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Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/uio-2.6 

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/uio-2.6:
  UIO: Hilscher CIF card driver
  UIO: Documentation
  UIO: Add the User IO core code
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Linus Torvalds 2007-07-18 18:27:50 -07:00
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4
Documentation/DocBook/kernel-api.tmpl
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@ -408,6 +408,10 @@ X!Edrivers/pnp/system.c
!Edrivers/pnp/manager.c
!Edrivers/pnp/support.c
</sect1>
<sect1><title>Userspace IO devices</title>
!Edrivers/uio/uio.c
!Iinclude/linux/uio_driver.h
</sect1>
</chapter>
<chapter id="blkdev">

611
Documentation/DocBook/uio-howto.tmpl Normal file
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@ -0,0 +1,611 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" []>
<book id="index">
<bookinfo>
<title>The Userspace I/O HOWTO</title>
<author>
<firstname>Hans-Jürgen</firstname>
<surname>Koch</surname>
<authorblurb><para>Linux developer, Linutronix</para></authorblurb>
<affiliation>
<orgname>
<ulink url="http://www.linutronix.de">Linutronix</ulink>
</orgname>
<address>
<email>hjk@linutronix.de</email>
</address>
</affiliation>
</author>
<pubdate>2006-12-11</pubdate>
<abstract>
<para>This HOWTO describes concept and usage of Linux kernel's
Userspace I/O system.</para>
</abstract>
<revhistory>
<revision>
<revnumber>0.3</revnumber>
<date>2007-04-29</date>
<authorinitials>hjk</authorinitials>
<revremark>Added section about userspace drivers.</revremark>
</revision>
<revision>
<revnumber>0.2</revnumber>
<date>2007-02-13</date>
<authorinitials>hjk</authorinitials>
<revremark>Update after multiple mappings were added.</revremark>
</revision>
<revision>
<revnumber>0.1</revnumber>
<date>2006-12-11</date>
<authorinitials>hjk</authorinitials>
<revremark>First draft.</revremark>
</revision>
</revhistory>
</bookinfo>
<chapter id="aboutthisdoc">
<?dbhtml filename="about.html"?>
<title>About this document</title>
<sect1 id="copyright">
<?dbhtml filename="copyright.html"?>
<title>Copyright and License</title>
<para>
Copyright (c) 2006 by Hans-Jürgen Koch.</para>
<para>
This documentation is Free Software licensed under the terms of the
GPL version 2.
</para>
</sect1>
<sect1 id="translations">
<?dbhtml filename="translations.html"?>
<title>Translations</title>
<para>If you know of any translations for this document, or you are
interested in translating it, please email me
<email>hjk@linutronix.de</email>.
</para>
</sect1>
<sect1 id="preface">
<title>Preface</title>
<para>
For many types of devices, creating a Linux kernel driver is
overkill. All that is really needed is some way to handle an
interrupt and provide access to the memory space of the
device. The logic of controlling the device does not
necessarily have to be within the kernel, as the device does
not need to take advantage of any of other resources that the
kernel provides. One such common class of devices that are
like this are for industrial I/O cards.
</para>
<para>
To address this situation, the userspace I/O system (UIO) was
designed. For typical industrial I/O cards, only a very small
kernel module is needed. The main part of the driver will run in
user space. This simplifies development and reduces the risk of
serious bugs within a kernel module.
</para>
</sect1>
<sect1 id="thanks">
<title>Acknowledgments</title>
<para>I'd like to thank Thomas Gleixner and Benedikt Spranger of
Linutronix, who have not only written most of the UIO code, but also
helped greatly writing this HOWTO by giving me all kinds of background
information.</para>
</sect1>
<sect1 id="feedback">
<title>Feedback</title>
<para>Find something wrong with this document? (Or perhaps something
right?) I would love to hear from you. Please email me at
<email>hjk@linutronix.de</email>.</para>
</sect1>
</chapter>
<chapter id="about">
<?dbhtml filename="about.html"?>
<title>About UIO</title>
<para>If you use UIO for your card's driver, here's what you get:</para>
<itemizedlist>
<listitem>
<para>only one small kernel module to write and maintain.</para>
</listitem>
<listitem>
<para>develop the main part of your driver in user space,
with all the tools and libraries you're used to.</para>
</listitem>
<listitem>
<para>bugs in your driver won't crash the kernel.</para>
</listitem>
<listitem>
<para>updates of your driver can take place without recompiling
the kernel.</para>
</listitem>
<listitem>
<para>if you need to keep some parts of your driver closed source,
you can do so without violating the GPL license on the kernel.</para>
</listitem>
</itemizedlist>
<sect1 id="how_uio_works">
<title>How UIO works</title>
<para>
Each UIO device is accessed through a device file and several
sysfs attribute files. The device file will be called
<filename>/dev/uio0</filename> for the first device, and
<filename>/dev/uio1</filename>, <filename>/dev/uio2</filename>
and so on for subsequent devices.
</para>
<para><filename>/dev/uioX</filename> is used to access the
address space of the card. Just use
<function>mmap()</function> to access registers or RAM
locations of your card.
</para>
<para>
Interrupts are handled by reading from
<filename>/dev/uioX</filename>. A blocking
<function>read()</function> from
<filename>/dev/uioX</filename> will return as soon as an
interrupt occurs. You can also use
<function>select()</function> on
<filename>/dev/uioX</filename> to wait for an interrupt. The
integer value read from <filename>/dev/uioX</filename>
represents the total interrupt count. You can use this number
to figure out if you missed some interrupts.
