drivers/input/keyboard/tsc2301_kp.c

   1 /*
   2  * TSC2301 keypad driver
   3  *
   4  * Copyright (C) 2005-2006 Nokia Corporation
   5  *
   6  * Written by Jarkko Oikarinen
   7  * Rewritten by Juha Yrjola <juha.yrjola@nokia.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  *
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/input.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/irq.h>
  30 #include <linux/delay.h>
  31 #include <linux/spi/spi.h>
  32
  33 #ifdef CONFIG_ARCH_OMAP
  34 #include <asm/arch/gpio.h>
  35 #endif
  36
  37 #include <linux/spi/tsc2301.h>
  38
  39 #define TSC2301_KEYBOARD_PRODUCT_ID      0x0051
  40 #define TSC2301_KEYBOARD_PRODUCT_VERSION 0x0001
  41 #define TSC2301_DEBOUNCE_TIME_2MS        0x0000
  42 #define TSC2301_DEBOUNCE_TIME_10MS       0x0800
  43 #define TSC2301_DEBOUNCE_TIME_20MS       0x1000
  44 #define TSC2301_DEBOUNCE_TIME_50MS       0x1800
  45 #define TSC2301_DEBOUNCE_TIME_60MS       0x2000
  46 #define TSC2301_DEBOUNCE_TIME_80MS       0x2800
  47 #define TSC2301_DEBOUNCE_TIME_100MS      0x3000
  48 #define TSC2301_DEBOUNCE_TIME_120MS      0x3800
  49
  50 #define TSC2301_DEBOUNCE_TIME           TSC2301_DEBOUNCE_TIME_20MS
  51
  52 #define TSC2301_RELEASE_TIMEOUT         50
  53
  54 struct tsc2301_kp {
  55         struct input_dev        *idev;
  56         char                    phys[32];
  57         spinlock_t              lock;
  58         struct mutex            mutex;
  59         struct timer_list       timer;
  60         u16                     keys_pressed;
  61         unsigned                pending:1;
  62         unsigned                user_disabled:1;
  63         unsigned                disable_depth;
  64
  65         struct spi_transfer     read_xfer[4];
  66         struct spi_message      read_msg;
  67
  68         u16                     data;
  69         u16                     mask;
  70
  71         int                     irq;
  72         s16                     keymap[16];
  73 };
  74
  75 static inline int tsc2301_kp_disabled(struct tsc2301 *tsc)
  76 {
  77         return tsc->kp->disable_depth != 0;
  78 }
  79
  80 static void tsc2301_kp_send_key_events(struct tsc2301 *tsc,
  81                                        u16 prev_state,
  82                                        u16 new_state)
  83 {
  84         struct tsc2301_kp *kp = tsc->kp;
  85         u16 common, released, pressed;
  86         int i;
  87
  88         common = prev_state & new_state;
  89         released = common ^ prev_state;
  90         pressed = common ^ new_state;
  91         if (!released && !pressed)
  92                 return;
  93         for (i = 0; i < 16 && (released || pressed); i++) {
  94                 if (released & 1) {
  95                         dev_dbg(&tsc->spi->dev, "key %d released\n", i);
  96                         input_report_key(kp->idev, kp->keymap[i], 0);
  97                 }
  98                 released >>= 1;
  99                 if (pressed & 1) {
 100                         dev_dbg(&tsc->spi->dev, "key %d pressed\n", i);
 101                         input_report_key(kp->idev, kp->keymap[i], 1);
 102                 }
 103                 pressed >>= 1;
 104         }
 105         input_sync(kp->idev);
 106 }
 107
 108 static inline void _filter_out(struct tsc2301 *tsc, u16 prev_state,
 109                                u16 *new_state, int row1, int row2, u8 rect_pat)
 110 {
 111         u16 mask;
 112
 113         mask = (rect_pat << (row1 * 4)) | (rect_pat << (row2 * 4));
 114         mask &= ~prev_state;
 115         *new_state &= ~mask;
 116         dev_dbg(&tsc->spi->dev, "filtering ghost keys %02x\n", mask);
 117 }
 118
 119 static void tsc2301_filter_ghost_keys(struct tsc2301 *tsc, u16 prev_state,
 120                                       u16 *new_state)
 121 {
 122         int row1, row2;
 123         u16 key_map;
 124         u16 row1_map;
 125         static const u8 rect_pat[] = {
 126                 0x3, 0x5, 0x9, 0x6, 0xa, 0xc, 0,
 127         };
 128
 129         key_map = *new_state;
 130         for (row1 = 0; row1 < 4; row1++) {
 131                 row1_map = (key_map >> (row1 * 4)) & 0xf;
 132                 if (!row1_map)
 133                         continue;
 134                 for (row2 = row1 + 1; row2 < 4; row2++) {
 135                         u16 rect_map = (key_map >> (row2 * 4)) & 0xf;
 136                         const u8 *rp;
 137
 138                         rect_map &= row1_map;
 139                         if (!rect_map)
 140                                 continue;
