Documentation: devicetree: Update Exynos MCT bindings description

This patch updates description of device tree bindings for Exynos MCT
(multicore timers). Namely:
 - added note about simplified specification of local timer interrupts,
   when using single per-processor interrupt for all local timers,
 - changed first example that was incorrectly suggesting that global
   timer interrupts are optional,
 - simplified example interrupt map,
 - added example showing simplified local timer interrupt specification.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This commit is contained in:
Tomasz Figa 2013-12-19 03:17:31 +09:00 committed by Kukjin Kim
parent 022cf308de
commit 5983255659
1 changed files with 37 additions and 17 deletions

View File

@ -31,38 +31,58 @@ Required properties:
7: ..
i: Local Timer Interrupt n
Example 1: In this example, the system uses only the first global timer
interrupt generated by MCT and the remaining three global timer
interrupts are unused. Two local timer interrupts have been
specified.
For MCT block that uses a per-processor interrupt for local timers, such
as ones compatible with "samsung,exynos4412-mct", only one local timer
interrupt might be specified, meaning that all local timers use the same
per processor interrupt.
Example 1: In this example, the IP contains two local timers, using separate
interrupts, so two local timer interrupts have been specified,
in addition to four global timer interrupts.
mct@10050000 {
compatible = "samsung,exynos4210-mct";
reg = <0x10050000 0x800>;
interrupts = <0 57 0>, <0 0 0>, <0 0 0>, <0 0 0>,
interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
<0 42 0>, <0 48 0>;
};
Example 2: In this example, the MCT global and local timer interrupts are
connected to two separate interrupt controllers. Hence, an
interrupt-map is created to map the interrupts to the respective
interrupt controllers.
Example 2: In this example, the timer interrupts are connected to two separate
interrupt controllers. Hence, an interrupt-map is created to map
the interrupts to the respective interrupt controllers.
mct@101C0000 {
compatible = "samsung,exynos4210-mct";
reg = <0x101C0000 0x800>;
interrupt-controller;
#interrups-cells = <2>;
interrupt-parent = <&mct_map>;
interrupts = <0 0>, <1 0>, <2 0>, <3 0>,
<4 0>, <5 0>;
interrupts = <0>, <1>, <2>, <3>, <4>, <5>;
mct_map: mct-map {
#interrupt-cells = <2>;
#interrupt-cells = <1>;
#address-cells = <0>;
#size-cells = <0>;
interrupt-map = <0x0 0 &combiner 23 3>,
<0x4 0 &gic 0 120 0>,
<0x5 0 &gic 0 121 0>;
interrupt-map = <0 &gic 0 57 0>,
<1 &gic 0 69 0>,
<2 &combiner 12 6>,
<3 &combiner 12 7>,
<4 &gic 0 42 0>,
<5 &gic 0 48 0>;
};
};
Example 3: In this example, the IP contains four local timers, but using
a per-processor interrupt to handle them. Either all the local
timer interrupts can be specified, with the same interrupt specifier
value or just the first one.
mct@10050000 {
compatible = "samsung,exynos4412-mct";
reg = <0x10050000 0x800>;
/* Both ways are possible in this case. Either: */
interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
<0 42 0>;
/* or: */
interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
<0 42 0>, <0 42 0>, <0 42 0>, <0 42 0>;
};