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 /* runs in an IRQ thread -- can (and will!) sleep */
  88 static 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  */
 116 static 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  */
 125 static inline void max7359_take_catnap(struct i2c_client *client)
 126 {
 127         max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
 128 }
 129
 130 static 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
 139 static 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
 146 static 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
 161 static 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
 251 static 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
 263 static 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
 277 static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
 278
 279 static const struct i2c_device_id max7359_ids[] = {
 280         { "max7359", 0 },
 281         { }
 282 };
 283 MODULE_DEVICE_TABLE(i2c, max7359_ids);
 284
 285 static 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
 294 module_i2c_driver(max7359_i2c_driver);
 295
 296 MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
 297 MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
 298 MODULE_LICENSE("GPL v2");