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