| Message ID | 20220617070847.186876-2-francesco.dolcini@toradex.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | imx: thermal: Allow trip point configuration from DT | expand |
On 17/06/2022 00:08, Francesco Dolcini wrote: > Move `trips` definition to `#/$defs/trips-base` and just reference it > from the trips node. This allows to easily re-use this binding from > another binding file. > > No functional changes expected. If you want to re-use trips, they should be rather moved to separate YAML file... but anyway this should not be done per-driver bindings, but in more general way. Either the problem - using one DTS for different temperature grades - looks generic or is wrong at the core. In the first option, the generic bindings should be fixed. In the second case - using same DTS for different HW is not correct approach and why only thermal should be specific? I can imagine that cooling devices might have different settings, regulator voltages for DVFS could be a bit different... Best regards, Krzysztof
Hello Krzysztof, thanks for your comment, let me try to provide you some additional background to better understand this change. On Fri, Jun 17, 2022 at 06:02:39PM -0700, Krzysztof Kozlowski wrote: > On 17/06/2022 00:08, Francesco Dolcini wrote: > > Move `trips` definition to `#/$defs/trips-base` and just reference it > > from the trips node. This allows to easily re-use this binding from > > another binding file. > > > > No functional changes expected. > > If you want to re-use trips, they should be rather moved to separate > YAML file... Fine, this should not be a big deal to achieve. Let's agree on the rest first, however. > but anyway this should not be done per-driver bindings, but > in more general way. Either the problem - using one DTS for different > temperature grades - looks generic or is wrong at the core. In the first > option, the generic bindings should be fixed. In the second case - using > same DTS for different HW is not correct approach and why only thermal > should be specific? I can imagine that cooling devices might have > different settings, regulator voltages for DVFS could be a bit different... Let me try to explain the problem I am trying to solve here. Currently the imx-thermal driver harcode the critical trip threshold, this trip point is read-only as it is considered a system property that should not be changed and it is set to a value that is less than the actual SoC maximum temperature. NO thermal_of driver used. Because of that there are systems that cannot work on some valid temperature range. We are currently looking at a solution that would be backward compatible with old device tree. I proposed the following: 1- just increase the threshold to the actual max value allowed according to the SoC thermal grade. As easy as - data->temp_critical = data->temp_max - (1000 * 5); + data->temp_critical = data->temp_max; in drivers/thermal/imx_thermal.c https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ It was not considered good enough by Lucas since this is a overall system design question, therefore should be configurable. 2- make the critical trip write-able from userspace/sysfs. Daniel is against this since critical trip point is a system property, not something the user should be allowed to change. 3- kernel parameter: https://lore.kernel.org/all/20220516190001.147919-1-francesco.dolcini@toradex.com/ Initially proposed by Daniel, but Marco did not like the idea. 4- New device tree property, fsl,tempmon-critical-offset, ditched also by Marco 5- The current solution in this patch, with the existing trip points that are hardcoded in the code exposed in the device tree as trips. Ideally one could just implement the imx6/7 thermal sensor reading and just make use of the thermal_of driver, however that would break compatibility with a lot of existing system ... to me this is just a no-go. Adding only one set of thermal trip point in the dts (no thermal-grade specific set) could work in some specific scenario, however it does not work for me since I have the same dts files using different temperature grade SoC. I would need to update this in the firmware before starting Linux. Krzysztof, what do you think? I would not mind to get back to one of the more simpler approach I proposed. Lucas, are you really that against the simple working solution I proposed initially [1]? I feel like I am running in circles ... Francesco
