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