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_new	= 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