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9#include <linux/bitops.h>
10#include <linux/module.h>
11#include <linux/input.h>
12#include <linux/of.h>
13#include <linux/i2c.h>
14#include <linux/irq.h>
15#include <linux/interrupt.h>
16
17#define AR1021_TOCUH_PKG_SIZE 5
18
19#define AR1021_MAX_X 4095
20#define AR1021_MAX_Y 4095
21
22#define AR1021_CMD 0x55
23
24#define AR1021_CMD_ENABLE_TOUCH 0x12
25
26struct ar1021_i2c {
27 struct i2c_client *client;
28 struct input_dev *input;
29 u8 data[AR1021_TOCUH_PKG_SIZE];
30};
31
32static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id)
33{
34 struct ar1021_i2c *ar1021 = dev_id;
35 struct input_dev *input = ar1021->input;
36 u8 *data = ar1021->data;
37 unsigned int x, y, button;
38 int retval;
39
40 retval = i2c_master_recv(ar1021->client,
41 ar1021->data, sizeof(ar1021->data));
42 if (retval != sizeof(ar1021->data))
43 goto out;
44
45
46 if (!(data[0] & BIT(7)))
47 goto out;
48
49 button = data[0] & BIT(0);
50 x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f);
51 y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f);
52
53 input_report_abs(input, ABS_X, x);
54 input_report_abs(input, ABS_Y, y);
55 input_report_key(input, BTN_TOUCH, button);
56 input_sync(input);
57
58out:
59 return IRQ_HANDLED;
60}
61
62static int ar1021_i2c_open(struct input_dev *dev)
63{
64 static const u8 cmd_enable_touch[] = {
65 AR1021_CMD,
66 0x01,
67 AR1021_CMD_ENABLE_TOUCH
68 };
69 struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
70 struct i2c_client *client = ar1021->client;
71 int error;
72
73 error = i2c_master_send(ar1021->client, cmd_enable_touch,
74 sizeof(cmd_enable_touch));
75 if (error < 0)
76 return error;
77
78 enable_irq(client->irq);
79
80 return 0;
81}
82
83static void ar1021_i2c_close(struct input_dev *dev)
84{
85 struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
86 struct i2c_client *client = ar1021->client;
87
88 disable_irq(client->irq);
89}
90
91static int ar1021_i2c_probe(struct i2c_client *client,
92 const struct i2c_device_id *id)
93{
94 struct ar1021_i2c *ar1021;
95 struct input_dev *input;
96 int error;
97
98 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
99 dev_err(&client->dev, "i2c_check_functionality error\n");
100 return -ENXIO;
101 }
102
103 ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL);
104 if (!ar1021)
105 return -ENOMEM;
106
107 input = devm_input_allocate_device(&client->dev);
108 if (!input)
109 return -ENOMEM;
110
111 ar1021->client = client;
112 ar1021->input = input;
113
114 input->name = "ar1021 I2C Touchscreen";
115 input->id.bustype = BUS_I2C;
116 input->dev.parent = &client->dev;
117 input->open = ar1021_i2c_open;
118 input->close = ar1021_i2c_close;
119
120 input_set_capability(input, EV_KEY, BTN_TOUCH);
121 input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0);
122 input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0);
123
124 input_set_drvdata(input, ar1021);
125
126 error = devm_request_threaded_irq(&client->dev, client->irq,
127 NULL, ar1021_i2c_irq,
128 IRQF_ONESHOT,
129 "ar1021_i2c", ar1021);
130 if (error) {
131 dev_err(&client->dev,
132 "Failed to enable IRQ, error: %d\n", error);
133 return error;
134 }
135
136
137 disable_irq(client->irq);
138
139 error = input_register_device(ar1021->input);
140 if (error) {
141 dev_err(&client->dev,
142 "Failed to register input device, error: %d\n", error);
143 return error;
144 }
145
146 return 0;
147}
148
149static int __maybe_unused ar1021_i2c_suspend(struct device *dev)
150{
151 struct i2c_client *client = to_i2c_client(dev);
152
153 disable_irq(client->irq);
154
155 return 0;
156}
157
158static int __maybe_unused ar1021_i2c_resume(struct device *dev)
159{
160 struct i2c_client *client = to_i2c_client(dev);
161
162 enable_irq(client->irq);
163
164 return 0;
165}
166
167static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume);
168
169static const struct i2c_device_id ar1021_i2c_id[] = {
170 { "ar1021", 0 },
171 { },
172};
173MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
174
175static const struct of_device_id ar1021_i2c_of_match[] = {
176 { .compatible = "microchip,ar1021-i2c", },
177 { }
178};
179MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match);
180
181static struct i2c_driver ar1021_i2c_driver = {
182 .driver = {
183 .name = "ar1021_i2c",
184 .pm = &ar1021_i2c_pm,
185 .of_match_table = ar1021_i2c_of_match,
186 },
187
188 .probe = ar1021_i2c_probe,
189 .id_table = ar1021_i2c_id,
190};
191module_i2c_driver(ar1021_i2c_driver);
192
193MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
194MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver");
195MODULE_LICENSE("GPL");
196
