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/interrupt.h>
  31 #include <linux/input.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/mfd/twl.h>
  34 #include <linux/slab.h>
  35 #include <linux/of.h>
  36
  37 /*
  38  * The TWL4030 family chips include a keypad controller that supports
  39  * up to an 8x8 switch matrix.  The controller can issue system wakeup
  40  * events, since it uses only the always-on 32KiHz oscillator, and has
  41  * an internal state machine that decodes pressed keys, including
  42  * multi-key combinations.
  43  *
  44  * This driver lets boards define what keycodes they wish to report for
  45  * which scancodes, as part of the "struct twl4030_keypad_data" used in
  46  * the probe() routine.
  47  *
  48  * See the TPS65950 documentation; that's the general availability
  49  * version of the TWL5030 second generation part.
  50  */
  51 #define TWL4030_MAX_ROWS        8       /* TWL4030 hard limit */
  52 #define TWL4030_MAX_COLS        8
  53 /*
  54  * Note that we add space for an extra column so that we can handle
  55  * row lines connected to the gnd (see twl4030_col_xlate()).
  56  */
  57 #define TWL4030_ROW_SHIFT       4
  58 #define TWL4030_KEYMAP_SIZE     (TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT)
  59
  60 struct twl4030_keypad {
  61         unsigned short  keymap[TWL4030_KEYMAP_SIZE];
  62         u16             kp_state[TWL4030_MAX_ROWS];
  63         bool            autorepeat;
  64         unsigned int    n_rows;
  65         unsigned int    n_cols;
  66         unsigned int    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         /*
 166          * If all bits in a row are active for all columns then
 167          * we have that row line connected to gnd. Mark this
 168          * key on as if it was on matrix position n_cols (i.e.
 169          * one higher than the size of the matrix).
 170          */
 171         if (col == 0xFF)
 172                 return 1 << kp->n_cols;
 173         else
 174                 return col & ((1 << kp->n_cols) - 1);
 175 }
 176
 177 static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
 178 {
 179         u8 new_state[TWL4030_MAX_ROWS];
 180         int row;
 181         int ret = twl4030_kpread(kp, new_state,
 182                                  KEYP_FULL_CODE_7_0, kp->n_rows);
 183         if (ret >= 0)
 184                 for (row = 0; row < kp->n_rows; row++)
 185                         state[row] = twl4030_col_xlate(kp, new_state[row]);
 186
 187         return ret;
 188 }
 189
 190 static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
 191 {
 192         int i;
 193         u16 check = 0;
 194
 195         for (i = 0; i < kp->n_rows; i++) {
 196                 u16 col = key_state[i];
 197
 198                 if ((col & check) && hweight16(col) > 1)
 199                         return true;
 200
 201                 check |= col;
 202         }
 203
 204         return false;
 205 }
 206
 207 static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
 208 {
 209         struct input_dev *input = kp->input;
 210         u16 new_state[TWL4030_MAX_ROWS];
 211         int col, row;
 212
 213         if (release_all) {
 214                 memset(new_state, 0, sizeof(new_state));
 215         } else {
 216                 /* check for any changes */
 217                 int ret = twl4030_read_kp_matrix_state(kp, new_state);
 218
 219                 if (ret < 0)    /* panic ... */
 220                         return;
 221
 222                 if (twl4030_is_in_ghost_state(kp, new_state))
 223                         return;
 224         }
 225
 226         /* check for changes and print those */
 227         for (row = 0; row < kp->n_rows; row++) {
 228                 int changed = new_state[row] ^ kp->kp_state[row];
 229
 230                 if (!changed)
 231                         continue;
 232
 233                 /* Extra column handles "all gnd" rows */
 234                 for (col = 0; col < kp->n_cols + 1; col++) {
 235                         int code;
 236
 237                         if (!(changed & (1 << col)))
 238                                 continue;
 239
 240                         dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
 241                                 (new_state[row] & (1 << col)) ?
 242                                 "press" : "release");
 243
 244                         code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
 245                         input_event(input, EV_MSC, MSC_SCAN, code);
 246                         input_report_key(input, kp->keymap[code],
 247                                          new_state[row] & (1 << col));
 248                 }
 249                 kp->kp_state[row] = new_state[row];
 250         }
 251         input_sync(input);
 252 }
 253
 254 /*
 255  * Keypad interrupt handler
 256  */
 257 static irqreturn_t do_kp_irq(int irq, void *_kp)
 258 {
 259         struct twl4030_keypad *kp = _kp;
 260         u8 reg;
 261         int ret;
 262
 263         /* Read & Clear TWL4030 pending interrupt */
 264         ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
 265
 266         /*
 267          * Release all keys if I2C has gone bad or
 268          * the KEYP has gone to idle state.
 269          */
 270         if (ret >= 0 && (reg & KEYP_IMR1_KP))
 271                 twl4030_kp_scan(kp, false);
 272         else
 273                 twl4030_kp_scan(kp, true);
 274
 275         return IRQ_HANDLED;
 276 }
 277
 278 static int twl4030_kp_program(struct twl4030_keypad *kp)
 279 {
 280         u8 reg;
 281         int i;
 282
 283         /* Enable controller, with hardware decoding but not autorepeat */
 284         reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
 285                 | KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
 286         if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
 287                 return -EIO;
 288
 289         /*
 290          * NOTE: we could use sih_setup() here to package keypad
 291          * event sources as four different IRQs ... but we don't.
