drivers/input/keyboard/stmpe-keypad.c

   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  */
  71 struct 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
  82 static 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  */
 128 struct 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
 140 static 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
 162 static 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
 194 static 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
 264 static 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
 313 static 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
 330 static 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
 406 static 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
 415 static 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 };
 421 module_platform_driver(stmpe_keypad_driver);
 422
 423 MODULE_LICENSE("GPL v2");
 424 MODULE_DESCRIPTION("STMPExxxx keypad driver");
 425 MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");