drivers/input/keyboard/twl4030_keypad.c

   1 /*
   2  * twl4030_keypad.c - driver for 8x8 keypad controller in twl4030 chips
   3  *
   4  * Copyright (C) 2007 Texas Instruments, Inc.
   5  * Copyright (C) 2008 Nokia Corporation
   6  *
   7  * Code re-written for 2430SDP by:
   8  * Syed Mohammed Khasim <x0khasim@ti.com>
   9  *
  10  * Initial Code:
  11  * Manjunatha G K <manjugk@ti.com>
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  26  */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/input.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/i2c/twl.h>
  35 #include <linux/slab.h>
  36
  37
  38 /*
  39  * The TWL4030 family chips include a keypad controller that supports
  40  * up to an 8x8 switch matrix.  The controller can issue system wakeup
  41  * events, since it uses only the always-on 32KiHz oscillator, and has
  42  * an internal state machine that decodes pressed keys, including
  43  * multi-key combinations.
  44  *
  45  * This driver lets boards define what keycodes they wish to report for
  46  * which scancodes, as part of the "struct twl4030_keypad_data" used in
  47  * the probe() routine.
  48  *
  49  * See the TPS65950 documentation; that's the general availability
  50  * version of the TWL5030 second generation part.
  51  */
  52 #define TWL4030_MAX_ROWS        8       /* TWL4030 hard limit */
  53 #define TWL4030_MAX_COLS        8
  54 /*
  55  * Note that we add space for an extra column so that we can handle
  56  * row lines connected to the gnd (see twl4030_col_xlate()).
  57  */
  58 #define TWL4030_ROW_SHIFT       4
  59 #define TWL4030_KEYMAP_SIZE     (TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT)
  60
  61 struct twl4030_keypad {
  62         unsigned short  keymap[TWL4030_KEYMAP_SIZE];
  63         u16             kp_state[TWL4030_MAX_ROWS];
  64         unsigned        n_rows;
  65         unsigned        n_cols;
  66         unsigned        irq;
  67
  68         struct device *dbg_dev;
  69         struct input_dev *input;
  70 };
  71
  72 /*----------------------------------------------------------------------*/
  73
  74 /* arbitrary prescaler value 0..7 */
  75 #define PTV_PRESCALER                   4
  76
  77 /* Register Offsets */
  78 #define KEYP_CTRL                       0x00
  79 #define KEYP_DEB                        0x01
  80 #define KEYP_LONG_KEY                   0x02
  81 #define KEYP_LK_PTV                     0x03
  82 #define KEYP_TIMEOUT_L                  0x04
  83 #define KEYP_TIMEOUT_H                  0x05
  84 #define KEYP_KBC                        0x06
  85 #define KEYP_KBR                        0x07
  86 #define KEYP_SMS                        0x08
  87 #define KEYP_FULL_CODE_7_0              0x09    /* row 0 column status */
  88 #define KEYP_FULL_CODE_15_8             0x0a    /* ... row 1 ... */
  89 #define KEYP_FULL_CODE_23_16            0x0b
  90 #define KEYP_FULL_CODE_31_24            0x0c
  91 #define KEYP_FULL_CODE_39_32            0x0d
  92 #define KEYP_FULL_CODE_47_40            0x0e
  93 #define KEYP_FULL_CODE_55_48            0x0f
  94 #define KEYP_FULL_CODE_63_56            0x10
  95 #define KEYP_ISR1                       0x11
  96 #define KEYP_IMR1                       0x12
  97 #define KEYP_ISR2                       0x13
  98 #define KEYP_IMR2                       0x14
  99 #define KEYP_SIR                        0x15
 100 #define KEYP_EDR                        0x16    /* edge triggers */
 101 #define KEYP_SIH_CTRL                   0x17
 102
 103 /* KEYP_CTRL_REG Fields */
 104 #define KEYP_CTRL_SOFT_NRST             BIT(0)
 105 #define KEYP_CTRL_SOFTMODEN             BIT(1)
 106 #define KEYP_CTRL_LK_EN                 BIT(2)
 107 #define KEYP_CTRL_TOE_EN                BIT(3)
 108 #define KEYP_CTRL_TOLE_EN               BIT(4)
 109 #define KEYP_CTRL_RP_EN                 BIT(5)
 110 #define KEYP_CTRL_KBD_ON                BIT(6)
 111
 112 /* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
 113 #define KEYP_PERIOD_US(t, prescale)     ((t) / (31 << (prescale + 1)) - 1)
 114
 115 /* KEYP_LK_PTV_REG Fields */
 116 #define KEYP_LK_PTV_PTV_SHIFT           5
 117
 118 /* KEYP_{IMR,ISR,SIR} Fields */
 119 #define KEYP_IMR1_MIS                   BIT(3)
 120 #define KEYP_IMR1_TO                    BIT(2)
