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 #define TWL4030_ROW_SHIFT       3
  55 #define TWL4030_KEYMAP_SIZE     (TWL4030_MAX_ROWS * TWL4030_MAX_COLS)
  56
  57 struct twl4030_keypad {
  58         unsigned short  keymap[TWL4030_KEYMAP_SIZE];
  59         u16             kp_state[TWL4030_MAX_ROWS];
  60         unsigned        n_rows;
  61         unsigned        n_cols;
  62         unsigned        irq;
  63
  64         struct device *dbg_dev;
  65         struct input_dev *input;
  66 };
  67
  68 /*----------------------------------------------------------------------*/
  69
  70 /* arbitrary prescaler value 0..7 */
  71 #define PTV_PRESCALER                   4
  72
  73 /* Register Offsets */
  74 #define KEYP_CTRL                       0x00
  75 #define KEYP_DEB                        0x01
  76 #define KEYP_LONG_KEY                   0x02
  77 #define KEYP_LK_PTV                     0x03
  78 #define KEYP_TIMEOUT_L                  0x04
  79 #define KEYP_TIMEOUT_H                  0x05
  80 #define KEYP_KBC                        0x06
  81 #define KEYP_KBR                        0x07
  82 #define KEYP_SMS                        0x08
  83 #define KEYP_FULL_CODE_7_0              0x09    /* row 0 column status */
  84 #define KEYP_FULL_CODE_15_8             0x0a    /* ... row 1 ... */
  85 #define KEYP_FULL_CODE_23_16            0x0b
  86 #define KEYP_FULL_CODE_31_24            0x0c
  87 #define KEYP_FULL_CODE_39_32            0x0d
  88 #define KEYP_FULL_CODE_47_40            0x0e
  89 #define KEYP_FULL_CODE_55_48            0x0f
  90 #define KEYP_FULL_CODE_63_56            0x10
  91 #define KEYP_ISR1                       0x11
  92 #define KEYP_IMR1                       0x12
  93 #define KEYP_ISR2                       0x13
  94 #define KEYP_IMR2                       0x14
  95 #define KEYP_SIR                        0x15
  96 #define KEYP_EDR                        0x16    /* edge triggers */
  97 #define KEYP_SIH_CTRL                   0x17
  98
  99 /* KEYP_CTRL_REG Fields */
 100 #define KEYP_CTRL_SOFT_NRST             BIT(0)
 101 #define KEYP_CTRL_SOFTMODEN             BIT(1)
 102 #define KEYP_CTRL_LK_EN                 BIT(2)
 103 #define KEYP_CTRL_TOE_EN                BIT(3)
 104 #define KEYP_CTRL_TOLE_EN               BIT(4)
 105 #define KEYP_CTRL_RP_EN                 BIT(5)
 106 #define KEYP_CTRL_KBD_ON                BIT(6)
 107
 108 /* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
 109 #define KEYP_PERIOD_US(t, prescale)     ((t) / (31 << (prescale + 1)) - 1)
 110
 111 /* KEYP_LK_PTV_REG Fields */
 112 #define KEYP_LK_PTV_PTV_SHIFT           5
 113
 114 /* KEYP_{IMR,ISR,SIR} Fields */
 115 #define KEYP_IMR1_MIS                   BIT(3)
 116 #define KEYP_IMR1_TO                    BIT(2)
 117 #define KEYP_IMR1_LK                    BIT(1)
 118 #define KEYP_IMR1_KP                    BIT(0)
 119
 120 /* KEYP_EDR Fields */
 121 #define KEYP_EDR_KP_FALLING             0x01
 122 #define KEYP_EDR_KP_RISING              0x02
 123 #define KEYP_EDR_KP_BOTH                0x03
 124 #define KEYP_EDR_LK_FALLING             0x04
 125 #define KEYP_EDR_LK_RISING              0x08
 126 #define KEYP_EDR_TO_FALLING             0x10
 127 #define KEYP_EDR_TO_RISING              0x20
 128 #define KEYP_EDR_MIS_FALLING            0x40
 129 #define KEYP_EDR_MIS_RISING             0x80
 130
 131
 132 /*----------------------------------------------------------------------*/
 133
 134 static int twl4030_kpread(struct twl4030_keypad *kp,
 135                 u8 *data, u32 reg, u8 num_bytes)
 136 {
 137         int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
 138
 139         if (ret < 0)
 140                 dev_warn(kp->dbg_dev,
 141                         "Couldn't read TWL4030: %X - ret %d[%x]\n",
 142                          reg, ret, ret);
 143
 144         return ret;
 145 }
 146
 147 static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
 148 {
 149         int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
 150
 151         if (ret < 0)
 152                 dev_warn(kp->dbg_dev,
 153                         "Could not write TWL4030: %X - ret %d[%x]\n",
 154                          reg, ret, ret);
 155
 156         return ret;
 157 }
 158
 159 static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
 160 {
 161         /* If all bits in a row are active for all coloumns then
 162          * we have that row line connected to gnd. Mark this
 163          * key on as if it was on matrix position n_cols (ie
 164          * one higher than the size of the matrix).
