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(adap: 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(p: &data[3]);
94 features->y_max = get_unaligned_le16(p: &data[5]);
95 features->pressure_max = get_unaligned_le16(p: &data[11]);
96 features->fw_version = get_unaligned_le16(p: &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(client: wac_i2c->client,
116 buf: wac_i2c->data, count: 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(p: (__le16 *)&data[4]);
125 y = le16_to_cpup(p: (__le16 *)&data[6]);
126 pressure = le16_to_cpup(p: (__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(dev: input, BTN_TOUCH, value: tsw || ers);
135 input_report_key(dev: input, code: wac_i2c->tool, value: wac_i2c->prox);
136 input_report_key(dev: input, BTN_STYLUS, value: f1);
137 input_report_key(dev: input, BTN_STYLUS2, value: f2);
138 input_report_abs(dev: input, ABS_X, value: x);
139 input_report_abs(dev: input, ABS_Y, value: y);
140 input_report_abs(dev: input, ABS_PRESSURE, value: pressure);
141 input_sync(dev: 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(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(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(adap: 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: &features);
179 if (error)
180 return error;
181
182 wac_i2c = devm_kzalloc(dev, size: 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(dev: input, ABS_X, min: 0, max: features.x_max, fuzz: 0, flat: 0);
210 input_set_abs_params(dev: input, ABS_Y, min: 0, max: features.y_max, fuzz: 0, flat: 0);
211 input_set_abs_params(dev: input, ABS_PRESSURE,
212 min: 0, max: features.pressure_max, fuzz: 0, flat: 0);
213
214 input_set_drvdata(dev: input, data: wac_i2c);
215
216 error = devm_request_threaded_irq(dev, irq: client->irq, NULL, thread_fn: wacom_i2c_irq,
217 IRQF_ONESHOT, devname: "wacom_i2c", dev_id: 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(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(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(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");
275

source code of linux/drivers/input/touchscreen/wacom_i2c.c