 121 #define KEYP_IMR1_LK                    BIT(1)
 122 #define KEYP_IMR1_KP                    BIT(0)
 123
 124 /* KEYP_EDR Fields */
 125 #define KEYP_EDR_KP_FALLING             0x01
 126 #define KEYP_EDR_KP_RISING              0x02
 127 #define KEYP_EDR_KP_BOTH                0x03
 128 #define KEYP_EDR_LK_FALLING             0x04
 129 #define KEYP_EDR_LK_RISING              0x08
 130 #define KEYP_EDR_TO_FALLING             0x10
 131 #define KEYP_EDR_TO_RISING              0x20
 132 #define KEYP_EDR_MIS_FALLING            0x40
 133 #define KEYP_EDR_MIS_RISING             0x80
 134
 135
 136 /*----------------------------------------------------------------------*/
 137
 138 static int twl4030_kpread(struct twl4030_keypad *kp,
 139                 u8 *data, u32 reg, u8 num_bytes)
 140 {
 141         int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
 142
 143         if (ret < 0)
 144                 dev_warn(kp->dbg_dev,
 145                         "Couldn't read TWL4030: %X - ret %d[%x]\n",
 146                          reg, ret, ret);
 147
 148         return ret;
 149 }
 150
 151 static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
 152 {
 153         int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
 154
 155         if (ret < 0)
 156                 dev_warn(kp->dbg_dev,
 157                         "Could not write TWL4030: %X - ret %d[%x]\n",
 158                          reg, ret, ret);
 159
 160         return ret;
 161 }
 162
 163 static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
 164 {
 165         /* If all bits in a row are active for all coloumns then
 166          * we have that row line connected to gnd. Mark this
 167          * key on as if it was on matrix position n_cols (ie
 168          * one higher than the size of the matrix).
 169          */
 170         if (col == 0xFF)
 171                 return 1 << kp->n_cols;
 172         else
 173                 return col & ((1 << kp->n_cols) - 1);
 174 }
 175
 176 static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
 177 {
 178         u8 new_state[TWL4030_MAX_ROWS];
 179         int row;
 180         int ret = twl4030_kpread(kp, new_state,
 181                                  KEYP_FULL_CODE_7_0, kp->n_rows);
 182         if (ret >= 0)
 183                 for (row = 0; row < kp->n_rows; row++)
 184                         state[row] = twl4030_col_xlate(kp, new_state[row]);
 185
 186         return ret;
 187 }
 188
 189 static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
 190 {
 191         int i;
 192         u16 check = 0;
 193
 194         for (i = 0; i < kp->n_rows; i++) {
 195                 u16 col = key_state[i];
 196
 197                 if ((col & check) && hweight16(col) > 1)
 198                         return true;
 199
 200                 check |= col;
 201         }
 202
 203         return false;
 204 }
 205
 206 static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
 207 {
 208         struct input_dev *input = kp->input;
 209         u16 new_state[TWL4030_MAX_ROWS];
 210         int col, row;
 211
 212         if (release_all)
 213                 memset(new_state, 0, sizeof(new_state));
 214         else {
 215                 /* check for any changes */
 216                 int ret = twl4030_read_kp_matrix_state(kp, new_state);
 217
 218                 if (ret < 0)    /* panic ... */
 219                         return;
 220
 221                 if (twl4030_is_in_ghost_state(kp, new_state))
 222                         return;
 223         }
 224
 225         /* check for changes and print those */
 226         for (row = 0; row < kp->n_rows; row++) {
 227                 int changed = new_state[row] ^ kp->kp_state[row];
 228
 229                 if (!changed)
 230                         continue;
 231
 232                 /* Extra column handles "all gnd" rows */
 233                 for (col = 0; col < kp->n_cols + 1; col++) {
 234                         int code;
 235
 236                         if (!(changed & (1 << col)))
 237                                 continue;
 238
 239                         dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
 240                                 (new_state[row] & (1 << col)) ?
