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
59struct 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
67static 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
77static 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/* runs in an IRQ thread -- can (and will!) sleep */
88static irqreturn_t max7359_interrupt(int irq, void *dev_id)
89{
90 struct max7359_keypad *keypad = dev_id;
91 struct input_dev *input_dev = keypad->input_dev;
92 int val, row, col, release, code;
93
94 val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
95 row = val & 0x7;
96 col = (val >> 3) & 0x7;
97 release = val & 0x40;
98
99 code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);
100
101 dev_dbg(&keypad->client->dev,
102 "key[%d:%d] %s\n", row, col, release ? "release" : "press");
103
104 input_event(input_dev, EV_MSC, MSC_SCAN, code);
105 input_report_key(input_dev, keypad->keycodes[code], !release);
106 input_sync(input_dev);
107
108 return IRQ_HANDLED;
109}
110
111/*
112 * Let MAX7359 fall into a deep sleep:
113 * If no keys are pressed, enter sleep mode for 8192 ms. And if any
114 * key is pressed, the MAX7359 returns to normal operating mode.
115 */
116static inline void max7359_fall_deepsleep(struct i2c_client *client)
117{
118 max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
119}
120
121/*
122 * Let MAX7359 take a catnap:
123 * Autosleep just for 256 ms.
124 */
125static inline void max7359_take_catnap(struct i2c_client *client)
126{
127 max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
128}
129
130static int max7359_open(struct input_dev *dev)
131{
132 struct max7359_keypad *keypad = input_get_drvdata(dev);
133
134 max7359_take_catnap(keypad->client);
135
136 return 0;
137}
138
139static void max7359_close(struct input_dev *dev)
140{
141 struct max7359_keypad *keypad = input_get_drvdata(dev);
142
143 max7359_fall_deepsleep(keypad->client);
144}
145
146static void max7359_initialize(struct i2c_client *client)
147{
148 max7359_write_reg(client, MAX7359_REG_CONFIG,
149 MAX7359_CFG_KEY_RELEASE | /* Key release enable */
150 MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
151
152 /* Full key-scan functionality */
153 max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
154
155 /* nINT asserts every debounce cycles */
156 max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
157
158 max7359_fall_deepsleep(client);
159}
160
161static int max7359_probe(struct i2c_client *client,
162 const struct i2c_device_id *id)
163{
164 const struct matrix_keymap_data *keymap_data =
165 dev_get_platdata(&client->dev);
166 struct max7359_keypad *keypad;
167 struct input_dev *input_dev;
168 int ret;
169 int error;
170
171 if (!client->irq) {
172 dev_err(&client->dev, "The irq number should not be zero\n");
173 return -EINVAL;
174 }
175
176 /* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
177 ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
178 if (ret < 0) {
179 dev_err(&client->dev, "failed to detect device\n");
180 return -ENODEV;
181 }
182
183 dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
184
185 keypad = devm_kzalloc(&client->dev, sizeof(struct max7359_keypad),
186 GFP_KERNEL);
187 if (!keypad) {
188 dev_err(&client->dev, "failed to allocate memory\n");
189 return -ENOMEM;
190 }
191
192 input_dev = devm_input_allocate_device(&client->dev);
193 if (!input_dev) {
194 dev_err(&client->dev, "failed to allocate input device\n");
195 return -ENOMEM;
196 }
197
198 keypad->client = client;
199 keypad->input_dev = input_dev;
200
201 input_dev->name = client->name;
202 input_dev->id.bustype = BUS_I2C;
203 input_dev->open = max7359_open;
204 input_dev->close = max7359_close;
205 input_dev->dev.parent = &client->dev;
206
207 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
208 input_dev->keycodesize = sizeof(keypad->keycodes[0]);
209 input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
210 input_dev->keycode = keypad->keycodes;
211
212 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
213 input_set_drvdata(input_dev, keypad);
214
215 error = matrix_keypad_build_keymap(keymap_data, NULL,
216 MAX7359_MAX_KEY_ROWS,
217 MAX7359_MAX_KEY_COLS,
218 keypad->keycodes,
219 input_dev);
220 if (error) {
221 dev_err(&client->dev, "failed to build keymap\n");
222 return error;
223 }
224
225 error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
226 max7359_interrupt,
227 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
228 client->name, keypad);
229 if (error) {
230 dev_err(&client->dev, "failed to register interrupt\n");
231 return error;
232 }
233
234 /* Register the input device */
235 error = input_register_device(input_dev);
236 if (error) {
237 dev_err(&client->dev, "failed to register input device\n");
238 return error;
239 }
240
241 /* Initialize MAX7359 */
242 max7359_initialize(client);
243
244 device_init_wakeup(&client->dev, 1);
245
246 return 0;
247}
248
249#ifdef CONFIG_PM_SLEEP
250static int max7359_suspend(struct device *dev)
251{
252 struct i2c_client *client = to_i2c_client(dev);
253
254 max7359_fall_deepsleep(client);
255
256 if (device_may_wakeup(&client->dev))
257 enable_irq_wake(client->irq);
258
259 return 0;
260}
261
262static int max7359_resume(struct device *dev)
263{
264 struct i2c_client *client = to_i2c_client(dev);
265
266 if (device_may_wakeup(&client->dev))
267 disable_irq_wake(client->irq);
268
269 /* Restore the default setting */
270 max7359_take_catnap(client);
271
272 return 0;
273}
274#endif
275
276static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
277
278static const struct i2c_device_id max7359_ids[] = {
279 { "max7359", 0 },
280 { }
281};
282MODULE_DEVICE_TABLE(i2c, max7359_ids);
283
284static struct i2c_driver max7359_i2c_driver = {
285 .driver = {
286 .name = "max7359",
287 .pm = &max7359_pm,
288 },
289 .probe = max7359_probe,
290 .id_table = max7359_ids,
291};
292
293module_i2c_driver(max7359_i2c_driver);
294
295MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
296MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
297MODULE_LICENSE("GPL v2");
298