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/i2c/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        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 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 200 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 twl4030_kp_probe(struct platform_device *pdev)
 333 {
 334         struct twl4030_keypad_data *pdata = dev_get_platdata(&pdev->dev);
 335         const struct matrix_keymap_data *keymap_data = NULL;
 336         struct twl4030_keypad *kp;
 337         struct input_dev *input;
 338         u8 reg;
 339         int error;
 340
 341         kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
 342         if (!kp)
 343                 return -ENOMEM;
 344
 345         input = devm_input_allocate_device(&pdev->dev);
 346         if (!input)
 347                 return -ENOMEM;
 348
 349         /* get the debug device */
 350         kp->dbg_dev             = &pdev->dev;
 351         kp->input               = input;
 352
 353         /* setup input device */
 354         input->name             = "TWL4030 Keypad";
 355         input->phys             = "twl4030_keypad/input0";
 356
 357         input->id.bustype       = BUS_HOST;
 358         input->id.vendor        = 0x0001;
 359         input->id.product       = 0x0001;
 360         input->id.version       = 0x0003;
 361
 362         if (pdata) {
 363                 if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
 364                         dev_err(&pdev->dev, "Missing platform_data\n");
 365                         return -EINVAL;
 366                 }
 367
 368                 kp->n_rows = pdata->rows;
 369                 kp->n_cols = pdata->cols;
 370                 kp->autorepeat = pdata->rep;
 371                 keymap_data = pdata->keymap_data;
 372         } else {
 373                 error = matrix_keypad_parse_of_params(&pdev->dev, &kp->n_rows,
 374                                                       &kp->n_cols);
 375                 if (error)
 376                         return error;
 377
 378                 kp->autorepeat = true;
 379         }
 380
 381         if (kp->n_rows > TWL4030_MAX_ROWS || kp->n_cols > TWL4030_MAX_COLS) {
 382                 dev_err(&pdev->dev,
 383                         "Invalid rows/cols amount specified in platform/devicetree data\n");
 384                 return -EINVAL;
 385         }
 386
 387         kp->irq = platform_get_irq(pdev, 0);
 388         if (!kp->irq) {
 389                 dev_err(&pdev->dev, "no keyboard irq assigned\n");
 390                 return -EINVAL;
 391         }
 392
 393         error = matrix_keypad_build_keymap(keymap_data, NULL,
 394                                            TWL4030_MAX_ROWS,
 395                                            1 << TWL4030_ROW_SHIFT,
 396                                            kp->keymap, input);
 397         if (error) {
 398                 dev_err(kp->dbg_dev, "Failed to build keymap\n");
 399                 return error;
 400         }
 401
 402         input_set_capability(input, EV_MSC, MSC_SCAN);
 403         /* Enable auto repeat feature of Linux input subsystem */
 404         if (kp->autorepeat)
 405                 __set_bit(EV_REP, input->evbit);
 406
 407         error = input_register_device(input);
 408         if (error) {
 409                 dev_err(kp->dbg_dev,
 410                         "Unable to register twl4030 keypad device\n");
 411                 return error;
 412         }
 413
 414         error = twl4030_kp_program(kp);
 415         if (error)
 416                 return error;
 417
 418         /*
 419          * This ISR will always execute in kernel thread context because of
 420          * the need to access the TWL4030 over the I2C bus.
 421          *
 422          * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
 423          */
 424         error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq,
 425                                           0, pdev->name, kp);
 426         if (error) {
 427                 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n",
 428                         kp->irq, error);
 429                 return error;
 430         }
 431
 432         /* Enable KP and TO interrupts now. */
 433         reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
 434         if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
 435                 /* mask all events - we don't care about the result */
 436                 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
 437                 return -EIO;
 438         }
 439
 440         platform_set_drvdata(pdev, kp);
 441         return 0;
 442 }
 443
 444 #ifdef CONFIG_OF
 445 static const struct of_device_id twl4030_keypad_dt_match_table[] = {
 446         { .compatible = "ti,twl4030-keypad" },
 447         {},
 448 };
 449 MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table);
 450 #endif
 451
 452 /*
 453  * NOTE: twl4030 are multi-function devices connected via I2C.
 454  * So this device is a child of an I2C parent, thus it needs to
 455  * support unplug/replug (which most platform devices don't).
 456  */
 457
 458 static struct platform_driver twl4030_kp_driver = {
 459         .probe          = twl4030_kp_probe,
 460         .driver         = {
 461                 .name   = "twl4030_keypad",
 462                 .of_match_table = of_match_ptr(twl4030_keypad_dt_match_table),
 463         },
 464 };
 465 module_platform_driver(twl4030_kp_driver);
 466
 467 MODULE_AUTHOR("Texas Instruments");
 468 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
 469 MODULE_LICENSE("GPL");
 470 MODULE_ALIAS("platform:twl4030_keypad");