 241                                 "press" : "release");
 242
 243                         code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
 244                         input_event(input, EV_MSC, MSC_SCAN, code);
 245                         input_report_key(input, kp->keymap[code],
 246                                          new_state[row] & (1 << col));
 247                 }
 248                 kp->kp_state[row] = new_state[row];
 249         }
 250         input_sync(input);
 251 }
 252
 253 /*
 254  * Keypad interrupt handler
 255  */
 256 static irqreturn_t do_kp_irq(int irq, void *_kp)
 257 {
 258         struct twl4030_keypad *kp = _kp;
 259         u8 reg;
 260         int ret;
 261
 262         /* Read & Clear TWL4030 pending interrupt */
 263         ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
 264
 265         /* Release all keys if I2C has gone bad or
 266          * the KEYP has gone to idle state */
 267         if (ret >= 0 && (reg & KEYP_IMR1_KP))
 268                 twl4030_kp_scan(kp, false);
 269         else
 270                 twl4030_kp_scan(kp, true);
 271
 272         return IRQ_HANDLED;
 273 }
 274
 275 static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
 276 {
 277         u8 reg;
 278         int i;
 279
 280         /* Enable controller, with hardware decoding but not autorepeat */
 281         reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
 282                 | KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
 283         if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
 284                 return -EIO;
 285
 286         /* NOTE:  we could use sih_setup() here to package keypad
 287          * event sources as four different IRQs ... but we don't.
 288          */
 289
 290         /* Enable TO rising and KP rising and falling edge detection */
 291         reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
 292         if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
 293                 return -EIO;
 294
 295         /* Set PTV prescaler Field */
 296         reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
 297         if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
 298                 return -EIO;
 299
 300         /* Set key debounce time to 20 ms */
 301         i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
 302         if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
 303                 return -EIO;
 304
 305         /* Set timeout period to 100 ms */
 306         i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
 307         if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
 308                 return -EIO;
 309
 310         if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
 311                 return -EIO;
 312
 313         /*
 314          * Enable Clear-on-Read; disable remembering events that fire
 315          * after the IRQ but before our handler acks (reads) them,
 316          */
 317         reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
 318         if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
 319                 return -EIO;
 320
 321         /* initialize key state; irqs update it from here on */
 322         if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
 323                 return -EIO;
 324
 325         return 0;
 326 }
 327
 328 /*
 329  * Registers keypad device with input subsystem
 330  * and configures TWL4030 keypad registers
 331  */
 332 static int __devinit twl4030_kp_probe(struct platform_device *pdev)
 333 {
 334         struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
 335         const struct matrix_keymap_data *keymap_data;
 336         struct twl4030_keypad *kp;
 337         struct input_dev *input;
 338         u8 reg;
 339         int error;
 340
 341         if (!pdata || !pdata->rows || !pdata->cols || !pdata->keymap_data ||
 342             pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
 343                 dev_err(&pdev->dev, "Invalid platform_data\n");
 344                 return -EINVAL;
 345         }
 346
 347         keymap_data = pdata->keymap_data;
 348
 349         kp = kzalloc(sizeof(*kp), GFP_KERNEL);
 350         input = input_allocate_device();
 351         if (!kp || !input) {
 352                 error = -ENOMEM;
 353                 goto err1;
