Kalhan Trisal | cfa3b24 | 2010-08-09 17:21:05 -0700 | [diff] [blame] | 1 | /* |
| 2 | * hmc6352.c - Honeywell Compass Driver |
| 3 | * |
| 4 | * Copyright (C) 2009 Intel Corp |
| 5 | * |
| 6 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; version 2 of the License. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, but |
| 13 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License along |
| 18 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 19 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
| 20 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 21 | * |
| 22 | */ |
| 23 | |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/i2c.h> |
| 28 | #include <linux/err.h> |
| 29 | #include <linux/delay.h> |
| 30 | #include <linux/sysfs.h> |
| 31 | |
| 32 | static DEFINE_MUTEX(compass_mutex); |
| 33 | |
| 34 | static int compass_command(struct i2c_client *c, u8 cmd) |
| 35 | { |
| 36 | int ret = i2c_master_send(c, &cmd, 1); |
| 37 | if (ret < 0) |
| 38 | dev_warn(&c->dev, "command '%c' failed.\n", cmd); |
| 39 | return ret; |
| 40 | } |
| 41 | |
| 42 | static int compass_store(struct device *dev, const char *buf, size_t count, |
| 43 | const char *map) |
| 44 | { |
| 45 | struct i2c_client *c = to_i2c_client(dev); |
| 46 | int ret; |
| 47 | unsigned long val; |
| 48 | |
Jingoo Han | f7b4127 | 2013-06-04 13:15:16 +0900 | [diff] [blame^] | 49 | ret = kstrtoul(buf, 10, &val); |
| 50 | if (ret) |
| 51 | return ret; |
Kalhan Trisal | cfa3b24 | 2010-08-09 17:21:05 -0700 | [diff] [blame] | 52 | if (val >= strlen(map)) |
| 53 | return -EINVAL; |
| 54 | mutex_lock(&compass_mutex); |
| 55 | ret = compass_command(c, map[val]); |
| 56 | mutex_unlock(&compass_mutex); |
| 57 | if (ret < 0) |
| 58 | return ret; |
| 59 | return count; |
| 60 | } |
| 61 | |
| 62 | static ssize_t compass_calibration_store(struct device *dev, |
| 63 | struct device_attribute *attr, const char *buf, size_t count) |
| 64 | { |
| 65 | return compass_store(dev, buf, count, "EC"); |
| 66 | } |
| 67 | |
| 68 | static ssize_t compass_power_mode_store(struct device *dev, |
| 69 | struct device_attribute *attr, const char *buf, size_t count) |
| 70 | { |
| 71 | return compass_store(dev, buf, count, "SW"); |
| 72 | } |
| 73 | |
| 74 | static ssize_t compass_heading_data_show(struct device *dev, |
| 75 | struct device_attribute *attr, char *buf) |
| 76 | { |
| 77 | struct i2c_client *client = to_i2c_client(dev); |
| 78 | unsigned char i2c_data[2]; |
Axel Lin | 6f7d485 | 2011-03-22 16:34:00 -0700 | [diff] [blame] | 79 | int ret; |
Kalhan Trisal | cfa3b24 | 2010-08-09 17:21:05 -0700 | [diff] [blame] | 80 | |
| 81 | mutex_lock(&compass_mutex); |
| 82 | ret = compass_command(client, 'A'); |
| 83 | if (ret != 1) { |
| 84 | mutex_unlock(&compass_mutex); |
| 85 | return ret; |
| 86 | } |
| 87 | msleep(10); /* sending 'A' cmd we need to wait for 7-10 millisecs */ |
| 88 | ret = i2c_master_recv(client, i2c_data, 2); |
| 89 | mutex_unlock(&compass_mutex); |
Axel Lin | 6f7d485 | 2011-03-22 16:34:00 -0700 | [diff] [blame] | 90 | if (ret < 0) { |
Kalhan Trisal | cfa3b24 | 2010-08-09 17:21:05 -0700 | [diff] [blame] | 91 | dev_warn(dev, "i2c read data cmd failed\n"); |
| 92 | return ret; |
| 93 | } |
| 94 | ret = (i2c_data[0] << 8) | i2c_data[1]; |
| 95 | return sprintf(buf, "%d.%d\n", ret/10, ret%10); |
| 96 | } |
| 97 | |
| 98 | |
| 99 | static DEVICE_ATTR(heading0_input, S_IRUGO, compass_heading_data_show, NULL); |
| 100 | static DEVICE_ATTR(calibration, S_IWUSR, NULL, compass_calibration_store); |
| 101 | static DEVICE_ATTR(power_state, S_IWUSR, NULL, compass_power_mode_store); |
| 102 | |
| 103 | static struct attribute *mid_att_compass[] = { |
| 104 | &dev_attr_heading0_input.attr, |
| 105 | &dev_attr_calibration.attr, |
| 106 | &dev_attr_power_state.attr, |
| 107 | NULL |
| 108 | }; |
| 109 | |
| 110 | static const struct attribute_group m_compass_gr = { |
| 111 | .name = "hmc6352", |
| 112 | .attrs = mid_att_compass |
| 113 | }; |
| 114 | |
| 115 | static int hmc6352_probe(struct i2c_client *client, |
| 116 | const struct i2c_device_id *id) |
| 117 | { |
| 118 | int res; |
| 119 | |
| 120 | res = sysfs_create_group(&client->dev.kobj, &m_compass_gr); |
| 121 | if (res) { |
| 122 | dev_err(&client->dev, "device_create_file failed\n"); |
| 123 | return res; |
| 124 | } |
| 125 | dev_info(&client->dev, "%s HMC6352 compass chip found\n", |
| 126 | client->name); |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | static int hmc6352_remove(struct i2c_client *client) |
| 131 | { |
| 132 | sysfs_remove_group(&client->dev.kobj, &m_compass_gr); |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | static struct i2c_device_id hmc6352_id[] = { |
| 137 | { "hmc6352", 0 }, |
| 138 | { } |
| 139 | }; |
| 140 | |
| 141 | MODULE_DEVICE_TABLE(i2c, hmc6352_id); |
| 142 | |
| 143 | static struct i2c_driver hmc6352_driver = { |
| 144 | .driver = { |
| 145 | .name = "hmc6352", |
| 146 | }, |
| 147 | .probe = hmc6352_probe, |
| 148 | .remove = hmc6352_remove, |
| 149 | .id_table = hmc6352_id, |
| 150 | }; |
| 151 | |
Axel Lin | a64fe2e | 2012-01-22 15:36:45 +0800 | [diff] [blame] | 152 | module_i2c_driver(hmc6352_driver); |
Kalhan Trisal | cfa3b24 | 2010-08-09 17:21:05 -0700 | [diff] [blame] | 153 | |
| 154 | MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com"); |
| 155 | MODULE_DESCRIPTION("hmc6352 Compass Driver"); |
| 156 | MODULE_LICENSE("GPL v2"); |