On 20/06/2022 17:48, Francesco Dolcini wrote: > Hello Krzysztof, > thanks for your comment, let me try to provide you some additional > background to better understand this change. > > On Fri, Jun 17, 2022 at 06:02:39PM -0700, Krzysztof Kozlowski wrote: >> On 17/06/2022 00:08, Francesco Dolcini wrote: >>> Move `trips` definition to `#/$defs/trips-base` and just reference it >>> from the trips node. This allows to easily re-use this binding from >>> another binding file. >>> >>> No functional changes expected. >> >> If you want to re-use trips, they should be rather moved to separate >> YAML file... > > Fine, this should not be a big deal to achieve. Let's agree on the rest > first, however. > >> but anyway this should not be done per-driver bindings, but >> in more general way. Either the problem - using one DTS for different >> temperature grades - looks generic or is wrong at the core. In the first >> option, the generic bindings should be fixed. In the second case - using >> same DTS for different HW is not correct approach and why only thermal >> should be specific? I can imagine that cooling devices might have >> different settings, regulator voltages for DVFS could be a bit different... > > Let me try to explain the problem I am trying to solve here. > > Currently the imx-thermal driver harcode the critical trip threshold, > this trip point is read-only as it is considered a system property that > should not be changed and it is set to a value that is less than the > actual SoC maximum temperature. NO thermal_of driver used. > > Because of that there are systems that cannot work on some valid > temperature range. > > We are currently looking at a solution that would be backward compatible > with old device tree. > > I proposed the following: > 1- just increase the threshold to the actual max value allowed according > to the SoC thermal grade. > > As easy as > > - data->temp_critical = data->temp_max - (1000 * 5); > + data->temp_critical = data->temp_max; > > in drivers/thermal/imx_thermal.c > > https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ > > It was not considered good enough by Lucas since this is a overall > system design question, therefore should be configurable. > > 2- make the critical trip write-able from userspace/sysfs. > > Daniel is against this since critical trip point is a system > property, not something the user should be allowed to change. > > 3- kernel parameter: https://lore.kernel.org/all/20220516190001.147919-1-francesco.dolcini@toradex.com/ > > Initially proposed by Daniel, but Marco did not like the idea. > > 4- New device tree property, fsl,tempmon-critical-offset, ditched also > by Marco > > 5- The current solution in this patch, with the existing trip points > that are hardcoded in the code exposed in the device tree as trips. Thanks for the explanation, I see the problem. > > Ideally one could just implement the imx6/7 thermal sensor reading and > just make use of the thermal_of driver, however that would break > compatibility with a lot of existing system ... to me this is just a > no-go. This I did not understand... What is not implemented in thermal sensor which would solve the issue? And why it cannot be implemented in backwards compatible way? Your change is also not backwards friendly, which means existing boards (old DTS) will not receive the update. > Adding only one set of thermal trip point in the dts (no thermal-grade > specific set) could work in some specific scenario, however it does not > work for me since I have the same dts files using different temperature > grade SoC. I would need to update this in the firmware before starting > Linux. Usually the bootloader loads the overlay and this is recommended approach to runtime tweaking DTB for some variant. > > Krzysztof, what do you think? I would not mind to get back to one of > the more simpler approach I proposed. As I said, I see the problem, but I am not sure that solution is correct. I can also rephrase the solution to a such one: "I want to support iMX6 and iMX7 with one DTS, so I will embed all properties from both DTS into one DTS and then during boot I will read soc-id register and choose some subset of the properties" No way... I also brought in previous reply trouble with regulator voltages or some other electric-properties. I don't want several duplicated properties per different variants of the same SoC. 1. If the devices are fully compatible, use one DTS. If you can squeeze different variants into the same DTS without any duplication so that entire DTS is used 100% by both variants - sure no, problem, less code. 2. If the devices are in general compatible but have discoverable differences, use one DTS, discover the differences and apply them dynamically via driver (e.g. read the temperature offset from some nvmem/OTP). 3. If the devices are partially the same but have differences, you can use overlays for that differences. This is quite flexible and clean solution as it also clearly documents the hardware in DTS and its overlays. 