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 
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 
95 static int mcs_touchkey_probe(struct i2c_client *client)
96 {
97 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
98 	const struct mcs_platform_data *pdata;
99 	struct mcs_touchkey_data *data;
100 	struct input_dev *input_dev;
101 	unsigned int fw_reg;
102 	int fw_ver;
103 	int error;
104 	int i;
105 
106 	pdata = dev_get_platdata(&client->dev);
107 	if (!pdata) {
108 		dev_err(&client->dev, "no platform data defined\n");
109 		return -EINVAL;
110 	}
111 
112 	data = kzalloc(struct_size(data, keycodes, pdata->key_maxval + 1),
113 		       GFP_KERNEL);
114 	input_dev = input_allocate_device();
115 	if (!data || !input_dev) {
116 		dev_err(&client->dev, "Failed to allocate memory\n");
117 		error = -ENOMEM;
118 		goto err_free_mem;
119 	}
120 
121 	data->client = client;
122 	data->input_dev = input_dev;
123 
124 	if (id->driver_data == MCS5000_TOUCHKEY) {
125 		data->chip.status_reg = MCS5000_TOUCHKEY_STATUS;
126 		data->chip.pressbit = MCS5000_TOUCHKEY_STATUS_PRESS;
127 		data->chip.baseval = MCS5000_TOUCHKEY_BASE_VAL;
128 		fw_reg = MCS5000_TOUCHKEY_FW;
129 	} else {
130 		data->chip.status_reg = MCS5080_TOUCHKEY_STATUS;
131 		data->chip.pressbit = MCS5080_TOUCHKEY_STATUS_PRESS;
132 		data->chip.press_invert = 1;
133 		data->chip.baseval = MCS5080_TOUCHKEY_BASE_VAL;
134 		fw_reg = MCS5080_TOUCHKEY_FW;
135 	}
136 
137 	fw_ver = i2c_smbus_read_byte_data(client, fw_reg);
138 	if (fw_ver < 0) {
139 		error = fw_ver;
140 		dev_err(&client->dev, "i2c read error[%d]\n", error);
141 		goto err_free_mem;
142 	}
143 	dev_info(&client->dev, "Firmware version: %d\n", fw_ver);
144 
145 	input_dev->name = "MELFAS MCS Touchkey";
146 	input_dev->id.bustype = BUS_I2C;
147 	input_dev->dev.parent = &client->dev;
148 	input_dev->evbit[0] = BIT_MASK(EV_KEY);
149 	if (!pdata->no_autorepeat)
150 		input_dev->evbit[0] |= BIT_MASK(EV_REP);
151 	input_dev->keycode = data->keycodes;
152 	input_dev->keycodesize = sizeof(data->keycodes[0]);
153 	input_dev->keycodemax = pdata->key_maxval + 1;
154 
155 	for (i = 0; i < pdata->keymap_size; i++) {
156 		unsigned int val = MCS_KEY_VAL(pdata->keymap[i]);
157 		unsigned int code = MCS_KEY_CODE(pdata->keymap[i]);
158 
159 		data->keycodes[val] = code;
160 		__set_bit(code, input_dev->keybit);
161 	}
162 
163 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
164 	input_set_drvdata(input_dev, data);
165 
166 	if (pdata->cfg_pin)
167 		pdata->cfg_pin();
168 
169 	if (pdata->poweron) {
170 		data->poweron = pdata->poweron;
171 		data->poweron(true);
172 	}
173 
174 	error = request_threaded_irq(client->irq, NULL, mcs_touchkey_interrupt,
175 				     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
176 				     client->dev.driver->name, data);
177 	if (error) {
178 		dev_err(&client->dev, "Failed to register interrupt\n");
179 		goto err_free_mem;
180 	}
181 
182 	error = input_register_device(input_dev);
183 	if (error)
184 		goto err_free_irq;
185 
186 	i2c_set_clientdata(client, data);
187 	return 0;
188 
189 err_free_irq:
190 	free_irq(client->irq, data);
191 err_free_mem:
192 	input_free_device(input_dev);
193 	kfree(data);
194 	return error;
195 }
196 
197 static void mcs_touchkey_remove(struct i2c_client *client)
198 {
199 	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
200 
201 	free_irq(client->irq, data);
202 	if (data->poweron)
203 		data->poweron(false);
204 	input_unregister_device(data->input_dev);
205 	kfree(data);
206 }
207 
208 static void mcs_touchkey_shutdown(struct i2c_client *client)
209 {
210 	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
211 
212 	if (data->poweron)
213 		data->poweron(false);
214 }
215 
216 static int mcs_touchkey_suspend(struct device *dev)
217 {
218 	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
219 	struct i2c_client *client = data->client;
220 
221 	/* Disable the work */
222 	disable_irq(client->irq);
223 
224 	/* Finally turn off the power */
225 	if (data->poweron)
226 		data->poweron(false);
227 
228 	return 0;
229 }
230 
231 static int mcs_touchkey_resume(struct device *dev)
232 {
233 	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
234 	struct i2c_client *client = data->client;
235 
236 	/* Enable the device first */
237 	if (data->poweron)
238 		data->poweron(true);
239 
240 	/* Enable irq again */
241 	enable_irq(client->irq);
242 
243 	return 0;
244 }
245 
246 static DEFINE_SIMPLE_DEV_PM_OPS(mcs_touchkey_pm_ops,
247 				mcs_touchkey_suspend, mcs_touchkey_resume);
248 
249 static const struct i2c_device_id mcs_touchkey_id[] = {
250 	{ "mcs5000_touchkey", MCS5000_TOUCHKEY },
251 	{ "mcs5080_touchkey", MCS5080_TOUCHKEY },
252 	{ }
253 };
254 MODULE_DEVICE_TABLE(i2c, mcs_touchkey_id);
255 
256 static struct i2c_driver mcs_touchkey_driver = {
257 	.driver = {
258 		.name	= "mcs_touchkey",
259 		.pm	= pm_sleep_ptr(&mcs_touchkey_pm_ops),
260 	},
261 	.probe		= mcs_touchkey_probe,
262 	.remove		= mcs_touchkey_remove,
263 	.shutdown       = mcs_touchkey_shutdown,
264 	.id_table	= mcs_touchkey_id,
265 };
266 
267 module_i2c_driver(mcs_touchkey_driver);
268 
269 /* Module information */
270 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
271 MODULE_AUTHOR("HeungJun Kim <riverful.kim@samsung.com>");
272 MODULE_DESCRIPTION("Touchkey driver for MELFAS MCS5000/5080 controller");
273 MODULE_LICENSE("GPL");
274