1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Microchip AR1020 and AR1021 driver for I2C |
4 | * |
5 | * Author: Christian Gmeiner <christian.gmeiner@gmail.com> |
6 | */ |
7 | |
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 | |
25 | struct ar1021_i2c { |
26 | struct i2c_client *client; |
27 | struct input_dev *input; |
28 | u8 data[AR1021_TOUCH_PKG_SIZE]; |
29 | }; |
30 | |
31 | static 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(client: ar1021->client, |
40 | buf: ar1021->data, count: sizeof(ar1021->data)); |
41 | if (retval != sizeof(ar1021->data)) |
42 | goto out; |
43 | |
44 | /* sync bit set ? */ |
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(dev: input, ABS_X, value: x); |
53 | input_report_abs(dev: input, ABS_Y, value: y); |
54 | input_report_key(dev: input, BTN_TOUCH, value: button); |
55 | input_sync(dev: input); |
56 | |
57 | out: |
58 | return IRQ_HANDLED; |
59 | } |
60 | |
61 | static int ar1021_i2c_open(struct input_dev *dev) |
62 | { |
63 | static const u8 cmd_enable_touch[] = { |
64 | AR1021_CMD, |
65 | 0x01, /* number of bytes after this */ |
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(client: ar1021->client, buf: cmd_enable_touch, |
73 | count: sizeof(cmd_enable_touch)); |
74 | if (error < 0) |
75 | return error; |
76 | |
77 | enable_irq(irq: client->irq); |
78 | |
79 | return 0; |
80 | } |
81 | |
82 | static 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(irq: client->irq); |
88 | } |
89 | |
90 | static int ar1021_i2c_probe(struct i2c_client *client) |
91 | { |
92 | struct ar1021_i2c *ar1021; |
93 | struct input_dev *input; |
94 | int error; |
95 | |
96 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_I2C)) { |
97 | dev_err(&client->dev, "i2c_check_functionality error\n" ); |
98 | return -ENXIO; |
99 | } |
100 | |
101 | ar1021 = devm_kzalloc(dev: &client->dev, size: sizeof(*ar1021), GFP_KERNEL); |
102 | if (!ar1021) |
103 | return -ENOMEM; |
104 | |
105 | input = devm_input_allocate_device(&client->dev); |
106 | if (!input) |
107 | return -ENOMEM; |
108 | |
109 | ar1021->client = client; |
110 | ar1021->input = input; |
111 | |
112 | input->name = "ar1021 I2C Touchscreen" ; |
113 | input->id.bustype = BUS_I2C; |
114 | input->dev.parent = &client->dev; |
115 | input->open = ar1021_i2c_open; |
116 | input->close = ar1021_i2c_close; |
117 | |
118 | __set_bit(INPUT_PROP_DIRECT, input->propbit); |
119 | input_set_capability(dev: input, EV_KEY, BTN_TOUCH); |
120 | input_set_abs_params(dev: input, ABS_X, min: 0, AR1021_MAX_X, fuzz: 0, flat: 0); |
121 | input_set_abs_params(dev: input, ABS_Y, min: 0, AR1021_MAX_Y, fuzz: 0, flat: 0); |
122 | |
123 | input_set_drvdata(dev: input, data: ar1021); |
124 | |
125 | error = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, |
126 | NULL, thread_fn: ar1021_i2c_irq, |
127 | IRQF_ONESHOT | IRQF_NO_AUTOEN, |
128 | devname: "ar1021_i2c" , dev_id: ar1021); |
129 | if (error) { |
130 | dev_err(&client->dev, |
131 | "Failed to enable IRQ, error: %d\n" , error); |
132 | return error; |
133 | } |
134 | |
135 | error = input_register_device(ar1021->input); |
136 | if (error) { |
137 | dev_err(&client->dev, |
138 | "Failed to register input device, error: %d\n" , error); |
139 | return error; |
140 | } |
141 | |
142 | return 0; |
143 | } |
144 | |
145 | static int ar1021_i2c_suspend(struct device *dev) |
146 | { |
147 | struct i2c_client *client = to_i2c_client(dev); |
148 | |
149 | disable_irq(irq: client->irq); |
150 | |
151 | return 0; |
152 | } |
153 | |
154 | static int ar1021_i2c_resume(struct device *dev) |
155 | { |
156 | struct i2c_client *client = to_i2c_client(dev); |
157 | |
158 | enable_irq(irq: client->irq); |
159 | |
160 | return 0; |
161 | } |
162 | |
163 | static DEFINE_SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, |
164 | ar1021_i2c_suspend, ar1021_i2c_resume); |
165 | |
166 | static const struct i2c_device_id ar1021_i2c_id[] = { |
167 | { "ar1021" , 0 }, |
168 | { }, |
169 | }; |
170 | MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id); |
171 | |
172 | static const struct of_device_id ar1021_i2c_of_match[] = { |
173 | { .compatible = "microchip,ar1021-i2c" , }, |
174 | { } |
175 | }; |
176 | MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match); |
177 | |
178 | static struct i2c_driver ar1021_i2c_driver = { |
179 | .driver = { |
180 | .name = "ar1021_i2c" , |
181 | .pm = pm_sleep_ptr(&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 | }; |
188 | module_i2c_driver(ar1021_i2c_driver); |
189 | |
190 | MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>" ); |
191 | MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver" ); |
192 | MODULE_LICENSE("GPL" ); |
193 | |