aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-16 11:27:10 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-16 11:27:10 -0400
commitab86e5765d41a5eb4239a1c04d613db87bea5ed8 (patch)
treea41224d4874c2f90e0b423786f00bedf6f3e8bfa /Documentation
parent7ea61767e41e2baedd6a968d13f56026522e1207 (diff)
parent2b2af54a5bb6f7e80ccf78f20084b93c398c3a8b (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev debugfs: Modify default debugfs directory for debugging pktcdvd. debugfs: Modified default dir of debugfs for debugging UHCI. debugfs: Change debugfs directory of IWMC3200 debugfs: Change debuhgfs directory of trace-events-sample.h debugfs: Fix mount directory of debugfs by default in events.txt hpilo: add poll f_op hpilo: add interrupt handler hpilo: staging for interrupt handling driver core: platform_device_add_data(): use kmemdup() Driver core: Add support for compatibility classes uio: add generic driver for PCI 2.3 devices driver-core: move dma-coherent.c from kernel to driver/base mem_class: fix bug mem_class: use minor as index instead of searching the array driver model: constify attribute groups UIO: remove 'default n' from Kconfig Driver core: Add accessor for device platform data Driver core: move dev_get/set_drvdata to drivers/base/dd.c Driver core: add new device to bus's list before probing
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DocBook/uio-howto.tmpl163
-rw-r--r--Documentation/trace/events.txt24
2 files changed, 175 insertions, 12 deletions
diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
index 8f6e3b2403c7..4d4ce0e61e42 100644
--- a/Documentation/DocBook/uio-howto.tmpl
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -25,6 +25,10 @@
25 <year>2006-2008</year> 25 <year>2006-2008</year>
26 <holder>Hans-Jürgen Koch.</holder> 26 <holder>Hans-Jürgen Koch.</holder>
27</copyright> 27</copyright>
28<copyright>
29 <year>2009</year>
30 <holder>Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)</holder>
31</copyright>
28 32
29<legalnotice> 33<legalnotice>
30<para> 34<para>
@@ -42,6 +46,13 @@ GPL version 2.
42 46
43<revhistory> 47<revhistory>
44 <revision> 48 <revision>
49 <revnumber>0.9</revnumber>
50 <date>2009-07-16</date>
51 <authorinitials>mst</authorinitials>
52 <revremark>Added generic pci driver
53 </revremark>
54 </revision>
55 <revision>
45 <revnumber>0.8</revnumber> 56 <revnumber>0.8</revnumber>
46 <date>2008-12-24</date> 57 <date>2008-12-24</date>
47 <authorinitials>hjk</authorinitials> 58 <authorinitials>hjk</authorinitials>
@@ -809,6 +820,158 @@ framework to set up sysfs files for this region. Simply leave it alone.
809 820
810</chapter> 821</chapter>
811 822
823<chapter id="uio_pci_generic" xreflabel="Using Generic driver for PCI cards">
824<?dbhtml filename="uio_pci_generic.html"?>
825<title>Generic PCI UIO driver</title>
826 <para>
827 The generic driver is a kernel module named uio_pci_generic.
828 It can work with any device compliant to PCI 2.3 (circa 2002) and
829 any compliant PCI Express device. Using this, you only need to
830 write the userspace driver, removing the need to write
831 a hardware-specific kernel module.
832 </para>
833
834<sect1 id="uio_pci_generic_binding">
835<title>Making the driver recognize the device</title>
836 <para>
837Since the driver does not declare any device ids, it will not get loaded
838automatically and will not automatically bind to any devices, you must load it
839and allocate id to the driver yourself. For example:
840 <programlisting>
841 modprobe uio_pci_generic
842 echo &quot;8086 10f5&quot; &gt; /sys/bus/pci/drivers/uio_pci_generic/new_id
843 </programlisting>
844 </para>
845 <para>
846If there already is a hardware specific kernel driver for your device, the
847generic driver still won't bind to it, in this case if you want to use the
848generic driver (why would you?) you'll have to manually unbind the hardware
849specific driver and bind the generic driver, like this:
850 <programlisting>
851 echo -n 0000:00:19.0 &gt; /sys/bus/pci/drivers/e1000e/unbind
852 echo -n 0000:00:19.0 &gt; /sys/bus/pci/drivers/uio_pci_generic/bind
853 </programlisting>
854 </para>
855 <para>
856You can verify that the device has been bound to the driver
857by looking for it in sysfs, for example like the following:
858 <programlisting>
859 ls -l /sys/bus/pci/devices/0000:00:19.0/driver
860 </programlisting>
861Which if successful should print
862 <programlisting>
863 .../0000:00:19.0/driver -&gt; ../../../bus/pci/drivers/uio_pci_generic
864 </programlisting>
865Note that the generic driver will not bind to old PCI 2.2 devices.