 354         }
 355
 356         /* Get the debug Device */
 357         kp->dbg_dev = &pdev->dev;
 358         kp->input = input;
 359
 360         kp->n_rows = pdata->rows;
 361         kp->n_cols = pdata->cols;
 362         kp->irq = platform_get_irq(pdev, 0);
 363
 364         /* setup input device */
 365         __set_bit(EV_KEY, input->evbit);
 366
 367         /* Enable auto repeat feature of Linux input subsystem */
 368         if (pdata->rep)
 369                 __set_bit(EV_REP, input->evbit);
 370
 371         input_set_capability(input, EV_MSC, MSC_SCAN);
 372
 373         input->name             = "TWL4030 Keypad";
 374         input->phys             = "twl4030_keypad/input0";
 375         input->dev.parent       = &pdev->dev;
 376
 377         input->id.bustype       = BUS_HOST;
 378         input->id.vendor        = 0x0001;
 379         input->id.product       = 0x0001;
 380         input->id.version       = 0x0003;
 381
 382         input->keycode          = kp->keymap;
 383         input->keycodesize      = sizeof(kp->keymap[0]);
 384         input->keycodemax       = ARRAY_SIZE(kp->keymap);
 385
 386         matrix_keypad_build_keymap(keymap_data, TWL4030_ROW_SHIFT,
 387                                    input->keycode, input->keybit);
 388
 389         error = input_register_device(input);
 390         if (error) {
 391                 dev_err(kp->dbg_dev,
 392                         "Unable to register twl4030 keypad device\n");
 393                 goto err1;
 394         }
 395
 396         error = twl4030_kp_program(kp);
 397         if (error)
 398                 goto err2;
 399
 400         /*
 401          * This ISR will always execute in kernel thread context because of
 402          * the need to access the TWL4030 over the I2C bus.
 403          *
 404          * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
 405          */
 406         error = request_threaded_irq(kp->irq, NULL, do_kp_irq,
 407                         0, pdev->name, kp);
 408         if (error) {
 409                 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n",
 410                         kp->irq);
 411                 goto err2;
 412         }
 413
 414         /* Enable KP and TO interrupts now. */
 415         reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
 416         if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
 417                 error = -EIO;
 418                 goto err3;
 419         }
 420
 421         platform_set_drvdata(pdev, kp);
 422         return 0;
 423
 424 err3:
 425         /* mask all events - we don't care about the result */
 426         (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
 427         free_irq(kp->irq, NULL);
 428 err2:
 429         input_unregister_device(input);
 430         input = NULL;
 431 err1:
 432         input_free_device(input);
 433         kfree(kp);
 434         return error;
 435 }
 436
 437 static int __devexit twl4030_kp_remove(struct platform_device *pdev)
 438 {
 439         struct twl4030_keypad *kp = platform_get_drvdata(pdev);
 440
 441         free_irq(kp->irq, kp);
 442         input_unregister_device(kp->input);
 443         platform_set_drvdata(pdev, NULL);
 444         kfree(kp);
 445
 446         return 0;
 447 }
 448
 449 /*
 450  * NOTE: twl4030 are multi-function devices connected via I2C.
 451  * So this device is a child of an I2C parent, thus it needs to
 452  * support unplug/replug (which most platform devices don't).
 453  */
 454
 455 static struct platform_driver twl4030_kp_driver = {
 456         .probe          = twl4030_kp_probe,
 457         .remove         = __devexit_p(twl4030_kp_remove),
 458         .driver         = {
 459                 .name   = "twl4030_keypad",
 460                 .owner  = THIS_MODULE,
 461         },
 462 };
 463
 464 static int __init twl4030_kp_init(void)
 465 {
 466         return platform_driver_register(&twl4030_kp_driver);
 467 }
 468 module_init(twl4030_kp_init);
 469
 470 static void __exit twl4030_kp_exit(void)
 471 {
 472         platform_driver_unregister(&twl4030_kp_driver);
 473 }
 474 module_exit(twl4030_kp_exit);
 475
 476 MODULE_AUTHOR("Texas Instruments");
 477 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
 478 MODULE_LICENSE("GPL");
 479 MODULE_ALIAS("platform:twl4030_keypad");
 480