drivers/input/keyboard/twl4030_keypad.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * twl4030_keypad.c - driver for 8x8 keypad controller in twl4030 chips
   4  *
   5  * Copyright (C) 2007 Texas Instruments, Inc.
   6  * Copyright (C) 2008 Nokia Corporation
   7  *
   8  * Code re-written for 2430SDP by:
   9  * Syed Mohammed Khasim <x0khasim@ti.com>
  10  *
  11  * Initial Code:
  12  * Manjunatha G K <manjugk@ti.com>
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/input.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/mfd/twl.h>
  21 #include <linux/slab.h>
  22 #include <linux/of.h>
  23
  24 /*
  25  * The TWL4030 family chips include a keypad controller that supports
  26  * up to an 8x8 switch matrix.  The controller can issue system wakeup
  27  * events, since it uses only the always-on 32KiHz oscillator, and has
  28  * an internal state machine that decodes pressed keys, including
  29  * multi-key combinations.
  30  *
  31  * This driver lets boards define what keycodes they wish to report for
  32  * which scancodes, as part of the "struct twl4030_keypad_data" used in
  33  * the probe() routine.
  34  *
  35  * See the TPS65950 documentation; that's the general availability
  36  * version of the TWL5030 second generation part.
  37  */
  38 #define TWL4030_MAX_ROWS        8       /* TWL4030 hard limit */
  39 #define TWL4030_MAX_COLS        8
  40 /*
  41  * Note that we add space for an extra column so that we can handle
  42  * row lines connected to the gnd (see twl4030_col_xlate()).
  43  */
  44 #define TWL4030_ROW_SHIFT       4
  45 #define TWL4030_KEYMAP_SIZE     (TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT)
  46
  47 struct twl4030_keypad {
  48         unsigned short  keymap[TWL4030_KEYMAP_SIZE];
  49         u16             kp_state[TWL4030_MAX_ROWS];
  50         bool            autorepeat;
  51         unsigned int    n_rows;
  52         unsigned int    n_cols;
  53         int             irq;
  54
  55         struct device *dbg_dev;
  56         struct input_dev *input;
  57 };
  58
  59 /*----------------------------------------------------------------------*/
  60
  61 /* arbitrary prescaler value 0..7 */
  62 #define PTV_PRESCALER                   4
  63
  64 /* Register Offsets */
  65 #define KEYP_CTRL                       0x00
  66 #define KEYP_DEB                        0x01
  67 #define KEYP_LONG_KEY                   0x02
  68 #define KEYP_LK_PTV                     0x03
  69 #define KEYP_TIMEOUT_L                  0x04
  70 #define KEYP_TIMEOUT_H                  0x05
  71 #define KEYP_KBC                        0x06
  72 #define KEYP_KBR                        0x07
  73 #define KEYP_SMS                        0x08
  74 #define KEYP_FULL_CODE_7_0              0x09    /* row 0 column status */
  75 #define KEYP_FULL_CODE_15_8             0x0a    /* ... row 1 ... */
  76 #define KEYP_FULL_CODE_23_16            0x0b
  77 #define KEYP_FULL_CODE_31_24            0x0c
  78 #define KEYP_FULL_CODE_39_32            0x0d
  79 #define KEYP_FULL_CODE_47_40            0x0e
  80 #define KEYP_FULL_CODE_55_48            0x0f
  81 #define KEYP_FULL_CODE_63_56            0x10
  82 #define KEYP_ISR1                       0x11
  83 #define KEYP_IMR1                       0x12
  84 #define KEYP_ISR2                       0x13
  85 #define KEYP_IMR2                       0x14
  86 #define KEYP_SIR                        0x15
  87 #define KEYP_EDR                        0x16    /* edge triggers */
  88 #define KEYP_SIH_CTRL                   0x17
  89
  90 /* KEYP_CTRL_REG Fields */
  91 #define KEYP_CTRL_SOFT_NRST             BIT(0)
  92 #define KEYP_CTRL_SOFTMODEN             BIT(1)
  93 #define KEYP_CTRL_LK_EN                 BIT(2)
  94 #define KEYP_CTRL_TOE_EN                BIT(3)
  95 #define KEYP_CTRL_TOLE_EN               BIT(4)
  96 #define KEYP_CTRL_RP_EN                 BIT(5)
  97 #define KEYP_CTRL_KBD_ON                BIT(6)
  98
  99 /* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
 100 #define KEYP_PERIOD_US(t, prescale)     ((t) / (31 << ((prescale) + 1)) - 1)
 101
 102 /* KEYP_LK_PTV_REG Fields */
 103 #define KEYP_LK_PTV_PTV_SHIFT           5
 104
 105 /* KEYP_{IMR,ISR,SIR} Fields */
 106 #define KEYP_IMR1_MIS                   BIT(3)
