]>
Commit | Line | Data |
---|---|---|
873e65bc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
cfa3b24c KT |
2 | /* |
3 | * hmc6352.c - Honeywell Compass Driver | |
4 | * | |
5 | * Copyright (C) 2009 Intel Corp | |
6 | * | |
7 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
8 | * | |
cfa3b24c | 9 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
cfa3b24c KT |
10 | */ |
11 | ||
12 | #include <linux/module.h> | |
cfa3b24c KT |
13 | #include <linux/slab.h> |
14 | #include <linux/i2c.h> | |
15 | #include <linux/err.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/sysfs.h> | |
de916736 | 18 | #include <linux/nospec.h> |
cfa3b24c KT |
19 | |
20 | static DEFINE_MUTEX(compass_mutex); | |
21 | ||
22 | static int compass_command(struct i2c_client *c, u8 cmd) | |
23 | { | |
24 | int ret = i2c_master_send(c, &cmd, 1); | |
25 | if (ret < 0) | |
26 | dev_warn(&c->dev, "command '%c' failed.\n", cmd); | |
27 | return ret; | |
28 | } | |
29 | ||
30 | static int compass_store(struct device *dev, const char *buf, size_t count, | |
31 | const char *map) | |
32 | { | |
33 | struct i2c_client *c = to_i2c_client(dev); | |
34 | int ret; | |
35 | unsigned long val; | |
36 | ||
f7b41276 JH |
37 | ret = kstrtoul(buf, 10, &val); |
38 | if (ret) | |
39 | return ret; | |
cfa3b24c KT |
40 | if (val >= strlen(map)) |
41 | return -EINVAL; | |
de916736 | 42 | val = array_index_nospec(val, strlen(map)); |
cfa3b24c KT |
43 | mutex_lock(&compass_mutex); |
44 | ret = compass_command(c, map[val]); | |
45 | mutex_unlock(&compass_mutex); | |
46 | if (ret < 0) | |
47 | return ret; | |
48 | return count; | |
49 | } | |
50 | ||
51 | static ssize_t compass_calibration_store(struct device *dev, | |
52 | struct device_attribute *attr, const char *buf, size_t count) | |
53 | { | |
54 | return compass_store(dev, buf, count, "EC"); | |
55 | } | |
56 | ||
57 | static ssize_t compass_power_mode_store(struct device *dev, | |
58 | struct device_attribute *attr, const char *buf, size_t count) | |
59 | { | |
60 | return compass_store(dev, buf, count, "SW"); | |
61 | } | |
62 | ||
63 | static ssize_t compass_heading_data_show(struct device *dev, | |
64 | struct device_attribute *attr, char *buf) | |
65 | { | |
66 | struct i2c_client *client = to_i2c_client(dev); | |
67 | unsigned char i2c_data[2]; | |
6f7d485e | 68 | int ret; |
cfa3b24c KT |
69 | |
70 | mutex_lock(&compass_mutex); | |
71 | ret = compass_command(client, 'A'); | |
72 | if (ret != 1) { | |
73 | mutex_unlock(&compass_mutex); | |
74 | return ret; | |
75 | } | |
76 | msleep(10); /* sending 'A' cmd we need to wait for 7-10 millisecs */ | |
77 | ret = i2c_master_recv(client, i2c_data, 2); | |
78 | mutex_unlock(&compass_mutex); | |
6f7d485e | 79 | if (ret < 0) { |
cfa3b24c KT |
80 | dev_warn(dev, "i2c read data cmd failed\n"); |
81 | return ret; | |
82 | } | |
83 | ret = (i2c_data[0] << 8) | i2c_data[1]; | |
84 | return sprintf(buf, "%d.%d\n", ret/10, ret%10); | |
85 | } | |
86 | ||
87 | ||
88 | static DEVICE_ATTR(heading0_input, S_IRUGO, compass_heading_data_show, NULL); | |
89 | static DEVICE_ATTR(calibration, S_IWUSR, NULL, compass_calibration_store); | |
90 | static DEVICE_ATTR(power_state, S_IWUSR, NULL, compass_power_mode_store); | |
91 | ||
92 | static struct attribute *mid_att_compass[] = { | |
93 | &dev_attr_heading0_input.attr, | |
94 | &dev_attr_calibration.attr, | |
95 | &dev_attr_power_state.attr, | |
96 | NULL | |
97 | }; | |
98 | ||
99 | static const struct attribute_group m_compass_gr = { | |
100 | .name = "hmc6352", | |
101 | .attrs = mid_att_compass | |
102 | }; | |
103 | ||
104 | static int hmc6352_probe(struct i2c_client *client, | |
105 | const struct i2c_device_id *id) | |
106 | { | |
107 | int res; | |
108 | ||
109 | res = sysfs_create_group(&client->dev.kobj, &m_compass_gr); | |
110 | if (res) { | |
111 | dev_err(&client->dev, "device_create_file failed\n"); | |
112 | return res; | |
113 | } | |
114 | dev_info(&client->dev, "%s HMC6352 compass chip found\n", | |
115 | client->name); | |
116 | return 0; | |
117 | } | |
118 | ||
119 | static int hmc6352_remove(struct i2c_client *client) | |
120 | { | |
121 | sysfs_remove_group(&client->dev.kobj, &m_compass_gr); | |
122 | return 0; | |
123 | } | |
124 | ||
b8dbb502 | 125 | static const struct i2c_device_id hmc6352_id[] = { |
cfa3b24c KT |
126 | { "hmc6352", 0 }, |
127 | { } | |
128 | }; | |
129 | ||
130 | MODULE_DEVICE_TABLE(i2c, hmc6352_id); | |
131 | ||
132 | static struct i2c_driver hmc6352_driver = { | |
133 | .driver = { | |
134 | .name = "hmc6352", | |
135 | }, | |
136 | .probe = hmc6352_probe, | |
137 | .remove = hmc6352_remove, | |
138 | .id_table = hmc6352_id, | |
139 | }; | |
140 | ||
a64fe2ed | 141 | module_i2c_driver(hmc6352_driver); |
cfa3b24c KT |
142 | |
143 | MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com"); | |
144 | MODULE_DESCRIPTION("hmc6352 Compass Driver"); | |
145 | MODULE_LICENSE("GPL v2"); |