linux/drivers/input/keyboard/stmpe-keypad.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) ST-Ericsson SA 2010
   4 *
   5 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/slab.h>
  10#include <linux/input.h>
  11#include <linux/interrupt.h>
  12#include <linux/platform_device.h>
  13#include <linux/input/matrix_keypad.h>
  14#include <linux/mfd/stmpe.h>
  15
  16/* These are at the same addresses in all STMPE variants */
  17#define STMPE_KPC_COL                   0x60
  18#define STMPE_KPC_ROW_MSB               0x61
  19#define STMPE_KPC_ROW_LSB               0x62
  20#define STMPE_KPC_CTRL_MSB              0x63
  21#define STMPE_KPC_CTRL_LSB              0x64
  22#define STMPE_KPC_COMBI_KEY_0           0x65
  23#define STMPE_KPC_COMBI_KEY_1           0x66
  24#define STMPE_KPC_COMBI_KEY_2           0x67
  25#define STMPE_KPC_DATA_BYTE0            0x68
  26#define STMPE_KPC_DATA_BYTE1            0x69
  27#define STMPE_KPC_DATA_BYTE2            0x6a
  28#define STMPE_KPC_DATA_BYTE3            0x6b
  29#define STMPE_KPC_DATA_BYTE4            0x6c
  30
  31#define STMPE_KPC_CTRL_LSB_SCAN         (0x1 << 0)
  32#define STMPE_KPC_CTRL_LSB_DEBOUNCE     (0x7f << 1)
  33#define STMPE_KPC_CTRL_MSB_SCAN_COUNT   (0xf << 4)
  34
  35#define STMPE_KPC_ROW_MSB_ROWS          0xff
  36
  37#define STMPE_KPC_DATA_UP               (0x1 << 7)
  38#define STMPE_KPC_DATA_ROW              (0xf << 3)
  39#define STMPE_KPC_DATA_COL              (0x7 << 0)
  40#define STMPE_KPC_DATA_NOKEY_MASK       0x78
  41
  42#define STMPE_KEYPAD_MAX_DEBOUNCE       127
  43#define STMPE_KEYPAD_MAX_SCAN_COUNT     15
  44
  45#define STMPE_KEYPAD_MAX_ROWS           8
  46#define STMPE_KEYPAD_MAX_COLS           8
  47#define STMPE_KEYPAD_ROW_SHIFT          3
  48#define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
  49        (STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
  50
  51
  52#define STMPE1601_NUM_DATA      5
  53#define STMPE2401_NUM_DATA      3
  54#define STMPE2403_NUM_DATA      5
  55
  56/* Make sure it covers all cases above */
  57#define MAX_NUM_DATA            5
  58
  59/**
  60 * struct stmpe_keypad_variant - model-specific attributes
  61 * @auto_increment: whether the KPC_DATA_BYTE register address
  62 *                  auto-increments on multiple read
  63 * @set_pullup: whether the pins need to have their pull-ups set
  64 * @num_data: number of data bytes
  65 * @num_normal_data: number of normal keys' data bytes
  66 * @max_cols: maximum number of columns supported
  67 * @max_rows: maximum number of rows supported
  68 * @col_gpios: bitmask of gpios which can be used for columns
  69 * @row_gpios: bitmask of gpios which can be used for rows
  70 */
  71struct stmpe_keypad_variant {
  72        bool            auto_increment;
  73        bool            set_pullup;
  74        int             num_data;
  75        int             num_normal_data;
  76        int             max_cols;
  77        int             max_rows;
  78        unsigned int    col_gpios;
  79        unsigned int    row_gpios;
  80};
  81
  82static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
  83        [STMPE1601] = {
  84                .auto_increment         = true,
  85                .num_data               = STMPE1601_NUM_DATA,
  86                .num_normal_data        = 3,
  87                .max_cols               = 8,
  88                .max_rows               = 8,
  89                .col_gpios              = 0x000ff,      /* GPIO 0 - 7 */
  90                .row_gpios              = 0x0ff00,      /* GPIO 8 - 15 */
  91        },
  92        [STMPE2401] = {
  93                .auto_increment         = false,
  94                .set_pullup             = true,
  95                .num_data               = STMPE2401_NUM_DATA,
  96                .num_normal_data        = 2,
  97                .max_cols               = 8,
  98                .max_rows               = 12,
  99                .col_gpios              = 0x0000ff,     /* GPIO 0 - 7*/
 100                .row_gpios              = 0x1f7f00,     /* GPIO 8-14, 16-20 */
 101        },
 102        [STMPE2403] = {
 103                .auto_increment         = true,
 104                .set_pullup             = true,
 105                .num_data               = STMPE2403_NUM_DATA,
 106                .num_normal_data        = 3,
 107                .max_cols               = 8,
 108                .max_rows               = 12,
 109                .col_gpios              = 0x0000ff,     /* GPIO 0 - 7*/
 110                .row_gpios              = 0x1fef00,     /* GPIO 8-14, 16-20 */
 111        },
 112};
 113
 114/**
 115 * struct stmpe_keypad - STMPE keypad state container
 116 * @stmpe: pointer to parent STMPE device
 117 * @input: spawned input device
 118 * @variant: STMPE variant
 119 * @debounce_ms: debounce interval, in ms.  Maximum is
 120 *               %STMPE_KEYPAD_MAX_DEBOUNCE.
