1/*
  2 * Wacom Penabled Driver for I2C
  3 *
  4 * Copyright (c) 2011 Tatsunosuke Tobita, Wacom.
  5 * <tobita.tatsunosuke@wacom.co.jp>
  6 *
  7 * This program is free software; you can redistribute it
  8 * and/or modify it under the terms of the GNU General
  9 * Public License as published by the Free Software
 10 * Foundation; either version of 2 of the License,
 11 * or (at your option) any later version.
 12 */
 13
 14#include <linux/module.h>
 15#include <linux/input.h>
 16#include <linux/i2c.h>
 17#include <linux/slab.h>
 18#include <linux/irq.h>
 19#include <linux/interrupt.h>
 20#include <linux/gpio.h>
 21#include <asm/unaligned.h>
 22
 23#define WACOM_CMD_QUERY0	0x04
 24#define WACOM_CMD_QUERY1	0x00
 25#define WACOM_CMD_QUERY2	0x33
 26#define WACOM_CMD_QUERY3	0x02
 27#define WACOM_CMD_THROW0	0x05
 28#define WACOM_CMD_THROW1	0x00
 29#define WACOM_QUERY_SIZE	19
 30#define WACOM_RETRY_CNT		100
 31
 32struct wacom_features {
 33	int x_max;
 34	int y_max;
 35	int pressure_max;
 36	char fw_version;
 37};
 38
 39struct wacom_i2c {
 40	struct i2c_client *client;
 41	struct input_dev *input;
 42	u8 data[WACOM_QUERY_SIZE];
 43};
 44
 45static int wacom_query_device(struct i2c_client *client,
 46			      struct wacom_features *features)
 47{
 48	int ret;
 49	u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
 50			WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
 51	u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
 52	u8 data[WACOM_QUERY_SIZE];
 53	struct i2c_msg msgs[] = {
 54		{
 55			.addr = client->addr,
 56			.flags = 0,
 57			.len = sizeof(cmd1),
 58			.buf = cmd1,
 59		},
 60		{
 61			.addr = client->addr,
 62			.flags = 0,
 63			.len = sizeof(cmd2),
 64			.buf = cmd2,
 65		},
 66		{
 67			.addr = client->addr,
 68			.flags = I2C_M_RD,
 69			.len = sizeof(data),
 70			.buf = data,
 71		},
 72	};
 73
 74	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 75	if (ret < 0)
 76		return ret;
 77	if (ret != ARRAY_SIZE(msgs))
 78		return -EIO;
 79
 80	features->x_max = get_unaligned_le16(&data[3]);
 81	features->y_max = get_unaligned_le16(&data[5]);
 82	features->pressure_max = get_unaligned_le16(&data[11]);
 83	features->fw_version = get_unaligned_le16(&data[13]);
 84
 85	dev_dbg(&client->dev,
 86		"x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
 87		features->x_max, features->y_max,
 88		features->pressure_max, features->fw_version);
 89
 90	return 0;
 91}
 92
 93static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
 94{
 95	struct wacom_i2c *wac_i2c = dev_id;
 96	struct input_dev *input = wac_i2c->input;
 97	u8 *data = wac_i2c->data;
 98	unsigned int x, y, pressure;
 99	unsigned char tsw, f1, f2, ers;
100	int error;
101
102	error = i2c_master_recv(wac_i2c->client,
103				wac_i2c->data, sizeof(wac_i2c->data));
104	if (error < 0)
105		goto out;
106
107	tsw = data[3] & 0x01;
108	ers = data[3] & 0x04;
109	f1 = data[3] & 0x02;
110	f2 = data[3] & 0x10;
111	x = le16_to_cpup((__le16 *)&data[4]);
112	y = le16_to_cpup((__le16 *)&data[6]);
113	pressure = le16_to_cpup((__le16 *)&data[8]);
114
115	input_report_key(input, BTN_TOUCH, tsw || ers);
116	input_report_key(input, BTN_TOOL_PEN, tsw);
117	input_report_key(input, BTN_TOOL_RUBBER, ers);
118	input_report_key(input, BTN_STYLUS, f1);
119	input_report_key(input, BTN_STYLUS2, f2);
120	input_report_abs(input, ABS_X, x);
121	input_report_abs(input, ABS_Y, y);
122	input_report_abs(input, ABS_PRESSURE, pressure);
123	input_sync(input);
124
125out:
126	return IRQ_HANDLED;
127}
128
129static int wacom_i2c_open(struct input_dev *dev)
130{
131	struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
132	struct i2c_client *client = wac_i2c->client;
133
134	enable_irq(client->irq);
135
136	return 0;
137}
138
139static void wacom_i2c_close(struct input_dev *dev)
