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authorLinus Torvalds <torvalds@linux-foundation.org>2009-12-22 17:18:13 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-22 17:18:13 -0500
commitdd508ae2dbff0cfc7401eb6e278339fc56bc5033 (patch)
treedaa9f88a4e2e65e86b351ffa2d52dcc07e753c1e /Documentation
parent7801edb0b8b66e83c13623b483bc2e846c007c9d (diff)
parent95cd34b42b43c0ed5a89a764e023189bfe7b1530 (diff)
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (36 commits) powerpc/gc/wii: Remove get_irq_desc() powerpc/gc/wii: hlwd-pic: convert irq_desc.lock to raw_spinlock powerpc/gamecube/wii: Fix off-by-one error in ugecon/usbgecko_udbg powerpc/mpic: Fix problem that affinity is not updated powerpc/mm: Fix stupid bug in subpge protection handling powerpc/iseries: use DECLARE_COMPLETION_ONSTACK for non-constant completion powerpc: Fix MSI support on U4 bridge PCIe slot powerpc: Handle VSX alignment faults correctly in little-endian mode powerpc/mm: Fix typo of cpumask_clear_cpu() powerpc/mm: Fix hash_utils_64.c compile errors with DEBUG enabled. powerpc: Convert BUG() to use unreachable() powerpc/pseries: Make declarations of cpu_hotplug_driver_lock() ANSI compatible. powerpc/pseries: Don't panic when H_PROD fails during cpu-online. powerpc/mm: Fix a WARN_ON() with CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_VM powerpc/defconfigs: Set HZ=100 on pseries and ppc64 defconfigs powerpc/defconfigs: Disable token ring in powerpc defconfigs powerpc/defconfigs: Reduce 64bit vmlinux by making acenic and cramfs modules powerpc/pseries: Select XICS and PCI_MSI PSERIES powerpc/85xx: Wrong variable returned on error powerpc/iseries: Convert to proc_fops ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/powerpc/dts-bindings/fsl/mpic.txt42
1 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/powerpc/dts-bindings/fsl/mpic.txt b/Documentation/powerpc/dts-bindings/fsl/mpic.txt
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1* OpenPIC and its interrupt numbers on Freescale's e500/e600 cores
2
3The OpenPIC specification does not specify which interrupt source has to
4become which interrupt number. This is up to the software implementation
5of the interrupt controller. The only requirement is that every
6interrupt source has to have an unique interrupt number / vector number.
7To accomplish this the current implementation assigns the number zero to
8the first source, the number one to the second source and so on until
9all interrupt sources have their unique number.
10Usually the assigned vector number equals the interrupt number mentioned
11in the documentation for a given core / CPU. This is however not true
12for the e500 cores (MPC85XX CPUs) where the documentation distinguishes
13between internal and external interrupt sources and starts counting at
14zero for both of them.
15
16So what to write for external interrupt source X or internal interrupt
17source Y into the device tree? Here is an example:
18
19The memory map for the interrupt controller in the MPC8544[0] shows,
20that the first interrupt source starts at 0x5_0000 (PIC Register Address
21Map-Interrupt Source Configuration Registers). This source becomes the
22number zero therefore:
23 External interrupt 0 = interrupt number 0
24 External interrupt 1 = interrupt number 1
25 External interrupt 2 = interrupt number 2
26 ...
27Every interrupt number allocates 0x20 bytes register space. So to get
28its number it is sufficient to shift the lower 16bits to right by five.
29So for the external interrupt 10 we have:
30 0x0140 >> 5 = 10
31
32After the external sources, the internal sources follow. The in core I2C
33controller on the MPC8544 for instance has the internal source number
3427. Oo obtain its interrupt number we take the lower 16bits of its memory
35address (0x5_0560) and shift it right:
36 0x0560 >> 5 = 43
37
38Therefore the I2C device node for the MPC8544 CPU has to have the
39interrupt number 43 specified in the device tree.
40
41[0] MPC8544E PowerQUICCTM III, Integrated Host Processor Family Reference Manual
42 MPC8544ERM Rev. 1 10/2007