 141                         for (rp = rect_pat; *rp; rp++)
 142                                 if ((rect_map & *rp) == *rp)
 143                                         _filter_out(tsc, prev_state, new_state,
 144                                                     row1, row2, *rp);
 145                 }
 146         }
 147 }
 148
 149 static void tsc2301_kp_timer(unsigned long arg)
 150 {
 151         struct tsc2301 *tsc = (void *) arg;
 152         struct tsc2301_kp *kp = tsc->kp;
 153         unsigned long flags;
 154
 155         tsc2301_kp_send_key_events(tsc, kp->keys_pressed, 0);
 156         spin_lock_irqsave(&kp->lock, flags);
 157         kp->keys_pressed = 0;
 158         spin_unlock_irqrestore(&kp->lock, flags);
 159 }
 160
 161 static void tsc2301_kp_rx(void *arg)
 162 {
 163         struct tsc2301 *tsc = arg;
 164         struct tsc2301_kp *kp = tsc->kp;
 165         unsigned long flags;
 166         u16 kp_data;
 167
 168         kp_data = kp->data;
 169         dev_dbg(&tsc->spi->dev, "KP data %04x\n", kp_data);
 170
 171         tsc2301_filter_ghost_keys(tsc, kp->keys_pressed, &kp_data);
 172         tsc2301_kp_send_key_events(tsc, kp->keys_pressed, kp_data);
 173         spin_lock_irqsave(&kp->lock, flags);
 174         kp->keys_pressed = kp_data;
 175         kp->pending = 0;
 176         spin_unlock_irqrestore(&kp->lock, flags);
 177 }
 178
 179 static irqreturn_t tsc2301_kp_irq_handler(int irq, void *dev_id)
 180 {
 181         struct tsc2301 *tsc = dev_id;
 182         struct tsc2301_kp *kp = tsc->kp;
 183         unsigned long flags;
 184         int r;
 185
 186         spin_lock_irqsave(&kp->lock, flags);
 187         if (tsc2301_kp_disabled(tsc)) {
 188                 spin_unlock_irqrestore(&kp->lock, flags);
 189                 return IRQ_HANDLED;
 190         }
 191         kp->pending = 1;
 192         spin_unlock_irqrestore(&kp->lock, flags);
 193         mod_timer(&kp->timer,
 194                  jiffies + msecs_to_jiffies(TSC2301_RELEASE_TIMEOUT));
 195         r = spi_async(tsc->spi, &tsc->kp->read_msg);
 196         if (r)
 197                 dev_err(&tsc->spi->dev, "kp: spi_async() failed");
 198         return IRQ_HANDLED;
 199 }
 200
 201 static void tsc2301_kp_start_scan(struct tsc2301 *tsc)
 202 {
 203         tsc2301_write_reg(tsc, TSC2301_REG_KPMASK, tsc->kp->mask);
 204         tsc2301_write_reg(tsc, TSC2301_REG_KEY, TSC2301_DEBOUNCE_TIME);
 205 }
 206
 207 static void tsc2301_kp_stop_scan(struct tsc2301 *tsc)
 208 {
 209         tsc2301_write_reg(tsc, TSC2301_REG_KEY, 1 << 14);
 210 }
 211
 212 /* Must be called with the mutex held */
 213 static void tsc2301_kp_enable(struct tsc2301 *tsc)
 214 {
 215         struct tsc2301_kp *kp = tsc->kp;
 216         unsigned long flags;
 217
 218         spin_lock_irqsave(&kp->lock, flags);
 219         BUG_ON(!tsc2301_kp_disabled(tsc));
 220         if (--kp->disable_depth != 0) {
 221                 spin_unlock_irqrestore(&kp->lock, flags);
 222                 return;
 223         }
 224         spin_unlock_irqrestore(&kp->lock, flags);
 225
 226         set_irq_type(kp->irq, IRQT_FALLING);
 227         tsc2301_kp_start_scan(tsc);
 228         enable_irq(kp->irq);
 229 }
 230
 231 /* Must be called with the mutex held */
 232 static int tsc2301_kp_disable(struct tsc2301 *tsc, int release_keys)
 233 {
 234         struct tsc2301_kp *kp = tsc->kp;
 235         unsigned long flags;
 236
 237         spin_lock_irqsave(&kp->lock, flags);
 238         if (kp->disable_depth++ != 0) {
 239                 spin_unlock_irqrestore(&kp->lock, flags);
 240                 goto out;
 241         }
 242         disable_irq_nosync(kp->irq);
 243         set_irq_type(kp->irq, IRQT_NOEDGE);
 244         spin_unlock_irqrestore(&kp->lock, flags);
 245
 246         while (kp->pending) {
 247                 msleep(1);
 248         }
 249
 250         tsc2301_kp_stop_scan(tsc);
 251 out:
 252         if (!release_keys)
 253                 del_timer(&kp->timer); /* let timeout release keys */
 254
 255         return 0;
 256 }
 257
 258 /* The following workaround is needed for a HW bug triggered by the
 259  * following:
 260  * 1. keep any key pressed
 261  * 2. disable keypad
 262  * 3. release all keys
 263  * 4. reenable keypad
 264  * 5. disable touch screen controller
 265  *
 266  * After this the keypad scanner will get stuck in busy state and won't
 267  * report any interrupts for further keypresses. One way to recover is to
 268  * restart the keypad scanner whenever we enable / disable the
 269  * touchscreen controller.
