While it is possible to force SMBus-based hardware monitoring chip
drivers to drive a not officially supported device, we do not have this
possibility for Super-I/O-based drivers. That's unfortunate because
sometimes newer chips are fully compatible and just forcing the driver
to load would work. Instead of that we have to tell the users to
recompile the kernel driver, which isn't an easy task for everyone.
So, I propose that we add a module parameter to all Super-I/O based
hardware monitoring drivers, letting advanced users force the driver
to load on their machine. The user has to provide the device ID of a
supposedly compatible device. This requires looking at the source code or
a datasheet, so I am confident that users can't randomly force a driver
without knowing what they are doing. Thus this should be relatively safe.
As you can see from the code, the implementation is pretty simple and
unintrusive.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Convert from class_device to device for hwmon_device_register/unregister
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Fix a potential race condition when some hardware monitoring platform
drivers are being unloaded. I believe that the driver data pointer
shouldn't be cleared before all the sysfs files are removed, otherwise
a sysfs callback might attempt to dereference a NULL pointer. I'm not
sure exactly what the driver core protects drivers against, so let's
play it safe.
While we're here, clear the driver data pointer when probe fails, so
as to not leave an invalid pointer behind us.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
My understanding of the resource management in the Linux 2.6 device
driver model is that the devices should declare their resources, and
then when a driver attaches to a device, it should request the
resources it will be using, so as to mark them busy. This is how the
PCI and PNP subsystems work, you can clearly see the two levels of
resources (declaration and request) in /proc/ioports for these
devices.
So I believe that our platform hardware monitoring drivers should
follow the same logic. At the moment, we only declare the resources
but we do not request them. This patch adds the I/O region request
and release calls.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Juerg Haefliger <juergh@gmail.com>
This is a new hardware monitoring driver for the National Semiconductor
PC87427 Super-I/O chip. It only supports fan speed monitoring for now,
while the chip can do much more.
Thanks to Amir Habibi at Candelis for setting up a test system, and to
Michael Kress for testing several iterations of this driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Jean Delvare