linux/drivers/input/keyboard/twl4030_keypad.c
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   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
  60struct 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
 138static 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
 151static 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
 163static 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
 177static 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
 190static 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
 207static 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 */
 257static 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
 278static 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 */
 336static 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_of_params(&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        platform_set_drvdata(pdev, kp);
 445        return 0;
 446}
 447
 448#ifdef CONFIG_OF
 449static const struct of_device_id twl4030_keypad_dt_match_table[] = {
 450        { .compatible = "ti,twl4030-keypad" },
 451        {},
 452};
 453MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table);
 454#endif
 455
 456/*
 457 * NOTE: twl4030 are multi-function devices connected via I2C.
 458 * So this device is a child of an I2C parent, thus it needs to
 459 * support unplug/replug (which most platform devices don't).
 460 */
 461
 462static struct platform_driver twl4030_kp_driver = {
 463        .probe          = twl4030_kp_probe,
 464        .driver         = {
 465                .name   = "twl4030_keypad",
 466                .of_match_table = of_match_ptr(twl4030_keypad_dt_match_table),
 467        },
 468};
 469module_platform_driver(twl4030_kp_driver);
 470
 471MODULE_AUTHOR("Texas Instruments");
 472MODULE_DESCRIPTION("TWL4030 Keypad Driver");
 473MODULE_LICENSE("GPL");
 474MODULE_ALIAS("platform:twl4030_keypad");
 475