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1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)2%YAML 1.23---4$id: http://devicetree.org/schemas/watchdog/ti,rti-wdt.yaml#5$schema: http://devicetree.org/meta-schemas/core.yaml#6 7title: Texas Instruments K3 SoC Watchdog Timer8 9maintainers:10 - Tero Kristo <t-kristo@ti.com>11 12description:13 The TI K3 SoC watchdog timer is implemented via the RTI (Real Time14 Interrupt) IP module. This timer adds a support for windowed watchdog15 mode, which will signal an error if it is pinged outside the watchdog16 time window, meaning either too early or too late. The error signal17 generated can be routed to either interrupt a safety controller or18 to directly reset the SoC.19 20allOf:21 - $ref: watchdog.yaml#22 23properties:24 compatible:25 enum:26 - ti,j7-rti-wdt27 28 reg:29 maxItems: 130 31 clocks:32 maxItems: 133 34 power-domains:35 maxItems: 136 37 memory-region:38 maxItems: 139 description:40 Contains the watchdog reserved memory. It is optional.41 In the reserved memory, the specified values, which are42 PON_REASON_SOF_NUM(0xBBBBCCCC), PON_REASON_MAGIC_NUM(0xDDDDDDDD),43 and PON_REASON_EOF_NUM(0xCCCCBBBB), are pre-stored at the first44 3 * 4 bytes to tell that last boot was caused by watchdog reset.45 Once the PON reason is captured by driver(rti_wdt.c), the driver46 is supposed to wipe the whole memory region. Surely, if this47 property is set, at least 12 bytes reserved memory starting from48 specific memory address(0xa220000) should be set. More please49 refer to example.50 51required:52 - compatible53 - reg54 - clocks55 - power-domains56 57unevaluatedProperties: false58 59examples:60 - |61 /*62 * RTI WDT in main domain on J721e SoC. Assigned clocks are used to63 * select the source clock for the watchdog, forcing it to tick with64 * a 32kHz clock in this case. Add a reserved memory(optional) to keep65 * the watchdog reset cause persistent, which was be written in 12 bytes66 * starting from 0xa2200000 by RTI Watchdog Firmware, then make it67 * possible to get watchdog reset cause in driver.68 *69 * Reserved memory should be defined as follows:70 * reserved-memory {71 * wdt_reset_memory_region: wdt-memory@a2200000 {72 * reg = <0x00 0xa2200000 0x00 0x1000>;73 * no-map;74 * };75 * }76 */77 #include <dt-bindings/soc/ti,sci_pm_domain.h>78 79 watchdog@2200000 {80 compatible = "ti,j7-rti-wdt";81 reg = <0x2200000 0x100>;82 clocks = <&k3_clks 252 1>;83 power-domains = <&k3_pds 252 TI_SCI_PD_EXCLUSIVE>;84 assigned-clocks = <&k3_clks 252 1>;85 assigned-clock-parents = <&k3_clks 252 5>;86 memory-region = <&wdt_reset_memory_region>;87 };88