866If binding the device failed, run the following command:
867 <programlisting>
868 dmesg
869 </programlisting>
870and look in the output for failure reasons
871 </para>
872</sect1>
873
874<sect1 id="uio_pci_generic_internals">
875<title>Things to know about uio_pci_generic</title>
876 <para>
877Interrupts are handled using the Interrupt Disable bit in the PCI command
878register and Interrupt Status bit in the PCI status register. All devices
879compliant to PCI 2.3 (circa 2002) and all compliant PCI Express devices should
880support these bits. uio_pci_generic detects this support, and won't bind to
881devices which do not support the Interrupt Disable Bit in the command register.
882 </para>
883 <para>
884On each interrupt, uio_pci_generic sets the Interrupt Disable bit.
885This prevents the device from generating further interrupts
886until the bit is cleared. The userspace driver should clear this
887bit before blocking and waiting for more interrupts.
888 </para>
889</sect1>
890<sect1 id="uio_pci_generic_userspace">
891<title>Writing userspace driver using uio_pci_generic</title>
892 <para>
893Userspace driver can use pci sysfs interface, or the
894libpci libray that wraps it, to talk to the device and to
895re-enable interrupts by writing to the command register.
896 </para>
897</sect1>
898<sect1 id="uio_pci_generic_example">
899<title>Example code using uio_pci_generic</title>
900 <para>
901Here is some sample userspace driver code using uio_pci_generic:
902<programlisting>
903#include &lt;stdlib.h&gt;
904#include &lt;stdio.h&gt;
905#include &lt;unistd.h&gt;
906#include &lt;sys/types.h&gt;
907#include &lt;sys/stat.h&gt;
908#include &lt;fcntl.h&gt;
909#include &lt;errno.h&gt;
910
911int main()
912{
913 int uiofd;
914 int configfd;
915 int err;
916 int i;
917 unsigned icount;
918 unsigned char command_high;
919
920 uiofd = open(&quot;/dev/uio0&quot;, O_RDONLY);
921 if (uiofd &lt; 0) {
922 perror(&quot;uio open:&quot;);
923 return errno;
924 }
925 configfd = open(&quot;/sys/class/uio/uio0/device/config&quot;, O_RDWR);
926 if (uiofd &lt; 0) {
927 perror(&quot;config open:&quot;);
928 return errno;
929 }
930
931 /* Read and cache command value */
932 err = pread(configfd, &amp;command_high, 1, 5);
933 if (err != 1) {
934 perror(&quot;command config read:&quot;);
935 return errno;
936 }
937 command_high &amp;= ~0x4;
938
939 for(i = 0;; ++i) {
940 /* Print out a message, for debugging. */
941 if (i == 0)
942 fprintf(stderr, &quot;Started uio test driver.\n&quot;);
943 else
944 fprintf(stderr, &quot;Interrupts: %d\n&quot;, icount);
945
946 /****************************************/
947 /* Here we got an interrupt from the
948 device. Do something to it. */
949 /****************************************/
950
951 /* Re-enable interrupts. */
952 err = pwrite(configfd, &amp;command_high, 1, 5);
953 if (err != 1) {
954 perror(&quot;config write:&quot;);
955 break;
956 }
957
958 /* Wait for next interrupt. */
959 err = read(uiofd, &amp;icount, 4);
960 if (err != 4) {
961 perror(&quot;uio read:&quot;);
962 break;
963 }
964
965 }
966 return errno;
967}
968
969</programlisting>
970 </para>
971</sect1>
972
973</chapter>
974
812<appendix id="app1"> 975<appendix id="app1">
813<title>Further information</title> 976<title>Further information</title>
814<itemizedlist> 977<itemizedlist>
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index 2bcc8d4dea29..90e8b3383ba2 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -22,12 +22,12 @@ tracing information should be printed.