 121 * @scan_count: number of key scanning cycles to confirm key data.
 122 *              Maximum is %STMPE_KEYPAD_MAX_SCAN_COUNT.
 123 * @no_autorepeat: disable key autorepeat
 124 * @rows: bitmask for the rows
 125 * @cols: bitmask for the columns
 126 * @keymap: the keymap
 127 */
 128struct stmpe_keypad {
 129        struct stmpe *stmpe;
 130        struct input_dev *input;
 131        const struct stmpe_keypad_variant *variant;
 132        unsigned int debounce_ms;
 133        unsigned int scan_count;
 134        bool no_autorepeat;
 135        unsigned int rows;
 136        unsigned int cols;
 137        unsigned short keymap[STMPE_KEYPAD_KEYMAP_MAX_SIZE];
 138};
 139
 140static int stmpe_keypad_read_data(struct stmpe_keypad *keypad, u8 *data)
 141{
 142        const struct stmpe_keypad_variant *variant = keypad->variant;
 143        struct stmpe *stmpe = keypad->stmpe;
 144        int ret;
 145        int i;
 146
 147        if (variant->auto_increment)
 148                return stmpe_block_read(stmpe, STMPE_KPC_DATA_BYTE0,
 149                                        variant->num_data, data);
 150
 151        for (i = 0; i < variant->num_data; i++) {
 152                ret = stmpe_reg_read(stmpe, STMPE_KPC_DATA_BYTE0 + i);
 153                if (ret < 0)
 154                        return ret;
 155
 156                data[i] = ret;
 157        }
 158
 159        return 0;
 160}
 161
 162static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
 163{
 164        struct stmpe_keypad *keypad = dev;
 165        struct input_dev *input = keypad->input;
 166        const struct stmpe_keypad_variant *variant = keypad->variant;
 167        u8 fifo[MAX_NUM_DATA];
 168        int ret;
 169        int i;
 170
 171        ret = stmpe_keypad_read_data(keypad, fifo);
 172        if (ret < 0)
 173                return IRQ_NONE;
 174
 175        for (i = 0; i < variant->num_normal_data; i++) {
 176                u8 data = fifo[i];
 177                int row = (data & STMPE_KPC_DATA_ROW) >> 3;
 178                int col = data & STMPE_KPC_DATA_COL;
 179                int code = MATRIX_SCAN_CODE(row, col, STMPE_KEYPAD_ROW_SHIFT);
 180                bool up = data & STMPE_KPC_DATA_UP;
 181
 182                if ((data & STMPE_KPC_DATA_NOKEY_MASK)
 183                        == STMPE_KPC_DATA_NOKEY_MASK)
 184                        continue;
 185
 186                input_event(input, EV_MSC, MSC_SCAN, code);
 187                input_report_key(input, keypad->keymap[code], !up);
 188                input_sync(input);
 189        }
 190
 191        return IRQ_HANDLED;
 192}
 193
 194static int stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad)
 195{
 196        const struct stmpe_keypad_variant *variant = keypad->variant;
 197        unsigned int col_gpios = variant->col_gpios;
 198        unsigned int row_gpios = variant->row_gpios;
 199        struct stmpe *stmpe = keypad->stmpe;
 200        u8 pureg = stmpe->regs[STMPE_IDX_GPPUR_LSB];
 201        unsigned int pins = 0;
 202        unsigned int pu_pins = 0;
 203        int ret;
 204        int i;
 205
 206        /*
 207         * Figure out which pins need to be set to the keypad alternate
 208         * function.
