On 06/17/10 12:50, Alan Cox wrote: >>> + struct i2c_msg msg1[] = { >>> + { client->addr, 0, 1, &cmd1 }, >>> + }; >> >> It's quite overkill IMHO to have two messages here. In the end you send >> only one. It would make sense if you made these messages static const, > > They can't be const but I cleaned it up based on your other suggestions and > then jumped up and down on it a bit more. > > > hmc6352: Add driver for the HMC6352 compass > > From: Kalhan Trisal <kalhan.trisal@xxxxxxxxx> > > This driver will report the heading values in degrees to the sysfs interface. > The values returned are headings . e.g. 245.6 > > Cleanups requested now all folded in and a sysfs description to keep Andrew > happy. > > Signed-off-by: Kalhan Trisal <kalhan.trisal@xxxxxxxxx> > Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx> Hi Alan, I guess it is pretty unlikely anyone would ever have more than one compass and if they do they can deal with the mutex sharing if they care. I think there is a small issue where the code and documentation don't match for the calibration attribute. The version in the docs makes more sense to me and I think it will slightly simplify the code. Fix that and I'm happy to add: Acked-by: Jonathan Cameron <jic23@xxxxxxxxx> > --- > > .../ABI/testing/sysfs-bus-i2c-devices-hm6352 | 21 +++ > drivers/misc/Kconfig | 7 + > drivers/misc/Makefile | 1 > drivers/misc/hmc6352.c | 165 ++++++++++++++++++++ > 4 files changed, 194 insertions(+), 0 deletions(-) > create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-devices-hm6352 > create mode 100644 drivers/misc/hmc6352.c > > > diff --git a/Documentation/ABI/testing/sysfs-bus-i2c-devices-hm6352 b/Documentation/ABI/testing/sysfs-bus-i2c-devices-hm6352 > new file mode 100644 > index 0000000..feb2e4a > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-i2c-devices-hm6352 > @@ -0,0 +1,21 @@ > +Where: /sys/bus/i2c/devices/.../heading0_input > +Date: April 2010 > +Kernel Version: 2.6.36? > +Contact: alan.cox@xxxxxxxxx > +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@xxxxxxxxx > +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@xxxxxxxxx > +Description: Sets the calibration on or off (1 = on, 0 = off). See the > + chip data sheet. I think there is a disrepancy between what is described here and what the code does. Looks to me like values are 1 for on and 2 for off in the code (which is a little odd). > + > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig > index 26386a9..9e825cb 100644 > --- a/drivers/misc/Kconfig > +++ b/drivers/misc/Kconfig > @@ -304,6 +304,13 @@ config SENSORS_TSL2550 > This driver can also be built as a module. If so, the module > will be called tsl2550. > > +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 > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile > index 6ed06a1..48597df 100644 > --- a/drivers/misc/Makefile > +++ b/drivers/misc/Makefile > @@ -28,6 +28,7 @@ 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 > index 0000000..3243c8c > --- /dev/null > +++ b/drivers/misc/hmc6352.c > @@ -0,0 +1,165 @@ > +/* > + * 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 < 0 || val >= strlen(map) || map[val] == ' ') > + return -EINVAL; > + mutex_lock(&compass_mutex); > + ret = compass_command(c, map[val]); > + mutex_unlock(&compass_mutex); > + return ret; > +} > + > +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, " CE"); > +} > + > +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); > +} > + If we are being ludicrously fussy, no point in 2 blank lines here... > + > +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@xxxxxxxxx"); > +MODULE_DESCRIPTION("hmc6352 Compass Driver"); > +MODULE_LICENSE("GPL v2"); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html