</para>
<para>
To handle interrupts properly, your custom kernel module can
provide its own interrupt handler. It will automatically be
called by the built-in handler.
</para>
<para>
For cards that don't generate interrupts but need to be
polled, there is the possibility to set up a timer that
triggers the interrupt handler at configurable time intervals.
See <filename>drivers/uio/uio_dummy.c</filename> for an
example of this technique.
</para>
<para>
Each driver provides attributes that are used to read or write
variables. These attributes are accessible through sysfs
files. A custom kernel driver module can add its own
attributes to the device owned by the uio driver, but not added
to the UIO device itself at this time. This might change in the
future if it would be found to be useful.
</para>
<para>
The following standard attributes are provided by the UIO
framework:
</para>
<itemizedlist>
<listitem>
<para>
<filename>name</filename>: The name of your device. It is
recommended to use the name of your kernel module for this.
</para>
</listitem>
<listitem>
<para>
<filename>version</filename>: A version string defined by your
driver. This allows the user space part of your driver to deal
with different versions of the kernel module.
</para>
</listitem>
<listitem>
<para>
<filename>event</filename>: The total number of interrupts
handled by the driver since the last time the device node was
read.
</para>
</listitem>
</itemizedlist>
<para>
These attributes appear under the
<filename>/sys/class/uio/uioX</filename> directory. Please
note that this directory might be a symlink, and not a real
directory. Any userspace code that accesses it must be able
to handle this.
</para>
<para>
Each UIO device can make one or more memory regions available for
memory mapping. This is necessary because some industrial I/O cards
require access to more than one PCI memory region in a driver.
</para>
<para>
Each mapping has its own directory in sysfs, the first mapping
appears as <filename>/sys/class/uio/uioX/maps/map0/</filename>.
Subsequent mappings create directories <filename>map1/</filename>,
<filename>map2/</filename>, and so on. These directories will only
appear if the size of the mapping is not 0.
</para>
<para>
Each <filename>mapX/</filename> directory contains two read-only files
that show start address and size of the memory:
</para>
<itemizedlist>
<listitem>
<para>
<filename>addr</filename>: The address of memory that can be mapped.
</para>
</listitem>
<listitem>
<para>
<filename>size</filename>: The size, in bytes, of the memory
pointed to by addr.
</para>
</listitem>
</itemizedlist>
<para>
From userspace, the different mappings are distinguished by adjusting
the <varname>offset</varname> parameter of the
<function>mmap()</function> call. To map the memory of mapping N, you
have to use N times the page size as your offset:
</para>
<programlisting format="linespecific">
offset = N * getpagesize();
</programlisting>
</sect1>
</chapter>
<chapter id="using-uio_dummy" xreflabel="Using uio_dummy">
<?dbhtml filename="using-uio_dummy.html"?>
<title>Using uio_dummy</title>
<para>
Well, there is no real use for uio_dummy. Its only purpose is
to test most parts of the UIO system (everything except
hardware interrupts), and to serve as an example for the
kernel module that you will have to write yourself.
</para>
<sect1 id="what_uio_dummy_does">
<title>What uio_dummy does</title>
<para>
The kernel module <filename>uio_dummy.ko</filename> creates a
device that uses a timer to generate periodic interrupts. The
interrupt handler does nothing but increment a counter. The
driver adds two custom attributes, <varname>count</varname>
and <varname>freq</varname>, that appear under
<filename>/sys/devices/platform/uio_dummy/</filename>.
</para>
<para>
The attribute <varname>count</varname> can be read and
written. The associated file
<filename>/sys/devices/platform/uio_dummy/count</filename>
appears as a normal text file and contains the total number of
timer interrupts. If you look at it (e.g. using
<function>cat</function>), you'll notice it is slowly counting
up.
</para>
<para>
The attribute <varname>freq</varname> can be read and written.
The content of
<filename>/sys/devices/platform/uio_dummy/freq</filename>
represents the number of system timer ticks between two timer
interrupts. The default value of <varname>freq</varname> is
the value of the kernel variable <varname>HZ</varname>, which
gives you an interval of one second. Lower values will
increase the frequency. Try the following:
</para>
<programlisting format="linespecific">
cd /sys/devices/platform/uio_dummy/
echo 100 > freq
</programlisting>
<para>
Use <function>cat count</function> to see how the interrupt
frequency changes.
</para>
</sect1>
</chapter>
<chapter id="custom_kernel_module" xreflabel="Writing your own kernel module">
<?dbhtml filename="custom_kernel_module.html"?>
<title>Writing your own kernel module</title>
<para>
Please have a look at <filename>uio_dummy.c</filename> as an
example. The following paragraphs explain the different
sections of this file.
</para>
<sect1 id="uio_info">
<title>struct uio_info</title>
<para>
This structure tells the framework the details of your driver,
Some of the members are required, others are optional.
</para>
<itemizedlist>
<listitem><para>
<varname>char *name</varname>: Required. The name of your driver as
it will appear in sysfs. I recommend using the name of your module for this.
</para></listitem>
<listitem><para>
<varname>char *version</varname>: Required. This string appears in
<filename>/sys/class/uio/uioX/version</filename>.
</para></listitem>
<listitem><para>
<varname>struct uio_mem mem[ MAX_UIO_MAPS ]</varname>: Required if you
have memory that can be mapped with <function>mmap()</function>. For each
mapping you need to fill one of the <varname>uio_mem</varname> structures.
