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
56struct 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
64static 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
74static 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 */
85static 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 */
113static 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 */
122static inline void max7359_take_catnap(struct i2c_client *client)
123{
124	max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
125}
126
127static 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
136static 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
143static 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
158static 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
245static 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
257static 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
270static DEFINE_SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);
271
272static const struct i2c_device_id max7359_ids[] = {
273	{ "max7359", 0 },
274	{ }
275};
276MODULE_DEVICE_TABLE(i2c, max7359_ids);
277
278static struct i2c_driver max7359_i2c_driver = {
279	.driver = {
280		.name = "max7359",
281		.pm   = pm_sleep_ptr(&max7359_pm),
282	},
283	.probe		= max7359_probe,
284	.id_table	= max7359_ids,
285};
286
287module_i2c_driver(max7359_i2c_driver);
288
289MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
290MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
291MODULE_LICENSE("GPL v2");
292