drivers/input/keyboard/stmpe-keypad.c

   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  */
  63 struct 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
  74 static 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  */
 120 struct 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
 132 static 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
 154 static 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
 186 static 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
 256 static 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
 305 static 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
 322 static 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
 398 static 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
 407 static 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 };
 413 module_platform_driver(stmpe_keypad_driver);
 414
 415 MODULE_LICENSE("GPL v2");
 416 MODULE_DESCRIPTION("STMPExxxx keypad driver");
 417 MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");