See the description below for details.
</para></listitem>
<listitem><para>
<varname>long irq</varname>: Required. If your hardware generates an
interrupt, it's your modules task to determine the irq number during
initialization. If you don't have a hardware generated interrupt but
want to trigger the interrupt handler in some other way, set
<varname>irq</varname> to <varname>UIO_IRQ_CUSTOM</varname>. The
uio_dummy module does this as it triggers the event mechanism in a timer
routine. If you had no interrupt at all, you could set
<varname>irq</varname> to <varname>UIO_IRQ_NONE</varname>, though this
rarely makes sense.
</para></listitem>
<listitem><para>
<varname>unsigned long irq_flags</varname>: Required if you've set
<varname>irq</varname> to a hardware interrupt number. The flags given
here will be used in the call to <function>request_irq()</function>.
</para></listitem>
<listitem><para>
<varname>int (*mmap)(struct uio_info *info, struct vm_area_struct
*vma)</varname>: Optional. If you need a special
<function>mmap()</function> function, you can set it here. If this
pointer is not NULL, your <function>mmap()</function> will be called
instead of the built-in one.
</para></listitem>
<listitem><para>
<varname>int (*open)(struct uio_info *info, struct inode *inode)
</varname>: Optional. You might want to have your own
<function>open()</function>, e.g. to enable interrupts only when your
device is actually used.
</para></listitem>
<listitem><para>
<varname>int (*release)(struct uio_info *info, struct inode *inode)
</varname>: Optional. If you define your own
<function>open()</function>, you will probably also want a custom
<function>release()</function> function.
</para></listitem>
</itemizedlist>
<para>
Usually, your device will have one or more memory regions that can be mapped
to user space. For each region, you have to set up a
<varname>struct uio_mem</varname> in the <varname>mem[]</varname> array.
Here's a description of the fields of <varname>struct uio_mem</varname>:
</para>
<itemizedlist>
<listitem><para>
<varname>int memtype</varname>: Required if the mapping is used. Set this to
<varname>UIO_MEM_PHYS</varname> if you you have physical memory on your
card to be mapped. Use <varname>UIO_MEM_LOGICAL</varname> for logical
memory (e.g. allocated with <function>kmalloc()</function>). There's also
<varname>UIO_MEM_VIRTUAL</varname> for virtual memory.
</para></listitem>
<listitem><para>
<varname>unsigned long addr</varname>: Required if the mapping is used.
Fill in the address of your memory block. This address is the one that
appears in sysfs.
</para></listitem>
<listitem><para>
<varname>unsigned long size</varname>: Fill in the size of the
memory block that <varname>addr</varname> points to. If <varname>size</varname>
is zero, the mapping is considered unused. Note that you
<emphasis>must</emphasis> initialize <varname>size</varname> with zero for
all unused mappings.
</para></listitem>
<listitem><para>
<varname>void *internal_addr</varname>: If you have to access this memory
region from within your kernel module, you will want to map it internally by
using something like <function>ioremap()</function>. Addresses
returned by this function cannot be mapped to user space, so you must not
store it in <varname>addr</varname>. Use <varname>internal_addr</varname>
instead to remember such an address.
</para></listitem>
</itemizedlist>
<para>
Please do not touch the <varname>kobj</varname> element of
<varname>struct uio_mem</varname>! It is used by the UIO framework
to set up sysfs files for this mapping. Simply leave it alone.
</para>
</sect1>
<sect1 id="adding_irq_handler">
<title>Adding an interrupt handler</title>
<para>
What you need to do in your interrupt handler depends on your
hardware and on how you want to handle it. You should try to
keep the amount of code in your kernel interrupt handler low.
If your hardware requires no action that you
<emphasis>have</emphasis> to perform after each interrupt,
then your handler can be empty.</para> <para>If, on the other
hand, your hardware <emphasis>needs</emphasis> some action to
be performed after each interrupt, then you
<emphasis>must</emphasis> do it in your kernel module. Note
that you cannot rely on the userspace part of your driver. Your
userspace program can terminate at any time, possibly leaving
your hardware in a state where proper interrupt handling is
still required.
</para>
<para>
There might also be applications where you want to read data
from your hardware at each interrupt and buffer it in a piece
of kernel memory you've allocated for that purpose. With this
technique you could avoid loss of data if your userspace
program misses an interrupt.
</para>
<para>
A note on shared interrupts: Your driver should support
interrupt sharing whenever this is possible. It is possible if
and only if your driver can detect whether your hardware has
triggered the interrupt or not. This is usually done by looking
at an interrupt status register. If your driver sees that the
IRQ bit is actually set, it will perform its actions, and the
handler returns IRQ_HANDLED. If the driver detects that it was
not your hardware that caused the interrupt, it will do nothing
and return IRQ_NONE, allowing the kernel to call the next
possible interrupt handler.
</para>
<para>
If you decide not to support shared interrupts, your card
won't work in computers with no free interrupts. As this
frequently happens on the PC platform, you can save yourself a
lot of trouble by supporting interrupt sharing.
</para>
</sect1>
</chapter>
<chapter id="userspace_driver" xreflabel="Writing a driver in user space">
<?dbhtml filename="userspace_driver.html"?>
<title>Writing a driver in userspace</title>
<para>
Once you have a working kernel module for your hardware, you can
write the userspace part of your driver. You don't need any special
libraries, your driver can be written in any reasonable language,
you can use floating point numbers and so on. In short, you can
use all the tools and libraries you'd normally use for writing a
userspace application.
