drivers/input/keyboard/max7359_keypad.c

   1 /*
   2  * max7359_keypad.c - MAX7359 Key Switch Controller Driver
   3  *
   4  * Copyright (C) 2009 Samsung Electronics
   5  * Kim Kyuwon <q1.kim@samsung.com>
   6  *
   7  * Based on pxa27x_keypad.c
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * Datasheet: http://www.maxim-ic.com/quick_view2.cfm/qv_pk/5456
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/i2c.h>
  18 #include <linux/slab.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/pm.h>
  21 #include <linux/input.h>
  22 #include <linux/input/matrix_keypad.h>
  23
  24 #define MAX7359_MAX_KEY_ROWS    8
  25 #define MAX7359_MAX_KEY_COLS    8
  26 #define MAX7359_MAX_KEY_NUM     (MAX7359_MAX_KEY_ROWS * MAX7359_MAX_KEY_COLS)
  27 #define MAX7359_ROW_SHIFT       3
  28
  29 /*
  30  * MAX7359 registers
  31  */
  32 #define MAX7359_REG_KEYFIFO     0x00
  33 #define MAX7359_REG_CONFIG      0x01
  34 #define MAX7359_REG_DEBOUNCE    0x02
  35 #define MAX7359_REG_INTERRUPT   0x03
  36 #define MAX7359_REG_PORTS       0x04
  37 #define MAX7359_REG_KEYREP      0x05
  38 #define MAX7359_REG_SLEEP       0x06
  39
  40 /*
  41  * Configuration register bits
  42  */
  43 #define MAX7359_CFG_SLEEP       (1 << 7)
  44 #define MAX7359_CFG_INTERRUPT   (1 << 5)
  45 #define MAX7359_CFG_KEY_RELEASE (1 << 3)
  46 #define MAX7359_CFG_WAKEUP      (1 << 1)
  47 #define MAX7359_CFG_TIMEOUT     (1 << 0)
  48
  49 /*
  50  * Autosleep register values (ms)
  51  */
  52 #define MAX7359_AUTOSLEEP_8192  0x01
  53 #define MAX7359_AUTOSLEEP_4096  0x02
  54 #define MAX7359_AUTOSLEEP_2048  0x03
  55 #define MAX7359_AUTOSLEEP_1024  0x04
  56 #define MAX7359_AUTOSLEEP_512   0x05
  57 #define MAX7359_AUTOSLEEP_256   0x06
  58
  59 struct max7359_keypad {
  60         /* matrix key code map */
  61         unsigned short keycodes[MAX7359_MAX_KEY_NUM];
  62
  63         struct input_dev *input_dev;
  64         struct i2c_client *client;
  65 };
  66
  67 static int max7359_write_reg(struct i2c_client *client, u8 reg, u8 val)
  68 {
  69         int ret = i2c_smbus_write_byte_data(client, reg, val);
  70
  71         if (ret < 0)
  72                 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
  73                         __func__, reg, val, ret);
  74         return ret;
  75 }
  76
  77 static int max7359_read_reg(struct i2c_client *client, int reg)
  78 {
  79         int ret = i2c_smbus_read_byte_data(client, reg);
  80
  81         if (ret < 0)
  82                 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
  83                         __func__, reg, ret);
  84         return ret;
  85 }
  86
  87 static void max7359_build_keycode(struct max7359_keypad *keypad,
  88                                 const struct matrix_keymap_data *keymap_data)
  89 {
  90         struct input_dev *input_dev = keypad->input_dev;
  91         int i;
  92
  93         for (i = 0; i < keymap_data->keymap_size; i++) {
  94                 unsigned int key = keymap_data->keymap[i];
  95                 unsigned int row = KEY_ROW(key);
  96                 unsigned int col = KEY_COL(key);
  97                 unsigned int scancode = MATRIX_SCAN_CODE(row, col,
  98                                                 MAX7359_ROW_SHIFT);
  99                 unsigned short keycode = KEY_VAL(key);
 100
 101                 keypad->keycodes[scancode] = keycode;
 102                 __set_bit(keycode, input_dev->keybit);
 103         }
 104         __clear_bit(KEY_RESERVED, input_dev->keybit);
 105 }
 106
 107 /* runs in an IRQ thread -- can (and will!) sleep */
 108 static irqreturn_t max7359_interrupt(int irq, void *dev_id)
 109 {
 110         struct max7359_keypad *keypad = dev_id;
 111         struct input_dev *input_dev = keypad->input_dev;
 112         int val, row, col, release, code;
 113
 114         val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
 115         row = val & 0x7;
 116         col = (val >> 3) & 0x7;
 117         release = val & 0x40;
 118
 119         code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);
 120
 121         dev_dbg(&keypad->client->dev,
 122                 "key[%d:%d] %s\n", row, col, release ? "release" : "press");
 123
 124         input_event(input_dev, EV_MSC, MSC_SCAN, code);
 125         input_report_key(input_dev, keypad->keycodes[code], !release);
 126         input_sync(input_dev);
 127
 128         return IRQ_HANDLED;
 129 }
 130
 131 /*
 132  * Let MAX7359 fall into a deep sleep:
 133  * If no keys are pressed, enter sleep mode for 8192 ms. And if any
 134  * key is pressed, the MAX7359 returns to normal operating mode.
 135  */
 136 static inline void max7359_fall_deepsleep(struct i2c_client *client)
 137 {
 138         max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
 139 }
 140
 141 /*
 142  * Let MAX7359 take a catnap:
 143  * Autosleep just for 256 ms.
