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 static void max7359_build_keycode(struct max7359_keypad *keypad,
88 				const struct matrix_keymap_data *keymap_data)
89 {
90 	struct input_dev *input_dev = keypad->input_dev;
91 	int i;
92 
93 	for (i = 0; i < keymap_data->keymap_size; i++) {
94 		unsigned int key = keymap_data->keymap[i];
95 		unsigned int row = KEY_ROW(key);
96 		unsigned int col = KEY_COL(key);
97 		unsigned int scancode = MATRIX_SCAN_CODE(row, col,
98 						MAX7359_ROW_SHIFT);
99 		unsigned short keycode = KEY_VAL(key);
100 
101 		keypad->keycodes[scancode] = keycode;
102 		__set_bit(keycode, input_dev->keybit);
103 	}
104 	__clear_bit(KEY_RESERVED, input_dev->keybit);
105 }
106 
107 /* runs in an IRQ thread -- can (and will!) sleep */
108 static irqreturn_t max7359_interrupt(int irq, void *dev_id)
109 {
110 	struct max7359_keypad *keypad = dev_id;
111 	struct input_dev *input_dev = keypad->input_dev;
112 	int val, row, col, release, code;
113 
114 	val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
115 	row = val & 0x7;
116 	col = (val >> 3) & 0x7;
117 	release = val & 0x40;
118 
119 	code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);
120 
121 	dev_dbg(&keypad->client->dev,
122 		"key[%d:%d] %s\n", row, col, release ? "release" : "press");
123 
124 	input_event(input_dev, EV_MSC, MSC_SCAN, code);
125 	input_report_key(input_dev, keypad->keycodes[code], !release);
126 	input_sync(input_dev);
127 
128 	return IRQ_HANDLED;
129 }
130 
131 /*
132  * Let MAX7359 fall into a deep sleep:
133  * If no keys are pressed, enter sleep mode for 8192 ms. And if any
134  * key is pressed, the MAX7359 returns to normal operating mode.
135  */
136 static inline void max7359_fall_deepsleep(struct i2c_client *client)
137 {
138 	max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
139 }
140 
141 /*
142  * Let MAX7359 take a catnap:
143  * Autosleep just for 256 ms.
144  */
145 static inline void max7359_take_catnap(struct i2c_client *client)
146 {
147 	max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
148 }
149 
150 static int max7359_open(struct input_dev *dev)
151 {
152 	struct max7359_keypad *keypad = input_get_drvdata(dev);
153 
154 	max7359_take_catnap(keypad->client);
155 
156 	return 0;
157 }
158 
159 static void max7359_close(struct input_dev *dev)
160 {
161 	struct max7359_keypad *keypad = input_get_drvdata(dev);
162 
163 	max7359_fall_deepsleep(keypad->client);
164 }
165 
166 static void max7359_initialize(struct i2c_client *client)
167 {
168 	max7359_write_reg(client, MAX7359_REG_CONFIG,
169 		MAX7359_CFG_INTERRUPT | /* Irq clears after host read */
170 		MAX7359_CFG_KEY_RELEASE | /* Key release enable */
171 		MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
172 
173 	/* Full key-scan functionality */
174 	max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
175 
176 	/* nINT asserts every debounce cycles */
177 	max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
178 
179 	max7359_fall_deepsleep(client);
180 }
181 
182 static int max7359_probe(struct i2c_client *client,
183 					const struct i2c_device_id *id)
184 {
185 	const struct matrix_keymap_data *keymap_data =
186 			dev_get_platdata(&client->dev);
187 	struct max7359_keypad *keypad;
188 	struct input_dev *input_dev;
189 	int ret;
190 	int error;
191 
192 	if (!client->irq) {
193 		dev_err(&client->dev, "The irq number should not be zero\n");
194 		return -EINVAL;
195 	}
196 
197 	/* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
198 	ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
199 	if (ret < 0) {
200 		dev_err(&client->dev, "failed to detect device\n");
201 		return -ENODEV;
202 	}
203 
204 	dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
205 
206 	keypad = devm_kzalloc(&client->dev, sizeof(struct max7359_keypad),
207 			      GFP_KERNEL);
208 	if (!keypad) {
209 		dev_err(&client->dev, "failed to allocate memory\n");
210 		return -ENOMEM;
211 	}
212 
213 	input_dev = devm_input_allocate_device(&client->dev);
214 	if (!input_dev) {
215 		dev_err(&client->dev, "failed to allocate input device\n");
216 		return -ENOMEM;
217 	}
218 
219 	keypad->client = client;
220 	keypad->input_dev = input_dev;
221 
222 	input_dev->name = client->name;
223 	input_dev->id.bustype = BUS_I2C;
224 	input_dev->open = max7359_open;
225 	input_dev->close = max7359_close;
226 	input_dev->dev.parent = &client->dev;
227 
228 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
229 	input_dev->keycodesize = sizeof(keypad->keycodes[0]);
230 	input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
231 	input_dev->keycode = keypad->keycodes;
232 
233 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
234 	input_set_drvdata(input_dev, keypad);
235 
236 	max7359_build_keycode(keypad, keymap_data);
237 
238 	error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
239 					  max7359_interrupt,
240 					  IRQF_TRIGGER_LOW | IRQF_ONESHOT,
241 					  client->name, keypad);
242 	if (error) {
243 		dev_err(&client->dev, "failed to register interrupt\n");
244 		return error;
245 	}
246 
247 	/* Register the input device */
248 	error = input_register_device(input_dev);
249 	if (error) {
250 		dev_err(&client->dev, "failed to register input device\n");
251 		return error;
252 	}
253 
254 	/* Initialize MAX7359 */
255 	max7359_initialize(client);
256 
257 	i2c_set_clientdata(client, keypad);
258 	device_init_wakeup(&client->dev, 1);
259 
260 	return 0;
261 }
262 
263 #ifdef CONFIG_PM_SLEEP
264 static int max7359_suspend(struct device *dev)
265 {
266 	struct i2c_client *client = to_i2c_client(dev);
267 
268 	max7359_fall_deepsleep(client);
269 
270 	if (device_may_wakeup(&client->dev))
271 		enable_irq_wake(client->irq);
272 
273 	return 0;
274 }
275 
276 static int max7359_resume(struct device *dev)
277 {
278 	struct i2c_client *client = to_i2c_client(dev);
279 
280 	if (device_may_wakeup(&client->dev))
281 		disable_irq_wake(client->irq);
282 
283 	/* Restore the default setting */
284 	max7359_take_catnap(client);
285 
286 	return 0;
287 }
288 #endif
289 
290 static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
291 
292 static const struct i2c_device_id max7359_ids[] = {
293 	{ "max7359", 0 },
294 	{ }
295 };
296 MODULE_DEVICE_TABLE(i2c, max7359_ids);
297 
298 static struct i2c_driver max7359_i2c_driver = {
299 	.driver = {
300 		.name = "max7359",
301 		.pm   = &max7359_pm,
302 	},
303 	.probe		= max7359_probe,
304 	.id_table	= max7359_ids,
305 };
306 
307 module_i2c_driver(max7359_i2c_driver);
308 
309 MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
310 MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
311 MODULE_LICENSE("GPL v2");
312