</para>
<sect1 id="getting_uio_information">
<title>Getting information about your UIO device</title>
<para>
Information about all UIO devices is available in sysfs. The
first thing you should do in your driver is check
<varname>name</varname> and <varname>version</varname> to
make sure your talking to the right device and that its kernel
driver has the version you expect.
</para>
<para>
You should also make sure that the memory mapping you need
exists and has the size you expect.
</para>
<para>
There is a tool called <varname>lsuio</varname> that lists
UIO devices and their attributes. It is available here:
</para>
<para>
<ulink url="http://www.osadl.org/projects/downloads/UIO/user/">
http://www.osadl.org/projects/downloads/UIO/user/</ulink>
</para>
<para>
With <varname>lsuio</varname> you can quickly check if your
kernel module is loaded and which attributes it exports.
Have a look at the manpage for details.
</para>
<para>
The source code of <varname>lsuio</varname> can serve as an
example for getting information about an UIO device.
The file <filename>uio_helper.c</filename> contains a lot of
functions you could use in your userspace driver code.
</para>
</sect1>
<sect1 id="mmap_device_memory">
<title>mmap() device memory</title>
<para>
After you made sure you've got the right device with the
memory mappings you need, all you have to do is to call
<function>mmap()</function> to map the device's memory
to userspace.
</para>
<para>
The parameter <varname>offset</varname> of the
<function>mmap()</function> call has a special meaning
for UIO devices: It is used to select which mapping of
your device you want to map. To map the memory of
mapping N, you have to use N times the page size as
your offset:
</para>
<programlisting format="linespecific">
offset = N * getpagesize();
</programlisting>
<para>
N starts from zero, so if you've got only one memory
range to map, set <varname>offset = 0</varname>.
A drawback of this technique is that memory is always
mapped beginning with its start address.
</para>
</sect1>
<sect1 id="wait_for_interrupts">
<title>Waiting for interrupts</title>
<para>
After you successfully mapped your devices memory, you
can access it like an ordinary array. Usually, you will
perform some initialization. After that, your hardware
starts working and will generate an interrupt as soon
as it's finished, has some data available, or needs your
attention because an error occured.
</para>
<para>
<filename>/dev/uioX</filename> is a read-only file. A
<function>read()</function> will always block until an
interrupt occurs. There is only one legal value for the
<varname>count</varname> parameter of
<function>read()</function>, and that is the size of a
signed 32 bit integer (4). Any other value for
<varname>count</varname> causes <function>read()</function>
to fail. The signed 32 bit integer read is the interrupt
count of your device. If the value is one more than the value
you read the last time, everything is OK. If the difference
is greater than one, you missed interrupts.
</para>
<para>
You can also use <function>select()</function> on
<filename>/dev/uioX</filename>.
</para>
</sect1>
</chapter>
<appendix id="app1">
<title>Further information</title>
<itemizedlist>
<listitem><para>
<ulink url="http://www.osadl.org">
OSADL homepage.</ulink>
</para></listitem>
<listitem><para>
<ulink url="http://www.linutronix.de">
Linutronix homepage.</ulink>
</para></listitem>
</itemizedlist>
</appendix>
</book>

1
drivers/Kconfig
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@ -84,4 +84,5 @@ source "drivers/auxdisplay/Kconfig"
source "drivers/kvm/Kconfig"
source "drivers/uio/Kconfig"
endmenu

1
drivers/Makefile
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@ -40,6 +40,7 @@ obj-$(CONFIG_ATA) += ata/
obj-$(CONFIG_FUSION) += message/
obj-$(CONFIG_FIREWIRE) += firewire/
obj-$(CONFIG_IEEE1394) += ieee1394/
obj-$(CONFIG_UIO) += uio/
obj-y += cdrom/
obj-y += auxdisplay/
obj-$(CONFIG_MTD) += mtd/

29
drivers/uio/Kconfig Normal file
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@ -0,0 +1,29 @@
menu "Userspace I/O"
depends on !S390
config UIO
tristate "Userspace I/O drivers"
default n
help
Enable this to allow the userspace driver core code to be
built. This code allows userspace programs easy access to
kernel interrupts and memory locations, allowing some drivers
to be written in userspace. Note that a small kernel driver
is also required for interrupt handling to work properly.
If you don't know what to do here, say N.
config UIO_CIF
tristate "generic Hilscher CIF Card driver"
depends on UIO && PCI
default n
help
Driver for Hilscher CIF DeviceNet and Profibus cards. This
driver requires a userspace component that handles all of the
heavy lifting and can be found at:
http://www.osadl.org/projects/downloads/UIO/user/cif-*
To compile this driver as a module, choose M here: the module
will be called uio_cif.