 209         *
 210         * {cols,rows}_gpios are bitmasks of which pins on the chip can be used
 211         * for the keypad.
 212         *
 213         * keypad->{cols,rows} are a bitmask of which pins (of the ones useable
 214         * for the keypad) are used on the board.
 215         */
 216
 217        for (i = 0; i < variant->max_cols; i++) {
 218                int num = __ffs(col_gpios);
 219
 220                if (keypad->cols & (1 << i)) {
 221                        pins |= 1 << num;
 222                        pu_pins |= 1 << num;
 223                }
 224
 225                col_gpios &= ~(1 << num);
 226        }
 227
 228        for (i = 0; i < variant->max_rows; i++) {
 229                int num = __ffs(row_gpios);
 230
 231                if (keypad->rows & (1 << i))
 232                        pins |= 1 << num;
 233
 234                row_gpios &= ~(1 << num);
 235        }
 236
 237        ret = stmpe_set_altfunc(stmpe, pins, STMPE_BLOCK_KEYPAD);
 238        if (ret)
 239                return ret;
 240
 241        /*
 242         * On STMPE24xx, set pin bias to pull-up on all keypad input
 243         * pins (columns), this incidentally happen to be maximum 8 pins
 244         * and placed at GPIO0-7 so only the LSB of the pull up register
 245         * ever needs to be written.
 246         */
 247        if (variant->set_pullup) {
 248                u8 val;
 249
 250                ret = stmpe_reg_read(stmpe, pureg);
 251                if (ret)
 252                        return ret;
 253
 254                /* Do not touch unused pins, may be used for GPIO */
 255                val = ret & ~pu_pins;
 256                val |= pu_pins;
 257
 258                ret = stmpe_reg_write(stmpe, pureg, val);
 259        }
 260
 261        return 0;
 262}
 263
 264static int stmpe_keypad_chip_init(struct stmpe_keypad *keypad)
 265{
 266        const struct stmpe_keypad_variant *variant = keypad->variant;
 267        struct stmpe *stmpe = keypad->stmpe;
 268        int ret;
 269
 270        if (keypad->debounce_ms > STMPE_KEYPAD_MAX_DEBOUNCE)
 271                return -EINVAL;
 272
 273        if (keypad->scan_count > STMPE_KEYPAD_MAX_SCAN_COUNT)
 274                return -EINVAL;
 275
 276        ret = stmpe_enable(stmpe, STMPE_BLOCK_KEYPAD);
 277        if (ret < 0)
 278                return ret;
 279
 280        ret = stmpe_keypad_altfunc_init(keypad);
 281        if (ret < 0)
 282                return ret;
 283
 284        ret = stmpe_reg_write(stmpe, STMPE_KPC_COL, keypad->cols);
 285        if (ret < 0)
 286                return ret;
 287
 288        ret = stmpe_reg_write(stmpe, STMPE_KPC_ROW_LSB, keypad->rows);
 289        if (ret < 0)
 290                return ret;
 291
 292        if (variant->max_rows > 8) {
 293                ret = stmpe_set_bits(stmpe, STMPE_KPC_ROW_MSB,
 294                                     STMPE_KPC_ROW_MSB_ROWS,
 295                                     keypad->rows >> 8);
 296                if (ret < 0)
 297                        return ret;
 298        }
 299
 300        ret = stmpe_set_bits(stmpe, STMPE_KPC_CTRL_MSB,
 301                             STMPE_KPC_CTRL_MSB_SCAN_COUNT,
 302                             keypad->scan_count << 4);
 303        if (ret < 0)
 304                return ret;
 305
 306        return stmpe_set_bits(stmpe, STMPE_KPC_CTRL_LSB,
 307                              STMPE_KPC_CTRL_LSB_SCAN |
 308                              STMPE_KPC_CTRL_LSB_DEBOUNCE,
 309                              STMPE_KPC_CTRL_LSB_SCAN |
 310                              (keypad->debounce_ms << 1));
 311}
 312
 313static void stmpe_keypad_fill_used_pins(struct stmpe_keypad *keypad,
 314                                        u32 used_rows, u32 used_cols)
 315{
 316        int row, col;
 317
 318        for (row = 0; row < used_rows; row++) {
