1 /*
2  * Touchkey driver for MELFAS MCS5000/5080 controller
3  *
4  * Copyright (C) 2010 Samsung Electronics Co.Ltd
5  * Author: HeungJun Kim <riverful.kim@samsung.com>
6  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  */
13 
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/i2c.h>
17 #include <linux/i2c/mcs.h>
18 #include <linux/interrupt.h>
19 #include <linux/input.h>
20 #include <linux/irq.h>
21 #include <linux/slab.h>
22 #include <linux/pm.h>
23 
24 /* MCS5000 Touchkey */
25 #define MCS5000_TOUCHKEY_STATUS		0x04
26 #define MCS5000_TOUCHKEY_STATUS_PRESS	7
27 #define MCS5000_TOUCHKEY_FW		0x0a
28 #define MCS5000_TOUCHKEY_BASE_VAL	0x61
29 
30 /* MCS5080 Touchkey */
31 #define MCS5080_TOUCHKEY_STATUS		0x00
32 #define MCS5080_TOUCHKEY_STATUS_PRESS	3
33 #define MCS5080_TOUCHKEY_FW		0x01
34 #define MCS5080_TOUCHKEY_BASE_VAL	0x1
35 
36 enum mcs_touchkey_type {
37 	MCS5000_TOUCHKEY,
38 	MCS5080_TOUCHKEY,
39 };
40 
41 struct mcs_touchkey_chip {
42 	unsigned int status_reg;
43 	unsigned int pressbit;
44 	unsigned int press_invert;
45 	unsigned int baseval;
46 };
47 
48 struct mcs_touchkey_data {
49 	void (*poweron)(bool);
50 
51 	struct i2c_client *client;
52 	struct input_dev *input_dev;
53 	struct mcs_touchkey_chip chip;
54 	unsigned int key_code;
55 	unsigned int key_val;
56 	unsigned short keycodes[];
57 };
58 
59 static irqreturn_t mcs_touchkey_interrupt(int irq, void *dev_id)
60 {
61 	struct mcs_touchkey_data *data = dev_id;
62 	struct mcs_touchkey_chip *chip = &data->chip;
63 	struct i2c_client *client = data->client;
64 	struct input_dev *input = data->input_dev;
65 	unsigned int key_val;
66 	unsigned int pressed;
67 	int val;
68 
69 	val = i2c_smbus_read_byte_data(client, chip->status_reg);
70 	if (val < 0) {
71 		dev_err(&client->dev, "i2c read error [%d]\n", val);
72 		goto out;
73 	}
74 
75 	pressed = (val & (1 << chip->pressbit)) >> chip->pressbit;
76 	if (chip->press_invert)
77 		pressed ^= chip->press_invert;
78 
79 	/* key_val is 0 when released, so we should use key_val of press. */
80 	if (pressed) {
81 		key_val = val & (0xff >> (8 - chip->pressbit));
82 		if (!key_val)
83 			goto out;
84 		key_val -= chip->baseval;
85 		data->key_code = data->keycodes[key_val];
86 		data->key_val = key_val;
87 	}
88 
89 	input_event(input, EV_MSC, MSC_SCAN, data->key_val);
90 	input_report_key(input, data->key_code, pressed);
91 	input_sync(input);
92 
93 	dev_dbg(&client->dev, "key %d %d %s\n", data->key_val, data->key_code,
94 		pressed ? "pressed" : "released");
95 
96  out:
97 	return IRQ_HANDLED;
98 }
99 
100 static int mcs_touchkey_probe(struct i2c_client *client,
101 		const struct i2c_device_id *id)
102 {
103 	const struct mcs_platform_data *pdata;
104 	struct mcs_touchkey_data *data;
105 	struct input_dev *input_dev;
106 	unsigned int fw_reg;
107 	int fw_ver;
108 	int error;
109 	int i;
110 
111 	pdata = client->dev.platform_data;
112 	if (!pdata) {
113 		dev_err(&client->dev, "no platform data defined\n");
114 		return -EINVAL;
115 	}
116 
117 	data = kzalloc(sizeof(struct mcs_touchkey_data) +
118 			sizeof(data->keycodes[0]) * (pdata->key_maxval + 1),
119 			GFP_KERNEL);
120 	input_dev = input_allocate_device();
121 	if (!data || !input_dev) {
122 		dev_err(&client->dev, "Failed to allocate memory\n");
123 		error = -ENOMEM;
124 		goto err_free_mem;
125 	}
126 
127 	data->client = client;
128 	data->input_dev = input_dev;
129 
130 	if (id->driver_data == MCS5000_TOUCHKEY) {
131 		data->chip.status_reg = MCS5000_TOUCHKEY_STATUS;
132 		data->chip.pressbit = MCS5000_TOUCHKEY_STATUS_PRESS;
133 		data->chip.baseval = MCS5000_TOUCHKEY_BASE_VAL;
134 		fw_reg = MCS5000_TOUCHKEY_FW;
135 	} else {
136 		data->chip.status_reg = MCS5080_TOUCHKEY_STATUS;
137 		data->chip.pressbit = MCS5080_TOUCHKEY_STATUS_PRESS;
138 		data->chip.press_invert = 1;
139 		data->chip.baseval = MCS5080_TOUCHKEY_BASE_VAL;
140 		fw_reg = MCS5080_TOUCHKEY_FW;
141 	}
142 
143 	fw_ver = i2c_smbus_read_byte_data(client, fw_reg);