endmenu

2
drivers/uio/Makefile Normal file
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@ -0,0 +1,2 @@
obj-$(CONFIG_UIO) += uio.o
obj-$(CONFIG_UIO_CIF) += uio_cif.o

701
drivers/uio/uio.c Normal file
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@ -0,0 +1,701 @@
/*
* drivers/uio/uio.c
*
* Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
* Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
* Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
*
* Userspace IO
*
* Base Functions
*
* Licensed under the GPLv2 only.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/mm.h>
#include <linux/idr.h>
#include <linux/string.h>
#include <linux/kobject.h>
#include <linux/uio_driver.h>
#define UIO_MAX_DEVICES 255
struct uio_device {
struct module *owner;
struct device *dev;
int minor;
atomic_t event;
struct fasync_struct *async_queue;
wait_queue_head_t wait;
int vma_count;
struct uio_info *info;
struct kset map_attr_kset;
};
static int uio_major;
static DEFINE_IDR(uio_idr);
static struct file_operations uio_fops;
/* UIO class infrastructure */
static struct uio_class {
struct kref kref;
struct class *class;
} *uio_class;
/*
* attributes
*/
static struct attribute attr_addr = {
.name = "addr",
.mode = S_IRUGO,
};
static struct attribute attr_size = {
.name = "size",
.mode = S_IRUGO,
};
static struct attribute* map_attrs[] = {
&attr_addr, &attr_size, NULL
};
static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
struct uio_mem *mem = container_of(kobj, struct uio_mem, kobj);
if (strncmp(attr->name,"addr",4) == 0)
return sprintf(buf, "0x%lx\n", mem->addr);
if (strncmp(attr->name,"size",4) == 0)
return sprintf(buf, "0x%lx\n", mem->size);
return -ENODEV;
}
static void map_attr_release(struct kobject *kobj)
{
/* TODO ??? */
}
static struct sysfs_ops map_attr_ops = {
.show = map_attr_show,
};
static struct kobj_type map_attr_type = {
.release = map_attr_release,
.sysfs_ops = &map_attr_ops,
.default_attrs = map_attrs,
};
static ssize_t show_name(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct uio_device *idev = dev_get_drvdata(dev);
if (idev)
return sprintf(buf, "%s\n", idev->info->name);
else
return -ENODEV;
}
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
static ssize_t show_version(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct uio_device *idev = dev_get_drvdata(dev);
if (idev)
return sprintf(buf, "%s\n", idev->info->version);
else
return -ENODEV;
}
static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
static ssize_t show_event(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct uio_device *idev = dev_get_drvdata(dev);
if (idev)
return sprintf(buf, "%u\n",
(unsigned int)atomic_read(&idev->event));
else
return -ENODEV;
}
static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
static struct attribute *uio_attrs[] = {
&dev_attr_name.attr,
&dev_attr_version.attr,
&dev_attr_event.attr,
NULL,
};
static struct attribute_group uio_attr_grp = {
.attrs = uio_attrs,
};
/*
* device functions
*/
static int uio_dev_add_attributes(struct uio_device *idev)
{
int ret;
int mi;
int map_found = 0;
struct uio_mem *mem;
ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
if (ret)
goto err_group;
for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
mem = &idev->info->mem[mi];
if (mem->size == 0)
break;
if (!map_found) {
map_found = 1;
kobject_set_name(&idev->map_attr_kset.kobj,"maps");
idev->map_attr_kset.ktype = &map_attr_type;
idev->map_attr_kset.kobj.parent = &idev->dev->kobj;
ret = kset_register(&idev->map_attr_kset);
if (ret)
goto err_remove_group;
}
kobject_init(&mem->kobj);
kobject_set_name(&mem->kobj,"map%d",mi);
mem->kobj.parent = &idev->map_attr_kset.kobj;
mem->kobj.kset = &idev->map_attr_kset;
ret = kobject_add(&mem->kobj);
if (ret)
goto err_remove_maps;
}
return 0;
err_remove_maps:
for (mi--; mi>=0; mi--) {
mem = &idev->info->mem[mi];
kobject_unregister(&mem->kobj);
}
kset_unregister(&idev->map_attr_kset); /* Needed ? */
err_remove_group:
sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
err_group:
dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
return ret;
}
static void uio_dev_del_attributes(struct uio_device *idev)
{
int mi;
struct uio_mem *mem;
for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
mem = &idev->info->mem[mi];
if (mem->size == 0)
break;
kobject_unregister(&mem->kobj);
}
kset_unregister(&idev->map_attr_kset);
sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
}
static int uio_get_minor(struct uio_device *idev)
{
static DEFINE_MUTEX(minor_lock);
int retval = -ENOMEM;
int id;
mutex_lock(&minor_lock);
if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
goto exit;
retval = idr_get_new(&uio_idr, idev, &id);
if (retval < 0) {
if (retval == -EAGAIN)
retval = -ENOMEM;
goto exit;
}
idev->minor = id & MAX_ID_MASK;
exit:
mutex_unlock(&minor_lock);
return retval;
}
static void uio_free_minor(struct uio_device *idev)
{
idr_remove(&uio_idr, idev->minor);
}
/**
* uio_event_notify - trigger an interrupt event
* @info: UIO device capabilities
*/
void uio_event_notify(struct uio_info *info)
{
struct uio_device *idev = info->uio_dev;
atomic_inc(&idev->event);
wake_up_interruptible(&idev->wait);
kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
}
EXPORT_SYMBOL_GPL(uio_event_notify);
/**
* uio_interrupt - hardware interrupt handler
* @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
* @dev_id: Pointer to the devices uio_device structure
*/
static irqreturn_t uio_interrupt(int irq, void *dev_id)
{
struct uio_device *idev = (struct uio_device *)dev_id;
irqreturn_t ret = idev->info->handler(irq, idev->info);
if (ret == IRQ_HANDLED)
uio_event_notify(idev->info);
return ret;
}
struct uio_listener {
struct uio_device *dev;
s32 event_count;
};
static int uio_open(struct inode *inode, struct file *filep)
{
struct uio_device *idev;
struct uio_listener *listener;
int ret = 0;
idev = idr_find(&uio_idr, iminor(inode));
if (!idev)
return -ENODEV;
listener = kmalloc(sizeof(*listener), GFP_KERNEL);
