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; 307 308 coco = readl(tsc->adc_regs + REG_ADC_HS); 309 if (coco & 0x01) { 310 readl(tsc->adc_regs + REG_ADC_R0); 311 complete(&tsc->completion); 312 } 313 314 return IRQ_HANDLED; 315 } 316 317 static int imx6ul_tsc_start(struct imx6ul_tsc *tsc) 318 { 319 int err; 320 321 err = clk_prepare_enable(tsc->adc_clk); 322 if (err) { 323 dev_err(tsc->dev, 324 "Could not prepare or enable the adc clock: %d\n", 325 err); 326 return err; 327 } 328 329 err = clk_prepare_enable(tsc->tsc_clk); 330 if (err) { 331 dev_err(tsc->dev, 332 "Could not prepare or enable the tsc clock: %d\n", 333 err); 334 goto disable_adc_clk; 335 } 336 337 err = imx6ul_tsc_init(tsc); 338 if (err) 339 goto disable_tsc_clk; 340 341 return 0; 342 343 disable_tsc_clk: 344 clk_disable_unprepare(tsc->tsc_clk); 345 disable_adc_clk: 346 clk_disable_unprepare(tsc->adc_clk); 347 return err; 348 } 349 350 static void imx6ul_tsc_stop(struct imx6ul_tsc *tsc) 351 { 352 imx6ul_tsc_disable(tsc); 353 354 clk_disable_unprepare(tsc->tsc_clk); 355 clk_disable_unprepare(tsc->adc_clk); 356 } 357 358 359 static int imx6ul_tsc_open(struct input_dev *input_dev) 360 { 361 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); 362 363 return imx6ul_tsc_start(tsc); 364 } 365 366 static void imx6ul_tsc_close(struct input_dev *input_dev) 367 { 368 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); 369 370 imx6ul_tsc_stop(tsc); 371 } 372 373 static int imx6ul_tsc_probe(struct platform_device *pdev) 374 { 375 struct device_node *np = pdev->dev.of_node; 376 struct imx6ul_tsc *tsc; 377 struct input_dev *input_dev; 378 int err; 379 int tsc_irq; 380 int adc_irq; 381 u32 average_samples; 382 383 tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL); 384 if (!tsc) 385 return -ENOMEM; 386 387 input_dev = devm_input_allocate_device(&pdev->dev); 388 if (!input_dev) 389 return -ENOMEM; 390 391 input_dev->name = "iMX6UL Touchscreen Controller"; 392 input_dev->id.bustype = BUS_HOST; 393 394 input_dev->open = imx6ul_tsc_open; 395 input_dev->close = imx6ul_tsc_close; 396 397 input_set_capability(input_dev, EV_KEY, BTN_TOUCH); 398 input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0); 399 input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0); 400 401 input_set_drvdata(input_dev, tsc); 402 403 tsc->dev = &pdev->dev; 404 tsc->input = input_dev; 405 init_completion(&tsc->completion); 406 407 tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN); 408 if (IS_ERR(tsc->xnur_gpio)) { 409 err = PTR_ERR(tsc->xnur_gpio); 410 dev_err(&pdev->dev, 411 "failed to request GPIO tsc_X- (xnur): %d\n", err); 412 return err; 413 } 414 415 tsc->tsc_regs = devm_platform_ioremap_resource(pdev, 0); 416 if (IS_ERR(tsc->tsc_regs)) { 417 err = PTR_ERR(tsc->tsc_regs); 418 dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err); 419 return err; 420 } 421 422 tsc->adc_regs = devm_platform_ioremap_resource(pdev, 1); 423 if (IS_ERR(tsc->adc_regs)) { 424 err = PTR_ERR(tsc->adc_regs); 425 dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err); 426 return err; 427 } 428 429 tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc"); 430 if (IS_ERR(tsc->tsc_clk)) { 431 err = PTR_ERR(tsc->tsc_clk); 432 dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err); 433 return err; 434 } 435 436 tsc->adc_clk = devm_clk_get(&pdev->dev, "adc"); 437 if (IS_ERR(tsc->adc_clk)) { 438 err = PTR_ERR(tsc->adc_clk); 439 dev_err(&pdev->dev, "failed getting adc clock: %d\n", err); 440 return err; 441 } 442 443 tsc_irq = platform_get_irq(pdev, 0); 444 if (tsc_irq < 0) 445 return tsc_irq; 446 447 adc_irq = platform_get_irq(pdev, 1); 448 if (adc_irq < 0) 449 return adc_irq; 450 451 err = devm_request_threaded_irq(tsc->dev, tsc_irq, 452 NULL, tsc_irq_fn, IRQF_ONESHOT, 453 dev_name(&pdev->dev), tsc); 454 if (err) { 455 dev_err(&pdev->dev, 456 "failed requesting tsc irq %d: %d\n", 457 tsc_irq, err); 458 return err; 459 } 460 461 err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0, 462 dev_name(&pdev->dev), tsc); 463 if (err) { 464 dev_err(&pdev->dev, 465 "failed requesting adc irq %d: %d\n", 466 adc_irq, err); 467 return err; 468 } 469 470 err = of_property_read_u32(np, "measure-delay-time", 471 &tsc->measure_delay_time); 472 if (err) 473 tsc->measure_delay_time = 0xffff; 474 475 err = of_property_read_u32(np, "pre-charge-time", 476 &tsc->pre_charge_time); 477 if (err) 478 tsc->pre_charge_time = 0xfff; 479 480 err = of_property_read_u32(np, "touchscreen-average-samples", 481 &average_samples); 482 if (err) 483 average_samples = 1; 484 485 switch (average_samples) { 486 case 1: 487 tsc->average_enable = false; 488 tsc->average_select = 0; /* value unused; initialize anyway */ 489 break; 490 case 4: 491 case 8: 492 case 16: 493 case 32: 494 tsc->average_enable = true; 495 tsc->average_select = ilog2(average_samples) - 2; 496 break; 497 default: 498 dev_err(&pdev->dev, 499 "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n", 500 average_samples); 501 return -EINVAL; 502 } 503 504 err = input_register_device(tsc->input); 505 if (err) { 506 dev_err(&pdev->dev, 507 "failed to register input device: %d\n", err); 508 return err; 509 } 510 511 platform_set_drvdata(pdev, tsc); 512 return 0; 513 } 514 515 static int imx6ul_tsc_suspend(struct device *dev) 516 { 517 struct platform_device *pdev = to_platform_device(dev); 518 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); 519 struct input_dev *input_dev = tsc->input; 520 521 mutex_lock(&input_dev->mutex); 522 523 if (input_device_enabled(input_dev)) 524 imx6ul_tsc_stop(tsc); 525 526 mutex_unlock(&input_dev->mutex); 527 528 return 0; 529 } 530 531 static int imx6ul_tsc_resume(struct device *dev) 532 { 533 struct platform_device *pdev = to_platform_device(dev); 534 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); 535 struct input_dev *input_dev = tsc->input; 536 int retval = 0; 537 538 mutex_lock(&input_dev->mutex); 539 540 if (input_device_enabled(input_dev)) 541 retval = imx6ul_tsc_start(tsc); 542 543 mutex_unlock(&input_dev->mutex); 544 545 return retval; 546 } 547 548 static DEFINE_SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops, 549 imx6ul_tsc_suspend, imx6ul_tsc_resume); 550 551 static const struct of_device_id imx6ul_tsc_match[] = { 552 { .compatible = "fsl,imx6ul-tsc", }, 553 { /* sentinel */ } 554 }; 555 MODULE_DEVICE_TABLE(of, imx6ul_tsc_match); 556 557 static struct platform_driver imx6ul_tsc_driver = { 558 .driver = { 559 .name = "imx6ul-tsc", 560 .of_match_table = imx6ul_tsc_match, 561 .pm = pm_sleep_ptr(&imx6ul_tsc_pm_ops), 562 }, 563 .probe = imx6ul_tsc_probe, 564 }; 565 module_platform_driver(imx6ul_tsc_driver); 566 567 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>"); 568 MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver"); 569 MODULE_LICENSE("GPL v2"); 570