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/slab.h>
  30 #include <linux/gpio.h>
  31 #include <linux/input.h>
  32 #include <linux/init.h>
  33 #include <linux/delay.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/clk.h>
  37 #include <linux/io.h>
  38
  39 #include <plat/adc.h>
  40 #include <plat/regs-adc.h>
  41
  42 #include <mach/regs-gpio.h>
  43 #include <mach/ts.h>
  44
  45 #define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
  46
  47 #define INT_DOWN        (0)
  48 #define INT_UP          (1 << 8)
  49
  50 #define WAIT4INT        (S3C2410_ADCTSC_YM_SEN | \
  51                          S3C2410_ADCTSC_YP_SEN | \
  52                          S3C2410_ADCTSC_XP_SEN | \
  53                          S3C2410_ADCTSC_XY_PST(3))
  54
  55 #define AUTOPST         (S3C2410_ADCTSC_YM_SEN | \
  56                          S3C2410_ADCTSC_YP_SEN | \
  57                          S3C2410_ADCTSC_XP_SEN | \
  58                          S3C2410_ADCTSC_AUTO_PST | \
  59                          S3C2410_ADCTSC_XY_PST(0))
  60
  61 /* Per-touchscreen data. */
  62
  63 /**
  64  * struct s3c2410ts - driver touchscreen state.
  65  * @client: The ADC client we registered with the core driver.
  66  * @dev: The device we are bound to.
  67  * @input: The input device we registered with the input subsystem.
  68  * @clock: The clock for the adc.
  69  * @io: Pointer to the IO base.
  70  * @xp: The accumulated X position data.
  71  * @yp: The accumulated Y position data.
  72  * @irq_tc: The interrupt number for pen up/down interrupt
  73  * @count: The number of samples collected.
  74  * @shift: The log2 of the maximum count to read in one go.
  75  */
  76 struct s3c2410ts {
  77         struct s3c_adc_client *client;
  78         struct device *dev;
  79         struct input_dev *input;
  80         struct clk *clock;
  81         void __iomem *io;
  82         unsigned long xp;
  83         unsigned long yp;
  84         int irq_tc;
  85         int count;
  86         int shift;
  87 };
  88
  89 static struct s3c2410ts ts;
  90
  91 /**
  92  * s3c2410_ts_connect - configure gpio for s3c2410 systems
  93  *
  94  * Configure the GPIO for the S3C2410 system, where we have external FETs
  95  * connected to the device (later systems such as the S3C2440 integrate
  96  * these into the device).
  97 */
  98 static inline void s3c2410_ts_connect(void)
  99 {
 100         s3c2410_gpio_cfgpin(S3C2410_GPG(12), S3C2410_GPG12_XMON);
 101         s3c2410_gpio_cfgpin(S3C2410_GPG(13), S3C2410_GPG13_nXPON);
 102         s3c2410_gpio_cfgpin(S3C2410_GPG(14), S3C2410_GPG14_YMON);
 103         s3c2410_gpio_cfgpin(S3C2410_GPG(15), S3C2410_GPG15_nYPON);
 104 }
 105
 106 /**
 107  * get_down - return the down state of the pen
 108  * @data0: The data read from ADCDAT0 register.
 109  * @data1: The data read from ADCDAT1 register.
 110  *
 111  * Return non-zero if both readings show that the pen is down.
 112  */
 113 static inline bool get_down(unsigned long data0, unsigned long data1)
 114 {
 115         /* returns true if both data values show stylus down */
 116         return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
 117                 !(data1 & S3C2410_ADCDAT0_UPDOWN));
 118 }
 119
 120 static void touch_timer_fire(unsigned long data)
 121 {
 122         unsigned long data0;
 123         unsigned long data1;
 124         bool down;
 125
 126         data0 = readl(ts.io + S3C2410_ADCDAT0);
 127         data1 = readl(ts.io + S3C2410_ADCDAT1);
 128
 129         down = get_down(data0, data1);
 130
 131         if (down) {
 132                 if (ts.count == (1 << ts.shift)) {
 133                         ts.xp >>= ts.shift;
 134                         ts.yp >>= ts.shift;
 135
 136                         dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
 137                                 __func__, ts.xp, ts.yp, ts.count);
 138
 139                         input_report_abs(ts.input, ABS_X, ts.xp);
 140                         input_report_abs(ts.input, ABS_Y, ts.yp);
 141
 142                         input_report_key(ts.input, BTN_TOUCH, 1);
 143                         input_sync(ts.input);
 144
 145                         ts.xp = 0;
 146                         ts.yp = 0;
 147                         ts.count = 0;
 148                 }
 149
 150                 s3c_adc_start(ts.client, 0, 1 << ts.shift);
 151         } else {
 152                 ts.xp = 0;
 153                 ts.yp = 0;
 154                 ts.count = 0;
 155
 156                 input_report_key(ts.input, BTN_TOUCH, 0);
 157                 input_sync(ts.input);
 158
 159                 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 160         }
 161 }
 162
 163 static DEFINE_TIMER(touch_timer, touch_timer_fire, 0, 0);
 164
 165 /**
 166  * stylus_irq - touchscreen stylus event interrupt
 167  * @irq: The interrupt number
 168  * @dev_id: The device ID.
