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 
31 enum mcs_touchkey_type {
32 	MCS5000_TOUCHKEY,
33 	MCS5080_TOUCHKEY,
34 };
35 
36 struct mcs_touchkey_chip {
37 	unsigned int status_reg;
38 	unsigned int pressbit;
39 	unsigned int press_invert;
40 	unsigned int baseval;
41 };
42 
43 struct 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 
mcs_touchkey_interrupt(int irq,void * dev_id)54 static 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 
mcs_touchkey_poweroff(void * data)95 static void mcs_touchkey_poweroff(void *data)
96 {
97 	struct mcs_touchkey_data *touchkey = data;
98 
99 	touchkey->poweron(false);
100 }
101 
mcs_touchkey_probe(struct i2c_client * client)102 static 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 
mcs_touchkey_shutdown(struct i2c_client * client)204 static 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 
mcs_touchkey_suspend(struct device * dev)212 static 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 
mcs_touchkey_resume(struct device * dev)227 static 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 
242 static DEFINE_SIMPLE_DEV_PM_OPS(mcs_touchkey_pm_ops,
243 				mcs_touchkey_suspend, mcs_touchkey_resume);
244 
245 static const struct i2c_device_id mcs_touchkey_id[] = {
246 	{ "mcs5000_touchkey", MCS5000_TOUCHKEY },
247 	{ "mcs5080_touchkey", MCS5080_TOUCHKEY },
248 	{ }
249 };
250 MODULE_DEVICE_TABLE(i2c, mcs_touchkey_id);
251 
252 static 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 
262 module_i2c_driver(mcs_touchkey_driver);
263 
264 /* Module information */
265 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
266 MODULE_AUTHOR("HeungJun Kim <riverful.kim@samsung.com>");
267 MODULE_DESCRIPTION("Touchkey driver for MELFAS MCS5000/5080 controller");
268 MODULE_LICENSE("GPL");
269