 107 #define KEYP_IMR1_TO                    BIT(2)
 108 #define KEYP_IMR1_LK                    BIT(1)
 109 #define KEYP_IMR1_KP                    BIT(0)
 110
 111 /* KEYP_EDR Fields */
 112 #define KEYP_EDR_KP_FALLING             0x01
 113 #define KEYP_EDR_KP_RISING              0x02
 114 #define KEYP_EDR_KP_BOTH                0x03
 115 #define KEYP_EDR_LK_FALLING             0x04
 116 #define KEYP_EDR_LK_RISING              0x08
 117 #define KEYP_EDR_TO_FALLING             0x10
 118 #define KEYP_EDR_TO_RISING              0x20
 119 #define KEYP_EDR_MIS_FALLING            0x40
 120 #define KEYP_EDR_MIS_RISING             0x80
 121
 122
 123 /*----------------------------------------------------------------------*/
 124
 125 static int twl4030_kpread(struct twl4030_keypad *kp,
 126                 u8 *data, u32 reg, u8 num_bytes)
 127 {
 128         int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
 129
 130         if (ret < 0)
 131                 dev_warn(kp->dbg_dev,
 132                         "Couldn't read TWL4030: %X - ret %d[%x]\n",
 133                          reg, ret, ret);
 134
 135         return ret;
 136 }
 137
 138 static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
 139 {
 140         int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
 141
 142         if (ret < 0)
 143                 dev_warn(kp->dbg_dev,
 144                         "Could not write TWL4030: %X - ret %d[%x]\n",
 145                          reg, ret, ret);
 146
 147         return ret;
 148 }
 149
 150 static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
 151 {
 152         /*
 153          * If all bits in a row are active for all columns then
 154          * we have that row line connected to gnd. Mark this
 155          * key on as if it was on matrix position n_cols (i.e.
 156          * one higher than the size of the matrix).
 157          */
 158         if (col == 0xFF)
 159                 return 1 << kp->n_cols;
 160         else
 161                 return col & ((1 << kp->n_cols) - 1);
 162 }
 163
 164 static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
 165 {
 166         u8 new_state[TWL4030_MAX_ROWS];
 167         int row;
 168         int ret = twl4030_kpread(kp, new_state,
 169                                  KEYP_FULL_CODE_7_0, kp->n_rows);
 170         if (ret >= 0)
 171                 for (row = 0; row < kp->n_rows; row++)
 172                         state[row] = twl4030_col_xlate(kp, new_state[row]);
 173
 174         return ret;
 175 }
 176
 177 static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
 178 {
 179         int i;
 180         u16 check = 0;
 181
 182         for (i = 0; i < kp->n_rows; i++) {
 183                 u16 col = key_state[i];
 184
 185                 if ((col & check) && hweight16(col) > 1)
 186                         return true;
 187
 188                 check |= col;
 189         }
 190
 191         return false;
 192 }
 193
 194 static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
 195 {
 196         struct input_dev *input = kp->input;
 197         u16 new_state[TWL4030_MAX_ROWS];
 198         int col, row;
 199
 200         if (release_all) {
 201                 memset(new_state, 0, sizeof(new_state));
 202         } else {
 203                 /* check for any changes */
 204                 int ret = twl4030_read_kp_matrix_state(kp, new_state);
 205
 206                 if (ret < 0)    /* panic ... */
 207                         return;
 208
 209                 if (twl4030_is_in_ghost_state(kp, new_state))
 210                         return;
 211         }
 212
 213         /* check for changes and print those */
 214         for (row = 0; row < kp->n_rows; row++) {
 215                 int changed = new_state[row] ^ kp->kp_state[row];
 216
 217                 if (!changed)
 218                         continue;
 219
 220                 /* Extra column handles "all gnd" rows */
 221                 for (col = 0; col < kp->n_cols + 1; col++) {
 222                         int code;
 223
 224                         if (!(changed & (1 << col)))
 225                                 continue;
 226
 227                         dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
 228                                 (new_state[row] & (1 << col)) ?