 169  *
 170  * Called when the IRQ_TC is fired for a pen up or down event.
 171  */
 172 static irqreturn_t stylus_irq(int irq, void *dev_id)
 173 {
 174         unsigned long data0;
 175         unsigned long data1;
 176         bool down;
 177
 178         data0 = readl(ts.io + S3C2410_ADCDAT0);
 179         data1 = readl(ts.io + S3C2410_ADCDAT1);
 180
 181         down = get_down(data0, data1);
 182
 183         /* TODO we should never get an interrupt with down set while
 184          * the timer is running, but maybe we ought to verify that the
 185          * timer isn't running anyways. */
 186
 187         if (down)
 188                 s3c_adc_start(ts.client, 0, 1 << ts.shift);
 189         else
 190                 dev_info(ts.dev, "%s: count=%d\n", __func__, ts.count);
 191
 192         return IRQ_HANDLED;
 193 }
 194
 195 /**
 196  * s3c24xx_ts_conversion - ADC conversion callback
 197  * @client: The client that was registered with the ADC core.
 198  * @data0: The reading from ADCDAT0.
 199  * @data1: The reading from ADCDAT1.
 200  * @left: The number of samples left.
 201  *
 202  * Called when a conversion has finished.
 203  */
 204 static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
 205                                   unsigned data0, unsigned data1,
 206                                   unsigned *left)
 207 {
 208         dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
 209
 210         ts.xp += data0;
 211         ts.yp += data1;
 212
 213         ts.count++;
 214
 215         /* From tests, it seems that it is unlikely to get a pen-up
 216          * event during the conversion process which means we can
 217          * ignore any pen-up events with less than the requisite
 218          * count done.
 219          *
 220          * In several thousand conversions, no pen-ups where detected
 221          * before count completed.
 222          */
 223 }
 224
 225 /**
 226  * s3c24xx_ts_select - ADC selection callback.
 227  * @client: The client that was registered with the ADC core.
 228  * @select: The reason for select.
 229  *
 230  * Called when the ADC core selects (or deslects) us as a client.
 231  */
 232 static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
 233 {
 234         if (select) {
 235                 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
 236                        ts.io + S3C2410_ADCTSC);
 237         } else {
 238                 mod_timer(&touch_timer, jiffies+1);
 239                 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
 240         }
 241 }
 242
 243 /**
 244  * s3c2410ts_probe - device core probe entry point
 245  * @pdev: The device we are being bound to.
 246  *
 247  * Initialise, find and allocate any resources we need to run and then
 248  * register with the ADC and input systems.
 249  */
 250 static int __devinit s3c2410ts_probe(struct platform_device *pdev)
 251 {
 252         struct s3c2410_ts_mach_info *info;
 253         struct device *dev = &pdev->dev;
 254         struct input_dev *input_dev;
 255         struct resource *res;
 256         int ret = -EINVAL;
 257
 258         /* Initialise input stuff */
 259         memset(&ts, 0, sizeof(struct s3c2410ts));
 260
 261         ts.dev = dev;
 262
 263         info = pdev->dev.platform_data;
 264         if (!info) {
 265                 dev_err(dev, "no platform data, cannot attach\n");
 266                 return -EINVAL;
 267         }
 268
 269         dev_dbg(dev, "initialising touchscreen\n");
 270
 271         ts.clock = clk_get(dev, "adc");
 272         if (IS_ERR(ts.clock)) {
 273                 dev_err(dev, "cannot get adc clock source\n");
 274                 return -ENOENT;
 275         }
 276
 277         clk_enable(ts.clock);
 278         dev_dbg(dev, "got and enabled clocks\n");
 279
 280         ts.irq_tc = ret = platform_get_irq(pdev, 0);
 281         if (ret < 0) {
 282                 dev_err(dev, "no resource for interrupt\n");
 283                 goto err_clk;
 284         }
 285
 286         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 287         if (!res) {
 288                 dev_err(dev, "no resource for registers\n");
 289                 ret = -ENOENT;
 290                 goto err_clk;
 291         }
 292
 293         ts.io = ioremap(res->start, resource_size(res));
 294         if (ts.io == NULL) {
 295                 dev_err(dev, "cannot map registers\n");
 296                 ret = -ENOMEM;
 297                 goto err_clk;
 298         }
 299
 300         /* Configure the touchscreen external FETs on the S3C2410 */
 301         if (!platform_get_device_id(pdev)->driver_data)
 302                 s3c2410_ts_connect();
 303
 304         ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
 305                                      s3c24xx_ts_conversion, 1);
 306         if (IS_ERR(ts.client)) {
 307                 dev_err(dev, "failed to register adc client\n");