 144  */
 145 static inline void max7359_take_catnap(struct i2c_client *client)
 146 {
 147         max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
 148 }
 149
 150 static int max7359_open(struct input_dev *dev)
 151 {
 152         struct max7359_keypad *keypad = input_get_drvdata(dev);
 153
 154         max7359_take_catnap(keypad->client);
 155
 156         return 0;
 157 }
 158
 159 static void max7359_close(struct input_dev *dev)
 160 {
 161         struct max7359_keypad *keypad = input_get_drvdata(dev);
 162
 163         max7359_fall_deepsleep(keypad->client);
 164 }
 165
 166 static void max7359_initialize(struct i2c_client *client)
 167 {
 168         max7359_write_reg(client, MAX7359_REG_CONFIG,
 169                 MAX7359_CFG_INTERRUPT | /* Irq clears after host read */
 170                 MAX7359_CFG_KEY_RELEASE | /* Key release enable */
 171                 MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
 172
 173         /* Full key-scan functionality */
 174         max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
 175
 176         /* nINT asserts every debounce cycles */
 177         max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
 178
 179         max7359_fall_deepsleep(client);
 180 }
 181
 182 static int max7359_probe(struct i2c_client *client,
 183                                         const struct i2c_device_id *id)
 184 {
 185         const struct matrix_keymap_data *keymap_data =
 186                         dev_get_platdata(&client->dev);
 187         struct max7359_keypad *keypad;
 188         struct input_dev *input_dev;
 189         int ret;
 190         int error;
 191
 192         if (!client->irq) {
 193                 dev_err(&client->dev, "The irq number should not be zero\n");
 194                 return -EINVAL;
 195         }
 196
 197         /* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
 198         ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
 199         if (ret < 0) {
 200                 dev_err(&client->dev, "failed to detect device\n");
 201                 return -ENODEV;
 202         }
 203
 204         dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
 205
 206         keypad = kzalloc(sizeof(struct max7359_keypad), GFP_KERNEL);
 207         input_dev = input_allocate_device();
 208         if (!keypad || !input_dev) {
 209                 dev_err(&client->dev, "failed to allocate memory\n");
 210                 error = -ENOMEM;
 211                 goto failed_free_mem;
 212         }
 213
 214         keypad->client = client;
 215         keypad->input_dev = input_dev;
 216
 217         input_dev->name = client->name;
 218         input_dev->id.bustype = BUS_I2C;
 219         input_dev->open = max7359_open;
 220         input_dev->close = max7359_close;
 221         input_dev->dev.parent = &client->dev;
 222
 223         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
 224         input_dev->keycodesize = sizeof(keypad->keycodes[0]);
 225         input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
 226         input_dev->keycode = keypad->keycodes;
 227
 228         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 229         input_set_drvdata(input_dev, keypad);
 230
 231         max7359_build_keycode(keypad, keymap_data);
 232
 233         error = request_threaded_irq(client->irq, NULL, max7359_interrupt,
 234                                      IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 235                                      client->name, keypad);
 236         if (error) {
 237                 dev_err(&client->dev, "failed to register interrupt\n");
 238                 goto failed_free_mem;
 239         }
 240
 241         /* Register the input device */
 242         error = input_register_device(input_dev);
 243         if (error) {
 244                 dev_err(&client->dev, "failed to register input device\n");
 245                 goto failed_free_irq;
 246         }
 247
 248         /* Initialize MAX7359 */
 249         max7359_initialize(client);
 250
 251         i2c_set_clientdata(client, keypad);
 252         device_init_wakeup(&client->dev, 1);
 253
 254         return 0;
 255
 256 failed_free_irq:
 257         free_irq(client->irq, keypad);
 258 failed_free_mem:
 259         input_free_device(input_dev);
 260         kfree(keypad);
 261         return error;
 262 }
 263
 264 static int max7359_remove(struct i2c_client *client)
 265 {
 266         struct max7359_keypad *keypad = i2c_get_clientdata(client);
 267
 268         free_irq(client->irq, keypad);
 269         input_unregister_device(keypad->input_dev);
 270         kfree(keypad);
 271
 272         return 0;
 273 }
 274
 275 #ifdef CONFIG_PM_SLEEP
 276 static int max7359_suspend(struct device *dev)
 277 {
 278         struct i2c_client *client = to_i2c_client(dev);
 279
 280         max7359_fall_deepsleep(client);
 281
 282         if (device_may_wakeup(&client->dev))
 283                 enable_irq_wake(client->irq);
 284
 285         return 0;
 286 }
 287
 288 static int max7359_resume(struct device *dev)
 289 {
 290         struct i2c_client *client = to_i2c_client(dev);
 291
 292         if (device_may_wakeup(&client->dev))
 293                 disable_irq_wake(client->irq);
 294
 295         /* Restore the default setting */
 296         max7359_take_catnap(client);
 297
 298         return 0;
 299 }
 300 #endif
 301
 302 static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
 303
 304 static const struct i2c_device_id max7359_ids[] = {
 305         { "max7359", 0 },
 306         { }
 307 };
 308 MODULE_DEVICE_TABLE(i2c, max7359_ids);
 309
 310 static struct i2c_driver max7359_i2c_driver = {
 311         .driver = {
 312                 .name = "max7359",
 313                 .pm   = &max7359_pm,
 314         },
 315         .probe          = max7359_probe,
 316         .remove         = max7359_remove,
 317         .id_table       = max7359_ids,
 318 };
 319
 320 module_i2c_driver(max7359_i2c_driver);
 321
 322 MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
 323 MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
 324 MODULE_LICENSE("GPL v2");