drivers/input/keyboard/max7359_keypad.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * max7359_keypad.c - MAX7359 Key Switch Controller Driver
   4  *
   5  * Copyright (C) 2009 Samsung Electronics
   6  * Kim Kyuwon <q1.kim@samsung.com>
   7  *
   8  * Based on pxa27x_keypad.c
   9  *
  10  * Datasheet: http://www.maxim-ic.com/quick_view2.cfm/qv_pk/5456
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/i2c.h>
  15 #include <linux/slab.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/pm.h>
  18 #include <linux/input.h>
  19 #include <linux/input/matrix_keypad.h>
  20
  21 #define MAX7359_MAX_KEY_ROWS    8
  22 #define MAX7359_MAX_KEY_COLS    8
  23 #define MAX7359_MAX_KEY_NUM     (MAX7359_MAX_KEY_ROWS * MAX7359_MAX_KEY_COLS)
  24 #define MAX7359_ROW_SHIFT       3
  25
  26 /*
  27  * MAX7359 registers
  28  */
  29 #define MAX7359_REG_KEYFIFO     0x00
  30 #define MAX7359_REG_CONFIG      0x01
  31 #define MAX7359_REG_DEBOUNCE    0x02
  32 #define MAX7359_REG_INTERRUPT   0x03
  33 #define MAX7359_REG_PORTS       0x04
  34 #define MAX7359_REG_KEYREP      0x05
  35 #define MAX7359_REG_SLEEP       0x06
  36
  37 /*
  38  * Configuration register bits
  39  */
  40 #define MAX7359_CFG_SLEEP       (1 << 7)
  41 #define MAX7359_CFG_INTERRUPT   (1 << 5)
  42 #define MAX7359_CFG_KEY_RELEASE (1 << 3)
  43 #define MAX7359_CFG_WAKEUP      (1 << 1)
  44 #define MAX7359_CFG_TIMEOUT     (1 << 0)
  45
  46 /*
  47  * Autosleep register values (ms)
  48  */
  49 #define MAX7359_AUTOSLEEP_8192  0x01
  50 #define MAX7359_AUTOSLEEP_4096  0x02
  51 #define MAX7359_AUTOSLEEP_2048  0x03
  52 #define MAX7359_AUTOSLEEP_1024  0x04
  53 #define MAX7359_AUTOSLEEP_512   0x05
  54 #define MAX7359_AUTOSLEEP_256   0x06
  55
  56 struct max7359_keypad {
  57         /* matrix key code map */
  58         unsigned short keycodes[MAX7359_MAX_KEY_NUM];
  59
  60         struct input_dev *input_dev;
  61         struct i2c_client *client;
  62 };
  63
  64 static int max7359_write_reg(struct i2c_client *client, u8 reg, u8 val)
  65 {
  66         int ret = i2c_smbus_write_byte_data(client, reg, val);
  67
  68         if (ret < 0)
  69                 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
  70                         __func__, reg, val, ret);
  71         return ret;
  72 }
  73
  74 static int max7359_read_reg(struct i2c_client *client, int reg)
  75 {
  76         int ret = i2c_smbus_read_byte_data(client, reg);
  77
  78         if (ret < 0)
  79                 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
  80                         __func__, reg, ret);
  81         return ret;
  82 }
  83
  84 /* runs in an IRQ thread -- can (and will!) sleep */
  85 static irqreturn_t max7359_interrupt(int irq, void *dev_id)
  86 {
  87         struct max7359_keypad *keypad = dev_id;
  88         struct input_dev *input_dev = keypad->input_dev;
  89         int val, row, col, release, code;
  90
  91         val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
  92         row = val & 0x7;
  93         col = (val >> 3) & 0x7;
  94         release = val & 0x40;
  95
  96         code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);
  97
  98         dev_dbg(&keypad->client->dev,
  99                 "key[%d:%d] %s\n", row, col, release ? "release" : "press");
 100
 101         input_event(input_dev, EV_MSC, MSC_SCAN, code);
 102         input_report_key(input_dev, keypad->keycodes[code], !release);
 103         input_sync(input_dev);
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108 /*
 109  * Let MAX7359 fall into a deep sleep:
 110  * If no keys are pressed, enter sleep mode for 8192 ms. And if any
 111  * key is pressed, the MAX7359 returns to normal operating mode.
 112  */
 113 static inline void max7359_fall_deepsleep(struct i2c_client *client)
 114 {
 115         max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
 116 }
 117
 118 /*
 119  * Let MAX7359 take a catnap:
 120  * Autosleep just for 256 ms.