 165          */
 166         if (col == 0xFF)
 167                 return 1 << kp->n_cols;
 168         else
 169                 return col & ((1 << kp->n_cols) - 1);
 170 }
 171
 172 static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
 173 {
 174         u8 new_state[TWL4030_MAX_ROWS];
 175         int row;
 176         int ret = twl4030_kpread(kp, new_state,
 177                                  KEYP_FULL_CODE_7_0, kp->n_rows);
 178         if (ret >= 0)
 179                 for (row = 0; row < kp->n_rows; row++)
 180                         state[row] = twl4030_col_xlate(kp, new_state[row]);
 181
 182         return ret;
 183 }
 184
 185 static int twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
 186 {
 187         int i;
 188         u16 check = 0;
 189
 190         for (i = 0; i < kp->n_rows; i++) {
 191                 u16 col = key_state[i];
 192
 193                 if ((col & check) && hweight16(col) > 1)
 194                         return 1;
 195
 196                 check |= col;
 197         }
 198
 199         return 0;
 200 }
 201
 202 static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
 203 {
 204         struct input_dev *input = kp->input;
 205         u16 new_state[TWL4030_MAX_ROWS];
 206         int col, row;
 207
 208         if (release_all)
 209                 memset(new_state, 0, sizeof(new_state));
 210         else {
 211                 /* check for any changes */
 212                 int ret = twl4030_read_kp_matrix_state(kp, new_state);
 213
 214                 if (ret < 0)    /* panic ... */
 215                         return;
 216
 217                 if (twl4030_is_in_ghost_state(kp, new_state))
 218                         return;
 219         }
 220
 221         /* check for changes and print those */
 222         for (row = 0; row < kp->n_rows; row++) {
 223                 int changed = new_state[row] ^ kp->kp_state[row];
 224
 225                 if (!changed)
 226                         continue;
 227
 228                 for (col = 0; col < kp->n_cols; col++) {
 229                         int code;
 230
 231                         if (!(changed & (1 << col)))
 232                                 continue;
 233
 234                         dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
 235                                 (new_state[row] & (1 << col)) ?
 236                                 "press" : "release");
 237
 238                         code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
 239                         input_event(input, EV_MSC, MSC_SCAN, code);
 240                         input_report_key(input, kp->keymap[code],
 241                                          new_state[row] & (1 << col));
 242                 }
 243                 kp->kp_state[row] = new_state[row];
 244         }
 245         input_sync(input);
 246 }
 247
 248 /*
 249  * Keypad interrupt handler
 250  */
 251 static irqreturn_t do_kp_irq(int irq, void *_kp)
 252 {
 253         struct twl4030_keypad *kp = _kp;
 254         u8 reg;
 255         int ret;
 256
 257         /* Read & Clear TWL4030 pending interrupt */
 258         ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
 259
 260         /* Release all keys if I2C has gone bad or
 261          * the KEYP has gone to idle state */
 262         if (ret >= 0 && (reg & KEYP_IMR1_KP))
 263                 twl4030_kp_scan(kp, false);
 264         else
 265                 twl4030_kp_scan(kp, true);
 266
 267         return IRQ_HANDLED;
 268 }
 269
 270 static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
 271 {
 272         u8 reg;
 273         int i;
 274
 275         /* Enable controller, with hardware decoding but not autorepeat */
 276         reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
 277                 | KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
 278         if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
 279                 return -EIO;
 280
 281         /* NOTE:  we could use sih_setup() here to package keypad
 282          * event sources as four different IRQs ... but we don't.