 270  */
 271 void tsc2301_kp_restart(struct tsc2301 *tsc)
 272 {
 273         if (!tsc2301_kp_disabled(tsc)) {
 274                 tsc2301_kp_start_scan(tsc);
 275         }
 276 }
 277
 278 static ssize_t tsc2301_kp_disable_show(struct device *dev,
 279                                        struct device_attribute *attr, char *buf)
 280 {
 281         struct tsc2301          *tsc = dev_get_drvdata(dev);
 282
 283         return sprintf(buf, "%u\n", tsc2301_kp_disabled(tsc) ? 1 : 0);
 284 }
 285
 286 static ssize_t tsc2301_kp_disable_store(struct device *dev,
 287                                         struct device_attribute *attr,
 288                                         const char *buf, size_t count)
 289 {
 290         struct tsc2301          *tsc = dev_get_drvdata(dev);
 291         struct tsc2301_kp       *kp = tsc->kp;
 292         char *endp;
 293         int i;
 294
 295         i = simple_strtoul(buf, &endp, 10);
 296         i = i ? 1 : 0;
 297
 298         mutex_lock(&kp->mutex);
 299         if (i == kp->user_disabled) {
 300                 mutex_unlock(&kp->mutex);
 301                 return count;
 302         }
 303         kp->user_disabled = i;
 304
 305         if (i)
 306                 tsc2301_kp_disable(tsc, 1);
 307         else
 308                 tsc2301_kp_enable(tsc);
 309         mutex_unlock(&kp->mutex);
 310
 311         return count;
 312 }
 313
 314 static DEVICE_ATTR(disable_kp, 0664, tsc2301_kp_disable_show,
 315                    tsc2301_kp_disable_store);
 316
 317 static const u16 tsc2301_kp_read_data = 0x8000 | TSC2301_REG_KPDATA;
 318
 319 static void tsc2301_kp_setup_spi_xfer(struct tsc2301 *tsc)
 320 {
 321         struct tsc2301_kp *kp = tsc->kp;
 322         struct spi_message *m = &kp->read_msg;
 323         struct spi_transfer *x = &kp->read_xfer[0];
 324
 325         spi_message_init(&kp->read_msg);
 326
 327         x->tx_buf = &tsc2301_kp_read_data;
 328         x->len = 2;
 329         spi_message_add_tail(x, m);
 330         x++;
 331
 332         x->rx_buf = &kp->data;
 333         x->len = 2;
 334         spi_message_add_tail(x, m);
 335
 336         m->complete = tsc2301_kp_rx;
 337         m->context = tsc;
 338 }
 339
 340 #ifdef CONFIG_PM
 341 int tsc2301_kp_suspend(struct tsc2301 *tsc)
 342 {
 343         struct tsc2301_kp *kp = tsc->kp;
 344
 345         mutex_lock(&kp->mutex);
 346         tsc2301_kp_disable(tsc, 1);
 347         mutex_unlock(&kp->mutex);
 348         return 0;
 349 }
 350
 351 void tsc2301_kp_resume(struct tsc2301 *tsc)
 352 {
 353         struct tsc2301_kp *kp = tsc->kp;
 354
 355         mutex_lock(&kp->mutex);
 356         tsc2301_kp_enable(tsc);
 357         mutex_unlock(&kp->mutex);
 358 }
 359 #endif
 360
 361 int __devinit tsc2301_kp_init(struct tsc2301 *tsc,
 362                               struct tsc2301_platform_data *pdata)
 363 {
 364         struct input_dev *idev;
 365         struct tsc2301_kp *kp;
 366         int r, i;
 367         u16 mask;
 368
 369         if (pdata->keyb_int < 0) {
 370                 dev_err(&tsc->spi->dev, "need kbirq");
 371                 return -EINVAL;
 372         }
 373
 374         kp = kzalloc(sizeof(*kp), GFP_KERNEL);
 375         if (kp == NULL)
 376                 return -ENOMEM;
