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13#include <linux/bitops.h>
14#include <linux/device.h>
15#include <linux/i2c.h>
16#include <linux/input.h>
17#include <linux/input/mt.h>
18#include <linux/input/touchscreen.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/timer.h>
23#include <asm/unaligned.h>
24
25#define EXC3000_NUM_SLOTS 10
26#define EXC3000_SLOTS_PER_FRAME 5
27#define EXC3000_LEN_FRAME 66
28#define EXC3000_LEN_POINT 10
29#define EXC3000_MT_EVENT 6
30#define EXC3000_TIMEOUT_MS 100
31
32struct exc3000_data {
33 struct i2c_client *client;
34 struct input_dev *input;
35 struct touchscreen_properties prop;
36 struct timer_list timer;
37 u8 buf[2 * EXC3000_LEN_FRAME];
38};
39
40static void exc3000_report_slots(struct input_dev *input,
41 struct touchscreen_properties *prop,
42 const u8 *buf, int num)
43{
44 for (; num--; buf += EXC3000_LEN_POINT) {
45 if (buf[0] & BIT(0)) {
46 input_mt_slot(input, buf[1]);
47 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
48 touchscreen_report_pos(input, prop,
49 get_unaligned_le16(buf + 2),
50 get_unaligned_le16(buf + 4),
51 true);
52 }
53 }
54}
55
56static void exc3000_timer(struct timer_list *t)
57{
58 struct exc3000_data *data = from_timer(data, t, timer);
59
60 input_mt_sync_frame(data->input);
61 input_sync(data->input);
62}
63
64static int exc3000_read_frame(struct i2c_client *client, u8 *buf)
65{
66 int ret;
67
68 ret = i2c_master_send(client, "'", 2);
69 if (ret < 0)
70 return ret;
71
72 if (ret != 2)
73 return -EIO;
74
75 ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME);
76 if (ret < 0)
77 return ret;
78
79 if (ret != EXC3000_LEN_FRAME)
80 return -EIO;
81
82 if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME ||
83 buf[2] != EXC3000_MT_EVENT)
84 return -EINVAL;
85
86 return 0;
87}
88
89static int exc3000_read_data(struct i2c_client *client,
90 u8 *buf, int *n_slots)
91{
92 int error;
93
94 error = exc3000_read_frame(client, buf);
95 if (error)
96 return error;
97
98 *n_slots = buf[3];
99 if (!*n_slots || *n_slots > EXC3000_NUM_SLOTS)
100 return -EINVAL;
101
102 if (*n_slots > EXC3000_SLOTS_PER_FRAME) {
103
104 error = exc3000_read_frame(client, buf + EXC3000_LEN_FRAME);
105 if (error)
106 return error;
107
108
109 if (buf[EXC3000_LEN_FRAME + 3] != 0)
110 return -EINVAL;
111 }
112
113 return 0;
114}
115
116static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
117{
118 struct exc3000_data *data = dev_id;
119 struct input_dev *input = data->input;
120 u8 *buf = data->buf;
121 int slots, total_slots;
122 int error;
123
124 error = exc3000_read_data(data->client, buf, &total_slots);
125 if (error) {
126
127 mod_timer(&data->timer,
128 jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
129 goto out;
130 }
131
132
133
134
135 del_timer_sync(&data->timer);
136
137 while (total_slots > 0) {
138 slots = min(total_slots, EXC3000_SLOTS_PER_FRAME);
139 exc3000_report_slots(input, &data->prop, buf + 4, slots);
140 total_slots -= slots;
141 buf += EXC3000_LEN_FRAME;
142 }
143
144 input_mt_sync_frame(input);
145 input_sync(input);
146
147out:
148 return IRQ_HANDLED;
149}
150
151static int exc3000_probe(struct i2c_client *client,
152 const struct i2c_device_id *id)
153{
154 struct exc3000_data *data;
155 struct input_dev *input;
156 int error;
157
158 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
159 if (!data)
160 return -ENOMEM;
161
162 data->client = client;
163 timer_setup(&data->timer, exc3000_timer, 0);
164
165 input = devm_input_allocate_device(&client->dev);
166 if (!input)
167 return -ENOMEM;
168
169 data->input = input;
170
171 input->name = "EETI EXC3000 Touch Screen";
172 input->id.bustype = BUS_I2C;
173
174 input_set_abs_params(input, ABS_MT_POSITION_X, 0, 4095, 0, 0);
175 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 4095, 0, 0);
176 touchscreen_parse_properties(input, true, &data->prop);
177
178 error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
179 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
180 if (error)
181 return error;
182
183 error = input_register_device(input);
184 if (error)
185 return error;
186
187 error = devm_request_threaded_irq(&client->dev, client->irq,
188 NULL, exc3000_interrupt, IRQF_ONESHOT,
189 client->name, data);
190 if (error)
191 return error;
192
193 return 0;
194}
195
196static const struct i2c_device_id exc3000_id[] = {
197 { "exc3000", 0 },
198 { }
199};
200MODULE_DEVICE_TABLE(i2c, exc3000_id);
201
202#ifdef CONFIG_OF
203static const struct of_device_id exc3000_of_match[] = {
204 { .compatible = "eeti,exc3000" },
205 { }
206};
207MODULE_DEVICE_TABLE(of, exc3000_of_match);
208#endif
209
210static struct i2c_driver exc3000_driver = {
211 .driver = {
212 .name = "exc3000",
213 .of_match_table = of_match_ptr(exc3000_of_match),
214 },
215 .id_table = exc3000_id,
216 .probe = exc3000_probe,
217};
218
219module_i2c_driver(exc3000_driver);
220
221MODULE_AUTHOR("Ahmet Inan <inan@distec.de>");
222MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
223MODULE_LICENSE("GPL v2");
224
