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