 imx6ul_tsc_disable(tsc); 514 515 clk_disable_unprepare(tsc->tsc_clk); 516 clk_disable_unprepare(tsc->adc_clk); 517 } 518 519 mutex_unlock(&input_dev->mutex); 520 521 return 0; 522 } 523 524 static int __maybe_unused imx6ul_tsc_resume(struct device *dev) 525 { 526 struct platform_device *pdev = to_platform_device(dev); 527 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); 528 struct input_dev *input_dev = tsc->input; 529 int retval = 0; 530 531 mutex_lock(&input_dev->mutex); 532 533 if (input_dev->users) { 534 retval = clk_prepare_enable(tsc->adc_clk); 535 if (retval) 536 goto out; 537 538 retval = clk_prepare_enable(tsc->tsc_clk); 539 if (retval) { 540 clk_disable_unprepare(tsc->adc_clk); 541 goto out; 542 } 543 544 retval = imx6ul_tsc_init(tsc); 545 } 546 547 out: 548 mutex_unlock(&input_dev->mutex); 549 return retval; 550 } 551 552 static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops, 553 imx6ul_tsc_suspend, imx6ul_tsc_resume); 554 555 static const struct of_device_id imx6ul_tsc_match[] = { 556 { .compatible = "fsl,imx6ul-tsc", }, 557 { /* sentinel */ } 558 }; 559 MODULE_DEVICE_TABLE(of, imx6ul_tsc_match); 560 561 static struct platform_driver imx6ul_tsc_driver = { 562 .driver = { 563 .name = "imx6ul-tsc", 564 .of_match_table = imx6ul_tsc_match, 565 .pm = &imx6ul_tsc_pm_ops, 566 }, 567 .probe = imx6ul_tsc_probe, 568 }; 569 module_platform_driver(imx6ul_tsc_driver); 570 571 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>"); 572 MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver"); 573 MODULE_LICENSE("GPL v2"); 574