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https://github.com/brain-hackers/u-boot-brain
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038b13ee81
This patch adds a generic reset driver. It is designed to be useful when one has a register in a regmap which contains bits that reset other devices. I thought this seemed like a very generic use, so here is a generic driver. The overall structure has been modeled on the syscon-reboot driver. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
37 lines
1.1 KiB
Plaintext
37 lines
1.1 KiB
Plaintext
Generic SYSCON mapped register reset driver
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This is a generic reset driver using syscon to map the reset register.
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The reset is generally performed with a write to the reset register
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defined by the register map pointed by syscon reference plus the offset and
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shifted by the reset specifier/
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To assert a reset on some device, the equivalent of the following operation is
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performed, where reset_id is the reset specifier from the device's resets
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property.
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if (BIT(reset_id) & mask)
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regmap[offset][reset_id] = assert-high;
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Required properties:
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- compatible: should contain "syscon-reset"
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- #reset-cells: must be 1
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- regmap: this is phandle to the register map node
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- offset: offset in the register map for the reboot register (in bytes)
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Optional properties:
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- mask: accept only the reset specifiers defined by the mask (32 bit)
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- assert-high: Bit to write when asserting a reset. Defaults to 1.
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Default will be little endian mode, 32 bit access only.
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Example:
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reset-controller {
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compatible = "syscon-reset";
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#reset-cells = <1>;
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regmap = <&sysctl>;
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offset = <0x20>;
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mask = <0x27FFFFFF>;
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assert-high = <0>;
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};
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