ARM: at91: Document new TCB bindings

The current binding for the TCB is not flexible enough for some use cases
and prevents proper utilization of all the channels.

Acked-by: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Alexandre Belloni 2016-06-08 15:16:49 +02:00
parent ed4ced0c00
commit 296cc300bd
2 changed files with 56 additions and 32 deletions

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@ -90,38 +90,6 @@ System Timer (ST) required properties:
Its subnodes can be:
- watchdog: compatible should be "atmel,at91rm9200-wdt"
TC/TCLIB Timer required properties:
- compatible: Should be "atmel,<chip>-tcb".
<chip> can be "at91rm9200" or "at91sam9x5"
- reg: Should contain registers location and length
- interrupts: Should contain all interrupts for the TC block
Note that you can specify several interrupt cells if the TC
block has one interrupt per channel.
- clock-names: tuple listing input clock names.
Required elements: "t0_clk", "slow_clk"
Optional elements: "t1_clk", "t2_clk"
- clocks: phandles to input clocks.
Examples:
One interrupt per TC block:
tcb0: timer@fff7c000 {
compatible = "atmel,at91rm9200-tcb";
reg = <0xfff7c000 0x100>;
interrupts = <18 4>;
clocks = <&tcb0_clk>;
clock-names = "t0_clk";
};
One interrupt per TC channel in a TC block:
tcb1: timer@fffdc000 {
compatible = "atmel,at91rm9200-tcb";
reg = <0xfffdc000 0x100>;
interrupts = <26 4 27 4 28 4>;
clocks = <&tcb1_clk>;
clock-names = "t0_clk";
};
RSTC Reset Controller required properties:
- compatible: Should be "atmel,<chip>-rstc".
<chip> can be "at91sam9260" or "at91sam9g45" or "sama5d3"

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@ -0,0 +1,56 @@
* Device tree bindings for Atmel Timer Counter Blocks
- compatible: Should be "atmel,<chip>-tcb", "simple-mfd", "syscon".
<chip> can be "at91rm9200" or "at91sam9x5"
- reg: Should contain registers location and length
- #address-cells: has to be 1
- #size-cells: has to be 0
- interrupts: Should contain all interrupts for the TC block
Note that you can specify several interrupt cells if the TC
block has one interrupt per channel.
- clock-names: tuple listing input clock names.
Required elements: "t0_clk", "slow_clk"
Optional elements: "t1_clk", "t2_clk"
- clocks: phandles to input clocks.
The TCB can expose multiple subdevices:
* a timer
- compatible: Should be "atmel,tcb-timer"
- reg: Should contain the TCB channels to be used. If the
counter width is 16 bits (at91rm9200-tcb), two consecutive
channels are needed. Else, only one channel will be used.
Examples:
One interrupt per TC block:
tcb0: timer@fff7c000 {
compatible = "atmel,at91rm9200-tcb", "simple-mfd", "syscon";
#address-cells = <1>;
#size-cells = <0>;
reg = <0xfff7c000 0x100>;
interrupts = <18 4>;
clocks = <&tcb0_clk>, <&clk32k>;
clock-names = "t0_clk", "slow_clk";
timer@0 {
compatible = "atmel,tcb-timer";
reg = <0>, <1>;
};
timer@2 {
compatible = "atmel,tcb-timer";
reg = <2>;
};
};
One interrupt per TC channel in a TC block:
tcb1: timer@fffdc000 {
compatible = "atmel,at91rm9200-tcb", "simple-mfd", "syscon";
#address-cells = <1>;
#size-cells = <0>;
reg = <0xfffdc000 0x100>;
interrupts = <26 4>, <27 4>, <28 4>;
clocks = <&tcb1_clk>, <&clk32k>;
clock-names = "t0_clk", "slow_clk";
};