drivers/input/touchscreen/s3c2410_ts.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Samsung S3C24XX touchscreen driver
   4  *
   5  * Copyright 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
   6  * Copyright 2008 Ben Dooks <ben-linux@fluff.org>
   7  * Copyright 2009 Simtec Electronics <linux@simtec.co.uk>
   8  *
   9  * Additional work by Herbert Pötzl <herbert@13thfloor.at> and
  10  * Harald Welte <laforge@openmoko.org>
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/input.h>
  17 #include <linux/delay.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/clk.h>
  21 #include <linux/io.h>
  22
  23 #include <linux/soc/samsung/s3c-adc.h>
  24 #include <linux/platform_data/touchscreen-s3c2410.h>
  25
  26 #define S3C2410_ADCCON                  (0x00)
  27 #define S3C2410_ADCTSC                  (0x04)
  28 #define S3C2410_ADCDLY                  (0x08)
  29 #define S3C2410_ADCDAT0                 (0x0C)
  30 #define S3C2410_ADCDAT1                 (0x10)
  31 #define S3C64XX_ADCUPDN                 (0x14)
  32 #define S3C2443_ADCMUX                  (0x18)
  33 #define S3C64XX_ADCCLRINT               (0x18)
  34 #define S5P_ADCMUX                      (0x1C)
  35 #define S3C64XX_ADCCLRINTPNDNUP         (0x20)
  36
  37 /* ADCTSC Register Bits */
  38 #define S3C2443_ADCTSC_UD_SEN           (1 << 8)
  39 #define S3C2410_ADCTSC_YM_SEN           (1<<7)
  40 #define S3C2410_ADCTSC_YP_SEN           (1<<6)
  41 #define S3C2410_ADCTSC_XM_SEN           (1<<5)
  42 #define S3C2410_ADCTSC_XP_SEN           (1<<4)
  43 #define S3C2410_ADCTSC_PULL_UP_DISABLE  (1<<3)
  44 #define S3C2410_ADCTSC_AUTO_PST         (1<<2)
  45 #define S3C2410_ADCTSC_XY_PST(x)        (((x)&0x3)<<0)
  46
  47 /* ADCDAT0 Bits */
  48 #define S3C2410_ADCDAT0_UPDOWN          (1<<15)
  49 #define S3C2410_ADCDAT0_AUTO_PST        (1<<14)
  50 #define S3C2410_ADCDAT0_XY_PST          (0x3<<12)
  51 #define S3C2410_ADCDAT0_XPDATA_MASK     (0x03FF)
  52
  53 /* ADCDAT1 Bits */
  54 #define S3C2410_ADCDAT1_UPDOWN          (1<<15)
  55 #define S3C2410_ADCDAT1_AUTO_PST        (1<<14)
  56 #define S3C2410_ADCDAT1_XY_PST          (0x3<<12)
  57 #define S3C2410_ADCDAT1_YPDATA_MASK     (0x03FF)
  58
  59
  60 #define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
  61
  62 #define INT_DOWN        (0)
  63 #define INT_UP          (1 << 8)
  64
  65 #define WAIT4INT        (S3C2410_ADCTSC_YM_SEN | \
  66                          S3C2410_ADCTSC_YP_SEN | \
  67                          S3C2410_ADCTSC_XP_SEN | \
  68                          S3C2410_ADCTSC_XY_PST(3))
  69
  70 #define AUTOPST         (S3C2410_ADCTSC_YM_SEN | \
  71                          S3C2410_ADCTSC_YP_SEN | \
  72                          S3C2410_ADCTSC_XP_SEN | \
  73                          S3C2410_ADCTSC_AUTO_PST | \
  74                          S3C2410_ADCTSC_XY_PST(0))
  75
  76 #define FEAT_PEN_IRQ    (1 << 0)        /* HAS ADCCLRINTPNDNUP */
  77
  78 /* Per-touchscreen data. */
  79
  80 /**
  81  * struct s3c2410ts - driver touchscreen state.
  82  * @client: The ADC client we registered with the core driver.
  83  * @dev: The device we are bound to.
  84  * @input: The input device we registered with the input subsystem.
  85  * @clock: The clock for the adc.
