1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Wacom Penabled Driver for I2C
  4 *
  5 * Copyright (c) 2011 - 2013 Tatsunosuke Tobita, Wacom.
  6 * <tobita.tatsunosuke@wacom.co.jp>
  7 */
  8
  9#include <linux/bits.h>
 10#include <linux/module.h>
 11#include <linux/input.h>
 12#include <linux/i2c.h>
 13#include <linux/slab.h>
 14#include <linux/irq.h>
 15#include <linux/interrupt.h>
 16#include <asm/unaligned.h>
 17
 18/* Bitmasks (for data[3]) */
 19#define WACOM_TIP_SWITCH	BIT(0)
 20#define WACOM_BARREL_SWITCH	BIT(1)
 21#define WACOM_ERASER		BIT(2)
 22#define WACOM_INVERT		BIT(3)
 23#define WACOM_BARREL_SWITCH_2	BIT(4)
 24#define WACOM_IN_PROXIMITY	BIT(5)
 25
 26/* Registers */
 27#define WACOM_COMMAND_LSB	0x04
 28#define WACOM_COMMAND_MSB	0x00
 29
 30#define WACOM_DATA_LSB		0x05
 31#define WACOM_DATA_MSB		0x00
 32
 33/* Report types */
 34#define REPORT_FEATURE		0x30
 35
 36/* Requests / operations */
 37#define OPCODE_GET_REPORT	0x02
 38
 39#define WACOM_QUERY_REPORT	3
 40#define WACOM_QUERY_SIZE	19
 41
 42struct wacom_features {
 43	int x_max;
 44	int y_max;
 45	int pressure_max;
 46	char fw_version;
 47};
 48
 49struct wacom_i2c {
 50	struct i2c_client *client;
 51	struct input_dev *input;
 52	u8 data[WACOM_QUERY_SIZE];
 53	bool prox;
 54	int tool;
 55};
 56
 57static int wacom_query_device(struct i2c_client *client,
 58			      struct wacom_features *features)
 59{
 60	u8 get_query_data_cmd[] = {
 61		WACOM_COMMAND_LSB,
 62		WACOM_COMMAND_MSB,
 63		REPORT_FEATURE | WACOM_QUERY_REPORT,
 64		OPCODE_GET_REPORT,
 65		WACOM_DATA_LSB,
 66		WACOM_DATA_MSB,
 67	};
 68	u8 data[WACOM_QUERY_SIZE];
 69	int ret;
 70
 71	struct i2c_msg msgs[] = {
 72		/* Request reading of feature ReportID: 3 (Pen Query Data) */
 73		{
 74			.addr = client->addr,
 75			.flags = 0,
 76			.len = sizeof(get_query_data_cmd),
 77			.buf = get_query_data_cmd,
 78		},
 79		{
 80			.addr = client->addr,
 81			.flags = I2C_M_RD,
 82			.len = sizeof(data),
 83			.buf = data,
 84		},
 85	};
 86
 87	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 88	if (ret < 0)
 89		return ret;
 90	if (ret != ARRAY_SIZE(msgs))
 91		return -EIO;
 92
 93	features->x_max = get_unaligned_le16(&data[3]);
 94	features->y_max = get_unaligned_le16(&data[5]);
 95	features->pressure_max = get_unaligned_le16(&data[11]);
 96	features->fw_version = get_unaligned_le16(&data[13]);
 97
 98	dev_dbg(&client->dev,
 99		"x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
100		features->x_max, features->y_max,
101		features->pressure_max, features->fw_version);
102
103	return 0;
104}
105
106static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
107{
108	struct wacom_i2c *wac_i2c = dev_id;
109	struct input_dev *input = wac_i2c->input;
110	u8 *data = wac_i2c->data;
111	unsigned int x, y, pressure;
112	unsigned char tsw, f1, f2, ers;
113	int error;
114
115	error = i2c_master_recv(wac_i2c->client,
116				wac_i2c->data, sizeof(wac_i2c->data));
117	if (error < 0)
118		goto out;
119
120	tsw = data[3] & WACOM_TIP_SWITCH;
121	ers = data[3] & WACOM_ERASER;
122	f1 = data[3] & WACOM_BARREL_SWITCH;
123	f2 = data[3] & WACOM_BARREL_SWITCH_2;
124	x = le16_to_cpup((__le16 *)&data[4]);
125	y = le16_to_cpup((__le16 *)&data[6]);
126	pressure = le16_to_cpup((__le16 *)&data[8]);
127
128	if (!wac_i2c->prox)
129		wac_i2c->tool = (data[3] & (WACOM_ERASER | WACOM_INVERT)) ?
