65 lines
2.3 KiB
YAML
65 lines
2.3 KiB
YAML
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# Copyright 2023 NXP
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# SPDX-License-Identifier: Apache-2.0
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description: |
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FS26 System Basis Chip (SBC) watchdog driver.
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The FS26 features multiple voltage regulators to supply the microcontroller,
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peripheral ICs and communication interfaces. The FS26 also offers various
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functionalities for system control and monitoring, including a configurable
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watchdog counter to ensure the microcontroller is able to communicate with the
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FS26, which can react to any failure condition and place the system in a safe
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state. This driver covers only the watchdog functionality of FS26. The rest
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of the functionalities are not implemented.
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The FS26 uses a 32-bit SPI interface. The MCU is the primary driving MOSI and
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FS26 is the secondary driving MISO. Therefore the FS26 devicetree node must be
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in a SPI bus. For example, if FS26 is connected to spi3 bus, on Chip Select 0:
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&spi3 {
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// here there should be spi3 properties as needed
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status = "okay";
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fs26_wdt: watchdog@0 {
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compatible = "nxp,fs26-wdog";
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reg = <0>;
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spi-max-frequency = <DT_FREQ_M(5)>;
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type = "challenger";
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int-gpios = <&gpioa_h 3 GPIO_ACTIVE_LOW>;
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status = "okay";
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};
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};
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When an FS26 internal interrupt occurs, the INTB pin generates a pulse to
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inform the microcontroller. The driver masks all interrupt sources except for
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bad watchdog refresh (BAD_WD_M). The GPIO pin where the interrupt signal is
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received must be configured from devicetree. In the example above, this is
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indicated through int-gpios property. It is also required to configure the
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external interrupt controller to receive interrupts on this pin.
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compatible: "nxp,fs26-wdog"
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include: spi-device.yaml
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properties:
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type:
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required: true
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type: string
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enum:
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- simple
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- challenger
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description: |
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Watchdog type enabled on this device.
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The Challenger watchdog monitoring feature is enabled for ASIL D devices.
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This mode is based on a question/answer process with the microcontroller.
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The Simple watchdog monitoring feature is enabled for ASIL B devices. This
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mode uses a unique seed.
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int-gpios:
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type: phandle-array
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required: true
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description: |
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GPIO to use to receive external interrupts from INTB signal.
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