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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 <linux/gpio.h>
16#include <asm/unaligned.h>
17
18#define WACOM_CMD_QUERY0 0x04
19#define WACOM_CMD_QUERY1 0x00
20#define WACOM_CMD_QUERY2 0x33
21#define WACOM_CMD_QUERY3 0x02
22#define WACOM_CMD_THROW0 0x05
23#define WACOM_CMD_THROW1 0x00
24#define WACOM_QUERY_SIZE 19
25
26struct wacom_features {
27 int x_max;
28 int y_max;
29 int pressure_max;
30 char fw_version;
31};
32
33struct wacom_i2c {
34 struct i2c_client *client;
35 struct input_dev *input;
36 u8 data[WACOM_QUERY_SIZE];
37 bool prox;
38 int tool;
39};
40
41static int wacom_query_device(struct i2c_client *client,
42 struct wacom_features *features)
43{
44 int ret;
45 u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
46 WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
47 u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
48 u8 data[WACOM_QUERY_SIZE];
49 struct i2c_msg msgs[] = {
50 {
51 .addr = client->addr,
52 .flags = 0,
53 .len = sizeof(cmd1),
54 .buf = cmd1,
55 },
56 {
57 .addr = client->addr,
58 .flags = 0,
59 .len = sizeof(cmd2),
60 .buf = cmd2,
61 },
62 {
63 .addr = client->addr,
64 .flags = I2C_M_RD,
65 .len = sizeof(data),
66 .buf = data,
67 },
68 };
69
70 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
71 if (ret < 0)
72 return ret;
73 if (ret != ARRAY_SIZE(msgs))
74 return -EIO;
75
76 features->x_max = get_unaligned_le16(&data[3]);
77 features->y_max = get_unaligned_le16(&data[5]);
78 features->pressure_max = get_unaligned_le16(&data[11]);
79 features->fw_version = get_unaligned_le16(&data[13]);
80
81 dev_dbg(&client->dev,
82 "x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
83 features->x_max, features->y_max,
84 features->pressure_max, features->fw_version);
85
86 return 0;
87}
88
89static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
90{
91 struct wacom_i2c *wac_i2c = dev_id;
92 struct input_dev *input = wac_i2c->input;
93 u8 *data = wac_i2c->data;
94 unsigned int x, y, pressure;
95 unsigned char tsw, f1, f2, ers;
96 int error;
97
98 error = i2c_master_recv(wac_i2c->client,
99 wac_i2c->data, sizeof(wac_i2c->data));
100 if (error < 0)
101 goto out;
102
103 tsw = data[3] & 0x01;
104 ers = data[3] & 0x04;
105 f1 = data[3] & 0x02;
106 f2 = data[3] & 0x10;
107 x = le16_to_cpup((__le16 *)&data[4]);
108 y = le16_to_cpup((__le16 *)&data[6]);
109 pressure = le16_to_cpup((__le16 *)&data[8]);
110
111 if (!wac_i2c->prox)
112 wac_i2c->tool = (data[3] & 0x0c) ?
113 BTN_TOOL_RUBBER : BTN_TOOL_PEN;
114
115 wac_i2c->prox = data[3] & 0x20;
116
117 input_report_key(input, BTN_TOUCH, tsw || ers);
118 input_report_key(input, wac_i2c->tool, wac_i2c->prox);
119 input_report_key(input, BTN_STYLUS, f1);
120 input_report_key(input, BTN_STYLUS2, f2);
121 input_report_abs(input, ABS_X, x);
122 input_report_abs(input, ABS_Y, y);
123 input_report_abs(input, ABS_PRESSURE, pressure);
124 input_sync(input);
125
126out:
127 return IRQ_HANDLED;
128}
129
130static int wacom_i2c_open(struct input_dev *dev)
131{
132 struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
133 struct i2c_client *client = wac_i2c->client;
134
135 enable_irq(client->irq);
136
137 return 0;
138}
139
140static void wacom_i2c_close(struct input_dev *dev)
141{
142 struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
143 struct i2c_client *client = wac_i2c->client;
144
145 disable_irq(client->irq);
146}
147
148static int wacom_i2c_probe(struct i2c_client *client,
149 const struct i2c_device_id *id)
150{
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(&client->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 = kzalloc(sizeof(*wac_i2c), GFP_KERNEL);
166 input = input_allocate_device();
167 if (!wac_i2c || !input) {
168 error = -ENOMEM;
169 goto err_free_mem;
170 }
171
172 wac_i2c->client = client;
173 wac_i2c->input = input;
174
175 input->name = "Wacom I2C Digitizer";
176 input->id.bustype = BUS_I2C;
177 input->id.vendor = 0x56a;
178 input->id.version = features.fw_version;
179 input->dev.parent = &client->dev;
180 input->open = wacom_i2c_open;
181 input->close = wacom_i2c_close;
182
183 input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
184
185 __set_bit(BTN_TOOL_PEN, input->keybit);
186 __set_bit(BTN_TOOL_RUBBER, input->keybit);
187 __set_bit(BTN_STYLUS, input->keybit);
188 __set_bit(BTN_STYLUS2, input->keybit);
189 __set_bit(BTN_TOUCH, input->keybit);
190
191 input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
192 input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
193 input_set_abs_params(input, ABS_PRESSURE,
194 0, features.pressure_max, 0, 0);
195
196 input_set_drvdata(input, wac_i2c);
197
198 error = request_threaded_irq(client->irq, NULL, wacom_i2c_irq,
199 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
200 "wacom_i2c", wac_i2c);
201 if (error) {
202 dev_err(&client->dev,
203 "Failed to enable IRQ, error: %d\n", error);
204 goto err_free_mem;
205 }
206
207
208 disable_irq(client->irq);
209
210 error = input_register_device(wac_i2c->input);
211 if (error) {
212 dev_err(&client->dev,
213 "Failed to register input device, error: %d\n", error);
214 goto err_free_irq;
215 }
216
217 i2c_set_clientdata(client, wac_i2c);
218 return 0;
219
220err_free_irq:
221 free_irq(client->irq, wac_i2c);
222err_free_mem:
223 input_free_device(input);
224 kfree(wac_i2c);
225
226 return error;
227}
228
229static int wacom_i2c_remove(struct i2c_client *client)
230{
231 struct wacom_i2c *wac_i2c = i2c_get_clientdata(client);
232
233 free_irq(client->irq, wac_i2c);
234 input_unregister_device(wac_i2c->input);
235 kfree(wac_i2c);
236
237 return 0;
238}
239
240static int __maybe_unused 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 __maybe_unused 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
258static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
259
260static const struct i2c_device_id wacom_i2c_id[] = {
261 { "WAC_I2C_EMR", 0 },
262 { },
263};
264MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
265
266static struct i2c_driver wacom_i2c_driver = {
267 .driver = {
268 .name = "wacom_i2c",
269 .pm = &wacom_i2c_pm,
270 },
271
272 .probe = wacom_i2c_probe,
273 .remove = wacom_i2c_remove,
274 .id_table = wacom_i2c_id,
275};
276module_i2c_driver(wacom_i2c_driver);
277
278MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
279MODULE_DESCRIPTION("WACOM EMR I2C Driver");
280MODULE_LICENSE("GPL");
281