 283          */
 284
 285         /* Enable TO rising and KP rising and falling edge detection */
 286         reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
 287         if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
 288                 return -EIO;
 289
 290         /* Set PTV prescaler Field */
 291         reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
 292         if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
 293                 return -EIO;
 294
 295         /* Set key debounce time to 20 ms */
 296         i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
 297         if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
 298                 return -EIO;
 299
 300         /* Set timeout period to 100 ms */
 301         i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
 302         if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
 303                 return -EIO;
 304
 305         if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
 306                 return -EIO;
 307
 308         /*
 309          * Enable Clear-on-Read; disable remembering events that fire
 310          * after the IRQ but before our handler acks (reads) them,
 311          */
 312         reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
 313         if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
 314                 return -EIO;
 315
 316         /* initialize key state; irqs update it from here on */
 317         if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
 318                 return -EIO;
 319
 320         return 0;
 321 }
 322
 323 /*
 324  * Registers keypad device with input subsystem
 325  * and configures TWL4030 keypad registers
 326  */
 327 static int __devinit twl4030_kp_probe(struct platform_device *pdev)
 328 {
 329         struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
 330         const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
 331         struct twl4030_keypad *kp;
 332         struct input_dev *input;
 333         u8 reg;
 334         int error;
 335
 336         if (!pdata || !pdata->rows || !pdata->cols ||
 337             pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
 338                 dev_err(&pdev->dev, "Invalid platform_data\n");
 339                 return -EINVAL;
 340         }
 341
 342         kp = kzalloc(sizeof(*kp), GFP_KERNEL);
 343         input = input_allocate_device();
 344         if (!kp || !input) {
 345                 error = -ENOMEM;
 346                 goto err1;
 347         }
 348
 349         /* Get the debug Device */
 350         kp->dbg_dev = &pdev->dev;
 351         kp->input = input;
 352
 353         kp->n_rows = pdata->rows;
 354         kp->n_cols = pdata->cols;
 355         kp->irq = platform_get_irq(pdev, 0);
 356
 357         /* setup input device */
 358         __set_bit(EV_KEY, input->evbit);
 359
 360         /* Enable auto repeat feature of Linux input subsystem */
 361         if (pdata->rep)
 362                 __set_bit(EV_REP, input->evbit);
 363
 364         input_set_capability(input, EV_MSC, MSC_SCAN);
 365
 366         input->name             = "TWL4030 Keypad";
 367         input->phys             = "twl4030_keypad/input0";
 368         input->dev.parent       = &pdev->dev;
 369
 370         input->id.bustype       = BUS_HOST;
 371         input->id.vendor        = 0x0001;
 372         input->id.product       = 0x0001;
 373         input->id.version       = 0x0003;
 374
 375         input->keycode          = kp->keymap;
 376         input->keycodesize      = sizeof(kp->keymap[0]);
 377         input->keycodemax       = ARRAY_SIZE(kp->keymap);
 378
 379         matrix_keypad_build_keymap(keymap_data, TWL4030_ROW_SHIFT,
 380                                    input->keycode, input->keybit);
 381
 382         error = input_register_device(input);
 383         if (error) {
 384                 dev_err(kp->dbg_dev,
 385                         "Unable to register twl4030 keypad device\n");
 386                 goto err1;
 387         }
 388
 389         error = twl4030_kp_program(kp);
 390         if (error)
 391                 goto err2;
 392
 393         /*
 394          * This ISR will always execute in kernel thread context because of
 395          * the need to access the TWL4030 over the I2C bus.
 396          *
 397          * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
 398          */
 399         error = request_threaded_irq(kp->irq, NULL, do_kp_irq,
 400                         0, pdev->name, kp);
 401         if (error) {
 402                 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n",
 403                         kp->irq);
 404                 goto err3;
 405         }
 406
 407         /* Enable KP and TO interrupts now. */
 408         reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
 409         if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
 410                 error = -EIO;
 411                 goto err4;
 412         }
 413
 414         platform_set_drvdata(pdev, kp);
 415         return 0;
 416
 417 err4:
 418         /* mask all events - we don't care about the result */
 419         (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
 420 err3:
 421         free_irq(kp->irq, NULL);
 422 err2:
 423         input_unregister_device(input);
 424         input = NULL;
 425 err1:
 426         input_free_device(input);
 427         kfree(kp);
 428         return error;
 429 }
 430
 431 static int __devexit twl4030_kp_remove(struct platform_device *pdev)
 432 {
 433         struct twl4030_keypad *kp = platform_get_drvdata(pdev);
 434
 435         free_irq(kp->irq, kp);
 436         input_unregister_device(kp->input);
 437         platform_set_drvdata(pdev, NULL);
 438         kfree(kp);
 439
 440         return 0;
 441 }
 442
 443 /*
 444  * NOTE: twl4030 are multi-function devices connected via I2C.
 445  * So this device is a child of an I2C parent, thus it needs to
 446  * support unplug/replug (which most platform devices don't).
 447  */
 448
 449 static struct platform_driver twl4030_kp_driver = {
 450         .probe          = twl4030_kp_probe,
 451         .remove         = __devexit_p(twl4030_kp_remove),
 452         .driver         = {
 453                 .name   = "twl4030_keypad",
 454                 .owner  = THIS_MODULE,
 455         },
 456 };
 457
 458 static int __init twl4030_kp_init(void)
 459 {
 460         return platform_driver_register(&twl4030_kp_driver);
 461 }
 462 module_init(twl4030_kp_init);
 463
 464 static void __exit twl4030_kp_exit(void)
 465 {
 466         platform_driver_unregister(&twl4030_kp_driver);
 467 }
 468 module_exit(twl4030_kp_exit);
 469
 470 MODULE_AUTHOR("Texas Instruments");
 471 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
 472 MODULE_LICENSE("GPL");
 473 MODULE_ALIAS("platform:twl4030_keypad");
 474