if (!listener)
return -ENOMEM;
listener->dev = idev;
listener->event_count = atomic_read(&idev->event);
filep->private_data = listener;
if (idev->info->open) {
if (!try_module_get(idev->owner))
return -ENODEV;
ret = idev->info->open(idev->info, inode);
module_put(idev->owner);
}
if (ret)
kfree(listener);
return ret;
}
static int uio_fasync(int fd, struct file *filep, int on)
{
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
return fasync_helper(fd, filep, on, &idev->async_queue);
}
static int uio_release(struct inode *inode, struct file *filep)
{
int ret = 0;
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
if (idev->info->release) {
if (!try_module_get(idev->owner))
return -ENODEV;
ret = idev->info->release(idev->info, inode);
module_put(idev->owner);
}
if (filep->f_flags & FASYNC)
ret = uio_fasync(-1, filep, 0);
kfree(listener);
return ret;
}
static unsigned int uio_poll(struct file *filep, poll_table *wait)
{
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
if (idev->info->irq == UIO_IRQ_NONE)
return -EIO;
poll_wait(filep, &idev->wait, wait);
if (listener->event_count != atomic_read(&idev->event))
return POLLIN | POLLRDNORM;
return 0;
}
static ssize_t uio_read(struct file *filep, char __user *buf,
size_t count, loff_t *ppos)
{
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
DECLARE_WAITQUEUE(wait, current);
ssize_t retval;
s32 event_count;
if (idev->info->irq == UIO_IRQ_NONE)
return -EIO;
if (count != sizeof(s32))
return -EINVAL;
add_wait_queue(&idev->wait, &wait);
do {
set_current_state(TASK_INTERRUPTIBLE);
event_count = atomic_read(&idev->event);
if (event_count != listener->event_count) {
if (copy_to_user(buf, &event_count, count))
retval = -EFAULT;
else {
listener->event_count = event_count;
retval = count;
}
break;
}
if (filep->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
schedule();
} while (1);
__set_current_state(TASK_RUNNING);
remove_wait_queue(&idev->wait, &wait);
return retval;
}
static int uio_find_mem_index(struct vm_area_struct *vma)
{
int mi;
struct uio_device *idev = vma->vm_private_data;
for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
if (idev->info->mem[mi].size == 0)
return -1;
if (vma->vm_pgoff == mi)
return mi;
}
return -1;
}
static void uio_vma_open(struct vm_area_struct *vma)
{
struct uio_device *idev = vma->vm_private_data;
idev->vma_count++;
}
static void uio_vma_close(struct vm_area_struct *vma)
{
struct uio_device *idev = vma->vm_private_data;
idev->vma_count--;
}
static struct page *uio_vma_nopage(struct vm_area_struct *vma,
unsigned long address, int *type)
{
struct uio_device *idev = vma->vm_private_data;
struct page* page = NOPAGE_SIGBUS;
int mi = uio_find_mem_index(vma);
if (mi < 0)
return page;
if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
page = virt_to_page(idev->info->mem[mi].addr);
else
page = vmalloc_to_page((void*)idev->info->mem[mi].addr);
get_page(page);
if (type)
*type = VM_FAULT_MINOR;
return page;
}
static struct vm_operations_struct uio_vm_ops = {
.open = uio_vma_open,
.close = uio_vma_close,
.nopage = uio_vma_nopage,
};
static int uio_mmap_physical(struct vm_area_struct *vma)
{
struct uio_device *idev = vma->vm_private_data;
int mi = uio_find_mem_index(vma);
if (mi < 0)
return -EINVAL;
vma->vm_flags |= VM_IO | VM_RESERVED;
return remap_pfn_range(vma,
vma->vm_start,
idev->info->mem[mi].addr >> PAGE_SHIFT,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}
static int uio_mmap_logical(struct vm_area_struct *vma)
{
vma->vm_flags |= VM_RESERVED;
vma->vm_ops = &uio_vm_ops;
uio_vma_open(vma);
return 0;
}
static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
{
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
int mi;
unsigned long requested_pages, actual_pages;
int ret = 0;
if (vma->vm_end < vma->vm_start)
return -EINVAL;
vma->vm_private_data = idev;
mi = uio_find_mem_index(vma);
if (mi < 0)
return -EINVAL;
requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
if (requested_pages > actual_pages)
return -EINVAL;
if (idev->info->mmap) {
if (!try_module_get(idev->owner))
return -ENODEV;
ret = idev->info->mmap(idev->info, vma);
module_put(idev->owner);
return ret;
}
switch (idev->info->mem[mi].memtype) {
case UIO_MEM_PHYS:
return uio_mmap_physical(vma);
case UIO_MEM_LOGICAL:
case UIO_MEM_VIRTUAL:
return uio_mmap_logical(vma);
default:
return -EINVAL;
}
}
static struct file_operations uio_fops = {
.owner = THIS_MODULE,
.open = uio_open,
.release = uio_release,
.read = uio_read,
.mmap = uio_mmap,
.poll = uio_poll,
.fasync = uio_fasync,
};
static int uio_major_init(void)
{
uio_major = register_chrdev(0, "uio", &uio_fops);
if (uio_major < 0)
return uio_major;
return 0;
}
static void uio_major_cleanup(void)
{
unregister_chrdev(uio_major, "uio");
}
static int init_uio_class(void)
{
int ret = 0;
if (uio_class != NULL) {
kref_get(&uio_class->kref);
goto exit;
}
/* This is the first time in here, set everything up properly */
ret = uio_major_init();
if (ret)
goto exit;
uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
if (!uio_class) {
ret = -ENOMEM;
goto err_kzalloc;
}
kref_init(&uio_class->kref);
uio_class->class = class_create(THIS_MODULE, "uio");
if (IS_ERR(uio_class->class)) {
ret = IS_ERR(uio_class->class);
printk(KERN_ERR "class_create failed for uio\n");
goto err_class_create;
}
return 0;
err_class_create:
kfree(uio_class);
uio_class = NULL;
err_kzalloc:
uio_major_cleanup();
exit:
return ret;
}
static void release_uio_class(struct kref *kref)
{
/* Ok, we cheat as we know we only have one uio_class */
class_destroy(uio_class->class);
kfree(uio_class);
uio_major_cleanup();
uio_class = NULL;
}
static void uio_class_destroy(void)
{
if (uio_class)
kref_put(&uio_class->kref, release_uio_class);
}
/**
* uio_register_device - register a new userspace IO device
* @owner: module that creates the new device
* @parent: parent device
* @info: UIO device capabilities
*
* returns zero on success or a negative error code.