  86  * @io: Pointer to the IO base.
  87  * @xp: The accumulated X position data.
  88  * @yp: The accumulated Y position data.
  89  * @irq_tc: The interrupt number for pen up/down interrupt
  90  * @count: The number of samples collected.
  91  * @shift: The log2 of the maximum count to read in one go.
  92  * @features: The features supported by the TSADC MOdule.
  93  */
  94 struct s3c2410ts {
  95         struct s3c_adc_client *client;
  96         struct device *dev;
  97         struct input_dev *input;
  98         struct clk *clock;
  99         void __iomem *io;
 100         unsigned long xp;
 101         unsigned long yp;
 102         int irq_tc;
 103         int count;
 104         int shift;
 105         int features;
 106 };
 107
 108 static struct s3c2410ts ts;
 109
 110 /**
 111  * get_down - return the down state of the pen
 112  * @data0: The data read from ADCDAT0 register.
 113  * @data1: The data read from ADCDAT1 register.
 114  *
 115  * Return non-zero if both readings show that the pen is down.
 116  */
 117 static inline bool get_down(unsigned long data0, unsigned long data1)
 118 {
 119         /* returns true if both data values show stylus down */
 120         return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
 121                 !(data1 & S3C2410_ADCDAT0_UPDOWN));
 122 }
 123
 124 static void touch_timer_fire(struct timer_list *unused)
 125 {
 126         unsigned long data0;
 127         unsigned long data1;
 128         bool down;
 129
 130         data0 = readl(ts.io + S3C2410_ADCDAT0);
 131         data1 = readl(ts.io + S3C2410_ADCDAT1);
 132
 133         down = get_down(data0, data1);
 134
 135         if (down) {
 136                 if (ts.count == (1 << ts.shift)) {
 137                         ts.xp >>= ts.shift;
 138                         ts.yp >>= ts.shift;
 139
 140                         dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
 141                                 __func__, ts.xp, ts.yp, ts.count);
 142
 143                         input_report_abs(ts.input, ABS_X, ts.xp);
 144                         input_report_abs(ts.input, ABS_Y, ts.yp);
 145
 146                         input_report_key(ts.input, BTN_TOUCH, 1);
 147                         input_sync(ts.input);
 148
 149                         ts.xp = 0;
 150                         ts.yp = 0;
 151                         ts.count = 0;
 152                 }
 153
 154                 s3c_adc_start(ts.client, 0, 1 << ts.shift);
 155         } else {
 156                 ts.xp = 0;
 157                 ts.yp = 0;
 158                 ts.count = 0;
 159
 160                 input_report_key(ts.input, BTN_TOUCH, 0);
 161                 input_sync(ts.input);
 162
 163                 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 164         }
 165 }
 166
 167 static DEFINE_TIMER(touch_timer, touch_timer_fire);
 168
 169 /**
 170  * stylus_irq - touchscreen stylus event interrupt
 171  * @irq: The interrupt number
 172  * @dev_id: The device ID.
 173  *
 174  * Called when the IRQ_TC is fired for a pen up or down event.
 175  */
 176 static irqreturn_t stylus_irq(int irq, void *dev_id)
 177 {
 178         unsigned long data0;
 179         unsigned long data1;
 180         bool down;
 181
 182         data0 = readl(ts.io + S3C2410_ADCDAT0);
 183         data1 = readl(ts.io + S3C2410_ADCDAT1);
 184
 185         down = get_down(data0, data1);
 186
 187         /* TODO we should never get an interrupt with down set while
 188          * the timer is running, but maybe we ought to verify that the
 189          * timer isn't running anyways. */
 190
 191         if (down)
 192                 s3c_adc_start(ts.client, 0, 1 << ts.shift);
 193         else
 194                 dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);
 195
 196         if (ts.features & FEAT_PEN_IRQ) {
 197                 /* Clear pen down/up interrupt */
 198                 writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
 199         }
 200
 201         return IRQ_HANDLED;
 202 }
 203
 204 /**
 205  * s3c24xx_ts_conversion - ADC conversion callback
 206  * @client: The client that was registered with the ADC core.
 207  * @data0: The reading from ADCDAT0.
