drivers/input/touchscreen/s3c2410_ts.c

   1 /*
   2  * Samsung S3C24XX touchscreen driver
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the term of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  *
  18  * Copyright 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
  19  * Copyright 2008 Ben Dooks <ben-linux@fluff.org>
  20  * Copyright 2009 Simtec Electronics <linux@simtec.co.uk>
  21  *
  22  * Additional work by Herbert Pötzl <herbert@13thfloor.at> and
  23  * Harald Welte <laforge@openmoko.org>
  24  */
  25
  26 #include <linux/errno.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/gpio.h>
  30 #include <linux/input.h>
  31 #include <linux/delay.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/clk.h>
  35 #include <linux/io.h>
  36
  37 #include <plat/adc.h>
  38 #include <plat/regs-adc.h>
  39 #include <linux/platform_data/touchscreen-s3c2410.h>
  40
  41 #define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
  42
  43 #define INT_DOWN        (0)
  44 #define INT_UP          (1 << 8)
  45
  46 #define WAIT4INT        (S3C2410_ADCTSC_YM_SEN | \
  47                          S3C2410_ADCTSC_YP_SEN | \
  48                          S3C2410_ADCTSC_XP_SEN | \
  49                          S3C2410_ADCTSC_XY_PST(3))
  50
  51 #define AUTOPST         (S3C2410_ADCTSC_YM_SEN | \
  52                          S3C2410_ADCTSC_YP_SEN | \
  53                          S3C2410_ADCTSC_XP_SEN | \
  54                          S3C2410_ADCTSC_AUTO_PST | \
  55                          S3C2410_ADCTSC_XY_PST(0))
  56
  57 #define FEAT_PEN_IRQ    (1 << 0)        /* HAS ADCCLRINTPNDNUP */
  58
  59 /* Per-touchscreen data. */
  60
  61 /**
  62  * struct s3c2410ts - driver touchscreen state.
  63  * @client: The ADC client we registered with the core driver.
  64  * @dev: The device we are bound to.
  65  * @input: The input device we registered with the input subsystem.
  66  * @clock: The clock for the adc.
  67  * @io: Pointer to the IO base.
  68  * @xp: The accumulated X position data.
  69  * @yp: The accumulated Y position data.
  70  * @irq_tc: The interrupt number for pen up/down interrupt
  71  * @count: The number of samples collected.
  72  * @shift: The log2 of the maximum count to read in one go.
  73  * @features: The features supported by the TSADC MOdule.
  74  */
  75 struct s3c2410ts {
  76         struct s3c_adc_client *client;
  77         struct device *dev;
  78         struct input_dev *input;
  79         struct clk *clock;
  80         void __iomem *io;
  81         unsigned long xp;
  82         unsigned long yp;
  83         int irq_tc;
  84         int count;
  85         int shift;
  86         int features;
  87 };
  88
  89 static struct s3c2410ts ts;
  90
  91 /**
  92  * get_down - return the down state of the pen
  93  * @data0: The data read from ADCDAT0 register.
  94  * @data1: The data read from ADCDAT1 register.
  95  *
  96  * Return non-zero if both readings show that the pen is down.
  97  */
  98 static inline bool get_down(unsigned long data0, unsigned long data1)
  99 {
 100         /* returns true if both data values show stylus down */
 101         return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
 102                 !(data1 & S3C2410_ADCDAT0_UPDOWN));
 103 }
 104
 105 static void touch_timer_fire(unsigned long data)
 106 {
 107         unsigned long data0;
 108         unsigned long data1;
 109         bool down;
 110
 111         data0 = readl(ts.io + S3C2410_ADCDAT0);
 112         data1 = readl(ts.io + S3C2410_ADCDAT1);
 113
 114         down = get_down(data0, data1);
 115
 116         if (down) {
 117                 if (ts.count == (1 << ts.shift)) {
 118                         ts.xp >>= ts.shift;
 119                         ts.yp >>= ts.shift;
 120
 121                         dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
 122                                 __func__, ts.xp, ts.yp, ts.count);
 123
 124                         input_report_abs(ts.input, ABS_X, ts.xp);
 125                         input_report_abs(ts.input, ABS_Y, ts.yp);
 126
 127                         input_report_key(ts.input, BTN_TOUCH, 1);
 128                         input_sync(ts.input);
 129
 130                         ts.xp = 0;
 131                         ts.yp = 0;
 132                         ts.count = 0;
 133                 }
 134
 135                 s3c_adc_start(ts.client, 0, 1 << ts.shift);
 136         } else {
 137                 ts.xp = 0;
 138                 ts.yp = 0;
 139                 ts.count = 0;
 140
 141                 input_report_key(ts.input, BTN_TOUCH, 0);
 142                 input_sync(ts.input);
 143
 144                 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 145         }
 146 }
 147
 148 static DEFINE_TIMER(touch_timer, touch_timer_fire, 0, 0);
 149
 150 /**
 151  * stylus_irq - touchscreen stylus event interrupt
 152  * @irq: The interrupt number
 153  * @dev_id: The device ID.
