hmc6352: add driver for the HMC6352 compass
Kalhan Trisal [Tue, 10 Aug 2010 00:21:05 +0000 (17:21 -0700)]
This driver will report the heading values in degrees to the sysfs
interface.  The values returned are headings .  e.g.  245.6

Alan: Cleanups requested now all folded in and a sysfs description to keep
Andrew happy. The sysfs description now resembles hwmon.

Signed-off-by: Kalhan Trisal <kalhan.trisal@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/ABI/testing/sysfs-bus-i2c-devices-hm6352 [new file with mode: 0644]
drivers/misc/Kconfig
drivers/misc/Makefile
drivers/misc/hmc6352.c [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-bus-i2c-devices-hm6352 b/Documentation/ABI/testing/sysfs-bus-i2c-devices-hm6352
new file mode 100644 (file)
index 0000000..feb2e4a
--- /dev/null
@@ -0,0 +1,21 @@
+Where:         /sys/bus/i2c/devices/.../heading0_input
+Date:          April 2010
+Kernel Version: 2.6.36?
+Contact:       alan.cox@intel.com
+Description:   Reports the current heading from the compass as a floating
+               point value in degrees.
+
+Where:         /sys/bus/i2c/devices/.../power_state
+Date:          April 2010
+Kernel Version: 2.6.36?
+Contact:       alan.cox@intel.com
+Description:   Sets the power state of the device. 0 sets the device into
+               sleep mode, 1 wakes it up.
+
+Where:         /sys/bus/i2c/devices/.../calibration
+Date:          April 2010
+Kernel Version: 2.6.36?
+Contact:       alan.cox@intel.com
+Description:   Sets the calibration on or off (1 = on, 0 = off). See the
+               chip data sheet.
+
index 3b4b756..0b591b6 100644 (file)
@@ -314,6 +314,13 @@ config SENSORS_BH1780
          This driver can also be built as a module.  If so, the module
          will be called bh1780gli.
 
+config HMC6352
+       tristate "Honeywell HMC6352 compass"
+       depends on I2C
+       help
+         This driver provides support for the Honeywell HMC6352 compass,
+         providing configuration and heading data via sysfs.
+
 config EP93XX_PWM
        tristate "EP93xx PWM support"
        depends on ARCH_EP93XX
index c0621fb..255a80d 100644 (file)
@@ -30,6 +30,7 @@ obj-$(CONFIG_DS1682)          += ds1682.o
 obj-$(CONFIG_TI_DAC7512)       += ti_dac7512.o
 obj-$(CONFIG_C2PORT)           += c2port/
 obj-$(CONFIG_IWMC3200TOP)      += iwmc3200top/
+obj-$(CONFIG_HMC6352)          += hmc6352.o
 obj-y                          += eeprom/
 obj-y                          += cb710/
 obj-$(CONFIG_VMWARE_BALLOON)   += vmware_balloon.o
diff --git a/drivers/misc/hmc6352.c b/drivers/misc/hmc6352.c
new file mode 100644 (file)
index 0000000..234bfca
--- /dev/null
@@ -0,0 +1,166 @@
+/*
+ * 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];
+       unsigned 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 != 1) {
+               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,
+};
+
+static int __init sensor_hmc6352_init(void)
+{
+       return i2c_add_driver(&hmc6352_driver);
+}
+
+static void  __exit sensor_hmc6352_exit(void)
+{
+       i2c_del_driver(&hmc6352_driver);
+}
+
+module_init(sensor_hmc6352_init);
+module_exit(sensor_hmc6352_exit);
+
+MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
+MODULE_DESCRIPTION("hmc6352 Compass Driver");
+MODULE_LICENSE("GPL v2");