4. In all other options devices are different, so I expect different DTS. We had similar cases already in the past - some SoC versions could work on higher frequencies with higher voltages (arch/arm/boot/dts/exynos4412-prime.dtsi). These variants identified as exactly the same SoC as the earlier/slower one. You cannot use one DTS for them. We have chosen different DTS. For Samsung other case, same SoC comes in different bins with slightly different voltages for CPU/memory. Same frequencies but different voltages. This might be the closest to your problem. This was detectable runtime, so we had one DTS and we adjusted the voltages based on static tables in the driver (exynos5422-asv.c). > Lucas, are you really that against the simple working solution I > proposed initially [1]? I feel like I am running in circles ... Yes, because it is not generic and skips other similar cases, like regulator voltages or battery properties. I can easily imagine that next week someone comes with duplicated opp tables, then duplicated voltages, then duplicated CPU nodes and finally we have one DTS for imx6 and imx7 but everything is in multiple variants. :) Also I am against because DTS describes one hardware, not multiple different variants. Best regards, Krzysztof
On 20/06/2022 17:48, Francesco Dolcini wrote: > Hello Krzysztof, > thanks for your comment, let me try to provide you some additional > background to better understand this change. > > On Fri, Jun 17, 2022 at 06:02:39PM -0700, Krzysztof Kozlowski wrote: >> On 17/06/2022 00:08, Francesco Dolcini wrote: >>> Move `trips` definition to `#/$defs/trips-base` and just reference it >>> from the trips node. This allows to easily re-use this binding from >>> another binding file. >>> >>> No functional changes expected. >> >> If you want to re-use trips, they should be rather moved to separate >> YAML file... > > Fine, this should not be a big deal to achieve. Let's agree on the rest > first, however. > >> but anyway this should not be done per-driver bindings, but >> in more general way. Either the problem - using one DTS for different >> temperature grades - looks generic or is wrong at the core. In the first >> option, the generic bindings should be fixed. In the second case - using >> same DTS for different HW is not correct approach and why only thermal >> should be specific? I can imagine that cooling devices might have >> different settings, regulator voltages for DVFS could be a bit different... > > Let me try to explain the problem I am trying to solve here. > > Currently the imx-thermal driver harcode the critical trip threshold, > this trip point is read-only as it is considered a system property that > should not be changed and it is set to a value that is less than the > actual SoC maximum temperature. NO thermal_of driver used. > > Because of that there are systems that cannot work on some valid > temperature range. > > We are currently looking at a solution that would be backward compatible > with old device tree. > > I proposed the following: > 1- just increase the threshold to the actual max value allowed according > to the SoC thermal grade. > > As easy as > > - data->temp_critical = data->temp_max - (1000 * 5); > + data->temp_critical = data->temp_max; > > in drivers/thermal/imx_thermal.c > > https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ > > It was not considered good enough by Lucas since this is a overall > system design question, therefore should be configurable. > > 2- make the critical trip write-able from userspace/sysfs. > > Daniel is against this since critical trip point is a system > property, not something the user should be allowed to change. > > 3- kernel parameter: https://lore.kernel.org/all/20220516190001.147919-1-francesco.dolcini@toradex.com/ > > Initially proposed by Daniel, but Marco did not like the idea. > > 4- New device tree property, fsl,tempmon-critical-offset, ditched also > by Marco > > 5- The current solution in this patch, with the existing trip points > that are hardcoded in the code exposed in the device tree as trips. > > > Ideally one could just implement the imx6/7 thermal sensor reading and > just make use of the thermal_of driver, however that would break > compatibility with a lot of existing system ... to me this is just a > no-go. > > Adding only one set of thermal trip point in the dts (no thermal-grade > specific set) could work in some specific scenario, however it does not > work for me since I have the same dts files using different temperature > grade SoC. I would need to update this in the firmware before starting > Linux. > > Krzysztof, what do you think? I would not mind to get back to one of > the more simpler approach I proposed. > > Lucas, are you really that against the simple working solution I > proposed initially [1]? I feel like I am running in circles ... BTW, the link [1] was missing in your email, so I understood that you meant this patchset. If [1] refers to something else, then we need to discuss that something else. Best regards, Krzysztof
