From mboxrd@z Thu Jan 1 00:00:00 1970 From: kernel@martin.sperl.org Subject: [PATCH V4 0/4] thermal: bcm2835: add thermal driver Date: Fri, 9 Sep 2016 07:49:53 +0000 Message-ID: <1473407397-29395-1-git-send-email-kernel@martin.sperl.org> Return-path: Sender: linux-pm-owner@vger.kernel.org To: Zhang Rui , Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Lee Jones , Eric Anholt , Russell King , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Cc: Martin Sperl List-Id: devicetree@vger.kernel.org From: Martin Sperl Add a thermal driver for the TSENSE device of the bcm2835 SOC. If the firmware enables the HW, then the configuration is not touched. In case the firmware has not enabled the device, then we try to set it up correctly (which unfortunately can not get tested). It exposes temperature and a critical trip point (using a hardcoded default of 80C or the temperature configured in the control register by the firmware, which reads as 407C currently) The calibrations are (potentially) different for bcm2835, bcm2836 and bcm2837 and can get selected by the compatible property in the device tree. The driver also exposes the registers via debugfs. Possible future enhancements: * the device has the ability to trigger interrupts on reaching the programmed critical temperature. I have no knowledge which interrupt could be responsible for this on the ARM side, so if we get to know which irq it is we can implement that. Instead the driver right now implements polling in 1 second intervals * the device can also reset the HW after the trip point has been reached (also with some delay, so that corrective actions can get taken) - this is currently not enabled by the firmware, but could. * we could define more trip points for THERMAL_TRIP_HOT * make the trip point limits modifiable (ops.set_trip_temp) Changelog: V1 -> V2: renamed dt-binding documentation file added specific settings depending on compatible added trip point based on register setting up ctrl-register if HW is not enabled by firmware as per recommendation of Eric (untested) check that clock frequency is in range (1.9 - 5MHz - as per comment in clk-bcm2835.c) added driver to multi_v7_defconfig V2 -> V3: made a module in multi_v7_defconfig fixed typo in dt-binding document V3 -> V4: moved driver back to thermal (not using bcm sub-directory) set polling interval to 1second (was 0ms, so interrupt driven) Martin Sperl (4): dt: bindings: add thermal device driver for bcm2835 thermal: bcm2835: add thermal driver for bcm2835 soc ARM: bcm2835: add thermal node to device-tree of bcm283x ARM: bcm2835: add thermal driver to default_config .../bindings/thermal/brcm,bcm2835-thermal.txt | 17 ++ arch/arm/boot/dts/bcm283x.dtsi | 6 + arch/arm/configs/bcm2835_defconfig | 2 + drivers/thermal/Kconfig | 5 + drivers/thermal/Makefile | 1 + drivers/thermal/bcm2835_thermal.c | 327 +++++++++++++++++++++ 6 files changed, 358 insertions(+) create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt create mode 100644 drivers/thermal/bcm2835_thermal.c -- 2.1.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: kernel@martin.sperl.org (kernel at martin.sperl.org) Date: Fri, 9 Sep 2016 07:49:53 +0000 Subject: [PATCH V4 0/4] thermal: bcm2835: add thermal driver Message-ID: <1473407397-29395-1-git-send-email-kernel@martin.sperl.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Martin Sperl Add a thermal driver for the TSENSE device of the bcm2835 SOC. If the firmware enables the HW, then the configuration is not touched. In case the firmware has not enabled the device, then we try to set it up correctly (which unfortunately can not get tested). It exposes temperature and a critical trip point (using a hardcoded default of 80C or the temperature configured in the control register by the firmware, which reads as 407C currently) The calibrations are (potentially) different for bcm2835, bcm2836 and bcm2837 and can get selected by the compatible property in the device tree. The driver also exposes the registers via debugfs. Possible future enhancements: * the device has the ability to trigger interrupts on reaching the programmed critical temperature. I have no knowledge which interrupt could be responsible for this on the ARM side, so if we get to know which irq it is we can implement that. Instead the driver right now implements polling in 1 second intervals * the device can also reset the HW after the trip point has been reached (also with some delay, so that corrective actions can get taken) - this is currently not enabled by the firmware, but could. * we could define more trip points for THERMAL_TRIP_HOT * make the trip point limits modifiable (ops.set_trip_temp) Changelog: V1 -> V2: renamed dt-binding documentation file added specific settings depending on compatible added trip point based on register setting up ctrl-register if HW is not enabled by firmware as per recommendation of Eric (untested) check that clock frequency is in range (1.9 - 5MHz - as per comment in clk-bcm2835.c) added driver to multi_v7_defconfig V2 -> V3: made a module in multi_v7_defconfig fixed typo in dt-binding document V3 -> V4: moved driver back to thermal (not using bcm sub-directory) set polling interval to 1second (was 0ms, so interrupt driven) Martin Sperl (4): dt: bindings: add thermal device driver for bcm2835 thermal: bcm2835: add thermal driver for bcm2835 soc ARM: bcm2835: add thermal node to device-tree of bcm283x ARM: bcm2835: add thermal driver to default_config .../bindings/thermal/brcm,bcm2835-thermal.txt | 17 ++ arch/arm/boot/dts/bcm283x.dtsi | 6 + arch/arm/configs/bcm2835_defconfig | 2 + drivers/thermal/Kconfig | 5 + drivers/thermal/Makefile | 1 + drivers/thermal/bcm2835_thermal.c | 327 +++++++++++++++++++++ 6 files changed, 358 insertions(+) create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt create mode 100644 drivers/thermal/bcm2835_thermal.c -- 2.1.4