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