144 	if (fw_ver < 0) {
145 		error = fw_ver;
146 		dev_err(&client->dev, "i2c read error[%d]\n", error);
147 		goto err_free_mem;
148 	}
149 	dev_info(&client->dev, "Firmware version: %d\n", fw_ver);
150 
151 	input_dev->name = "MELPAS MCS Touchkey";
152 	input_dev->id.bustype = BUS_I2C;
153 	input_dev->dev.parent = &client->dev;
154 	input_dev->evbit[0] = BIT_MASK(EV_KEY);
155 	if (!pdata->no_autorepeat)
156 		input_dev->evbit[0] |= BIT_MASK(EV_REP);
157 	input_dev->keycode = data->keycodes;
158 	input_dev->keycodesize = sizeof(data->keycodes[0]);
159 	input_dev->keycodemax = pdata->key_maxval + 1;
160 
161 	for (i = 0; i < pdata->keymap_size; i++) {
162 		unsigned int val = MCS_KEY_VAL(pdata->keymap[i]);
163 		unsigned int code = MCS_KEY_CODE(pdata->keymap[i]);
164 
165 		data->keycodes[val] = code;
166 		__set_bit(code, input_dev->keybit);
167 	}
168 
169 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
170 	input_set_drvdata(input_dev, data);
171 
172 	if (pdata->cfg_pin)
173 		pdata->cfg_pin();
174 
175 	if (pdata->poweron) {
176 		data->poweron = pdata->poweron;
177 		data->poweron(true);
178 	}
179 
180 	error = request_threaded_irq(client->irq, NULL, mcs_touchkey_interrupt,
181 				     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
182 				     client->dev.driver->name, data);
183 	if (error) {
184 		dev_err(&client->dev, "Failed to register interrupt\n");
185 		goto err_free_mem;
186 	}
187 
188 	error = input_register_device(input_dev);
189 	if (error)
190 		goto err_free_irq;
191 
192 	i2c_set_clientdata(client, data);
193 	return 0;
194 
195 err_free_irq:
196 	free_irq(client->irq, data);
197 err_free_mem:
198 	input_free_device(input_dev);
199 	kfree(data);
200 	return error;
201 }
202 
203 static int mcs_touchkey_remove(struct i2c_client *client)
204 {
205 	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
206 
207 	free_irq(client->irq, data);
208 	if (data->poweron)
209 		data->poweron(false);
210 	input_unregister_device(data->input_dev);
211 	kfree(data);
212 
213 	return 0;
214 }
215 
216 static void mcs_touchkey_shutdown(struct i2c_client *client)
217 {
218 	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
219 
220 	if (data->poweron)
221 		data->poweron(false);
222 }
223 
224 #ifdef CONFIG_PM_SLEEP
225 static int mcs_touchkey_suspend(struct device *dev)
226 {
227 	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
228 	struct i2c_client *client = data->client;
229 
230 	/* Disable the work */
231 	disable_irq(client->irq);
232 
233 	/* Finally turn off the power */
234 	if (data->poweron)
235 		data->poweron(false);
236 
237 	return 0;
238 }
239 
240 static int mcs_touchkey_resume(struct device *dev)
241 {
242 	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
243 	struct i2c_client *client = data->client;
244 
245 	/* Enable the device first */
246 	if (data->poweron)
247 		data->poweron(true);
248 
249 	/* Enable irq again */
250 	enable_irq(client->irq);
251 
252 	return 0;
253 }
254 #endif
255 
256 static SIMPLE_DEV_PM_OPS(mcs_touchkey_pm_ops,
257 			 mcs_touchkey_suspend, mcs_touchkey_resume);
258 
259 static const struct i2c_device_id mcs_touchkey_id[] = {
260 	{ "mcs5000_touchkey", MCS5000_TOUCHKEY },
261 	{ "mcs5080_touchkey", MCS5080_TOUCHKEY },
262 	{ }
263 };
264 MODULE_DEVICE_TABLE(i2c, mcs_touchkey_id);
265 
266 static struct i2c_driver mcs_touchkey_driver = {
267 	.driver = {
268 		.name	= "mcs_touchkey",
269 		.owner	= THIS_MODULE,
270 		.pm	= &mcs_touchkey_pm_ops,
271 	},
272 	.probe		= mcs_touchkey_probe,
273 	.remove		= mcs_touchkey_remove,
274 	.shutdown       = mcs_touchkey_shutdown,
275 	.id_table	= mcs_touchkey_id,
276 };
277 
278 module_i2c_driver(mcs_touchkey_driver);
279 
280 /* Module information */
281 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
282 MODULE_AUTHOR("HeungJun Kim <riverful.kim@samsung.com>");
283 MODULE_DESCRIPTION("Touchkey driver for MELFAS MCS5000/5080 controller");
284 MODULE_LICENSE("GPL");
285