diff options
| -rw-r--r-- | Documentation/DocBook/kernel-api.tmpl | 4 | ||||
| -rw-r--r-- | Documentation/DocBook/uio-howto.tmpl | 611 | ||||
| -rw-r--r-- | drivers/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/Makefile | 1 | ||||
| -rw-r--r-- | drivers/uio/Kconfig | 29 | ||||
| -rw-r--r-- | drivers/uio/Makefile | 2 | ||||
| -rw-r--r-- | drivers/uio/uio.c | 701 | ||||
| -rw-r--r-- | drivers/uio/uio_cif.c | 156 | ||||
| -rw-r--r-- | include/linux/uio_driver.h | 91 |
9 files changed, 1596 insertions, 0 deletions
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index fd2ef4d29b6d..a0af560ed740 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -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"> diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl new file mode 100644 index 000000000000..e3bb29a8d8dd --- /dev/null +++ b/Documentation/DocBook/uio-howto.tmpl @@ -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> diff --git a/drivers/Kconfig b/drivers/Kconfig index 7916f4b86d23..ae01d86070bb 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -84,4 +84,5 @@ source "drivers/auxdisplay/Kconfig" source "drivers/kvm/Kconfig" +source "drivers/uio/Kconfig" endmenu diff --git a/drivers/Makefile b/drivers/Makefile index 6d9d7fab77f5..c34c8efff609 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -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/ diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig new file mode 100644 index 000000000000..b778ed71f636 --- /dev/null +++ b/drivers/uio/Kconfig @@ -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 diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile new file mode 100644 index 000000000000..7fecfb459da5 --- /dev/null +++ b/drivers/uio/Makefile @@ -0,0 +1,2 @@ +obj-$(CONFIG_UIO) += uio.o +obj-$(CONFIG_UIO_CIF) += uio_cif.o diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c new file mode 100644 index 000000000000..865f32b63b5c --- /dev/null +++ b/drivers/uio/uio.c @@ -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"); diff --git a/drivers/uio/uio_cif.c b/drivers/uio/uio_cif.c new file mode 100644 index 000000000000..838bae460831 --- /dev/null +++ b/drivers/uio/uio_cif.c @@ -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"); diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h new file mode 100644 index 000000000000..44c28e94df50 --- /dev/null +++ b/include/linux/uio_driver.h @@ -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_ */ |