 229                                 "press" : "release");
 230
 231                         code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
 232                         input_event(input, EV_MSC, MSC_SCAN, code);
 233                         input_report_key(input, kp->keymap[code],
 234                                          new_state[row] & (1 << col));
 235                 }
 236                 kp->kp_state[row] = new_state[row];
 237         }
 238         input_sync(input);
 239 }
 240
 241 /*
 242  * Keypad interrupt handler
 243  */
 244 static irqreturn_t do_kp_irq(int irq, void *_kp)
 245 {
 246         struct twl4030_keypad *kp = _kp;
 247         u8 reg;
 248         int ret;
 249
 250         /* Read & Clear TWL4030 pending interrupt */
 251         ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
 252
 253         /*
 254          * Release all keys if I2C has gone bad or
 255          * the KEYP has gone to idle state.
 256          */
 257         if (ret >= 0 && (reg & KEYP_IMR1_KP))
 258                 twl4030_kp_scan(kp, false);
 259         else
 260                 twl4030_kp_scan(kp, true);
 261
 262         return IRQ_HANDLED;
 263 }
 264
 265 static int twl4030_kp_program(struct twl4030_keypad *kp)
 266 {
 267         u8 reg;
 268         int i;
 269
 270         /* Enable controller, with hardware decoding but not autorepeat */
 271         reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
 272                 | KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
 273         if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
 274                 return -EIO;
 275
 276         /*
 277          * NOTE: we could use sih_setup() here to package keypad
 278          * event sources as four different IRQs ... but we don't.
 279          */
 280
 281         /* Enable TO rising and KP rising and falling edge detection */
 282         reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
 283         if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
 284                 return -EIO;
 285
 286         /* Set PTV prescaler Field */
 287         reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
 288         if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
 289                 return -EIO;
 290
 291         /* Set key debounce time to 20 ms */
 292         i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
 293         if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
 294                 return -EIO;
 295
 296         /* Set timeout period to 200 ms */
 297         i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
 298         if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
 299                 return -EIO;
 300
 301         if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
 302                 return -EIO;
 303
 304         /*
 305          * Enable Clear-on-Read; disable remembering events that fire
 306          * after the IRQ but before our handler acks (reads) them.
