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/interrupt.h>
19 #include <linux/input.h>
20 #include <linux/input/matrix_keypad.h>
21 
22 #define MAX7359_MAX_KEY_ROWS	8
23 #define MAX7359_MAX_KEY_COLS	8
24 #define MAX7359_MAX_KEY_NUM	(MAX7359_MAX_KEY_ROWS * MAX7359_MAX_KEY_COLS)
25 #define MAX7359_ROW_SHIFT	3
26 
27 /*
28  * MAX7359 registers
29  */
30 #define MAX7359_REG_KEYFIFO	0x00
31 #define MAX7359_REG_CONFIG	0x01
32 #define MAX7359_REG_DEBOUNCE	0x02
33 #define MAX7359_REG_INTERRUPT	0x03
34 #define MAX7359_REG_PORTS	0x04
35 #define MAX7359_REG_KEYREP	0x05
36 #define MAX7359_REG_SLEEP	0x06
37 
38 /*
39  * Configuration register bits
40  */
41 #define MAX7359_CFG_SLEEP	(1 << 7)
42 #define MAX7359_CFG_INTERRUPT	(1 << 5)
43 #define MAX7359_CFG_KEY_RELEASE	(1 << 3)
44 #define MAX7359_CFG_WAKEUP	(1 << 1)
45 #define MAX7359_CFG_TIMEOUT	(1 << 0)
46 
47 /*
48  * Autosleep register values (ms)
49  */
50 #define MAX7359_AUTOSLEEP_8192	0x01
51 #define MAX7359_AUTOSLEEP_4096	0x02
52 #define MAX7359_AUTOSLEEP_2048	0x03
53 #define MAX7359_AUTOSLEEP_1024	0x04
54 #define MAX7359_AUTOSLEEP_512	0x05
55 #define MAX7359_AUTOSLEEP_256	0x06
56 
57 struct max7359_keypad {
58 	/* matrix key code map */
59 	unsigned short keycodes[MAX7359_MAX_KEY_NUM];
60 
61 	struct input_dev *input_dev;
62 	struct i2c_client *client;
63 };
64 
65 static int max7359_write_reg(struct i2c_client *client, u8 reg, u8 val)
66 {
67 	int ret = i2c_smbus_write_byte_data(client, reg, val);
68 
69 	if (ret < 0)
70 		dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
71 			__func__, reg, val, ret);
72 	return ret;
73 }
74 
75 static int max7359_read_reg(struct i2c_client *client, int reg)
76 {
77 	int ret = i2c_smbus_read_byte_data(client, reg);
78 
79 	if (ret < 0)
80 		dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
81 			__func__, reg, ret);
82 	return ret;
83 }
84 
85 static void max7359_build_keycode(struct max7359_keypad *keypad,
86 				const struct matrix_keymap_data *keymap_data)
87 {
88 	struct input_dev *input_dev = keypad->input_dev;
89 	int i;
90 
91 	for (i = 0; i < keymap_data->keymap_size; i++) {
92 		unsigned int key = keymap_data->keymap[i];
93 		unsigned int row = KEY_ROW(key);
94 		unsigned int col = KEY_COL(key);
95 		unsigned int scancode = MATRIX_SCAN_CODE(row, col,
96 						MAX7359_ROW_SHIFT);
97 		unsigned short keycode = KEY_VAL(key);
98 
99 		keypad->keycodes[scancode] = keycode;
100 		__set_bit(keycode, input_dev->keybit);
101 	}
102 	__clear_bit(KEY_RESERVED, input_dev->keybit);
103 }
104 
105 /* runs in an IRQ thread -- can (and will!) sleep */
106 static irqreturn_t max7359_interrupt(int irq, void *dev_id)
107 {
108 	struct max7359_keypad *keypad = dev_id;
109 	struct input_dev *input_dev = keypad->input_dev;
110 	int val, row, col, release, code;
111 
112 	val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
113 	row = val & 0x7;
114 	col = (val >> 3) & 0x7;
115 	release = val & 0x40;
116 
117 	code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);
118 
119 	dev_dbg(&keypad->client->dev,
120 		"key[%d:%d] %s\n", row, col, release ? "release" : "press");
121 
122 	input_event(input_dev, EV_MSC, MSC_SCAN, code);
123 	input_report_key(input_dev, keypad->keycodes[code], !release);
124 	input_sync(input_dev);
125 
126 	return IRQ_HANDLED;
127 }
128 
129 /*
130  * Let MAX7359 fall into a deep sleep:
131  * If no keys are pressed, enter sleep mode for 8192 ms. And if any
132  * key is pressed, the MAX7359 returns to normal operating mode.
133  */
134 static inline void max7359_fall_deepsleep(struct i2c_client *client)
135 {
136 	max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
137 }
138 
139 /*
140  * Let MAX7359 take a catnap:
141  * Autosleep just for 256 ms.
