From a3828519c39aa9c85bae14bad2572d12dc0d1da6 Mon Sep 17 00:00:00 2001 From: "Andrew F. Davis" Date: Mon, 27 Jun 2016 12:12:16 -0500 Subject: Documentation: dt: reset: Add TI syscon reset binding Add TI syscon reset controller binding. This will hook to the reset framework and use syscon/regmap to set reset bits. This allows reset control of individual SoC subsytems and devices with memory-mapped reset registers in a common register memory space. Signed-off-by: Andrew F. Davis Signed-off-by: Suman Anna Acked-by: Rob Herring Signed-off-by: Philipp Zabel --- .../devicetree/bindings/reset/ti-syscon-reset.txt | 91 ++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 Documentation/devicetree/bindings/reset/ti-syscon-reset.txt (limited to 'Documentation/devicetree/bindings/reset/ti-syscon-reset.txt') diff --git a/Documentation/devicetree/bindings/reset/ti-syscon-reset.txt b/Documentation/devicetree/bindings/reset/ti-syscon-reset.txt new file mode 100644 index 000000000000..164c7f34c451 --- /dev/null +++ b/Documentation/devicetree/bindings/reset/ti-syscon-reset.txt @@ -0,0 +1,91 @@ +TI SysCon Reset Controller +======================= + +Almost all SoCs have hardware modules that require reset control in addition +to clock and power control for their functionality. The reset control is +typically provided by means of memory-mapped I/O registers. These registers are +sometimes a part of a larger register space region implementing various +functionalities. This register range is best represented as a syscon node to +allow multiple entities to access their relevant registers in the common +register space. + +A SysCon Reset Controller node defines a device that uses a syscon node +and provides reset management functionality for various hardware modules +present on the SoC. + +SysCon Reset Controller Node +============================ +Each of the reset provider/controller nodes should be a child of a syscon +node and have the following properties. + +Required properties: +-------------------- + - compatible : Should be, + "ti,k2e-pscrst" + "ti,k2l-pscrst" + "ti,k2hk-pscrst" + "ti,syscon-reset" + - #reset-cells : Should be 1. Please see the reset consumer node below + for usage details + - ti,reset-bits : Contains the reset control register information + Should contain 7 cells for each reset exposed to + consumers, defined as: + Cell #1 : offset of the reset assert control + register from the syscon register base + Cell #2 : bit position of the reset in the reset + assert control register + Cell #3 : offset of the reset deassert control + register from the syscon register base + Cell #4 : bit position of the reset in the reset + deassert control register + Cell #5 : offset of the reset status register + from the syscon register base + Cell #6 : bit position of the reset in the + reset status register + Cell #7 : Flags used to control reset behavior, + availible flags defined in the DT include + file + +SysCon Reset Consumer Nodes +=========================== +Each of the reset consumer nodes should have the following properties, +in addition to their own properties. + +Required properties: +-------------------- + - resets : A phandle to the reset controller node and an index number + to a reset specifier as defined above. + +Please also refer to Documentation/devicetree/bindings/reset/reset.txt for +common reset controller usage by consumers. + +Example: +-------- +The following example demonstrates a syscon node, the reset controller node +using the syscon node, and a consumer (a DSP device) on the TI Keystone 2 +Edison SoC. + +/ { + soc { + psc: power-sleep-controller@02350000 { + compatible = "syscon", "simple-mfd"; + reg = <0x02350000 0x1000>; + + pscrst: psc-reset { + compatible = "ti,k2e-pscrst", "ti,syscon-reset"; + #reset-cells = <1>; + + ti,reset-bits = < + 0xa3c 8 0xa3c 8 0x83c 8 (ASSERT_SET|DEASSERT_CLEAR|STATUS_SET) /* 0: pcrst-dsp0 */ + 0xa40 5 0xa44 3 0 0 (ASSERT_SET|DEASSERT_CLEAR|STATUS_NONE) /* 1: pcrst-example */ + >; + }; + }; + + dsp0: dsp0 { + ... + resets = <&pscrst 0>; + ... + }; + }; +}; -- cgit