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
  87/* runs in an IRQ thread -- can (and will!) sleep */
  88static irqreturn_t max7359_interrupt(int irq, void *dev_id)
  89{
  90        struct max7359_keypad *keypad = dev_id;
  91        struct input_dev *input_dev = keypad->input_dev;
  92        int val, row, col, release, code;
  93
  94        val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
  95        row = val & 0x7;
  96        col = (val >> 3) & 0x7;
  97        release = val & 0x40;
  98
  99        code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);
 100
 101        dev_dbg(&keypad->client->dev,
 102                "key[%d:%d] %s\n", row, col, release ? "release" : "press");
 103
 104        input_event(input_dev, EV_MSC, MSC_SCAN, code);
 105        input_report_key(input_dev, keypad->keycodes[code], !release);
 106        input_sync(input_dev);
 107
 108        return IRQ_HANDLED;
 109}
 110
 111/*
 112 * Let MAX7359 fall into a deep sleep:
 113 * If no keys are pressed, enter sleep mode for 8192 ms. And if any
 114 * key is pressed, the MAX7359 returns to normal operating mode.
 115 */
 116static inline void max7359_fall_deepsleep(struct i2c_client *client)
 117{
 118        max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
 119}
 120
 121/*
 122 * Let MAX7359 take a catnap:
 123 * Autosleep just for 256 ms.
 124 */
 125static inline void max7359_take_catnap(struct i2c_client *client)
 126{
 127        max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
 128}
 129
 130static int max7359_open(struct input_dev *dev)
 131{
 132        struct max7359_keypad *keypad = input_get_drvdata(dev);
 133
 134        max7359_take_catnap(keypad->client);
 135
 136        return 0;
 137}
 138
 139static void max7359_close(struct input_dev *dev)
 140{
 141        struct max7359_keypad *keypad = input_get_drvdata(dev);
 142
 143        max7359_fall_deepsleep(keypad->client);
 144}
 145
 146static void max7359_initialize(struct i2c_client *client)
 147{
 148        max7359_write_reg(client, MAX7359_REG_CONFIG,
 149                MAX7359_CFG_KEY_RELEASE | /* Key release enable */
 150                MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
 151
 152        /* Full key-scan functionality */
 153        max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
 154
 155        /* nINT asserts every debounce cycles */
 156        max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
 157
 158        max7359_fall_deepsleep(client);
 159}
 160
 161static int max7359_probe(struct i2c_client *client,
 162                                        const struct i2c_device_id *id)
 163{
 164        const struct matrix_keymap_data *keymap_data =
 165                        dev_get_platdata(&client->dev);
 166        struct max7359_keypad *keypad;
 167        struct input_dev *input_dev;
 168        int ret;
 169        int error;
 170
 171        if (!client->irq) {
 172                dev_err(&client->dev, "The irq number should not be zero\n");
 173                return -EINVAL;
 174        }
 175
 176        /* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
 177        ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
 178        if (ret < 0) {
 179                dev_err(&client->dev, "failed to detect device\n");
 180                return -ENODEV;
 181        }
 182
 183        dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
 184
 185        keypad = devm_kzalloc(&client->dev, sizeof(struct max7359_keypad),
 186                              GFP_KERNEL);
 187        if (!keypad) {
 188                dev_err(&client->dev, "failed to allocate memory\n");
 189                return -ENOMEM;
 190        }
 191
 192        input_dev = devm_input_allocate_device(&client->dev);
 193        if (!input_dev) {
 194                dev_err(&client->dev, "failed to allocate input device\n");
 195                return -ENOMEM;
 196        }
 197
 198        keypad->client = client;
 199        keypad->input_dev = input_dev;
 200
 201        input_dev->name = client->name;
 202        input_dev->id.bustype = BUS_I2C;
 203        input_dev->open = max7359_open;
 204        input_dev->close = max7359_close;
 205        input_dev->dev.parent = &client->dev;
 206
 207        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
 208        input_dev->keycodesize = sizeof(keypad->keycodes[0]);
 209        input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
 210        input_dev->keycode = keypad->keycodes;
 211
 212        input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 213        input_set_drvdata(input_dev, keypad);
 214
 215        error = matrix_keypad_build_keymap(keymap_data, NULL,
 216                                           MAX7359_MAX_KEY_ROWS,
 217                                           MAX7359_MAX_KEY_COLS,
 218                                           keypad->keycodes,
 219                                           input_dev);
 220        if (error) {
 221                dev_err(&client->dev, "failed to build keymap\n");
 222                return error;
 223        }
 224
 225        error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 226                                          max7359_interrupt,
 227                                          IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 228                                          client->name, keypad);
 229        if (error) {
 230                dev_err(&client->dev, "failed to register interrupt\n");
 231                return error;
 232        }
 233
 234        /* Register the input device */
 235        error = input_register_device(input_dev);
 236        if (error) {
 237                dev_err(&client->dev, "failed to register input device\n");
 238                return error;
 239        }
 240
 241        /* Initialize MAX7359 */
 242        max7359_initialize(client);
 243
 244        i2c_set_clientdata(client, keypad);
 245        device_init_wakeup(&client->dev, 1);
 246
 247        return 0;
 248}
 249
 250#ifdef CONFIG_PM_SLEEP
 251static int max7359_suspend(struct device *dev)
 252{
 253        struct i2c_client *client = to_i2c_client(dev);
 254
 255        max7359_fall_deepsleep(client);
 256
 257        if (device_may_wakeup(&client->dev))
 258                enable_irq_wake(client->irq);
 259
 260        return 0;
 261}
 262
 263static int max7359_resume(struct device *dev)
 264{
 265        struct i2c_client *client = to_i2c_client(dev);
 266
 267        if (device_may_wakeup(&client->dev))
 268                disable_irq_wake(client->irq);
 269
 270        /* Restore the default setting */
 271        max7359_take_catnap(client);
 272
 273        return 0;
 274}
 275#endif
 276
 277static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
 278
 279static const struct i2c_device_id max7359_ids[] = {
 280        { "max7359", 0 },
 281        { }
 282};
 283MODULE_DEVICE_TABLE(i2c, max7359_ids);
 284
 285static struct i2c_driver max7359_i2c_driver = {
 286        .driver = {
 287                .name = "max7359",
 288                .pm   = &max7359_pm,
 289        },
 290        .probe          = max7359_probe,
 291        .id_table       = max7359_ids,
 292};
 293
 294module_i2c_driver(max7359_i2c_driver);
 295
 296MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
 297MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
 298MODULE_LICENSE("GPL v2");
 299