 154  *
 155  * Called when the IRQ_TC is fired for a pen up or down event.
 156  */
 157 static irqreturn_t stylus_irq(int irq, void *dev_id)
 158 {
 159         unsigned long data0;
 160         unsigned long data1;
 161         bool down;
 162
 163         data0 = readl(ts.io + S3C2410_ADCDAT0);
 164         data1 = readl(ts.io + S3C2410_ADCDAT1);
 165
 166         down = get_down(data0, data1);
 167
 168         /* TODO we should never get an interrupt with down set while
 169          * the timer is running, but maybe we ought to verify that the
 170          * timer isn't running anyways. */
 171
 172         if (down)
 173                 s3c_adc_start(ts.client, 0, 1 << ts.shift);
 174         else
 175                 dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);
 176
 177         if (ts.features & FEAT_PEN_IRQ) {
 178                 /* Clear pen down/up interrupt */
 179                 writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
 180         }
 181
 182         return IRQ_HANDLED;
 183 }
 184
 185 /**
 186  * s3c24xx_ts_conversion - ADC conversion callback
 187  * @client: The client that was registered with the ADC core.
 188  * @data0: The reading from ADCDAT0.
 189  * @data1: The reading from ADCDAT1.
 190  * @left: The number of samples left.
 191  *
 192  * Called when a conversion has finished.
 193  */
 194 static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
 195                                   unsigned data0, unsigned data1,
 196                                   unsigned *left)
 197 {
 198         dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
 199
 200         ts.xp += data0;
 201         ts.yp += data1;
 202
 203         ts.count++;
 204
 205         /* From tests, it seems that it is unlikely to get a pen-up
 206          * event during the conversion process which means we can
 207          * ignore any pen-up events with less than the requisite
 208          * count done.
 209          *
 210          * In several thousand conversions, no pen-ups where detected
 211          * before count completed.
 212          */
 213 }
 214
 215 /**
 216  * s3c24xx_ts_select - ADC selection callback.
 217  * @client: The client that was registered with the ADC core.
 218  * @select: The reason for select.
 219  *
 220  * Called when the ADC core selects (or deslects) us as a client.
 221  */
 222 static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
 223 {
 224         if (select) {
 225                 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
 226                        ts.io + S3C2410_ADCTSC);
 227         } else {
 228                 mod_timer(&touch_timer, jiffies+1);
 229                 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
 230         }
 231 }
 232
 233 /**
 234  * s3c2410ts_probe - device core probe entry point
 235  * @pdev: The device we are being bound to.
 236  *
 237  * Initialise, find and allocate any resources we need to run and then
 238  * register with the ADC and input systems.
 239  */
 240 static int s3c2410ts_probe(struct platform_device *pdev)
 241 {
 242         struct s3c2410_ts_mach_info *info;
 243         struct device *dev = &pdev->dev;
 244         struct input_dev *input_dev;
 245         struct resource *res;
 246         int ret = -EINVAL;
 247
 248         /* Initialise input stuff */
 249         memset(&ts, 0, sizeof(struct s3c2410ts));
 250
 251         ts.dev = dev;
 252
 253         info = dev_get_platdata(&pdev->dev);
 254         if (!info) {
 255                 dev_err(dev, "no platform data, cannot attach\n");
 256                 return -EINVAL;
 257         }
 258
 259         dev_dbg(dev, "initialising touchscreen\n");
 260
 261         ts.clock = clk_get(dev, "adc");
 262         if (IS_ERR(ts.clock)) {
 263                 dev_err(dev, "cannot get adc clock source\n");
 264                 return -ENOENT;
 265         }
 266
 267         clk_prepare_enable(ts.clock);
 268         dev_dbg(dev, "got and enabled clocks\n");
 269
 270         ts.irq_tc = ret = platform_get_irq(pdev, 0);
 271         if (ret < 0) {
 272                 dev_err(dev, "no resource for interrupt\n");
 273                 goto err_clk;
 274         }
 275
 276         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 277         if (!res) {
 278                 dev_err(dev, "no resource for registers\n");
 279                 ret = -ENOENT;
 280                 goto err_clk;
 281         }
 282
 283         ts.io = ioremap(res->start, resource_size(res));
 284         if (ts.io == NULL) {
 285                 dev_err(dev, "cannot map registers\n");
 286                 ret = -ENOMEM;
 287                 goto err_clk;
 288         }
 289
 290         /* inititalise the gpio */
 291         if (info->cfg_gpio)
 292                 info->cfg_gpio(to_platform_device(ts.dev));
 293
 294         ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