 208  * @data1: The reading from ADCDAT1.
 209  * @left: The number of samples left.
 210  *
 211  * Called when a conversion has finished.
 212  */
 213 static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
 214                                   unsigned data0, unsigned data1,
 215                                   unsigned *left)
 216 {
 217         dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
 218
 219         ts.xp += data0;
 220         ts.yp += data1;
 221
 222         ts.count++;
 223
 224         /* From tests, it seems that it is unlikely to get a pen-up
 225          * event during the conversion process which means we can
 226          * ignore any pen-up events with less than the requisite
 227          * count done.
 228          *
 229          * In several thousand conversions, no pen-ups where detected
 230          * before count completed.
 231          */
 232 }
 233
 234 /**
 235  * s3c24xx_ts_select - ADC selection callback.
 236  * @client: The client that was registered with the ADC core.
 237  * @select: The reason for select.
 238  *
 239  * Called when the ADC core selects (or deslects) us as a client.
 240  */
 241 static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
 242 {
 243         if (select) {
 244                 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
 245                        ts.io + S3C2410_ADCTSC);
 246         } else {
 247                 mod_timer(&touch_timer, jiffies+1);
 248                 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
 249         }
 250 }
 251
 252 /**
 253  * s3c2410ts_probe - device core probe entry point
 254  * @pdev: The device we are being bound to.
 255  *
 256  * Initialise, find and allocate any resources we need to run and then
 257  * register with the ADC and input systems.
 258  */
 259 static int s3c2410ts_probe(struct platform_device *pdev)
 260 {
 261         struct s3c2410_ts_mach_info *info;
 262         struct device *dev = &pdev->dev;
 263         struct input_dev *input_dev;
 264         struct resource *res;
 265         int ret = -EINVAL;
 266
 267         /* Initialise input stuff */
 268         memset(&ts, 0, sizeof(struct s3c2410ts));
 269
 270         ts.dev = dev;
 271
 272         info = dev_get_platdata(dev);
 273         if (!info) {
 274                 dev_err(dev, "no platform data, cannot attach\n");
 275                 return -EINVAL;
 276         }
 277
 278         dev_dbg(dev, "initialising touchscreen\n");
 279
 280         ts.clock = clk_get(dev, "adc");
 281         if (IS_ERR(ts.clock)) {
 282                 dev_err(dev, "cannot get adc clock source\n");
 283                 return -ENOENT;
 284         }
 285
 286         ret = clk_prepare_enable(ts.clock);
 287         if (ret) {
 288                 dev_err(dev, "Failed! to enabled clocks\n");
 289                 goto err_clk_get;
 290         }
 291         dev_dbg(dev, "got and enabled clocks\n");
 292
 293         ts.irq_tc = ret = platform_get_irq(pdev, 0);
 294         if (ret < 0) {
 295                 dev_err(dev, "no resource for interrupt\n");
 296                 goto err_clk;
 297         }
 298
 299         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 300         if (!res) {
 301                 dev_err(dev, "no resource for registers\n");
 302                 ret = -ENOENT;
 303                 goto err_clk;
 304         }
 305
 306         ts.io = ioremap(res->start, resource_size(res));
 307         if (ts.io == NULL) {
 308                 dev_err(dev, "cannot map registers\n");
 309                 ret = -ENOMEM;
 310                 goto err_clk;
 311         }
 312
 313         /* inititalise the gpio */
 314         if (info->cfg_gpio)
 315                 info->cfg_gpio(to_platform_device(ts.dev));
 316
 317         ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
 318                                      s3c24xx_ts_conversion, 1);
 319         if (IS_ERR(ts.client)) {
 320                 dev_err(dev, "failed to register adc client\n");
 321                 ret = PTR_ERR(ts.client);
 322                 goto err_iomap;
 323         }
 324
 325         /* Initialise registers */
 326         if ((info->delay & 0xffff) > 0)
 327                 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
 328
 329         writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 330
 331         input_dev = input_allocate_device();
