1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Touchkey driver for MELFAS MCS5000/5080 controller
4 *
5 * Copyright (C) 2010 Samsung Electronics Co.Ltd
6 * Author: HeungJun Kim <riverful.kim@samsung.com>
7 * Author: Joonyoung Shim <jy0922.shim@samsung.com>
8 */
9
10#include <linux/module.h>
11#include <linux/i2c.h>
12#include <linux/interrupt.h>
13#include <linux/input.h>
14#include <linux/irq.h>
15#include <linux/slab.h>
16#include <linux/platform_data/mcs.h>
17#include <linux/pm.h>
18
19/* MCS5000 Touchkey */
20#define MCS5000_TOUCHKEY_STATUS		0x04
21#define MCS5000_TOUCHKEY_STATUS_PRESS	7
22#define MCS5000_TOUCHKEY_FW		0x0a
23#define MCS5000_TOUCHKEY_BASE_VAL	0x61
24
25/* MCS5080 Touchkey */
26#define MCS5080_TOUCHKEY_STATUS		0x00
27#define MCS5080_TOUCHKEY_STATUS_PRESS	3
28#define MCS5080_TOUCHKEY_FW		0x01
29#define MCS5080_TOUCHKEY_BASE_VAL	0x1
30
31enum mcs_touchkey_type {
32	MCS5000_TOUCHKEY,
33	MCS5080_TOUCHKEY,
34};
35
36struct mcs_touchkey_chip {
37	unsigned int status_reg;
38	unsigned int pressbit;
39	unsigned int press_invert;
40	unsigned int baseval;
41};
42
43struct mcs_touchkey_data {
44	void (*poweron)(bool);
45
46	struct i2c_client *client;
47	struct input_dev *input_dev;
48	struct mcs_touchkey_chip chip;
49	unsigned int key_code;
50	unsigned int key_val;
51	unsigned short keycodes[];
52};
53
54static irqreturn_t mcs_touchkey_interrupt(int irq, void *dev_id)
55{
56	struct mcs_touchkey_data *data = dev_id;
57	struct mcs_touchkey_chip *chip = &data->chip;
58	struct i2c_client *client = data->client;
59	struct input_dev *input = data->input_dev;
60	unsigned int key_val;
61	unsigned int pressed;
62	int val;
63
64	val = i2c_smbus_read_byte_data(client, chip->status_reg);
65	if (val < 0) {
66		dev_err(&client->dev, "i2c read error [%d]\n", val);
67		goto out;
68	}
69
70	pressed = (val & (1 << chip->pressbit)) >> chip->pressbit;
71	if (chip->press_invert)
72		pressed ^= chip->press_invert;
73
74	/* key_val is 0 when released, so we should use key_val of press. */
75	if (pressed) {
76		key_val = val & (0xff >> (8 - chip->pressbit));
77		if (!key_val)
78			goto out;
79		key_val -= chip->baseval;
80		data->key_code = data->keycodes[key_val];
81		data->key_val = key_val;
82	}
83
84	input_event(input, EV_MSC, MSC_SCAN, data->key_val);
85	input_report_key(input, data->key_code, pressed);
86	input_sync(input);
87
88	dev_dbg(&client->dev, "key %d %d %s\n", data->key_val, data->key_code,
89		pressed ? "pressed" : "released");
90
91 out:
92	return IRQ_HANDLED;
93}
94
95static void mcs_touchkey_poweroff(void *data)
96{
97	struct mcs_touchkey_data *touchkey = data;
98
99	touchkey->poweron(false);
100}
101
102static int mcs_touchkey_probe(struct i2c_client *client)
103{
104	const struct i2c_device_id *id = i2c_client_get_device_id(client);
105	const struct mcs_platform_data *pdata;
106	struct mcs_touchkey_data *data;
107	struct input_dev *input_dev;
108	unsigned int fw_reg;
109	int fw_ver;
110	int error;
111	int i;
112
113	pdata = dev_get_platdata(&client->dev);
114	if (!pdata) {
115		dev_err(&client->dev, "no platform data defined\n");
116		return -EINVAL;
117	}
118
119	data = devm_kzalloc(&client->dev,
120			    struct_size(data, keycodes, pdata->key_maxval + 1),
121			    GFP_KERNEL);
122	if (!data)
123		return -ENOMEM;
124
125	input_dev = devm_input_allocate_device(&client->dev);
126	if (!input_dev) {
127		dev_err(&client->dev, "Failed to allocate input device\n");
128		return -ENOMEM;
129	}
130
131	data->client = client;
132	data->input_dev = input_dev;
133
134	if (id->driver_data == MCS5000_TOUCHKEY) {
135		data->chip.status_reg = MCS5000_TOUCHKEY_STATUS;
136		data->chip.pressbit = MCS5000_TOUCHKEY_STATUS_PRESS;
137		data->chip.baseval = MCS5000_TOUCHKEY_BASE_VAL;
