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