1 /*
2  * STMicroelectronics hts221 i2c driver
3  *
4  * Copyright 2016 STMicroelectronics Inc.
5  *
6  * Lorenzo Bianconi <lorenzo.bianconi@st.com>
7  *
8  * Licensed under the GPL-2.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/acpi.h>
14 #include <linux/i2c.h>
15 #include <linux/slab.h>
16 #include "hts221.h"
17 
18 #define I2C_AUTO_INCREMENT	0x80
19 
20 static int hts221_i2c_read(struct device *dev, u8 addr, int len, u8 *data)
21 {
22 	struct i2c_msg msg[2];
23 	struct i2c_client *client = to_i2c_client(dev);
24 
25 	if (len > 1)
26 		addr |= I2C_AUTO_INCREMENT;
27 
28 	msg[0].addr = client->addr;
29 	msg[0].flags = client->flags;
30 	msg[0].len = 1;
31 	msg[0].buf = &addr;
32 
33 	msg[1].addr = client->addr;
34 	msg[1].flags = client->flags | I2C_M_RD;
35 	msg[1].len = len;
36 	msg[1].buf = data;
37 
38 	return i2c_transfer(client->adapter, msg, 2);
39 }
40 
41 static int hts221_i2c_write(struct device *dev, u8 addr, int len, u8 *data)
42 {
43 	u8 send[len + 1];
44 	struct i2c_msg msg;
45 	struct i2c_client *client = to_i2c_client(dev);
46 
47 	if (len > 1)
48 		addr |= I2C_AUTO_INCREMENT;
49 
50 	send[0] = addr;
51 	memcpy(&send[1], data, len * sizeof(u8));
52 
53 	msg.addr = client->addr;
54 	msg.flags = client->flags;
55 	msg.len = len + 1;
56 	msg.buf = send;
57 
58 	return i2c_transfer(client->adapter, &msg, 1);
59 }
60 
61 static const struct hts221_transfer_function hts221_transfer_fn = {
62 	.read = hts221_i2c_read,
63 	.write = hts221_i2c_write,
64 };
65 
66 static int hts221_i2c_probe(struct i2c_client *client,
67 			    const struct i2c_device_id *id)
68 {
69 	return hts221_probe(&client->dev, client->irq,
70 			    client->name, &hts221_transfer_fn);
71 }
72 
73 static const struct acpi_device_id hts221_acpi_match[] = {
74 	{"SMO9100", 0},
75 	{ },
76 };
77 MODULE_DEVICE_TABLE(acpi, hts221_acpi_match);
78 
79 static const struct of_device_id hts221_i2c_of_match[] = {
80 	{ .compatible = "st,hts221", },
81 	{},
82 };
83 MODULE_DEVICE_TABLE(of, hts221_i2c_of_match);
84 
85 static const struct i2c_device_id hts221_i2c_id_table[] = {
86 	{ HTS221_DEV_NAME },
87 	{},
88 };
89 MODULE_DEVICE_TABLE(i2c, hts221_i2c_id_table);
90 
91 static struct i2c_driver hts221_driver = {
92 	.driver = {
93 		.name = "hts221_i2c",
94 		.pm = &hts221_pm_ops,
95 		.of_match_table = of_match_ptr(hts221_i2c_of_match),
96 		.acpi_match_table = ACPI_PTR(hts221_acpi_match),
97 	},
98 	.probe = hts221_i2c_probe,
99 	.id_table = hts221_i2c_id_table,
100 };
101 module_i2c_driver(hts221_driver);
102 
103 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
104 MODULE_DESCRIPTION("STMicroelectronics hts221 i2c driver");
105 MODULE_LICENSE("GPL v2");
106