 121  */
 122 static inline void max7359_take_catnap(struct i2c_client *client)
 123 {
 124         max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
 125 }
 126
 127 static int max7359_open(struct input_dev *dev)
 128 {
 129         struct max7359_keypad *keypad = input_get_drvdata(dev);
 130
 131         max7359_take_catnap(keypad->client);
 132
 133         return 0;
 134 }
 135
 136 static void max7359_close(struct input_dev *dev)
 137 {
 138         struct max7359_keypad *keypad = input_get_drvdata(dev);
 139
 140         max7359_fall_deepsleep(keypad->client);
 141 }
 142
 143 static void max7359_initialize(struct i2c_client *client)
 144 {
 145         max7359_write_reg(client, MAX7359_REG_CONFIG,
 146                 MAX7359_CFG_KEY_RELEASE | /* Key release enable */
 147                 MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
 148
 149         /* Full key-scan functionality */
 150         max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
 151
 152         /* nINT asserts every debounce cycles */
 153         max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
 154
 155         max7359_fall_deepsleep(client);
 156 }
 157
 158 static int max7359_probe(struct i2c_client *client)
 159 {
 160         const struct matrix_keymap_data *keymap_data =
 161                         dev_get_platdata(&client->dev);
 162         struct max7359_keypad *keypad;
 163         struct input_dev *input_dev;
 164         int ret;
 165         int error;
 166
 167         if (!client->irq) {
 168                 dev_err(&client->dev, "The irq number should not be zero\n");
 169                 return -EINVAL;
 170         }
 171
 172         /* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
 173         ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
 174         if (ret < 0) {
 175                 dev_err(&client->dev, "failed to detect device\n");
 176                 return -ENODEV;
 177         }
 178
 179         dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
 180
 181         keypad = devm_kzalloc(&client->dev, sizeof(struct max7359_keypad),
 182                               GFP_KERNEL);
 183         if (!keypad) {
 184                 dev_err(&client->dev, "failed to allocate memory\n");
 185                 return -ENOMEM;
 186         }
 187
 188         input_dev = devm_input_allocate_device(&client->dev);
 189         if (!input_dev) {
 190                 dev_err(&client->dev, "failed to allocate input device\n");
 191                 return -ENOMEM;
 192         }
 193
 194         keypad->client = client;
 195         keypad->input_dev = input_dev;
 196
 197         input_dev->name = client->name;
 198         input_dev->id.bustype = BUS_I2C;
 199         input_dev->open = max7359_open;
 200         input_dev->close = max7359_close;
 201         input_dev->dev.parent = &client->dev;
 202
 203         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
 204         input_dev->keycodesize = sizeof(keypad->keycodes[0]);
 205         input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
 206         input_dev->keycode = keypad->keycodes;
 207
 208         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 209         input_set_drvdata(input_dev, keypad);
 210
 211         error = matrix_keypad_build_keymap(keymap_data, NULL,
 212                                            MAX7359_MAX_KEY_ROWS,
 213                                            MAX7359_MAX_KEY_COLS,
 214                                            keypad->keycodes,
 215                                            input_dev);
 216         if (error) {
 217                 dev_err(&client->dev, "failed to build keymap\n");
 218                 return error;
 219         }
 220
 221         error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 222                                           max7359_interrupt,
 223                                           IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 224                                           client->name, keypad);
 225         if (error) {
 226                 dev_err(&client->dev, "failed to register interrupt\n");
 227                 return error;
 228         }
 229
 230         /* Register the input device */
 231         error = input_register_device(input_dev);
 232         if (error) {
 233                 dev_err(&client->dev, "failed to register input device\n");
 234                 return error;
 235         }
 236
 237         /* Initialize MAX7359 */
 238         max7359_initialize(client);
 239
 240         device_init_wakeup(&client->dev, 1);
 241
 242         return 0;
 243 }
 244
 245 static int max7359_suspend(struct device *dev)
 246 {
 247         struct i2c_client *client = to_i2c_client(dev);
 248
 249         max7359_fall_deepsleep(client);
 250
 251         if (device_may_wakeup(&client->dev))
 252                 enable_irq_wake(client->irq);
 253
 254         return 0;
 255 }
 256
 257 static int max7359_resume(struct device *dev)
 258 {
 259         struct i2c_client *client = to_i2c_client(dev);
 260
 261         if (device_may_wakeup(&client->dev))
 262                 disable_irq_wake(client->irq);
 263
 264         /* Restore the default setting */
 265         max7359_take_catnap(client);
 266
 267         return 0;
 268 }
 269
 270 static DEFINE_SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
 271
 272 static const struct i2c_device_id max7359_ids[] = {
 273         { "max7359" },
 274         { }
 275 };
 276 MODULE_DEVICE_TABLE(i2c, max7359_ids);
 277
 278 static struct i2c_driver max7359_i2c_driver = {
 279         .driver = {
 280                 .name = "max7359",
 281                 .pm   = pm_sleep_ptr(&max7359_pm),
 282         },
 283         .probe          = max7359_probe,
 284         .id_table       = max7359_ids,
 285 };
 286
 287 module_i2c_driver(max7359_i2c_driver);
 288
 289 MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
 290 MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
 291 MODULE_LICENSE("GPL v2");