On Mon, Jun 20, 2022 at 06:44:23PM +0200, Krzysztof Kozlowski wrote: > On 20/06/2022 17:48, Francesco Dolcini wrote: > > On Fri, Jun 17, 2022 at 06:02:39PM -0700, Krzysztof Kozlowski wrote: > >> but anyway this should not be done per-driver bindings, but > >> in more general way. Either the problem - using one DTS for different > >> temperature grades - looks generic or is wrong at the core. In the first > >> option, the generic bindings should be fixed. In the second case - using > >> same DTS for different HW is not correct approach and why only thermal > >> should be specific? I can imagine that cooling devices might have > >> different settings, regulator voltages for DVFS could be a bit different... > > > > Let me try to explain the problem I am trying to solve here. > > > > Currently the imx-thermal driver harcode the critical trip threshold, > > this trip point is read-only as it is considered a system property that > > should not be changed and it is set to a value that is less than the > > actual SoC maximum temperature. NO thermal_of driver used. > > > > Because of that there are systems that cannot work on some valid > > temperature range. > > > > We are currently looking at a solution that would be backward compatible > > with old device tree. > > > > I proposed the following: > > 1- just increase the threshold to the actual max value allowed according > > to the SoC thermal grade. > > > > As easy as > > > > - data->temp_critical = data->temp_max - (1000 * 5); > > + data->temp_critical = data->temp_max; > > > > in drivers/thermal/imx_thermal.c > > > > https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ > > > > It was not considered good enough by Lucas since this is a overall > > system design question, therefore should be configurable. > > > > 2- make the critical trip write-able from userspace/sysfs. > > > > Daniel is against this since critical trip point is a system > > property, not something the user should be allowed to change. > > > > 3- kernel parameter: https://lore.kernel.org/all/20220516190001.147919-1-francesco.dolcini@toradex.com/ > > > > Initially proposed by Daniel, but Marco did not like the idea. > > > > 4- New device tree property, fsl,tempmon-critical-offset, ditched also > > by Marco > > > > 5- The current solution in this patch, with the existing trip points > > that are hardcoded in the code exposed in the device tree as trips. > > Thanks for the explanation, I see the problem. > > > > > Ideally one could just implement the imx6/7 thermal sensor reading and > > just make use of the thermal_of driver, however that would break > > compatibility with a lot of existing system ... to me this is just a > > no-go. > > This I did not understand... What is not implemented in thermal sensor > which would solve the issue? And why it cannot be implemented in > backwards compatible way? Currently the imx_thermal driver defines its own trip points. How would you change the code to work with old device tree binaries using the generic thermal_of driver? imx_thermal would need to be changed to be a thermal sensor device, all the thermal trip point code removed. The driver is using thermal_zone_device_register(). Maybe I am missing an obvious solution, just correct me if I am wrong. > Your change is also not backwards friendly, which means existing boards > (old DTS) will not receive the update. The change proposed in this series is 100% backward compatible, the code-defined trip point are optionally overwritten by the dts. > > Adding only one set of thermal trip point in the dts (no thermal-grade > > specific set) could work in some specific scenario, however it does not > > work for me since I have the same dts files using different temperature > > grade SoC. I would need to update this in the firmware before starting > > Linux. > > 2. If the devices are in general compatible but have discoverable > differences, use one DTS, discover the differences and apply them > dynamically via driver (e.g. read the temperature offset from some > nvmem/OTP). Yes, of course, I agree. That would work and it would be a reasonable approach in general, but it has one big drawback, it will force an update on the firmware on well-established products. Anyway, would you accept a change on the thermal_imx driver using a single set of trips from the dts, but not using the thermal_of driver? > > Lucas, are you really that against the simple working solution I > > proposed initially [1]? I feel like I am running in circles ... > > Yes, because it is not generic and skips other similar cases, like > regulator voltages or battery properties. I can easily imagine that next > week someone comes with duplicated opp tables, then duplicated voltages, > then duplicated CPU nodes and finally we have one DTS for imx6 and imx7 > but everything is in multiple variants. :) The patch I proposed in [1] was just making the hard-coded threshold more reasonable, instead of setting the critical threshold to max-5 to just max. Your concern here does not really applies. Here the patch https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ Francesco