142  */
143 static inline void max7359_take_catnap(struct i2c_client *client)
144 {
145 	max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
146 }
147 
148 static int max7359_open(struct input_dev *dev)
149 {
150 	struct max7359_keypad *keypad = input_get_drvdata(dev);
151 
152 	max7359_take_catnap(keypad->client);
153 
154 	return 0;
155 }
156 
157 static void max7359_close(struct input_dev *dev)
158 {
159 	struct max7359_keypad *keypad = input_get_drvdata(dev);
160 
161 	max7359_fall_deepsleep(keypad->client);
162 }
163 
164 static void max7359_initialize(struct i2c_client *client)
165 {
166 	max7359_write_reg(client, MAX7359_REG_CONFIG,
167 		MAX7359_CFG_INTERRUPT | /* Irq clears after host read */
168 		MAX7359_CFG_KEY_RELEASE | /* Key release enable */
169 		MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
170 
171 	/* Full key-scan functionality */
172 	max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
173 
174 	/* nINT asserts every debounce cycles */
175 	max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
176 
177 	max7359_fall_deepsleep(client);
178 }
179 
180 static int __devinit max7359_probe(struct i2c_client *client,
181 					const struct i2c_device_id *id)
182 {
183 	const struct matrix_keymap_data *keymap_data = client->dev.platform_data;
184 	struct max7359_keypad *keypad;
185 	struct input_dev *input_dev;
186 	int ret;
187 	int error;
188 
189 	if (!client->irq) {
190 		dev_err(&client->dev, "The irq number should not be zero\n");
191 		return -EINVAL;
192 	}
193 
194 	/* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
195 	ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
196 	if (ret < 0) {
197 		dev_err(&client->dev, "failed to detect device\n");
198 		return -ENODEV;
199 	}
200 
201 	dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
202 
203 	keypad = kzalloc(sizeof(struct max7359_keypad), GFP_KERNEL);
204 	input_dev = input_allocate_device();
205 	if (!keypad || !input_dev) {
206 		dev_err(&client->dev, "failed to allocate memory\n");
207 		error = -ENOMEM;
208 		goto failed_free_mem;
209 	}
210 
211 	keypad->client = client;
212 	keypad->input_dev = input_dev;
213 
214 	input_dev->name = client->name;
215 	input_dev->id.bustype = BUS_I2C;
216 	input_dev->open = max7359_open;
217 	input_dev->close = max7359_close;
218 	input_dev->dev.parent = &client->dev;
219 
220 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
221 	input_dev->keycodesize = sizeof(keypad->keycodes[0]);
222 	input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
223 	input_dev->keycode = keypad->keycodes;
224 
225 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
226 	input_set_drvdata(input_dev, keypad);
227 
228 	max7359_build_keycode(keypad, keymap_data);
229 
230 	error = request_threaded_irq(client->irq, NULL, max7359_interrupt,
231 				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
232 				     client->name, keypad);
233 	if (error) {
234 		dev_err(&client->dev, "failed to register interrupt\n");
235 		goto failed_free_mem;
236 	}
237 
238 	/* Register the input device */
239 	error = input_register_device(input_dev);
240 	if (error) {
241 		dev_err(&client->dev, "failed to register input device\n");
242 		goto failed_free_irq;
243 	}
244 
245 	/* Initialize MAX7359 */
246 	max7359_initialize(client);
247 
248 	i2c_set_clientdata(client, keypad);
249 	device_init_wakeup(&client->dev, 1);
250 
251 	return 0;
252 
253 failed_free_irq:
254 	free_irq(client->irq, keypad);
255 failed_free_mem:
256 	input_free_device(input_dev);
257 	kfree(keypad);
258 	return error;
259 }
260 
261 static int __devexit max7359_remove(struct i2c_client *client)
262 {
263 	struct max7359_keypad *keypad = i2c_get_clientdata(client);
264 
265 	free_irq(client->irq, keypad);
266 	input_unregister_device(keypad->input_dev);
267 	i2c_set_clientdata(client, NULL);
268 	kfree(keypad);
269 
270 	return 0;
271 }
272 
273 #ifdef CONFIG_PM
274 static int max7359_suspend(struct i2c_client *client, pm_message_t mesg)
275 {
276 	max7359_fall_deepsleep(client);
277 
278 	if (device_may_wakeup(&client->dev))
279 		enable_irq_wake(client->irq);
280 
281 	return 0;
282 }
283 
284 static int max7359_resume(struct i2c_client *client)
285 {
286 	if (device_may_wakeup(&client->dev))
287 		disable_irq_wake(client->irq);
288 
289 	/* Restore the default setting */
290 	max7359_take_catnap(client);
291 
292 	return 0;
293 }
294 #else
295 #define max7359_suspend	NULL
296 #define max7359_resume	NULL
297 #endif
298 
299 static const struct i2c_device_id max7359_ids[] = {
300 	{ "max7359", 0 },
301 	{ }
302 };
303 MODULE_DEVICE_TABLE(i2c, max7359_ids);
304 
305 static struct i2c_driver max7359_i2c_driver = {
306 	.driver = {
307 		.name = "max7359",
308 	},
309 	.probe		= max7359_probe,
310 	.remove		= __devexit_p(max7359_remove),
311 	.suspend	= max7359_suspend,
312 	.resume		= max7359_resume,
313 	.id_table	= max7359_ids,
314 };
315 
316 static int __init max7359_init(void)
317 {
318 	return i2c_add_driver(&max7359_i2c_driver);
319 }
320 module_init(max7359_init);
321 
322 static void __exit max7359_exit(void)
323 {
324 	i2c_del_driver(&max7359_i2c_driver);
325 }
326 module_exit(max7359_exit);
327 
328 MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
329 MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
330 MODULE_LICENSE("GPL v2");
331