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