This source file includes following definitions.
- exc3000_report_slots
- exc3000_timer
- exc3000_read_frame
- exc3000_read_data
- exc3000_interrupt
- exc3000_probe
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10 #include <linux/bitops.h>
11 #include <linux/device.h>
12 #include <linux/i2c.h>
13 #include <linux/input.h>
14 #include <linux/input/mt.h>
15 #include <linux/input/touchscreen.h>
16 #include <linux/interrupt.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/timer.h>
20 #include <asm/unaligned.h>
21
22 #define EXC3000_NUM_SLOTS 10
23 #define EXC3000_SLOTS_PER_FRAME 5
24 #define EXC3000_LEN_FRAME 66
25 #define EXC3000_LEN_POINT 10
26 #define EXC3000_MT_EVENT 6
27 #define EXC3000_TIMEOUT_MS 100
28
29 struct exc3000_data {
30 struct i2c_client *client;
31 struct input_dev *input;
32 struct touchscreen_properties prop;
33 struct timer_list timer;
34 u8 buf[2 * EXC3000_LEN_FRAME];
35 };
36
37 static void exc3000_report_slots(struct input_dev *input,
38 struct touchscreen_properties *prop,
39 const u8 *buf, int num)
40 {
41 for (; num--; buf += EXC3000_LEN_POINT) {
42 if (buf[0] & BIT(0)) {
43 input_mt_slot(input, buf[1]);
44 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
45 touchscreen_report_pos(input, prop,
46 get_unaligned_le16(buf + 2),
47 get_unaligned_le16(buf + 4),
48 true);
49 }
50 }
51 }
52
53 static void exc3000_timer(struct timer_list *t)
54 {
55 struct exc3000_data *data = from_timer(data, t, timer);
56
57 input_mt_sync_frame(data->input);
58 input_sync(data->input);
59 }
60
61 static int exc3000_read_frame(struct i2c_client *client, u8 *buf)
62 {
63 int ret;
64
65 ret = i2c_master_send(client, "'", 2);
66 if (ret < 0)
67 return ret;
68
69 if (ret != 2)
70 return -EIO;
71
72 ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME);
73 if (ret < 0)
74 return ret;
75
76 if (ret != EXC3000_LEN_FRAME)
77 return -EIO;
78
79 if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME ||
80 buf[2] != EXC3000_MT_EVENT)
81 return -EINVAL;
82
83 return 0;
84 }
85
86 static int exc3000_read_data(struct i2c_client *client,
87 u8 *buf, int *n_slots)
88 {
89 int error;
90
91 error = exc3000_read_frame(client, buf);
92 if (error)
93 return error;
94
95 *n_slots = buf[3];
96 if (!*n_slots || *n_slots > EXC3000_NUM_SLOTS)
97 return -EINVAL;
98
99 if (*n_slots > EXC3000_SLOTS_PER_FRAME) {
100
101 error = exc3000_read_frame(client, buf + EXC3000_LEN_FRAME);
102 if (error)
103 return error;
104
105
106 if (buf[EXC3000_LEN_FRAME + 3] != 0)
107 return -EINVAL;
108 }
109
110 return 0;
111 }
112
113 static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
114 {
115 struct exc3000_data *data = dev_id;
116 struct input_dev *input = data->input;
117 u8 *buf = data->buf;
118 int slots, total_slots;
119 int error;
120
121 error = exc3000_read_data(data->client, buf, &total_slots);
122 if (error) {
123
124 mod_timer(&data->timer,
125 jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
126 goto out;
127 }
128
129
130
131
132 del_timer_sync(&data->timer);
133
134 while (total_slots > 0) {
135 slots = min(total_slots, EXC3000_SLOTS_PER_FRAME);
136 exc3000_report_slots(input, &data->prop, buf + 4, slots);
137 total_slots -= slots;
138 buf += EXC3000_LEN_FRAME;
139 }
140
141 input_mt_sync_frame(input);
142 input_sync(input);
143
144 out:
145 return IRQ_HANDLED;
146 }
147
148 static int exc3000_probe(struct i2c_client *client,
149 const struct i2c_device_id *id)
150 {
151 struct exc3000_data *data;
152 struct input_dev *input;
153 int error;
154
155 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
156 if (!data)
157 return -ENOMEM;
158
159 data->client = client;
160 timer_setup(&data->timer, exc3000_timer, 0);
161
162 input = devm_input_allocate_device(&client->dev);
163 if (!input)
164 return -ENOMEM;
165
166 data->input = input;
167
168 input->name = "EETI EXC3000 Touch Screen";
169 input->id.bustype = BUS_I2C;
170
171 input_set_abs_params(input, ABS_MT_POSITION_X, 0, 4095, 0, 0);
172 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 4095, 0, 0);
173 touchscreen_parse_properties(input, true, &data->prop);
174
175 error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
176 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
177 if (error)
178 return error;
179
180 error = input_register_device(input);
181 if (error)
182 return error;
183
184 error = devm_request_threaded_irq(&client->dev, client->irq,
185 NULL, exc3000_interrupt, IRQF_ONESHOT,
186 client->name, data);
187 if (error)
188 return error;
189
190 return 0;
191 }
192
193 static const struct i2c_device_id exc3000_id[] = {
194 { "exc3000", 0 },
195 { }
196 };
197 MODULE_DEVICE_TABLE(i2c, exc3000_id);
198
199 #ifdef CONFIG_OF
200 static const struct of_device_id exc3000_of_match[] = {
201 { .compatible = "eeti,exc3000" },
202 { }
203 };
204 MODULE_DEVICE_TABLE(of, exc3000_of_match);
205 #endif
206
207 static struct i2c_driver exc3000_driver = {
208 .driver = {
209 .name = "exc3000",
210 .of_match_table = of_match_ptr(exc3000_of_match),
211 },
212 .id_table = exc3000_id,
213 .probe = exc3000_probe,
214 };
215
216 module_i2c_driver(exc3000_driver);
217
218 MODULE_AUTHOR("Ahmet Inan <inan@distec.de>");
219 MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
220 MODULE_LICENSE("GPL v2");