On Mon, Jun 20, 2022 at 06:45:41PM +0200, Krzysztof Kozlowski wrote: > On 20/06/2022 17:48, Francesco Dolcini wrote: > > Lucas, are you really that against the simple working solution I > > proposed initially [1]? I feel like I am running in circles ... > > BTW, the link [1] was missing in your email, so I understood that you > meant this patchset. If [1] refers to something else, then we need to > discuss that something else. We misunderstood each other, this is what I meant: > 1- just increase the threshold to the actual max value allowed according > to the SoC thermal grade. > > As easy as > > - data->temp_critical = data->temp_max - (1000 * 5); > + data->temp_critical = data->temp_max; > > in drivers/thermal/imx_thermal.c > > https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ > > It was not considered good enough by Lucas since this is a overall > system design question, therefore should be configurable. Francesco
On 20/06/2022 19:43, Francesco Dolcini wrote: > On Mon, Jun 20, 2022 at 06:44:23PM +0200, Krzysztof Kozlowski wrote: >> On 20/06/2022 17:48, Francesco Dolcini wrote: >>> On Fri, Jun 17, 2022 at 06:02:39PM -0700, Krzysztof Kozlowski wrote: >>>> but anyway this should not be done per-driver bindings, but >>>> in more general way. Either the problem - using one DTS for different >>>> temperature grades - looks generic or is wrong at the core. In the first >>>> option, the generic bindings should be fixed. In the second case - using >>>> same DTS for different HW is not correct approach and why only thermal >>>> should be specific? I can imagine that cooling devices might have >>>> different settings, regulator voltages for DVFS could be a bit different... >>> >>> Let me try to explain the problem I am trying to solve here. >>> >>> Currently the imx-thermal driver harcode the critical trip threshold, >>> this trip point is read-only as it is considered a system property that >>> should not be changed and it is set to a value that is less than the >>> actual SoC maximum temperature. NO thermal_of driver used. >>> >>> Because of that there are systems that cannot work on some valid >>> temperature range. >>> >>> We are currently looking at a solution that would be backward compatible >>> with old device tree. >>> >>> I proposed the following: >>> 1- just increase the threshold to the actual max value allowed according >>> to the SoC thermal grade. >>> >>> As easy as >>> >>> - data->temp_critical = data->temp_max - (1000 * 5); >>> + data->temp_critical = data->temp_max; >>> >>> in drivers/thermal/imx_thermal.c >>> >>> https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ >>> >>> It was not considered good enough by Lucas since this is a overall >>> system design question, therefore should be configurable. >>> >>> 2- make the critical trip write-able from userspace/sysfs. >>> >>> Daniel is against this since critical trip point is a system >>> property, not something the user should be allowed to change. >>> >>> 3- kernel parameter: https://lore.kernel.org/all/20220516190001.147919-1-francesco.dolcini@toradex.com/ >>> >>> Initially proposed by Daniel, but Marco did not like the idea. >>> >>> 4- New device tree property, fsl,tempmon-critical-offset, ditched also >>> by Marco >>> >>> 5- The current solution in this patch, with the existing trip points >>> that are hardcoded in the code exposed in the device tree as trips. >> >> Thanks for the explanation, I see the problem. >> >>> >>> Ideally one could just implement the imx6/7 thermal sensor reading and >>> just make use of the thermal_of driver, however that would break >>> compatibility with a lot of existing system ... to me this is just a >>> no-go. >> >> This I did not understand... What is not implemented in thermal sensor >> which would solve the issue? And why it cannot be implemented in >> backwards compatible way? > > Currently the imx_thermal driver defines its own trip points. How would > you change the code to work with old device tree binaries using the > generic thermal_of driver? imx_thermal would need to be changed to be a > thermal sensor device, all the thermal trip point code removed. > The driver is