*/
int __uio_register_device(struct module *owner,
struct device *parent,
struct uio_info *info)
{
struct uio_device *idev;
int ret = 0;
if (!parent || !info || !info->name || !info->version)
return -EINVAL;
info->uio_dev = NULL;
ret = init_uio_class();
if (ret)
return ret;
idev = kzalloc(sizeof(*idev), GFP_KERNEL);
if (!idev) {
ret = -ENOMEM;
goto err_kzalloc;
}
idev->owner = owner;
idev->info = info;
init_waitqueue_head(&idev->wait);
atomic_set(&idev->event, 0);
ret = uio_get_minor(idev);
if (ret)
goto err_get_minor;
idev->dev = device_create(uio_class->class, parent,
MKDEV(uio_major, idev->minor),
"uio%d", idev->minor);
if (IS_ERR(idev->dev)) {
printk(KERN_ERR "UIO: device register failed\n");
ret = PTR_ERR(idev->dev);
goto err_device_create;
}
dev_set_drvdata(idev->dev, idev);
ret = uio_dev_add_attributes(idev);
if (ret)
goto err_uio_dev_add_attributes;
info->uio_dev = idev;
if (idev->info->irq >= 0) {
ret = request_irq(idev->info->irq, uio_interrupt,
idev->info->irq_flags, idev->info->name, idev);
if (ret)
goto err_request_irq;
}
return 0;
err_request_irq:
uio_dev_del_attributes(idev);
err_uio_dev_add_attributes:
device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
err_device_create:
uio_free_minor(idev);
err_get_minor:
kfree(idev);
err_kzalloc:
uio_class_destroy();
return ret;
}
EXPORT_SYMBOL_GPL(__uio_register_device);
/**
* uio_unregister_device - unregister a industrial IO device
* @info: UIO device capabilities
*
*/
void uio_unregister_device(struct uio_info *info)
{
struct uio_device *idev;
if (!info || !info->uio_dev)
return;
idev = info->uio_dev;
uio_free_minor(idev);
if (info->irq >= 0)
free_irq(info->irq, idev);
uio_dev_del_attributes(idev);
dev_set_drvdata(idev->dev, NULL);
device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
kfree(idev);
uio_class_destroy();
return;
}
EXPORT_SYMBOL_GPL(uio_unregister_device);
static int __init uio_init(void)
{
return 0;
}
static void __exit uio_exit(void)
{
}
module_init(uio_init)
module_exit(uio_exit)
MODULE_LICENSE("GPL v2");

156
drivers/uio/uio_cif.c Normal file
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@ -0,0 +1,156 @@
/*
* UIO Hilscher CIF card driver
*
* (C) 2007 Hans J. Koch <hjk@linutronix.de>
* Original code (C) 2005 Benedikt Spranger <b.spranger@linutronix.de>
*
* Licensed under GPL version 2 only.