 308                 ret = PTR_ERR(ts.client);
 309                 goto err_iomap;
 310         }
 311
 312         /* Initialise registers */
 313         if ((info->delay & 0xffff) > 0)
 314                 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
 315
 316         writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 317
 318         input_dev = input_allocate_device();
 319         if (!input_dev) {
 320                 dev_err(dev, "Unable to allocate the input device !!\n");
 321                 ret = -ENOMEM;
 322                 goto err_iomap;
 323         }
 324
 325         ts.input = input_dev;
 326         ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 327         ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 328         input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
 329         input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
 330
 331         ts.input->name = "S3C24XX TouchScreen";
 332         ts.input->id.bustype = BUS_HOST;
 333         ts.input->id.vendor = 0xDEAD;
 334         ts.input->id.product = 0xBEEF;
 335         ts.input->id.version = 0x0102;
 336
 337         ts.shift = info->oversampling_shift;
 338
 339         ret = request_irq(ts.irq_tc, stylus_irq, IRQF_DISABLED,
 340                           "s3c2410_ts_pen", ts.input);
 341         if (ret) {
 342                 dev_err(dev, "cannot get TC interrupt\n");
 343                 goto err_inputdev;
 344         }
 345
 346         dev_info(dev, "driver attached, registering input device\n");
 347
 348         /* All went ok, so register to the input system */
 349         ret = input_register_device(ts.input);
 350         if (ret < 0) {
 351                 dev_err(dev, "failed to register input device\n");
 352                 ret = -EIO;
 353                 goto err_tcirq;
 354         }
 355
 356         return 0;
 357
 358  err_tcirq:
 359         free_irq(ts.irq_tc, ts.input);
 360  err_inputdev:
 361         input_unregister_device(ts.input);
 362  err_iomap:
 363         iounmap(ts.io);
 364  err_clk:
 365         del_timer_sync(&touch_timer);
 366         clk_put(ts.clock);
 367         return ret;
 368 }
 369
 370 /**
 371  * s3c2410ts_remove - device core removal entry point
 372  * @pdev: The device we are being removed from.
 373  *
 374  * Free up our state ready to be removed.
 375  */
 376 static int __devexit s3c2410ts_remove(struct platform_device *pdev)
 377 {
 378         free_irq(ts.irq_tc, ts.input);
 379         del_timer_sync(&touch_timer);
 380
 381         clk_disable(ts.clock);
 382         clk_put(ts.clock);
 383
 384         input_unregister_device(ts.input);
 385         iounmap(ts.io);
 386
 387         return 0;
 388 }
 389
 390 #ifdef CONFIG_PM
 391 static int s3c2410ts_suspend(struct device *dev)
 392 {
 393         writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
 394         disable_irq(ts.irq_tc);
 395         clk_disable(ts.clock);
 396
 397         return 0;
 398 }
 399
 400 static int s3c2410ts_resume(struct device *dev)
 401 {
 402         struct platform_device *pdev = to_platform_device(dev);
 403         struct s3c2410_ts_mach_info *info = pdev->dev.platform_data;
 404
 405         clk_enable(ts.clock);
 406         enable_irq(ts.irq_tc);
 407
 408         /* Initialise registers */
 409         if ((info->delay & 0xffff) > 0)
 410                 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
 411
 412         writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
 413
 414         return 0;
 415 }
 416
 417 static struct dev_pm_ops s3c_ts_pmops = {
 418         .suspend        = s3c2410ts_suspend,
 419         .resume         = s3c2410ts_resume,
 420 };
 421 #endif
 422
 423 static struct platform_device_id s3cts_driver_ids[] = {
 424         { "s3c2410-ts", 0 },
 425         { "s3c2440-ts", 1 },
 426         { }
 427 };
 428 MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
 429
 430 static struct platform_driver s3c_ts_driver = {
 431         .driver         = {
 432                 .name   = "s3c24xx-ts",
 433                 .owner  = THIS_MODULE,
 434 #ifdef CONFIG_PM
 435                 .pm     = &s3c_ts_pmops,
 436 #endif
 437         },
 438         .id_table       = s3cts_driver_ids,
 439         .probe          = s3c2410ts_probe,
 440         .remove         = __devexit_p(s3c2410ts_remove),
 441 };
 442
 443 static int __init s3c2410ts_init(void)
 444 {
 445         return platform_driver_register(&s3c_ts_driver);
 446 }
 447
 448 static void __exit s3c2410ts_exit(void)
 449 {
 450         platform_driver_unregister(&s3c_ts_driver);
 451 }
 452
 453 module_init(s3c2410ts_init);
 454 module_exit(s3c2410ts_exit);
 455
 456 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
 457               "Ben Dooks <ben@simtec.co.uk>, "
 458               "Simtec Electronics <linux@simtec.co.uk>");
 459 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
 460 MODULE_LICENSE("GPL v2");