using thermal_zone_device_register(). > > Maybe I am missing an obvious solution, just correct me if I am wrong. Probably you would need to support both solutions in the same driver, based on presence of thermal-sensor-cells property. It won't be particularly easy code, but maybe it is worth anyway... I am quite surprised to see that IMX thermal driver does not use generic framework and does not support generic bindings. >> Your change is also not backwards friendly, which means existing boards >> (old DTS) will not receive the update. > The change proposed in this series is 100% backward compatible, > the code-defined trip point are optionally overwritten by the dts. > > >>> Adding only one set of thermal trip point in the dts (no thermal-grade >>> specific set) could work in some specific scenario, however it does not >>> work for me since I have the same dts files using different temperature >>> grade SoC. I would need to update this in the firmware before starting >>> Linux. >> >> 2. If the devices are in general compatible but have discoverable >> differences, use one DTS, discover the differences and apply them >> dynamically via driver (e.g. read the temperature offset from some >> nvmem/OTP). > > Yes, of course, I agree. > That would work and it would be a reasonable approach in general, but it > has one big drawback, it will force an update on the firmware on > well-established products. Anyway, would you accept a change on the > thermal_imx driver using a single set of trips from the dts, but not > using the thermal_of driver? More comments were not concering the Linux IMX thermal implementation but rather bindings. From my point of view, you can use the same generic thermal bindings even if your implementation does not use thermal_of. > >>> Lucas, are you really that against the simple working solution I >>> proposed initially [1]? I feel like I am running in circles ... >> >> Yes, because it is not generic and skips other similar cases, like >> regulator voltages or battery properties. I can easily imagine that next >> week someone comes with duplicated opp tables, then duplicated voltages, >> then duplicated CPU nodes and finally we have one DTS for imx6 and imx7 >> but everything is in multiple variants. :) > > The patch I proposed in [1] was just making the hard-coded threshold > more reasonable, instead of setting the critical threshold to max-5 to > just max. Your concern here does not really applies. > > Here the patch https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/ Ah, that comment was not to me but to Lucas. Best regards, Krzysztof
Hello Krzysztof, thanks for the discussion and the review. On Mon, Jun 20, 2022 at 08:05:48PM +0200, Krzysztof Kozlowski wrote: > On 20/06/2022 19:43, Francesco Dolcini wrote: > > On Mon, Jun 20, 2022 at 06:44:23PM +0200, Krzysztof Kozlowski wrote: > >> On 20/06/2022 17:48, Francesco Dolcini wrote: > >>> Ideally one could just implement the imx6/7 thermal sensor reading and > >>> just make use of the thermal_of driver, however that would break > >>> compatibility with a lot of existing system ... to me this is just a > >>> no-go. > >> > >> This I did not understand... What is not implemented in thermal sensor > >> which would solve the issue? And why it cannot be implemented in > >> backwards compatible way? > > > > Currently the imx_thermal driver defines its own trip points. How would > > you change the code to work with old device tree binaries using the > > generic thermal_of driver? imx_thermal would need to be changed to be a > > thermal sensor device, all the thermal trip point code removed. > > The driver is using thermal_zone_device_register(). > > > > Maybe I am missing an obvious solution, just correct me if I am wrong. > > Probably you would need to support both solutions in the same driver, > based on presence of thermal-sensor-cells property. It won't be > particularly easy code, but maybe it is worth anyway... I am quite > surprised to see that IMX thermal driver does not use generic framework > and does not support generic bindings. #thermal-sensor-cells is already present in all dtsi using the imx_thermal driver without reason (see my previous comment on the topic [0]). From my point of view the situation is somehow a mess, not sure how to proceed to be honest. Francesco [0] https://lore.kernel.org/all/acbf8ed3-0b8c-a0b2-88ef-7b13ad0908d5@linaro.org/
