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", 0 }, 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"); 292