nxp,fs26-wdog (on spi bus)

Vendor: NXP Semiconductors N.V.

Note

An implementation of a driver matching this compatible is available in drivers/watchdog/wdt_nxp_fs26.c.

Description

FS26 System Basis Chip (SBC) watchdog driver.

The FS26 features multiple voltage regulators to supply the microcontroller,
peripheral ICs and communication interfaces. The FS26 also offers various
functionalities for system control and monitoring, including a configurable
watchdog counter to ensure the microcontroller is able to communicate with the
FS26, which can react to any failure condition and place the system in a safe
state. This driver covers only the watchdog functionality of FS26. The rest
of the functionalities are not implemented.

The FS26 uses a 32-bit SPI interface. The MCU is the primary driving MOSI and
FS26 is the secondary driving MISO. Therefore the FS26 devicetree node must be
in a SPI bus. For example, if FS26 is connected to spi3 bus, on Chip Select 0:

  &spi3 {
    // here there should be spi3 properties as needed
    status = "okay";

    fs26_wdt: watchdog@0 {
      compatible = "nxp,fs26-wdog";
      reg = <0>;
      spi-max-frequency = <DT_FREQ_M(5)>;
      type = "challenger";
      int-gpios = <&gpioa_h 3 GPIO_ACTIVE_LOW>;
      status = "okay";
    };
  };

When an FS26 internal interrupt occurs, the INTB pin generates a pulse to
inform the microcontroller. The driver masks all interrupt sources except for
bad watchdog refresh (BAD_WD_M). The GPIO pin where the interrupt signal is
received must be configured from devicetree. In the example above, this is
indicated through int-gpios property. It is also required to configure the
external interrupt controller to receive interrupts on this pin.

Properties

Node specific properties

Properties not inherited from the base binding file.

Name	Type	Details
type	string	Watchdog type enabled on this device. The Challenger watchdog monitoring feature is enabled for ASIL D devices. This mode is based on a question/answer process with the microcontroller. The Simple watchdog monitoring feature is enabled for ASIL B devices. This mode uses a unique seed. This property is required. Legal values: 'simple', 'challenger'
int-gpios	phandle-array	GPIO to use to receive external interrupts from INTB signal. This property is required.
spi-max-frequency	int	Maximum clock frequency of device's SPI interface in Hz This property is required.
duplex	int	Duplex mode, full or half. By default it's always full duplex thus 0 as this is, by far, the most common mode. Use the macros not the actual enum value, here is the concordance list (see dt-bindings/spi/spi.h) 0 SPI_FULL_DUPLEX 2048 SPI_HALF_DUPLEX Legal values: 0, 2048
frame-format	int	Motorola or TI frame format. By default it's always Motorola's, thus 0 as this is, by far, the most common format. Use the macros not the actual enum value, here is the concordance list (see dt-bindings/spi/spi.h) 0 SPI_FRAME_FORMAT_MOTOROLA 32768 SPI_FRAME_FORMAT_TI Legal values: 0, 32768
spi-cpol	boolean	SPI clock polarity which indicates the clock idle state. If it is used, the clock idle state is logic high; otherwise, low.
spi-cpha	boolean	SPI clock phase that indicates on which edge data is sampled. If it is used, data is sampled on the second edge; otherwise, on the first edge.
spi-hold-cs	boolean	In some cases, it is necessary for the master to manage SPI chip select under software control, so that multiple spi transactions can be performed without releasing it. A typical use case is variable length SPI packets where the first spi transaction reads the length and the second spi transaction reads length bytes.
supply-gpios	phandle-array	GPIO specifier that controls power to the device. This property should be provided when the device has a dedicated switch that controls power to the device. The supply state is entirely the responsibility of the device driver. Contrast with vin-supply.
vin-supply	phandle	Reference to the regulator that controls power to the device. The referenced devicetree node must have a regulator compatible. This property should be provided when device power is supplied by a shared regulator. The supply state is dependent on the request status of all devices fed by the regulator. Contrast with supply-gpios. If both properties are provided then the regulator must be requested before the supply GPIOS is set to an active state, and the supply GPIOS must be set to an inactive state before releasing the regulator.

Deprecated node specific properties

Deprecated properties not inherited from the base binding file.

(None)

Base properties

Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “nxp,fs26-wdog” compatible.

Name	Type	Details
reg	array	register space This property is required. See Important properties for more information.
status	string	indicates the operational status of a device Legal values: 'ok', 'okay', 'disabled', 'reserved', 'fail', 'fail-sss' See Important properties for more information.
compatible	string-array	compatible strings This property is required. See Important properties for more information.
reg-names	string-array	name of each register space
interrupts	array	interrupts for device See Important properties for more information.
interrupts-extended	compound	extended interrupt specifier for device
interrupt-names	string-array	name of each interrupt
interrupt-parent	phandle	phandle to interrupt controller node
label	string	Human readable string describing the device (used as device_get_binding() argument) See Important properties for more information. This property is deprecated.
clocks	phandle-array	Clock gate information
clock-names	string-array	name of each clock
#address-cells	int	number of address cells in reg property
#size-cells	int	number of size cells in reg property
dmas	phandle-array	DMA channels specifiers
dma-names	string-array	Provided names of DMA channel specifiers
io-channels	phandle-array	IO channels specifiers
io-channel-names	string-array	Provided names of IO channel specifiers
mboxes	phandle-array	mailbox / IPM channels specifiers
mbox-names	string-array	Provided names of mailbox / IPM channel specifiers
power-domains	phandle-array	Power domain specifiers
power-domain-names	string-array	Provided names of power domain specifiers
#power-domain-cells	int	Number of cells in power-domains property
zephyr,deferred-init	boolean	Do not initialize device automatically on boot. Device should be manually initialized using device_init().
wakeup-source	boolean	Property to identify that a device can be used as wake up source. When this property is provided a specific flag is set into the device that tells the system that the device is capable of wake up the system. Wake up capable devices are disabled (interruptions will not wake up the system) by default but they can be enabled at runtime if necessary.
zephyr,pm-device-runtime-auto	boolean	Automatically configure the device for runtime power management after the init function runs.
zephyr,disabling-power-states	phandles	List of power states that will disable this device power.