140{
141	struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
142	struct i2c_client *client = wac_i2c->client;
143
144	disable_irq(client->irq);
145}
146
147static int __devinit wacom_i2c_probe(struct i2c_client *client,
148				     const struct i2c_device_id *id)
149{
150	struct wacom_i2c *wac_i2c;
151	struct input_dev *input;
152	struct wacom_features features;
153	int error;
154
155	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
156		dev_err(&client->dev, "i2c_check_functionality error\n");
157		return -EIO;
158	}
159
160	error = wacom_query_device(client, &features);
161	if (error)
162		return error;
163
164	wac_i2c = kzalloc(sizeof(*wac_i2c), GFP_KERNEL);
165	input = input_allocate_device();
166	if (!wac_i2c || !input) {
167		error = -ENOMEM;
168		goto err_free_mem;
169	}
170
171	wac_i2c->client = client;
172	wac_i2c->input = input;
173
174	input->name = "Wacom I2C Digitizer";
175	input->id.bustype = BUS_I2C;
176	input->id.vendor = 0x56a;
177	input->id.version = features.fw_version;
178	input->dev.parent = &client->dev;
179	input->open = wacom_i2c_open;
180	input->close = wacom_i2c_close;
181
182	input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
183
184	__set_bit(BTN_TOOL_PEN, input->keybit);
185	__set_bit(BTN_TOOL_RUBBER, input->keybit);
186	__set_bit(BTN_STYLUS, input->keybit);
187	__set_bit(BTN_STYLUS2, input->keybit);
188	__set_bit(BTN_TOUCH, input->keybit);
189
190	input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
191	input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
192	input_set_abs_params(input, ABS_PRESSURE,
193			     0, features.pressure_max, 0, 0);
194
195	input_set_drvdata(input, wac_i2c);
196
197	error = request_threaded_irq(client->irq, NULL, wacom_i2c_irq,
198				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
199				     "wacom_i2c", wac_i2c);
200	if (error) {
201		dev_err(&client->dev,
202			"Failed to enable IRQ, error: %d\n", error);
203		goto err_free_mem;
204	}
205
206	/* Disable the IRQ, we'll enable it in wac_i2c_open() */
207	disable_irq(client->irq);
208
209	error = input_register_device(wac_i2c->input);
210	if (error) {
211		dev_err(&client->dev,
212			"Failed to register input device, error: %d\n", error);
213		goto err_free_irq;
214	}
215
216	i2c_set_clientdata(client, wac_i2c);
217	return 0;
218
219err_free_irq:
220	free_irq(client->irq, wac_i2c);
221err_free_mem:
222	input_free_device(input);
223	kfree(wac_i2c);
224
225	return error;
226}
227
228static int __devexit wacom_i2c_remove(struct i2c_client *client)
229{
230	struct wacom_i2c *wac_i2c = i2c_get_clientdata(client);
231
232	free_irq(client->irq, wac_i2c);
233	input_unregister_device(wac_i2c->input);
234	kfree(wac_i2c);
235
236	return 0;
237}
238
239#ifdef CONFIG_PM_SLEEP
240static int wacom_i2c_suspend(struct device *dev)
241{
242	struct i2c_client *client = to_i2c_client(dev);
243
244	disable_irq(client->irq);
245
246	return 0;
247}
248
249static int wacom_i2c_resume(struct device *dev)
250{
251	struct i2c_client *client = to_i2c_client(dev);
252
253	enable_irq(client->irq);
254
255	return 0;
256}
257#endif
258
259static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
260
261static const struct i2c_device_id wacom_i2c_id[] = {
262	{ "WAC_I2C_EMR", 0 },
263	{ },
264};
265MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
266
267static struct i2c_driver wacom_i2c_driver = {
268	.driver	= {
269		.name	= "wacom_i2c",
270		.owner	= THIS_MODULE,
271		.pm	= &wacom_i2c_pm,
272	},
273
274	.probe		= wacom_i2c_probe,
275	.remove		= __devexit_p(wacom_i2c_remove),
276	.id_table	= wacom_i2c_id,
277};
278module_i2c_driver(wacom_i2c_driver);
279
280MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
281MODULE_DESCRIPTION("WACOM EMR I2C Driver");
282MODULE_LICENSE("GPL");