linux/drivers/input/keyboard/max7359_keypad.c
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   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
  59struct 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
  67static 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
  77static 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
  87static 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 */
 108static 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 */
 136static 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 */
 145static inline void max7359_take_catnap(struct i2c_client *client)
 146{
 147        max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
 148}
 149
 150static 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
 159static 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
 166static 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
 182static int __devinit max7359_probe(struct i2c_client *client,
 183                                        const struct i2c_device_id *id)
 184{
 185        const struct matrix_keymap_data *keymap_data = client->dev.platform_data;
 186        struct max7359_keypad *keypad;
 187        struct input_dev *input_dev;
 188        int ret;
 189        int error;
 190
 191        if (!client->irq) {
 192                dev_err(&client->dev, "The irq number should not be zero\n");
 193                return -EINVAL;
 194        }
 195
 196        /* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
 197        ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
 198        if (ret < 0) {
 199                dev_err(&client->dev, "failed to detect device\n");
 200                return -ENODEV;
 201        }
 202
 203        dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
 204
 205        keypad = kzalloc(sizeof(struct max7359_keypad), GFP_KERNEL);
 206        input_dev = input_allocate_device();
 207        if (!keypad || !input_dev) {
 208                dev_err(&client->dev, "failed to allocate memory\n");
 209                error = -ENOMEM;
 210                goto failed_free_mem;
 211        }
 212
 213        keypad->client = client;
 214        keypad->input_dev = input_dev;
 215
 216        input_dev->name = client->name;
 217        input_dev->id.bustype = BUS_I2C;
 218        input_dev->open = max7359_open;
 219        input_dev->close = max7359_close;
 220        input_dev->dev.parent = &client->dev;
 221
 222        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
 223        input_dev->keycodesize = sizeof(keypad->keycodes[0]);
 224        input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
 225        input_dev->keycode = keypad->keycodes;
 226
 227        input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 228        input_set_drvdata(input_dev, keypad);
 229
 230        max7359_build_keycode(keypad, keymap_data);
 231
 232        error = request_threaded_irq(client->irq, NULL, max7359_interrupt,
 233                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 234                                     client->name, keypad);
 235        if (error) {
 236                dev_err(&client->dev, "failed to register interrupt\n");
 237                goto failed_free_mem;
 238        }
 239
 240        /* Register the input device */
 241        error = input_register_device(input_dev);
 242        if (error) {
 243                dev_err(&client->dev, "failed to register input device\n");
 244                goto failed_free_irq;
 245        }
 246
 247        /* Initialize MAX7359 */
 248        max7359_initialize(client);
 249
 250        i2c_set_clientdata(client, keypad);
 251        device_init_wakeup(&client->dev, 1);
 252
 253        return 0;
 254
 255failed_free_irq:
 256        free_irq(client->irq, keypad);
 257failed_free_mem:
 258        input_free_device(input_dev);
 259        kfree(keypad);
 260        return error;
 261}
 262
 263static int __devexit max7359_remove(struct i2c_client *client)
 264{
 265        struct max7359_keypad *keypad = i2c_get_clientdata(client);
 266
 267        free_irq(client->irq, keypad);
 268        input_unregister_device(keypad->input_dev);
 269        kfree(keypad);
 270
 271        return 0;
 272}
 273
 274#ifdef CONFIG_PM
 275static int max7359_suspend(struct device *dev)
 276{
 277        struct i2c_client *client = to_i2c_client(dev);
 278
 279        max7359_fall_deepsleep(client);
 280
 281        if (device_may_wakeup(&client->dev))
 282                enable_irq_wake(client->irq);
 283
 284        return 0;
 285}
 286
 287static int max7359_resume(struct device *dev)
 288{
 289        struct i2c_client *client = to_i2c_client(dev);
 290
 291        if (device_may_wakeup(&client->dev))
 292                disable_irq_wake(client->irq);
 293
 294        /* Restore the default setting */
 295        max7359_take_catnap(client);
 296
 297        return 0;
 298}
 299#endif
 300
 301static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
 302
 303static const struct i2c_device_id max7359_ids[] = {
 304        { "max7359", 0 },
 305        { }
 306};
 307MODULE_DEVICE_TABLE(i2c, max7359_ids);
 308
 309static struct i2c_driver max7359_i2c_driver = {
 310        .driver = {
 311                .name = "max7359",
 312                .pm   = &max7359_pm,
 313        },
 314        .probe          = max7359_probe,
 315        .remove         = __devexit_p(max7359_remove),
 316        .id_table       = max7359_ids,
 317};
 318
 319static int __init max7359_init(void)
 320{
 321        return i2c_add_driver(&max7359_i2c_driver);
 322}
 323module_init(max7359_init);
 324
 325static void __exit max7359_exit(void)
 326{
 327        i2c_del_driver(&max7359_i2c_driver);
 328}
 329module_exit(max7359_exit);
 330
 331MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
 332MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
 333MODULE_LICENSE("GPL v2");
 334