 319                for (col = 0; col < used_cols; col++) {
 320                        int code = MATRIX_SCAN_CODE(row, col,
 321                                                    STMPE_KEYPAD_ROW_SHIFT);
 322                        if (keypad->keymap[code] != KEY_RESERVED) {
 323                                keypad->rows |= 1 << row;
 324                                keypad->cols |= 1 << col;
 325                        }
 326                }
 327        }
 328}
 329
 330static int stmpe_keypad_probe(struct platform_device *pdev)
 331{
 332        struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
 333        struct device_node *np = pdev->dev.of_node;
 334        struct stmpe_keypad *keypad;
 335        struct input_dev *input;
 336        u32 rows;
 337        u32 cols;
 338        int error;
 339        int irq;
 340
 341        irq = platform_get_irq(pdev, 0);
 342        if (irq < 0)
 343                return irq;
 344
 345        keypad = devm_kzalloc(&pdev->dev, sizeof(struct stmpe_keypad),
 346                              GFP_KERNEL);
 347        if (!keypad)
 348                return -ENOMEM;
 349
 350        keypad->stmpe = stmpe;
 351        keypad->variant = &stmpe_keypad_variants[stmpe->partnum];
 352
 353        of_property_read_u32(np, "debounce-interval", &keypad->debounce_ms);
 354        of_property_read_u32(np, "st,scan-count", &keypad->scan_count);
 355        keypad->no_autorepeat = of_property_read_bool(np, "st,no-autorepeat");
 356
 357        input = devm_input_allocate_device(&pdev->dev);
 358        if (!input)
 359                return -ENOMEM;
 360
 361        input->name = "STMPE keypad";
 362        input->id.bustype = BUS_I2C;
 363        input->dev.parent = &pdev->dev;
 364
 365        error = matrix_keypad_parse_properties(&pdev->dev, &rows, &cols);
 366        if (error)
 367                return error;
 368
 369        error = matrix_keypad_build_keymap(NULL, NULL, rows, cols,
 370                                           keypad->keymap, input);
 371        if (error)
 372                return error;
 373
 374        input_set_capability(input, EV_MSC, MSC_SCAN);
 375        if (!keypad->no_autorepeat)
 376                __set_bit(EV_REP, input->evbit);
 377
 378        stmpe_keypad_fill_used_pins(keypad, rows, cols);
 379
 380        keypad->input = input;
 381
 382        error = stmpe_keypad_chip_init(keypad);
 383        if (error < 0)
 384                return error;
 385
 386        error = devm_request_threaded_irq(&pdev->dev, irq,
 387                                          NULL, stmpe_keypad_irq,
 388                                          IRQF_ONESHOT, "stmpe-keypad", keypad);
 389        if (error) {
 390                dev_err(&pdev->dev, "unable to get irq: %d\n", error);
 391                return error;
 392        }
 393
 394        error = input_register_device(input);
 395        if (error) {
 396                dev_err(&pdev->dev,
 397                        "unable to register input device: %d\n", error);
 398                return error;
 399        }
 400
 401        platform_set_drvdata(pdev, keypad);
 402
 403        return 0;
 404}
 405
 406static int stmpe_keypad_remove(struct platform_device *pdev)
 407{
 408        struct stmpe_keypad *keypad = platform_get_drvdata(pdev);
 409
 410        stmpe_disable(keypad->stmpe, STMPE_BLOCK_KEYPAD);
 411
 412        return 0;
 413}
 414
 415static struct platform_driver stmpe_keypad_driver = {
 416        .driver.name    = "stmpe-keypad",
 417        .driver.owner   = THIS_MODULE,
 418        .probe          = stmpe_keypad_probe,
 419        .remove         = stmpe_keypad_remove,
 420};
 421module_platform_driver(stmpe_keypad_driver);
 422
 423MODULE_LICENSE("GPL v2");
 424MODULE_DESCRIPTION("STMPExxxx keypad driver");
 425MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");
 426