1
2
3
4
5
6
7
8
9#include <linux/module.h>
10#include <linux/input.h>
11#include <linux/i2c.h>
12#include <linux/slab.h>
13#include <linux/irq.h>
14#include <linux/interrupt.h>
15#include <asm/unaligned.h>
16
17#define WACOM_CMD_QUERY0 0x04
18#define WACOM_CMD_QUERY1 0x00
19#define WACOM_CMD_QUERY2 0x33
20#define WACOM_CMD_QUERY3 0x02
21#define WACOM_CMD_THROW0 0x05
22#define WACOM_CMD_THROW1 0x00
23#define WACOM_QUERY_SIZE 19
24
25struct wacom_features {
26 int x_max;
27 int y_max;
28 int pressure_max;
29 char fw_version;
30};
31
32struct wacom_i2c {
33 struct i2c_client *client;
34 struct input_dev *input;
35 u8 data[WACOM_QUERY_SIZE];
36 bool prox;
37 int tool;
38};
39
40static int wacom_query_device(struct i2c_client *client,
41 struct wacom_features *features)
42{
43 int ret;
44 u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
45 WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
46 u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
47 u8 data[WACOM_QUERY_SIZE];
48 struct i2c_msg msgs[] = {
49 {
50 .addr = client->addr,
51 .flags = 0,
52 .len = sizeof(cmd1),
53 .buf = cmd1,
54 },
55 {
56 .addr = client->addr,
57 .flags = 0,
58 .len = sizeof(cmd2),
59 .buf = cmd2,
60 },
61 {
62 .addr = client->addr,
63 .flags = I2C_M_RD,
64 .len = sizeof(data),
65 .buf = data,
66 },
67 };
68
69 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
70 if (ret < 0)
71 return ret;
72 if (ret != ARRAY_SIZE(msgs))
73 return -EIO;
74
75 features->x_max = get_unaligned_le16(&data[3]);
76 features->y_max = get_unaligned_le16(&data[5]);
77 features->pressure_max = get_unaligned_le16(&data[11]);
78 features->fw_version = get_unaligned_le16(&data[13]);
79
80 dev_dbg(&client->dev,
81 "x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
82 features->x_max, features->y_max,
83 features->pressure_max, features->fw_version);
84
85 return 0;
86}
87
88static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
89{
90 struct wacom_i2c *wac_i2c = dev_id;
91 struct input_dev *input = wac_i2c->input;
92 u8 *data = wac_i2c->data;
93 unsigned int x, y, pressure;
94 unsigned char tsw, f1, f2, ers;
95 int error;
96
97 error = i2c_master_recv(wac_i2c->client,
98 wac_i2c->data, sizeof(wac_i2c->data));
99 if (error < 0)
100 goto out;
101
102 tsw = data[3] & 0x01;
103 ers = data[3] & 0x04;
104 f1 = data[3] & 0x02;
105 f2 = data[3] & 0x10;
106 x = le16_to_cpup((__le16 *)&data[4]);
107 y = le16_to_cpup((__le16 *)&data[6]);
108 pressure = le16_to_cpup((__le16 *)&data[8]);
109
110 if (!wac_i2c->prox)
111 wac_i2c->tool = (data[3] & 0x0c) ?
112 BTN_TOOL_RUBBER : BTN_TOOL_PEN;
113
114 wac_i2c->prox = data[3] & 0x20;
115
116 input_report_key(input, BTN_TOUCH, tsw || ers);
117 input_report_key(input, wac_i2c->tool, wac_i2c->prox);
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 wacom_i2c_probe(struct i2c_client *client,
148 const struct i2c_device_id *id)
149{
150 struct device *dev = &client->dev;
151 struct wacom_i2c *wac_i2c;
152 struct input_dev *input;
153 struct wacom_features features = { 0 };
154 int error;
155
156 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
157 dev_err(dev, "i2c_check_functionality error\n");
158 return -EIO;
159 }
160
161 error = wacom_query_device(client, &features);
162 if (error)
163 return error;
164
165 wac_i2c = devm_kzalloc(dev, sizeof(*wac_i2c), GFP_KERNEL);
166 if (!wac_i2c)
167 return -ENOMEM;
168
169 wac_i2c->client = client;
170
171 input = devm_input_allocate_device(dev);
172 if (!input)
173 return -ENOMEM;
174
175 wac_i2c->input = input;
176
177 input->name = "Wacom I2C Digitizer";
178 input->id.bustype = BUS_I2C;
179 input->id.vendor = 0x56a;
180 input->id.version = features.fw_version;
181 input->open = wacom_i2c_open;
182 input->close = wacom_i2c_close;
183
184 input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
185
186 __set_bit(BTN_TOOL_PEN, input->keybit);
187 __set_bit(BTN_TOOL_RUBBER, input->keybit);
188 __set_bit(BTN_STYLUS, input->keybit);
189 __set_bit(BTN_STYLUS2, input->keybit);
190 __set_bit(BTN_TOUCH, input->keybit);
191
192 input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
193 input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
194 input_set_abs_params(input, ABS_PRESSURE,
195 0, features.pressure_max, 0, 0);
196
197 input_set_drvdata(input, wac_i2c);
198
199 error = devm_request_threaded_irq(dev, client->irq, NULL, wacom_i2c_irq,
200 IRQF_ONESHOT, "wacom_i2c", wac_i2c);
201 if (error) {
202 dev_err(dev, "Failed to request IRQ: %d\n", error);
203 return error;
204 }
205
206
207 disable_irq(client->irq);
208
209 error = input_register_device(wac_i2c->input);
210 if (error) {
211 dev_err(dev, "Failed to register input device: %d\n", error);
212 return error;
213 }
214
215 return 0;
216}
217
218static int __maybe_unused wacom_i2c_suspend(struct device *dev)
219{
220 struct i2c_client *client = to_i2c_client(dev);
221
222 disable_irq(client->irq);
223
224 return 0;
225}
226
227static int __maybe_unused wacom_i2c_resume(struct device *dev)
228{
229 struct i2c_client *client = to_i2c_client(dev);
230
231 enable_irq(client->irq);
232
233 return 0;
234}
235
236static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
237
238static const struct i2c_device_id wacom_i2c_id[] = {
239 { "WAC_I2C_EMR", 0 },
240 { },
241};
242MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
243
244static struct i2c_driver wacom_i2c_driver = {
245 .driver = {
246 .name = "wacom_i2c",
247 .pm = &wacom_i2c_pm,
248 },
249
250 .probe = wacom_i2c_probe,
251 .id_table = wacom_i2c_id,
252};
253module_i2c_driver(wacom_i2c_driver);
254
255MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
256MODULE_DESCRIPTION("WACOM EMR I2C Driver");
257MODULE_LICENSE("GPL");
258
