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/interrupt.h>
17 #include <linux/input.h>
18 #include <linux/irq.h>
19 #include <linux/slab.h>
20 #include <linux/platform_data/mcs.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(struct_size(data, keycodes, pdata->key_maxval + 1),
117 		       GFP_KERNEL);
118 	input_dev = input_allocate_device();
119 	if (!data || !input_dev) {
120 		dev_err(&client->dev, "Failed to allocate memory\n");
121 		error = -ENOMEM;
122 		goto err_free_mem;
123 	}
124 
125 	data->client = client;
126 	data->input_dev = input_dev;
127 
128 	if (id->driver_data == MCS5000_TOUCHKEY) {
129 		data->chip.status_reg = MCS5000_TOUCHKEY_STATUS;
130 		data->chip.pressbit = MCS5000_TOUCHKEY_STATUS_PRESS;
131 		data->chip.baseval = MCS5000_TOUCHKEY_BASE_VAL;
132 		fw_reg = MCS5000_TOUCHKEY_FW;
133 	} else {
134 		data->chip.status_reg = MCS5080_TOUCHKEY_STATUS;
135 		data->chip.pressbit = MCS5080_TOUCHKEY_STATUS_PRESS;
136 		data->chip.press_invert = 1;
137 		data->chip.baseval = MCS5080_TOUCHKEY_BASE_VAL;
138 		fw_reg = MCS5080_TOUCHKEY_FW;
139 	}
140 
141 	fw_ver = i2c_smbus_read_byte_data(client, fw_reg);
142 	if (fw_ver < 0) {
143 		error = fw_ver;
144 		dev_err(&client->dev, "i2c read error[%d]\n", error);
145 		goto err_free_mem;
146 	}
147 	dev_info(&client->dev, "Firmware version: %d\n", fw_ver);
148 
149 	input_dev->name = "MELFAS MCS Touchkey";
150 	input_dev->id.bustype = BUS_I2C;
151 	input_dev->dev.parent = &client->dev;
152 	input_dev->evbit[0] = BIT_MASK(EV_KEY);
153 	if (!pdata->no_autorepeat)
154 		input_dev->evbit[0] |= BIT_MASK(EV_REP);
155 	input_dev->keycode = data->keycodes;
156 	input_dev->keycodesize = sizeof(data->keycodes[0]);
157 	input_dev->keycodemax = pdata->key_maxval + 1;
158 
159 	for (i = 0; i < pdata->keymap_size; i++) {
160 		unsigned int val = MCS_KEY_VAL(pdata->keymap[i]);
161 		unsigned int code = MCS_KEY_CODE(pdata->keymap[i]);
162 
163 		data->keycodes[val] = code;
164 		__set_bit(code, input_dev->keybit);
165 	}
166 
167 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
168 	input_set_drvdata(input_dev, data);
169 
170 	if (pdata->cfg_pin)
171 		pdata->cfg_pin();
172 
173 	if (pdata->poweron) {
174 		data->poweron = pdata->poweron;
175 		data->poweron(true);
176 	}
177 
178 	error = request_threaded_irq(client->irq, NULL, mcs_touchkey_interrupt,
179 				     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
180 				     client->dev.driver->name, data);
181 	if (error) {
182 		dev_err(&client->dev, "Failed to register interrupt\n");
183 		goto err_free_mem;
184 	}
185 
186 	error = input_register_device(input_dev);
187 	if (error)
188 		goto err_free_irq;
189 
190 	i2c_set_clientdata(client, data);
191 	return 0;
192 
193 err_free_irq:
194 	free_irq(client->irq, data);
195 err_free_mem:
196 	input_free_device(input_dev);
197 	kfree(data);
198 	return error;
199 }
200 
201 static int mcs_touchkey_remove(struct i2c_client *client)
202 {
203 	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
204 
205 	free_irq(client->irq, data);
206 	if (data->poweron)
207 		data->poweron(false);
208 	input_unregister_device(data->input_dev);
209 	kfree(data);
210 
211 	return 0;
212 }
213 
214 static void mcs_touchkey_shutdown(struct i2c_client *client)
215 {
216 	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
217 
218 	if (data->poweron)
219 		data->poweron(false);
220 }
221 
222 #ifdef CONFIG_PM_SLEEP
223 static int mcs_touchkey_suspend(struct device *dev)
224 {
225 	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
226 	struct i2c_client *client = data->client;
227 
228 	/* Disable the work */
229 	disable_irq(client->irq);
230 
231 	/* Finally turn off the power */
232 	if (data->poweron)
233 		data->poweron(false);
234 
235 	return 0;
236 }
237 
238 static int mcs_touchkey_resume(struct device *dev)
239 {
240 	struct mcs_touchkey_data *data = dev_get_drvdata(dev);
241 	struct i2c_client *client = data->client;
242 
243 	/* Enable the device first */
244 	if (data->poweron)
245 		data->poweron(true);
246 
247 	/* Enable irq again */
248 	enable_irq(client->irq);
249 
250 	return 0;
251 }
252 #endif
253 
254 static SIMPLE_DEV_PM_OPS(mcs_touchkey_pm_ops,
255 			 mcs_touchkey_suspend, mcs_touchkey_resume);
256 
257 static const struct i2c_device_id mcs_touchkey_id[] = {
258 	{ "mcs5000_touchkey", MCS5000_TOUCHKEY },
259 	{ "mcs5080_touchkey", MCS5080_TOUCHKEY },
260 	{ }
261 };
262 MODULE_DEVICE_TABLE(i2c, mcs_touchkey_id);
263 
264 static struct i2c_driver mcs_touchkey_driver = {
265 	.driver = {
266 		.name	= "mcs_touchkey",
267 		.pm	= &mcs_touchkey_pm_ops,
268 	},
269 	.probe		= mcs_touchkey_probe,
270 	.remove		= mcs_touchkey_remove,
271 	.shutdown       = mcs_touchkey_shutdown,
272 	.id_table	= mcs_touchkey_id,
273 };
274 
275 module_i2c_driver(mcs_touchkey_driver);
276 
277 /* Module information */
278 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
279 MODULE_AUTHOR("HeungJun Kim <riverful.kim@samsung.com>");
280 MODULE_DESCRIPTION("Touchkey driver for MELFAS MCS5000/5080 controller");
281 MODULE_LICENSE("GPL");
282