 292          */
 293
 294         /* Enable TO rising and KP rising and falling edge detection */
 295         reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
 296         if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
 297                 return -EIO;
 298
 299         /* Set PTV prescaler Field */
 300         reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
 301         if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
 302                 return -EIO;
 303
 304         /* Set key debounce time to 20 ms */
 305         i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
 306         if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
 307                 return -EIO;
 308
 309         /* Set timeout period to 200 ms */
 310         i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
 311         if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
 312                 return -EIO;
 313
 314         if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
 315                 return -EIO;
 316
 317         /*
 318          * Enable Clear-on-Read; disable remembering events that fire
 319          * after the IRQ but before our handler acks (reads) them.
 320          */
 321         reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
 322         if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
 323                 return -EIO;
 324
 325         /* initialize key state; irqs update it from here on */
 326         if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
 327                 return -EIO;
 328
 329         return 0;
 330 }
 331
 332 /*
 333  * Registers keypad device with input subsystem
 334  * and configures TWL4030 keypad registers
 335  */
 336 static int twl4030_kp_probe(struct platform_device *pdev)
 337 {
 338         struct twl4030_keypad_data *pdata = dev_get_platdata(&pdev->dev);
 339         const struct matrix_keymap_data *keymap_data = NULL;
 340         struct twl4030_keypad *kp;
 341         struct input_dev *input;
 342         u8 reg;
 343         int error;
 344
 345         kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
 346         if (!kp)
 347                 return -ENOMEM;
 348
 349         input = devm_input_allocate_device(&pdev->dev);
 350         if (!input)
 351                 return -ENOMEM;
 352
 353         /* get the debug device */
 354         kp->dbg_dev             = &pdev->dev;
 355         kp->input               = input;
 356
 357         /* setup input device */
 358         input->name             = "TWL4030 Keypad";
 359         input->phys             = "twl4030_keypad/input0";
 360
 361         input->id.bustype       = BUS_HOST;
 362         input->id.vendor        = 0x0001;
 363         input->id.product       = 0x0001;
 364         input->id.version       = 0x0003;
 365
 366         if (pdata) {
 367                 if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
 368                         dev_err(&pdev->dev, "Missing platform_data\n");
 369                         return -EINVAL;
 370                 }
 371
 372                 kp->n_rows = pdata->rows;
 373                 kp->n_cols = pdata->cols;
 374                 kp->autorepeat = pdata->rep;
 375                 keymap_data = pdata->keymap_data;
 376         } else {
 377                 error = matrix_keypad_parse_properties(&pdev->dev, &kp->n_rows,
 378                                                        &kp->n_cols);
 379                 if (error)
 380                         return error;
 381
 382                 kp->autorepeat = true;
 383         }
 384
 385         if (kp->n_rows > TWL4030_MAX_ROWS || kp->n_cols > TWL4030_MAX_COLS) {
 386                 dev_err(&pdev->dev,
 387                         "Invalid rows/cols amount specified in platform/devicetree data\n");
 388                 return -EINVAL;
 389         }
 390
 391         kp->irq = platform_get_irq(pdev, 0);
 392         if (!kp->irq) {
 393                 dev_err(&pdev->dev, "no keyboard irq assigned\n");
 394                 return -EINVAL;
 395         }
 396
 397         error = matrix_keypad_build_keymap(keymap_data, NULL,
 398                                            TWL4030_MAX_ROWS,
 399                                            1 << TWL4030_ROW_SHIFT,
 400                                            kp->keymap, input);
 401         if (error) {
 402                 dev_err(kp->dbg_dev, "Failed to build keymap\n");
 403                 return error;
 404         }
 405
 406         input_set_capability(input, EV_MSC, MSC_SCAN);
 407         /* Enable auto repeat feature of Linux input subsystem */
 408         if (kp->autorepeat)
 409                 __set_bit(EV_REP, input->evbit);
 410
 411         error = input_register_device(input);
 412         if (error) {
 413                 dev_err(kp->dbg_dev,
 414                         "Unable to register twl4030 keypad device\n");
 415                 return error;
 416         }
 417
 418         error = twl4030_kp_program(kp);
 419         if (error)
 420                 return error;
 421
 422         /*
 423          * This ISR will always execute in kernel thread context because of
 424          * the need to access the TWL4030 over the I2C bus.
 425          *
 426          * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
 427          */
 428         error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq,
 429                                           0, pdev->name, kp);
 430         if (error) {
 431                 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n",
 432                         kp->irq, error);
 433                 return error;
 434         }
 435
 436         /* Enable KP and TO interrupts now. */
 437         reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
 438         if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
 439                 /* mask all events - we don't care about the result */
 440                 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
 441                 return -EIO;
 442         }
 443
 444         return 0;
 445 }
 446
 447 #ifdef CONFIG_OF
 448 static const struct of_device_id twl4030_keypad_dt_match_table[] = {
 449         { .compatible = "ti,twl4030-keypad" },
 450         {},
 451 };
 452 MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table);
 453 #endif
 454
 455 /*
 456  * NOTE: twl4030 are multi-function devices connected via I2C.
 457  * So this device is a child of an I2C parent, thus it needs to
 458  * support unplug/replug (which most platform devices don't).
 459  */
 460
 461 static struct platform_driver twl4030_kp_driver = {
 462         .probe          = twl4030_kp_probe,
 463         .driver         = {
 464                 .name   = "twl4030_keypad",
 465                 .of_match_table = of_match_ptr(twl4030_keypad_dt_match_table),
 466         },
 467 };
 468 module_platform_driver(twl4030_kp_driver);
 469
 470 MODULE_AUTHOR("Texas Instruments");
 471 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
 472 MODULE_LICENSE("GPL");
 473 MODULE_ALIAS("platform:twl4030_keypad");