138		fw_reg = MCS5000_TOUCHKEY_FW;
139	} else {
140		data->chip.status_reg = MCS5080_TOUCHKEY_STATUS;
141		data->chip.pressbit = MCS5080_TOUCHKEY_STATUS_PRESS;
142		data->chip.press_invert = 1;
143		data->chip.baseval = MCS5080_TOUCHKEY_BASE_VAL;
144		fw_reg = MCS5080_TOUCHKEY_FW;
145	}
146
147	fw_ver = i2c_smbus_read_byte_data(client, fw_reg);
148	if (fw_ver < 0) {
149		dev_err(&client->dev, "i2c read error[%d]\n", fw_ver);
150		return fw_ver;
151	}
152	dev_info(&client->dev, "Firmware version: %d\n", fw_ver);
153
154	input_dev->name = "MELFAS MCS Touchkey";
155	input_dev->id.bustype = BUS_I2C;
156	input_dev->evbit[0] = BIT_MASK(EV_KEY);
157	if (!pdata->no_autorepeat)
158		input_dev->evbit[0] |= BIT_MASK(EV_REP);
159	input_dev->keycode = data->keycodes;
160	input_dev->keycodesize = sizeof(data->keycodes[0]);
161	input_dev->keycodemax = pdata->key_maxval + 1;
162
163	for (i = 0; i < pdata->keymap_size; i++) {
164		unsigned int val = MCS_KEY_VAL(pdata->keymap[i]);
165		unsigned int code = MCS_KEY_CODE(pdata->keymap[i]);
166
167		data->keycodes[val] = code;
168		__set_bit(code, input_dev->keybit);
169	}
170
171	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
172	input_set_drvdata(input_dev, data);
173
174	if (pdata->cfg_pin)
175		pdata->cfg_pin();
176
177	if (pdata->poweron) {
178		data->poweron = pdata->poweron;
179		data->poweron(true);
180
181		error = devm_add_action_or_reset(&client->dev,
182						 mcs_touchkey_poweroff, data);
183		if (error)
184			return error;
185	}
186
187	error = devm_request_threaded_irq(&client->dev, client->irq,
188					  NULL, mcs_touchkey_interrupt,
189					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
190					  client->dev.driver->name, data);
191	if (error) {
192		dev_err(&client->dev, "Failed to register interrupt\n");
193		return error;
194	}
195
196	error = input_register_device(input_dev);
197	if (error)
198		return error;
199
200	i2c_set_clientdata(client, data);
201	return 0;
202}
203
204static void mcs_touchkey_shutdown(struct i2c_client *client)
205{
206	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
207
208	if (data->poweron)
209		data->poweron(false);
210}
211
212static int mcs_touchkey_suspend(struct device *dev)
213{
214	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
215	struct i2c_client *client = data->client;
216
217	/* Disable the work */
218	disable_irq(client->irq);
219
220	/* Finally turn off the power */
221	if (data->poweron)
222		data->poweron(false);
223
224	return 0;
225}
226
227static int mcs_touchkey_resume(struct device *dev)
228{
229	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
230	struct i2c_client *client = data->client;
231
232	/* Enable the device first */
233	if (data->poweron)
234		data->poweron(true);
235
236	/* Enable irq again */
237	enable_irq(client->irq);
238
239	return 0;
240}
241
242static DEFINE_SIMPLE_DEV_PM_OPS(mcs_touchkey_pm_ops,
243				mcs_touchkey_suspend, mcs_touchkey_resume);
244
245static const struct i2c_device_id mcs_touchkey_id[] = {
246	{ "mcs5000_touchkey", MCS5000_TOUCHKEY },
247	{ "mcs5080_touchkey", MCS5080_TOUCHKEY },
248	{ }
249};
250MODULE_DEVICE_TABLE(i2c, mcs_touchkey_id);
251
252static struct i2c_driver mcs_touchkey_driver = {
253	.driver = {
254		.name	= "mcs_touchkey",
255		.pm	= pm_sleep_ptr(&mcs_touchkey_pm_ops),
256	},
257	.probe		= mcs_touchkey_probe,
258	.shutdown       = mcs_touchkey_shutdown,
259	.id_table	= mcs_touchkey_id,
260};
261
262module_i2c_driver(mcs_touchkey_driver);
263
264/* Module information */
265MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
266MODULE_AUTHOR("HeungJun Kim <riverful.kim@samsung.com>");
267MODULE_DESCRIPTION("Touchkey driver for MELFAS MCS5000/5080 controller");
268MODULE_LICENSE("GPL");
269