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