 295                                      s3c24xx_ts_conversion, 1);
 296         if (IS_ERR(ts.client)) {
 297                 dev_err(dev, "failed to register adc client\n");
 298                 ret = PTR_ERR(ts.client);
 299                 goto err_iomap;
 300         }
 301
 302         /* Initialise registers */
 303         if ((info->delay & 0xffff) > 0)
 304                 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
 305
 306         writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 307
 308         input_dev = input_allocate_device();
 309         if (!input_dev) {
 310                 dev_err(dev, "Unable to allocate the input device !!\n");
 311                 ret = -ENOMEM;
 312                 goto err_iomap;
 313         }
 314
 315         ts.input = input_dev;
 316         ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 317         ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 318         input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
 319         input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
 320
 321         ts.input->name = "S3C24XX TouchScreen";
 322         ts.input->id.bustype = BUS_HOST;
 323         ts.input->id.vendor = 0xDEAD;
 324         ts.input->id.product = 0xBEEF;
 325         ts.input->id.version = 0x0102;
 326
 327         ts.shift = info->oversampling_shift;
 328         ts.features = platform_get_device_id(pdev)->driver_data;
 329
 330         ret = request_irq(ts.irq_tc, stylus_irq, 0,
 331                           "s3c2410_ts_pen", ts.input);
 332         if (ret) {
 333                 dev_err(dev, "cannot get TC interrupt\n");
 334                 goto err_inputdev;
 335         }
 336
 337         dev_info(dev, "driver attached, registering input device\n");
 338
 339         /* All went ok, so register to the input system */
 340         ret = input_register_device(ts.input);
 341         if (ret < 0) {
 342                 dev_err(dev, "failed to register input device\n");
 343                 ret = -EIO;
 344                 goto err_tcirq;
 345         }
 346
 347         return 0;
 348
 349  err_tcirq:
 350         free_irq(ts.irq_tc, ts.input);
 351  err_inputdev:
 352         input_free_device(ts.input);
 353  err_iomap:
 354         iounmap(ts.io);
 355  err_clk:
 356         del_timer_sync(&touch_timer);
 357         clk_put(ts.clock);
 358         return ret;
 359 }
 360
 361 /**
 362  * s3c2410ts_remove - device core removal entry point
 363  * @pdev: The device we are being removed from.
 364  *
 365  * Free up our state ready to be removed.
 366  */
 367 static int s3c2410ts_remove(struct platform_device *pdev)
 368 {
 369         free_irq(ts.irq_tc, ts.input);
 370         del_timer_sync(&touch_timer);
 371
 372         clk_disable_unprepare(ts.clock);
 373         clk_put(ts.clock);
 374
 375         input_unregister_device(ts.input);
 376         iounmap(ts.io);
 377
 378         return 0;
 379 }
 380
 381 #ifdef CONFIG_PM
 382 static int s3c2410ts_suspend(struct device *dev)
 383 {
 384         writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
 385         disable_irq(ts.irq_tc);
 386         clk_disable(ts.clock);
 387
 388         return 0;
 389 }
 390
 391 static int s3c2410ts_resume(struct device *dev)
 392 {
 393         struct platform_device *pdev = to_platform_device(dev);
 394         struct s3c2410_ts_mach_info *info = dev_get_platdata(&pdev->dev);
 395
 396         clk_enable(ts.clock);
 397         enable_irq(ts.irq_tc);
 398
 399         /* Initialise registers */
 400         if ((info->delay & 0xffff) > 0)
 401                 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
 402
 403         writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 404
 405         return 0;
 406 }
 407
 408 static const struct dev_pm_ops s3c_ts_pmops = {
 409         .suspend        = s3c2410ts_suspend,
 410         .resume         = s3c2410ts_resume,
 411 };
 412 #endif
 413
 414 static struct platform_device_id s3cts_driver_ids[] = {
 415         { "s3c2410-ts", 0 },
 416         { "s3c2440-ts", 0 },
 417         { "s3c64xx-ts", FEAT_PEN_IRQ },
 418         { }
 419 };
 420 MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
 421
 422 static struct platform_driver s3c_ts_driver = {
 423         .driver         = {
 424                 .name   = "samsung-ts",
 425 #ifdef CONFIG_PM
 426                 .pm     = &s3c_ts_pmops,
 427 #endif
 428         },
 429         .id_table       = s3cts_driver_ids,
 430         .probe          = s3c2410ts_probe,
 431         .remove         = s3c2410ts_remove,
 432 };
 433 module_platform_driver(s3c_ts_driver);
 434
 435 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
 436               "Ben Dooks <ben@simtec.co.uk>, "
 437               "Simtec Electronics <linux@simtec.co.uk>");
 438 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
 439 MODULE_LICENSE("GPL v2");