 332         if (!input_dev) {
 333                 dev_err(dev, "Unable to allocate the input device !!\n");
 334                 ret = -ENOMEM;
 335                 goto err_iomap;
 336         }
 337
 338         ts.input = input_dev;
 339         ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 340         ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 341         input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
 342         input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
 343
 344         ts.input->name = "S3C24XX TouchScreen";
 345         ts.input->id.bustype = BUS_HOST;
 346         ts.input->id.vendor = 0xDEAD;
 347         ts.input->id.product = 0xBEEF;
 348         ts.input->id.version = 0x0102;
 349
 350         ts.shift = info->oversampling_shift;
 351         ts.features = platform_get_device_id(pdev)->driver_data;
 352
 353         ret = request_irq(ts.irq_tc, stylus_irq, 0,
 354                           "s3c2410_ts_pen", ts.input);
 355         if (ret) {
 356                 dev_err(dev, "cannot get TC interrupt\n");
 357                 goto err_inputdev;
 358         }
 359
 360         dev_info(dev, "driver attached, registering input device\n");
 361
 362         /* All went ok, so register to the input system */
 363         ret = input_register_device(ts.input);
 364         if (ret < 0) {
 365                 dev_err(dev, "failed to register input device\n");
 366                 ret = -EIO;
 367                 goto err_tcirq;
 368         }
 369
 370         return 0;
 371
 372  err_tcirq:
 373         free_irq(ts.irq_tc, ts.input);
 374  err_inputdev:
 375         input_free_device(ts.input);
 376  err_iomap:
 377         iounmap(ts.io);
 378  err_clk:
 379         clk_disable_unprepare(ts.clock);
 380         del_timer_sync(&touch_timer);
 381  err_clk_get:
 382         clk_put(ts.clock);
 383         return ret;
 384 }
 385
 386 /**
 387  * s3c2410ts_remove - device core removal entry point
 388  * @pdev: The device we are being removed from.
 389  *
 390  * Free up our state ready to be removed.
 391  */
 392 static int s3c2410ts_remove(struct platform_device *pdev)
 393 {
 394         free_irq(ts.irq_tc, ts.input);
 395         del_timer_sync(&touch_timer);
 396
 397         clk_disable_unprepare(ts.clock);
 398         clk_put(ts.clock);
 399
 400         input_unregister_device(ts.input);
 401         iounmap(ts.io);
 402
 403         return 0;
 404 }
 405
 406 #ifdef CONFIG_PM
 407 static int s3c2410ts_suspend(struct device *dev)
 408 {
 409         writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
 410         disable_irq(ts.irq_tc);
 411         clk_disable(ts.clock);
 412
 413         return 0;
 414 }
 415
 416 static int s3c2410ts_resume(struct device *dev)
 417 {
 418         struct platform_device *pdev = to_platform_device(dev);
 419         struct s3c2410_ts_mach_info *info = dev_get_platdata(&pdev->dev);
 420
 421         clk_enable(ts.clock);
 422         enable_irq(ts.irq_tc);
 423
 424         /* Initialise registers */
 425         if ((info->delay & 0xffff) > 0)
 426                 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
 427
 428         writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 429
 430         return 0;
 431 }
 432
 433 static const struct dev_pm_ops s3c_ts_pmops = {
 434         .suspend        = s3c2410ts_suspend,
 435         .resume         = s3c2410ts_resume,
 436 };
 437 #endif
 438
 439 static const struct platform_device_id s3cts_driver_ids[] = {
 440         { "s3c2410-ts", 0 },
 441         { "s3c2440-ts", 0 },
 442         { "s3c64xx-ts", FEAT_PEN_IRQ },
 443         { }
 444 };
 445 MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
 446
 447 static struct platform_driver s3c_ts_driver = {
 448         .driver         = {
 449                 .name   = "samsung-ts",
 450 #ifdef CONFIG_PM
 451                 .pm     = &s3c_ts_pmops,
 452 #endif
 453         },
 454         .id_table       = s3cts_driver_ids,
 455         .probe          = s3c2410ts_probe,
 456         .remove         = s3c2410ts_remove,
 457 };
 458 module_platform_driver(s3c_ts_driver);
 459
 460 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
 461               "Ben Dooks <ben@simtec.co.uk>, "
 462               "Simtec Electronics <linux@simtec.co.uk>");
 463 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
 464 MODULE_LICENSE("GPL v2");