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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
31struct wacom_features {
32 int x_max;
33 int y_max;
34 int pressure_max;
35 char fw_version;
36};
37
38struct wacom_i2c {
39 struct i2c_client *client;
40 struct input_dev *input;
41 u8 data[WACOM_QUERY_SIZE];
42 bool prox;
43 int tool;
44};
45
46static int wacom_query_device(struct i2c_client *client,
47 struct wacom_features *features)
48{
49 int ret;
50 u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
51 WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
52 u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
53 u8 data[WACOM_QUERY_SIZE];
54 struct i2c_msg msgs[] = {
55 {
56 .addr = client->addr,
57 .flags = 0,
58 .len = sizeof(cmd1),
59 .buf = cmd1,
60 },
61 {
62 .addr = client->addr,
63 .flags = 0,
64 .len = sizeof(cmd2),
65 .buf = cmd2,
66 },
67 {
68 .addr = client->addr,
69 .flags = I2C_M_RD,
70 .len = sizeof(data),
71 .buf = data,
72 },
73 };
74
75 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
76 if (ret < 0)
77 return ret;
78 if (ret != ARRAY_SIZE(msgs))
79 return -EIO;
80
81 features->x_max = get_unaligned_le16(&data[3]);
82 features->y_max = get_unaligned_le16(&data[5]);
83 features->pressure_max = get_unaligned_le16(&data[11]);
84 features->fw_version = get_unaligned_le16(&data[13]);
85
86 dev_dbg(&client->dev,
87 "x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
88 features->x_max, features->y_max,
89 features->pressure_max, features->fw_version);
90
91 return 0;
92}
93
94static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
95{
96 struct wacom_i2c *wac_i2c = dev_id;
97 struct input_dev *input = wac_i2c->input;
98 u8 *data = wac_i2c->data;
99 unsigned int x, y, pressure;
100 unsigned char tsw, f1, f2, ers;
101 int error;
102
103 error = i2c_master_recv(wac_i2c->client,
104 wac_i2c->data, sizeof(wac_i2c->data));
105 if (error < 0)
106 goto out;
107
108 tsw = data[3] & 0x01;
109 ers = data[3] & 0x04;
110 f1 = data[3] & 0x02;
111 f2 = data[3] & 0x10;
112 x = le16_to_cpup((__le16 *)&data[4]);
113 y = le16_to_cpup((__le16 *)&data[6]);
114 pressure = le16_to_cpup((__le16 *)&data[8]);
115
116 if (!wac_i2c->prox)
117 wac_i2c->tool = (data[3] & 0x0c) ?
118 BTN_TOOL_RUBBER : BTN_TOOL_PEN;
119
120 wac_i2c->prox = data[3] & 0x20;
121
122 input_report_key(input, BTN_TOUCH, tsw || ers);
123 input_report_key(input, wac_i2c->tool, wac_i2c->prox);
124 input_report_key(input, BTN_STYLUS, f1);
125 input_report_key(input, BTN_STYLUS2, f2);
126 input_report_abs(input, ABS_X, x);
127 input_report_abs(input, ABS_Y, y);
128 input_report_abs(input, ABS_PRESSURE, pressure);
129 input_sync(input);
130
131out:
132 return IRQ_HANDLED;
133}
134
135static int wacom_i2c_open(struct input_dev *dev)
136{
137 struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
138 struct i2c_client *client = wac_i2c->client;
139
140 enable_irq(client->irq);
141
142 return 0;
143}
144
145static void wacom_i2c_close(struct input_dev *dev)
146{
147 struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
148 struct i2c_client *client = wac_i2c->client;
149
150 disable_irq(client->irq);
151}
152
153static int wacom_i2c_probe(struct i2c_client *client,
154 const struct i2c_device_id *id)
155{
156 struct wacom_i2c *wac_i2c;
157 struct input_dev *input;
158 struct wacom_features features = { 0 };
159 int error;
160
161 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
162 dev_err(&client->dev, "i2c_check_functionality error\n");
163 return -EIO;
164 }
165
166 error = wacom_query_device(client, &features);
167 if (error)
168 return error;
169
170 wac_i2c = kzalloc(sizeof(*wac_i2c), GFP_KERNEL);
171 input = input_allocate_device();
172 if (!wac_i2c || !input) {
173 error = -ENOMEM;
174 goto err_free_mem;
175 }
176
177 wac_i2c->client = client;
178 wac_i2c->input = input;
179
180 input->name = "Wacom I2C Digitizer";
181 input->id.bustype = BUS_I2C;
182 input->id.vendor = 0x56a;
183 input->id.version = features.fw_version;
184 input->dev.parent = &client->dev;
185 input->open = wacom_i2c_open;
186 input->close = wacom_i2c_close;
187
188 input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
189
190 __set_bit(BTN_TOOL_PEN, input->keybit);
191 __set_bit(BTN_TOOL_RUBBER, input->keybit);
192 __set_bit(BTN_STYLUS, input->keybit);
193 __set_bit(BTN_STYLUS2, input->keybit);
194 __set_bit(BTN_TOUCH, input->keybit);
195
196 input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
197 input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
198 input_set_abs_params(input, ABS_PRESSURE,
199 0, features.pressure_max, 0, 0);
200
201 input_set_drvdata(input, wac_i2c);
202
203 error = request_threaded_irq(client->irq, NULL, wacom_i2c_irq,
204 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
205 "wacom_i2c", wac_i2c);
206 if (error) {
207 dev_err(&client->dev,
208 "Failed to enable IRQ, error: %d\n", error);
209 goto err_free_mem;
210 }
211
212
213 disable_irq(client->irq);
214
215 error = input_register_device(wac_i2c->input);
216 if (error) {
217 dev_err(&client->dev,
218 "Failed to register input device, error: %d\n", error);
219 goto err_free_irq;
220 }
221
222 i2c_set_clientdata(client, wac_i2c);
223 return 0;
224
225err_free_irq:
226 free_irq(client->irq, wac_i2c);
227err_free_mem:
228 input_free_device(input);
229 kfree(wac_i2c);
230
231 return error;
232}
233
234static int wacom_i2c_remove(struct i2c_client *client)
235{
236 struct wacom_i2c *wac_i2c = i2c_get_clientdata(client);
237
238 free_irq(client->irq, wac_i2c);
239 input_unregister_device(wac_i2c->input);
240 kfree(wac_i2c);
241
242 return 0;
243}
244
245static int __maybe_unused wacom_i2c_suspend(struct device *dev)
246{
247 struct i2c_client *client = to_i2c_client(dev);
248
249 disable_irq(client->irq);
250
251 return 0;
252}
253
254static int __maybe_unused wacom_i2c_resume(struct device *dev)
255{
256 struct i2c_client *client = to_i2c_client(dev);
257
258 enable_irq(client->irq);
259
260 return 0;
261}
262
263static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
264
265static const struct i2c_device_id wacom_i2c_id[] = {
266 { "WAC_I2C_EMR", 0 },
267 { },
268};
269MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
270
271static struct i2c_driver wacom_i2c_driver = {
272 .driver = {
273 .name = "wacom_i2c",
274 .pm = &wacom_i2c_pm,
275 },
276
277 .probe = wacom_i2c_probe,
278 .remove = wacom_i2c_remove,
279 .id_table = wacom_i2c_id,
280};
281module_i2c_driver(wacom_i2c_driver);
282
283MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
284MODULE_DESCRIPTION("WACOM EMR I2C Driver");
285MODULE_LICENSE("GPL");
286