 377         tsc->kp = kp;
 378
 379         kp->irq = pdata->keyb_int;
 380         spin_lock_init(&kp->lock);
 381         mutex_init(&kp->mutex);
 382
 383         init_timer(&kp->timer);
 384         kp->timer.data = (unsigned long) tsc;
 385         kp->timer.function = tsc2301_kp_timer;
 386
 387         idev = input_allocate_device();
 388         if (idev == NULL) {
 389                 r = -ENOMEM;
 390                 goto err1;
 391         }
 392         idev->name = "TSC2301 keypad";
 393         snprintf(kp->phys, sizeof(kp->phys), "%s/input-kp", tsc->spi->dev.bus_id);
 394         idev->phys = kp->phys;
 395
 396         mask = 0;
 397         idev->evbit[0] = BIT(EV_KEY);
 398         for (i = 0; i < 16; i++) {
 399                 if (pdata->keymap[i] > 0) {
 400                         set_bit(pdata->keymap[i], idev->keybit);
 401                         kp->keymap[i] = pdata->keymap[i];
 402                 } else {
 403                         kp->keymap[i] = -1;
 404                         mask |= 1 << i;
 405                 }
 406         }
 407
 408         if (pdata->kp_rep)
 409                 set_bit(EV_REP, idev->evbit);
 410
 411         kp->idev = idev;
 412
 413         tsc2301_kp_setup_spi_xfer(tsc);
 414
 415         r = device_create_file(&tsc->spi->dev, &dev_attr_disable_kp);
 416         if (r < 0)
 417                 goto err2;
 418
 419         tsc2301_kp_start_scan(tsc);
 420
 421         /* IRQ mode 0 is faulty, it can cause the KBIRQ to get stuck.
 422          * Mode 2 deasserts the IRQ at:
 423          * - HW or SW reset
 424          * - Setting SCS flag in REG_KEY register
 425          * - Releasing all keys
 426          * - Reading the REG_KPDATA
 427          */
 428         tsc2301_write_kbc(tsc, 2);
 429
 430         tsc2301_write_reg(tsc, TSC2301_REG_KPMASK, mask);
 431         kp->mask = mask;
 432
 433         set_irq_type(kp->irq, IRQT_FALLING);
 434
 435         r = request_irq(kp->irq, tsc2301_kp_irq_handler, IRQF_SAMPLE_RANDOM,
 436                         "tsc2301-kp", tsc);
 437         if (r < 0) {
 438                 dev_err(&tsc->spi->dev, "unable to get kbirq IRQ");
 439                 goto err3;
 440         }
 441         set_irq_wake(kp->irq, 1);
 442
 443         /* We need to read the register once..? */
 444         tsc2301_read_reg(tsc, TSC2301_REG_KPDATA);
 445
 446         r = input_register_device(idev);
 447         if (r < 0) {
 448                 dev_err(&tsc->spi->dev, "can't register keypad device\n");
 449                 goto err4;
 450         }
 451
 452         return 0;
 453
 454 err4:
 455         free_irq(kp->irq, tsc);
 456 err3:
 457         tsc2301_kp_stop_scan(tsc);
 458         device_remove_file(&tsc->spi->dev, &dev_attr_disable_kp);
 459 err2:
 460         input_free_device(kp->idev);
 461 err1:
 462         kfree(kp);
 463         return r;
 464 }
 465
 466 void __devexit tsc2301_kp_exit(struct tsc2301 *tsc)
 467 {
 468         struct tsc2301_kp *kp = tsc->kp;
 469
 470         tsc2301_kp_disable(tsc, 1);
 471         input_unregister_device(kp->idev);
 472         free_irq(kp->irq, tsc);
 473         device_remove_file(&tsc->spi->dev, &dev_attr_disable_kp);
 474
 475         kfree(kp);
 476 }