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path: root/include/linux/uio_driver.h
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2009-03-24UIO: Add name attributes for mappings and port regionsHans J. Koch
If a UIO device has several memory mappings, it can be difficult for userspace to find the right one. The situation becomes even worse if the UIO driver can handle different versions of a card that have different numbers of mappings. Benedikt Spranger has such cards and pointed this out to me. Thanks, Bene! To address this problem, this patch adds "name" sysfs attributes for each mapping. Userspace can use these to clearly identify each mapping. The name string is optional. If a driver doesn't set it, an empty string will be returned, so this patch won't break existing drivers. The same problem exists for port region information, so a "name" attribute is added there, too. Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-06uio: make uio_info's name and version constStephen Rothwell
These are only ever assigned constant strings and never modified. This was noticed because Wolfram Sang needed to cast the result of of_get_property() in order to assign it to the name field of a struct uio_info. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-06UIO: Pass information about ioports to userspace (V2)Hans J. Koch
Devices sometimes have memory where all or parts of it can not be mapped to userspace. But it might still be possible to access this memory from userspace by other means. An example are PCI cards that advertise not only mappable memory but also ioport ranges. On x86 architectures, these can be accessed with ioperm, iopl, inb, outb, and friends. Mike Frysinger (CCed) reported a similar problem on Blackfin arch where it doesn't seem to be easy to mmap non-cached memory but it can still be accessed from userspace. This patch allows kernel drivers to pass information about such ports to userspace. Similar to the existing mem[] array, it adds a port[] array to struct uio_info. Each port range is described by start, size, and porttype. If a driver fills in at least one such port range, the UIO core will simply pass this information to userspace by creating a new directory "portio" underneath /sys/class/uio/uioN/. Similar to the "mem" directory, it will contain a subdirectory (portX) for each port range given. Note that UIO simply passes this information to userspace, it performs no action whatsoever with this data. It's userspace's responsibility to obtain access to these ports and to solve arch dependent issues. The "porttype" attribute tells userspace what kind of port it is dealing with. This mechanism could also be used to give userspace information about GPIOs related to a device. You frequently find such hardware in embedded devices, so I added a UIO_PORT_GPIO definition. I'm not really sure if this is a good idea since there are other solutions to this problem, but it won't hurt much anyway. Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21UIO: minor style and comment fixesUwe Kleine-König
Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Signed-off-by: Hans J. Koch <hjk@linutronix.de>
2008-07-21UIO: Add write function to allow irq maskingHans J. Koch
Sometimes it is necessary to enable/disable the interrupt of a UIO device from the userspace part of the driver. With this patch, the UIO kernel driver can implement an "irqcontrol()" function that does this. Userspace can write an s32 value to /dev/uioX (usually 0 or 1 to turn the irq off or on). The UIO core will then call the driver's irqcontrol function. Signed-off-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Acked-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24UIO: fix kobject usageGreg Kroah-Hartman
The uio kobject code is "wierd". This patch should hopefully fix it up to be sane and not leak memory anymore. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Benedikt Spranger <b.spranger@linutronix.de> Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-18UIO: Add the User IO core codeHans J. Koch
This interface allows the ability to write the majority of a driver in userspace with only a very small shell of a driver in the kernel itself. It uses a char device and sysfs to interact with a userspace process to process interrupts and control memory accesses. See the docbook documentation for more details on how to use this interface. From: Hans J. Koch <hjk@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Benedikt Spranger <b.spranger@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>