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