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
max7359_write_reg(struct i2c_client * client,u8 reg,u8 val)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
max7359_read_reg(struct i2c_client * client,int reg)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 */
max7359_interrupt(int irq,void * dev_id)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 */
max7359_fall_deepsleep(struct i2c_client * client)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 */
max7359_take_catnap(struct i2c_client * client)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
max7359_open(struct input_dev * dev)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
max7359_close(struct input_dev * dev)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
max7359_initialize(struct i2c_client * client)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
max7359_probe(struct i2c_client * client,const struct i2c_device_id * id)158 static int max7359_probe(struct i2c_client *client,
159 const struct i2c_device_id *id)
160 {
161 const struct matrix_keymap_data *keymap_data =
162 dev_get_platdata(&client->dev);
163 struct max7359_keypad *keypad;
164 struct input_dev *input_dev;
165 int ret;
166 int error;
167
168 if (!client->irq) {
169 dev_err(&client->dev, "The irq number should not be zero\n");
170 return -EINVAL;
171 }
172
173 /* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
174 ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
175 if (ret < 0) {
176 dev_err(&client->dev, "failed to detect device\n");
177 return -ENODEV;
178 }
179
180 dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
181
182 keypad = devm_kzalloc(&client->dev, sizeof(struct max7359_keypad),
183 GFP_KERNEL);
184 if (!keypad) {
185 dev_err(&client->dev, "failed to allocate memory\n");
186 return -ENOMEM;
187 }
188
189 input_dev = devm_input_allocate_device(&client->dev);
190 if (!input_dev) {
191 dev_err(&client->dev, "failed to allocate input device\n");
192 return -ENOMEM;
193 }
194
195 keypad->client = client;
196 keypad->input_dev = input_dev;
197
198 input_dev->name = client->name;
199 input_dev->id.bustype = BUS_I2C;
200 input_dev->open = max7359_open;
201 input_dev->close = max7359_close;
202 input_dev->dev.parent = &client->dev;
203
204 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
205 input_dev->keycodesize = sizeof(keypad->keycodes[0]);
206 input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
207 input_dev->keycode = keypad->keycodes;
208
209 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
210 input_set_drvdata(input_dev, keypad);
211
212 error = matrix_keypad_build_keymap(keymap_data, NULL,
213 MAX7359_MAX_KEY_ROWS,
214 MAX7359_MAX_KEY_COLS,
215 keypad->keycodes,
216 input_dev);
217 if (error) {
218 dev_err(&client->dev, "failed to build keymap\n");
219 return error;
220 }
221
222 error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
223 max7359_interrupt,
224 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
225 client->name, keypad);
226 if (error) {
227 dev_err(&client->dev, "failed to register interrupt\n");
228 return error;
229 }
230
231 /* Register the input device */
232 error = input_register_device(input_dev);
233 if (error) {
234 dev_err(&client->dev, "failed to register input device\n");
235 return error;
236 }
237
238 /* Initialize MAX7359 */
239 max7359_initialize(client);
240
241 device_init_wakeup(&client->dev, 1);
242
243 return 0;
244 }
245
246 #ifdef CONFIG_PM_SLEEP
max7359_suspend(struct device * dev)247 static int max7359_suspend(struct device *dev)
248 {
249 struct i2c_client *client = to_i2c_client(dev);
250
251 max7359_fall_deepsleep(client);
252
253 if (device_may_wakeup(&client->dev))
254 enable_irq_wake(client->irq);
255
256 return 0;
257 }
258
max7359_resume(struct device * dev)259 static int max7359_resume(struct device *dev)
260 {
261 struct i2c_client *client = to_i2c_client(dev);
262
263 if (device_may_wakeup(&client->dev))
264 disable_irq_wake(client->irq);
265
266 /* Restore the default setting */
267 max7359_take_catnap(client);
268
269 return 0;
270 }
271 #endif
272
273 static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
274
275 static const struct i2c_device_id max7359_ids[] = {
276 { "max7359", 0 },
277 { }
278 };
279 MODULE_DEVICE_TABLE(i2c, max7359_ids);
280
281 static struct i2c_driver max7359_i2c_driver = {
282 .driver = {
283 .name = "max7359",
284 .pm = &max7359_pm,
285 },
286 .probe = max7359_probe,
287 .id_table = max7359_ids,
288 };
289
290 module_i2c_driver(max7359_i2c_driver);
291
292 MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
293 MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
294 MODULE_LICENSE("GPL v2");
295