diff options
Diffstat (limited to 'drivers/misc/hmc6352.c')
| -rw-r--r-- | drivers/misc/hmc6352.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/misc/hmc6352.c b/drivers/misc/hmc6352.c new file mode 100644 index 00000000..423cd40f --- /dev/null +++ b/drivers/misc/hmc6352.c @@ -0,0 +1,155 @@ +/* + * hmc6352.c - Honeywell Compass Driver + * + * Copyright (C) 2009 Intel Corp + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/sysfs.h> + +static DEFINE_MUTEX(compass_mutex); + +static int compass_command(struct i2c_client *c, u8 cmd) +{ + int ret = i2c_master_send(c, &cmd, 1); + if (ret < 0) + dev_warn(&c->dev, "command '%c' failed.\n", cmd); + return ret; +} + +static int compass_store(struct device *dev, const char *buf, size_t count, + const char *map) +{ + struct i2c_client *c = to_i2c_client(dev); + int ret; + unsigned long val; + + if (strict_strtoul(buf, 10, &val)) + return -EINVAL; + if (val >= strlen(map)) + return -EINVAL; + mutex_lock(&compass_mutex); + ret = compass_command(c, map[val]); + mutex_unlock(&compass_mutex); + if (ret < 0) + return ret; + return count; +} + +static ssize_t compass_calibration_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + return compass_store(dev, buf, count, "EC"); +} + +static ssize_t compass_power_mode_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + return compass_store(dev, buf, count, "SW"); +} + +static ssize_t compass_heading_data_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + unsigned char i2c_data[2]; + int ret; + + mutex_lock(&compass_mutex); + ret = compass_command(client, 'A'); + if (ret != 1) { + mutex_unlock(&compass_mutex); + return ret; + } + msleep(10); /* sending 'A' cmd we need to wait for 7-10 millisecs */ + ret = i2c_master_recv(client, i2c_data, 2); + mutex_unlock(&compass_mutex); + if (ret < 0) { + dev_warn(dev, "i2c read data cmd failed\n"); + return ret; + } + ret = (i2c_data[0] << 8) | i2c_data[1]; + return sprintf(buf, "%d.%d\n", ret/10, ret%10); +} + + +static DEVICE_ATTR(heading0_input, S_IRUGO, compass_heading_data_show, NULL); +static DEVICE_ATTR(calibration, S_IWUSR, NULL, compass_calibration_store); +static DEVICE_ATTR(power_state, S_IWUSR, NULL, compass_power_mode_store); + +static struct attribute *mid_att_compass[] = { + &dev_attr_heading0_input.attr, + &dev_attr_calibration.attr, + &dev_attr_power_state.attr, + NULL +}; + +static const struct attribute_group m_compass_gr = { + .name = "hmc6352", + .attrs = mid_att_compass +}; + +static int hmc6352_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int res; + + res = sysfs_create_group(&client->dev.kobj, &m_compass_gr); + if (res) { + dev_err(&client->dev, "device_create_file failed\n"); + return res; + } + dev_info(&client->dev, "%s HMC6352 compass chip found\n", + client->name); + return 0; +} + +static int hmc6352_remove(struct i2c_client *client) +{ + sysfs_remove_group(&client->dev.kobj, &m_compass_gr); + return 0; +} + +static struct i2c_device_id hmc6352_id[] = { + { "hmc6352", 0 }, + { } +}; + +MODULE_DEVICE_TABLE(i2c, hmc6352_id); + +static struct i2c_driver hmc6352_driver = { + .driver = { + .name = "hmc6352", + }, + .probe = hmc6352_probe, + .remove = hmc6352_remove, + .id_table = hmc6352_id, +}; + +module_i2c_driver(hmc6352_driver); + +MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com"); +MODULE_DESCRIPTION("hmc6352 Compass Driver"); +MODULE_LICENSE("GPL v2"); |