130			BTN_TOOL_RUBBER : BTN_TOOL_PEN;
131
132	wac_i2c->prox = data[3] & WACOM_IN_PROXIMITY;
133
134	input_report_key(input, BTN_TOUCH, tsw || ers);
135	input_report_key(input, wac_i2c->tool, wac_i2c->prox);
136	input_report_key(input, BTN_STYLUS, f1);
137	input_report_key(input, BTN_STYLUS2, f2);
138	input_report_abs(input, ABS_X, x);
139	input_report_abs(input, ABS_Y, y);
140	input_report_abs(input, ABS_PRESSURE, pressure);
141	input_sync(input);
142
143out:
144	return IRQ_HANDLED;
145}
146
147static int wacom_i2c_open(struct input_dev *dev)
148{
149	struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
150	struct i2c_client *client = wac_i2c->client;
151
152	enable_irq(client->irq);
153
154	return 0;
155}
156
157static void wacom_i2c_close(struct input_dev *dev)
158{
159	struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
160	struct i2c_client *client = wac_i2c->client;
161
162	disable_irq(client->irq);
163}
164
165static int wacom_i2c_probe(struct i2c_client *client)
166{
167	struct device *dev = &client->dev;
168	struct wacom_i2c *wac_i2c;
169	struct input_dev *input;
170	struct wacom_features features = { 0 };
171	int error;
172
173	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
174		dev_err(dev, "i2c_check_functionality error\n");
175		return -EIO;
176	}
177
178	error = wacom_query_device(client, &features);
179	if (error)
180		return error;
181
182	wac_i2c = devm_kzalloc(dev, sizeof(*wac_i2c), GFP_KERNEL);
183	if (!wac_i2c)
184		return -ENOMEM;
185
186	wac_i2c->client = client;
187
188	input = devm_input_allocate_device(dev);
189	if (!input)
190		return -ENOMEM;
191
192	wac_i2c->input = input;
193
194	input->name = "Wacom I2C Digitizer";
195	input->id.bustype = BUS_I2C;
196	input->id.vendor = 0x56a;
197	input->id.version = features.fw_version;
198	input->open = wacom_i2c_open;
199	input->close = wacom_i2c_close;
200
201	input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
202
203	__set_bit(BTN_TOOL_PEN, input->keybit);
204	__set_bit(BTN_TOOL_RUBBER, input->keybit);
205	__set_bit(BTN_STYLUS, input->keybit);
206	__set_bit(BTN_STYLUS2, input->keybit);
207	__set_bit(BTN_TOUCH, input->keybit);
208
209	input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
210	input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
211	input_set_abs_params(input, ABS_PRESSURE,
212			     0, features.pressure_max, 0, 0);
213
214	input_set_drvdata(input, wac_i2c);
215
216	error = devm_request_threaded_irq(dev, client->irq, NULL, wacom_i2c_irq,
217					  IRQF_ONESHOT, "wacom_i2c", wac_i2c);
218	if (error) {
219		dev_err(dev, "Failed to request IRQ: %d\n", error);
220		return error;
221	}
222
223	/* Disable the IRQ, we'll enable it in wac_i2c_open() */
224	disable_irq(client->irq);
225
226	error = input_register_device(wac_i2c->input);
227	if (error) {
228		dev_err(dev, "Failed to register input device: %d\n", error);
229		return error;
230	}
231
232	return 0;
233}
234
235static int wacom_i2c_suspend(struct device *dev)
236{
237	struct i2c_client *client = to_i2c_client(dev);
238
239	disable_irq(client->irq);
240
241	return 0;
242}
243
244static int wacom_i2c_resume(struct device *dev)
245{
246	struct i2c_client *client = to_i2c_client(dev);
247
248	enable_irq(client->irq);
249
250	return 0;
251}
252
253static DEFINE_SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
254
255static const struct i2c_device_id wacom_i2c_id[] = {
256	{ "WAC_I2C_EMR", 0 },
257	{ },
258};
259MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
260
261static struct i2c_driver wacom_i2c_driver = {
262	.driver	= {
263		.name	= "wacom_i2c",
264		.pm	= pm_sleep_ptr(&wacom_i2c_pm),
265	},
266
267	.probe		= wacom_i2c_probe,
268	.id_table	= wacom_i2c_id,
269};
270module_i2c_driver(wacom_i2c_driver);
271
272MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
273MODULE_DESCRIPTION("WACOM EMR I2C Driver");
274MODULE_LICENSE("GPL");