*
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/uio_driver.h>
#include <asm/io.h>
#ifndef PCI_DEVICE_ID_PLX_9030
#define PCI_DEVICE_ID_PLX_9030 0x9030
#endif
#define PLX9030_INTCSR 0x4C
#define INTSCR_INT1_ENABLE 0x01
#define INTSCR_INT1_STATUS 0x04
#define INT1_ENABLED_AND_ACTIVE (INTSCR_INT1_ENABLE | INTSCR_INT1_STATUS)
#define PCI_SUBVENDOR_ID_PEP 0x1518
#define CIF_SUBDEVICE_PROFIBUS 0x430
#define CIF_SUBDEVICE_DEVICENET 0x432
static irqreturn_t hilscher_handler(int irq, struct uio_info *dev_info)
{
void __iomem *plx_intscr = dev_info->mem[0].internal_addr
+ PLX9030_INTCSR;
if ((ioread8(plx_intscr) & INT1_ENABLED_AND_ACTIVE)
!= INT1_ENABLED_AND_ACTIVE)
return IRQ_NONE;
/* Disable interrupt */
iowrite8(ioread8(plx_intscr) & ~INTSCR_INT1_ENABLE, plx_intscr);
return IRQ_HANDLED;
}
static int __devinit hilscher_pci_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
struct uio_info *info;
info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
if (!info)
return -ENOMEM;
if (pci_enable_device(dev))
goto out_free;
if (pci_request_regions(dev, "hilscher"))
goto out_disable;
info->mem[0].addr = pci_resource_start(dev, 0);
if (!info->mem[0].addr)
goto out_release;
info->mem[0].internal_addr = ioremap(pci_resource_start(dev, 0),
pci_resource_len(dev, 0));
if (!info->mem[0].internal_addr)
goto out_release;
info->mem[0].size = pci_resource_len(dev, 0);
info->mem[0].memtype = UIO_MEM_PHYS;
info->mem[1].addr = pci_resource_start(dev, 2);
info->mem[1].size = pci_resource_len(dev, 2);
info->mem[1].memtype = UIO_MEM_PHYS;
switch (id->subdevice) {
case CIF_SUBDEVICE_PROFIBUS:
info->name = "CIF_Profibus";
break;
case CIF_SUBDEVICE_DEVICENET:
info->name = "CIF_Devicenet";
break;
default:
info->name = "CIF_???";
}
info->version = "0.0.1";
info->irq = dev->irq;
info->irq_flags = IRQF_DISABLED | IRQF_SHARED;
info->handler = hilscher_handler;
if (uio_register_device(&dev->dev, info))
goto out_unmap;
pci_set_drvdata(dev, info);
return 0;
out_unmap:
iounmap(info->mem[0].internal_addr);
out_release:
pci_release_regions(dev);
out_disable:
pci_disable_device(dev);
out_free:
kfree (info);
return -ENODEV;
}
static void hilscher_pci_remove(struct pci_dev *dev)
{
struct uio_info *info = pci_get_drvdata(dev);
uio_unregister_device(info);
pci_release_regions(dev);
pci_disable_device(dev);
pci_set_drvdata(dev, NULL);
iounmap(info->mem[0].internal_addr);
kfree (info);
}
static struct pci_device_id hilscher_pci_ids[] = {
{
.vendor = PCI_VENDOR_ID_PLX,
.device = PCI_DEVICE_ID_PLX_9030,
.subvendor = PCI_SUBVENDOR_ID_PEP,
.subdevice = CIF_SUBDEVICE_PROFIBUS,
},
{
.vendor = PCI_VENDOR_ID_PLX,
.device = PCI_DEVICE_ID_PLX_9030,
.subvendor = PCI_SUBVENDOR_ID_PEP,
.subdevice = CIF_SUBDEVICE_DEVICENET,
},
{ 0, }
};
static struct pci_driver hilscher_pci_driver = {
.name = "hilscher",
.id_table = hilscher_pci_ids,
.probe = hilscher_pci_probe,
.remove = hilscher_pci_remove,
};
static int __init hilscher_init_module(void)
{
return pci_register_driver(&hilscher_pci_driver);
}
static void __exit hilscher_exit_module(void)
{
pci_unregister_driver(&hilscher_pci_driver);
}
module_init(hilscher_init_module);
module_exit(hilscher_exit_module);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Hans J. Koch, Benedikt Spranger");

91
include/linux/uio_driver.h Normal file
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@ -0,0 +1,91 @@
/*
* include/linux/uio_driver.h
*
* Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
* Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
* Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
*
* Userspace IO driver.
*
* Licensed under the GPLv2 only.
*/
#ifndef _UIO_DRIVER_H_
#define _UIO_DRIVER_H_
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
/**
* struct uio_mem - description of a UIO memory region
* @kobj: kobject for this mapping
* @addr: address of the device's memory
* @size: size of IO
* @memtype: type of memory addr points to
* @internal_addr: ioremap-ped version of addr, for driver internal use
*/
struct uio_mem {
struct kobject kobj;
unsigned long addr;
unsigned long size;
int memtype;
void __iomem *internal_addr;
};
#define MAX_UIO_MAPS 5
struct uio_device;
/**
* struct uio_info - UIO device capabilities
* @uio_dev: the UIO device this info belongs to
* @name: device name
* @version: device driver version
* @mem: list of mappable memory regions, size==0 for end of list
* @irq: interrupt number or UIO_IRQ_CUSTOM
* @irq_flags: flags for request_irq()
* @priv: optional private data
* @handler: the device's irq handler
* @mmap: mmap operation for this uio device
* @open: open operation for this uio device
* @release: release operation for this uio device
*/
struct uio_info {
struct uio_device *uio_dev;
char *name;
char *version;
struct uio_mem mem[MAX_UIO_MAPS];
long irq;
unsigned long irq_flags;
void *priv;
irqreturn_t (*handler)(int irq, struct uio_info *dev_info);
int (*mmap)(struct uio_info *info, struct vm_area_struct *vma);
int (*open)(struct uio_info *info, struct inode *inode);
int (*release)(struct uio_info *info, struct inode *inode);
};
extern int __must_check
__uio_register_device(struct module *owner,
struct device *parent,
struct uio_info *info);
static inline int __must_check
uio_register_device(struct device *parent, struct uio_info *info)
{
return __uio_register_device(THIS_MODULE, parent, info);
}
extern void uio_unregister_device(struct uio_info *info);
extern void uio_event_notify(struct uio_info *info);
/* defines for uio_device->irq */
#define UIO_IRQ_CUSTOM -1
#define UIO_IRQ_NONE -2
/* defines for uio_device->memtype */
#define UIO_MEM_NONE 0
#define UIO_MEM_PHYS 1
#define UIO_MEM_LOGICAL 2
#define UIO_MEM_VIRTUAL 3
#endif /* _LINUX_UIO_DRIVER_H_ */