 307          */
 308         reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
 309         if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
 310                 return -EIO;
 311
 312         /* initialize key state; irqs update it from here on */
 313         if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
 314                 return -EIO;
 315
 316         return 0;
 317 }
 318
 319 /*
 320  * Registers keypad device with input subsystem
 321  * and configures TWL4030 keypad registers
 322  */
 323 static int twl4030_kp_probe(struct platform_device *pdev)
 324 {
 325         struct twl4030_keypad_data *pdata = dev_get_platdata(&pdev->dev);
 326         const struct matrix_keymap_data *keymap_data = NULL;
 327         struct twl4030_keypad *kp;
 328         struct input_dev *input;
 329         u8 reg;
 330         int error;
 331
 332         kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
 333         if (!kp)
 334                 return -ENOMEM;
 335
 336         input = devm_input_allocate_device(&pdev->dev);
 337         if (!input)
 338                 return -ENOMEM;
 339
 340         /* get the debug device */
 341         kp->dbg_dev             = &pdev->dev;
 342         kp->input               = input;
 343
 344         /* setup input device */
 345         input->name             = "TWL4030 Keypad";
 346         input->phys             = "twl4030_keypad/input0";
 347
 348         input->id.bustype       = BUS_HOST;
 349         input->id.vendor        = 0x0001;
 350         input->id.product       = 0x0001;
 351         input->id.version       = 0x0003;
 352
 353         if (pdata) {
 354                 if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
 355                         dev_err(&pdev->dev, "Missing platform_data\n");
 356                         return -EINVAL;
 357                 }
 358
 359                 kp->n_rows = pdata->rows;
 360                 kp->n_cols = pdata->cols;
 361                 kp->autorepeat = pdata->rep;
 362                 keymap_data = pdata->keymap_data;
 363         } else {
 364                 error = matrix_keypad_parse_properties(&pdev->dev, &kp->n_rows,
 365                                                        &kp->n_cols);
 366                 if (error)
 367                         return error;
 368
 369                 kp->autorepeat = true;
 370         }
 371
 372         if (kp->n_rows > TWL4030_MAX_ROWS || kp->n_cols > TWL4030_MAX_COLS) {
 373                 dev_err(&pdev->dev,
 374                         "Invalid rows/cols amount specified in platform/devicetree data\n");
 375                 return -EINVAL;
 376         }
 377
 378         kp->irq = platform_get_irq(pdev, 0);
 379         if (kp->irq < 0)
 380                 return kp->irq;
 381
 382         error = matrix_keypad_build_keymap(keymap_data, NULL,
 383                                            TWL4030_MAX_ROWS,
 384                                            1 << TWL4030_ROW_SHIFT,
 385                                            kp->keymap, input);
 386         if (error) {
 387                 dev_err(kp->dbg_dev, "Failed to build keymap\n");
 388                 return error;
 389         }
 390
 391         input_set_capability(input, EV_MSC, MSC_SCAN);
 392         /* Enable auto repeat feature of Linux input subsystem */
 393         if (kp->autorepeat)
 394                 __set_bit(EV_REP, input->evbit);
 395
 396         error = input_register_device(input);
 397         if (error) {
 398                 dev_err(kp->dbg_dev,
 399                         "Unable to register twl4030 keypad device\n");
 400                 return error;
 401         }
 402
 403         error = twl4030_kp_program(kp);
 404         if (error)
 405                 return error;
 406
 407         /*
 408          * This ISR will always execute in kernel thread context because of
 409          * the need to access the TWL4030 over the I2C bus.
 410          *
 411          * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
 412          */
 413         error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq,
 414                                           0, pdev->name, kp);
 415         if (error) {
 416                 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n",
 417                         kp->irq, error);
 418                 return error;
 419         }
 420
 421         /* Enable KP and TO interrupts now. */
 422         reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
 423         if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
 424                 /* mask all events - we don't care about the result */
 425                 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
 426                 return -EIO;
 427         }
 428
 429         return 0;
 430 }
 431
 432 #ifdef CONFIG_OF
 433 static const struct of_device_id twl4030_keypad_dt_match_table[] = {
 434         { .compatible = "ti,twl4030-keypad" },
 435         {},
 436 };
 437 MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table);
 438 #endif
 439
 440 /*
 441  * NOTE: twl4030 are multi-function devices connected via I2C.
 442  * So this device is a child of an I2C parent, thus it needs to
 443  * support unplug/replug (which most platform devices don't).
 444  */
 445
 446 static struct platform_driver twl4030_kp_driver = {
 447         .probe          = twl4030_kp_probe,
 448         .driver         = {
 449                 .name   = "twl4030_keypad",
 450                 .of_match_table = of_match_ptr(twl4030_keypad_dt_match_table),
 451         },
 452 };
 453 module_platform_driver(twl4030_kp_driver);
 454
 455 MODULE_AUTHOR("Texas Instruments");
 456 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
 457 MODULE_LICENSE("GPL");
 458 MODULE_ALIAS("platform:twl4030_keypad");