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8#include <linux/bitops.h>
9#include <linux/module.h>
10#include <linux/input.h>
11#include <linux/of.h>
12#include <linux/i2c.h>
13#include <linux/irq.h>
14#include <linux/interrupt.h>
15
16#define AR1021_TOUCH_PKG_SIZE 5
17
18#define AR1021_MAX_X 4095
19#define AR1021_MAX_Y 4095
20
21#define AR1021_CMD 0x55
22
23#define AR1021_CMD_ENABLE_TOUCH 0x12
24
25struct ar1021_i2c {
26 struct i2c_client *client;
27 struct input_dev *input;
28 u8 data[AR1021_TOUCH_PKG_SIZE];
29};
30
31static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id)
32{
33 struct ar1021_i2c *ar1021 = dev_id;
34 struct input_dev *input = ar1021->input;
35 u8 *data = ar1021->data;
36 unsigned int x, y, button;
37 int retval;
38
39 retval = i2c_master_recv(ar1021->client,
40 ar1021->data, sizeof(ar1021->data));
41 if (retval != sizeof(ar1021->data))
42 goto out;
43
44
45 if (!(data[0] & BIT(7)))
46 goto out;
47
48 button = data[0] & BIT(0);
49 x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f);
50 y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f);
51
52 input_report_abs(input, ABS_X, x);
53 input_report_abs(input, ABS_Y, y);
54 input_report_key(input, BTN_TOUCH, button);
55 input_sync(input);
56
57out:
58 return IRQ_HANDLED;
59}
60
61static int ar1021_i2c_open(struct input_dev *dev)
62{
63 static const u8 cmd_enable_touch[] = {
64 AR1021_CMD,
65 0x01,
66 AR1021_CMD_ENABLE_TOUCH
67 };
68 struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
69 struct i2c_client *client = ar1021->client;
70 int error;
71
72 error = i2c_master_send(ar1021->client, cmd_enable_touch,
73 sizeof(cmd_enable_touch));
74 if (error < 0)
75 return error;
76
77 enable_irq(client->irq);
78
79 return 0;
80}
81
82static void ar1021_i2c_close(struct input_dev *dev)
83{
84 struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
85 struct i2c_client *client = ar1021->client;
86
87 disable_irq(client->irq);
88}
89
90static int ar1021_i2c_probe(struct i2c_client *client,
91 const struct i2c_device_id *id)
92{
93 struct ar1021_i2c *ar1021;
94 struct input_dev *input;
95 int error;
96
97 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
98 dev_err(&client->dev, "i2c_check_functionality error\n");
99 return -ENXIO;
100 }
101
102 ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL);
103 if (!ar1021)
104 return -ENOMEM;
105
106 input = devm_input_allocate_device(&client->dev);
107 if (!input)
108 return -ENOMEM;
109
110 ar1021->client = client;
111 ar1021->input = input;
112
113 input->name = "ar1021 I2C Touchscreen";
114 input->id.bustype = BUS_I2C;
115 input->dev.parent = &client->dev;
116 input->open = ar1021_i2c_open;
117 input->close = ar1021_i2c_close;
118
119 __set_bit(INPUT_PROP_DIRECT, input->propbit);
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 | IRQF_NO_AUTOEN,
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 error = input_register_device(ar1021->input);
137 if (error) {
138 dev_err(&client->dev,
139 "Failed to register input device, error: %d\n", error);
140 return error;
141 }
142
143 return 0;
144}
145
146static int __maybe_unused ar1021_i2c_suspend(struct device *dev)
147{
148 struct i2c_client *client = to_i2c_client(dev);
149
150 disable_irq(client->irq);
151
152 return 0;
153}
154
155static int __maybe_unused ar1021_i2c_resume(struct device *dev)
156{
157 struct i2c_client *client = to_i2c_client(dev);
158
159 enable_irq(client->irq);
160
161 return 0;
162}
163
164static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume);
165
166static const struct i2c_device_id ar1021_i2c_id[] = {
167 { "ar1021", 0 },
168 { },
169};
170MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
171
172static const struct of_device_id ar1021_i2c_of_match[] = {
173 { .compatible = "microchip,ar1021-i2c", },
174 { }
175};
176MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match);
177
178static struct i2c_driver ar1021_i2c_driver = {
179 .driver = {
180 .name = "ar1021_i2c",
181 .pm = &ar1021_i2c_pm,
182 .of_match_table = ar1021_i2c_of_match,
183 },
184
185 .probe = ar1021_i2c_probe,
186 .id_table = ar1021_i2c_id,
187};
188module_i2c_driver(ar1021_i2c_driver);
189
190MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
191MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver");
192MODULE_LICENSE("GPL");
193