22--------------------------------- 22---------------------------------
23 23
24The events which are available for tracing can be found in the file 24The events which are available for tracing can be found in the file
25/debug/tracing/available_events. 25/sys/kernel/debug/tracing/available_events.
26 26
27To enable a particular event, such as 'sched_wakeup', simply echo it 27To enable a particular event, such as 'sched_wakeup', simply echo it
28to /debug/tracing/set_event. For example: 28to /sys/kernel/debug/tracing/set_event. For example:
29 29
30 # echo sched_wakeup >> /debug/tracing/set_event 30 # echo sched_wakeup >> /sys/kernel/debug/tracing/set_event
31 31
32[ Note: '>>' is necessary, otherwise it will firstly disable 32[ Note: '>>' is necessary, otherwise it will firstly disable
33 all the events. ] 33 all the events. ]
@@ -35,15 +35,15 @@ to /debug/tracing/set_event. For example:
35To disable an event, echo the event name to the set_event file prefixed 35To disable an event, echo the event name to the set_event file prefixed
36with an exclamation point: 36with an exclamation point:
37 37
38 # echo '!sched_wakeup' >> /debug/tracing/set_event 38 # echo '!sched_wakeup' >> /sys/kernel/debug/tracing/set_event
39 39
40To disable all events, echo an empty line to the set_event file: 40To disable all events, echo an empty line to the set_event file:
41 41
42 # echo > /debug/tracing/set_event 42 # echo > /sys/kernel/debug/tracing/set_event
43 43
44To enable all events, echo '*:*' or '*:' to the set_event file: 44To enable all events, echo '*:*' or '*:' to the set_event file:
45 45
46 # echo *:* > /debug/tracing/set_event 46 # echo *:* > /sys/kernel/debug/tracing/set_event
47 47
48The events are organized into subsystems, such as ext4, irq, sched, 48The events are organized into subsystems, such as ext4, irq, sched,
49etc., and a full event name looks like this: <subsystem>:<event>. The 49etc., and a full event name looks like this: <subsystem>:<event>. The
@@ -52,29 +52,29 @@ file. All of the events in a subsystem can be specified via the syntax
52"<subsystem>:*"; for example, to enable all irq events, you can use the 52"<subsystem>:*"; for example, to enable all irq events, you can use the
53command: 53command:
54 54
55 # echo 'irq:*' > /debug/tracing/set_event 55 # echo 'irq:*' > /sys/kernel/debug/tracing/set_event
56 56
572.2 Via the 'enable' toggle 572.2 Via the 'enable' toggle
58--------------------------- 58---------------------------
59 59
60The events available are also listed in /debug/tracing/events/ hierarchy 60The events available are also listed in /sys/kernel/debug/tracing/events/ hierarchy
61of directories. 61of directories.
62 62
63To enable event 'sched_wakeup': 63To enable event 'sched_wakeup':
64 64
65 # echo 1 > /debug/tracing/events/sched/sched_wakeup/enable 65 # echo 1 > /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable
66 66
67To disable it: 67To disable it:
68 68
69 # echo 0 > /debug/tracing/events/sched/sched_wakeup/enable 69 # echo 0 > /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable
70 70
71To enable all events in sched subsystem: 71To enable all events in sched subsystem:
72 72
73 # echo 1 > /debug/tracing/events/sched/enable 73 # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
74 74
75To eanble all events: 75To eanble all events:
76 76
77 # echo 1 > /debug/tracing/events/enable 77 # echo 1 > /sys/kernel/debug/tracing/events/enable
78 78
79When reading one of these enable files, there are four results: 79When reading one of these enable files, there are four results:
80 80