diff --git a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml index 2d34f3ccb257..ba84233d20b7 100644 --- a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml +++ b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml @@ -10,6 +10,72 @@ title: Thermal zone binding maintainers: - Amit Kucheria <amitk@kernel.org> +$defs: + trips-base: + type: object + description: + This node describes a set of points in the temperature domain at + which the thermal framework needs to take action. The actions to + be taken are defined in another node called cooling-maps. + + patternProperties: + "^[a-zA-Z][a-zA-Z0-9\\-_]{0,63}$": + type: object + + properties: + temperature: + $ref: /schemas/types.yaml#/definitions/int32 + minimum: -273000 + maximum: 200000 + description: + An integer expressing the trip temperature in millicelsius. + + hysteresis: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + An unsigned integer expressing the hysteresis delta with + respect to the trip temperature property above, also in + millicelsius. Any cooling action initiated by the framework is + maintained until the temperature falls below + (trip temperature - hysteresis). This potentially prevents a + situation where the trip gets constantly triggered soon after + cooling action is removed. + + type: + $ref: /schemas/types.yaml#/definitions/string + enum: + - active # enable active cooling e.g. fans + - passive # enable passive cooling e.g. throttling cpu + - hot # send notification to driver + - critical # send notification to driver, trigger shutdown + description: | + There are four valid trip types: active, passive, hot, + critical. + + The critical trip type is used to set the maximum + temperature threshold above which the HW becomes + unstable and underlying firmware might even trigger a + reboot. Hitting the critical threshold triggers a system + shutdown. + + The hot trip type can be used to send a notification to + the thermal driver (if a .notify callback is registered). + The action to be taken is left to the driver. + + The passive trip type can be used to slow down HW e.g. run + the CPU, GPU, bus at a lower frequency. + + The active trip type can be used to control other HW to + help in cooling e.g. fans can be sped up or slowed down + + required: + - temperature + - hysteresis + - type + additionalProperties: false + + additionalProperties: false + description: | Thermal management is achieved in devicetree by describing the sensor hardware and the software abstraction of cooling devices and thermal zones required to @@ -105,69 +171,7 @@ patternProperties: 10-inch tablet is around 4500mW. trips: - type: object - description: - This node describes a set of points in the temperature domain at - which the thermal framework needs to take action. The actions to - be taken are defined in another node called cooling-maps. - - patternProperties: - "^[a-zA-Z][a-zA-Z0-9\\-_]{0,63}$": - type: object - - properties: - temperature: - $ref: /schemas/types.yaml#/definitions/int32 - minimum: -273000 - maximum: 200000 - description: - An integer expressing the trip temperature in millicelsius. - - hysteresis: - $ref: /schemas/types.yaml#/definitions/uint32 - description: - An unsigned integer expressing the hysteresis delta with - respect to the trip temperature property above, also in - millicelsius. Any cooling action initiated by the framework is - maintained until the temperature falls below - (trip temperature - hysteresis). This potentially prevents a - situation where the trip gets constantly triggered soon after - cooling action is removed. - - type: - $ref: /schemas/types.yaml#/definitions/string - enum: - - active # enable active cooling e.g. fans - - passive # enable passive cooling e.g. throttling cpu - - hot # send notification to driver - - critical # send notification to driver, trigger shutdown - description: | - There are four valid trip types: active, passive, hot, - critical. - - The critical trip type is used to set the maximum - temperature threshold above which the HW becomes - unstable and underlying firmware might even trigger a - reboot. Hitting the critical threshold triggers a system - shutdown. - - The hot trip type can be used to send a notification to - the thermal driver (if a .notify callback is registered). - The action to be taken is left to the driver. - - The passive trip type can be used to slow down HW e.g. run - the CPU, GPU, bus at a lower frequency. - - The active trip type can be used to control other HW to - help in cooling e.g. fans can be sped up or slowed down - - required: - - temperature - - hysteresis - - type - additionalProperties: false - - additionalProperties: false + $ref: "#/$defs/trips-base" cooling-maps: type: object
Move `trips` definition to `#/$defs/trips-base` and just reference it from the trips node. This allows to easily re-use this binding from another binding file. No functional changes expected. Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com> --- v2: no changes --- .../bindings/thermal/thermal-zones.yaml | 130 +++++++++--------- 1 file changed, 67 insertions(+), 63 deletions(-)