Hello, On Wed, Nov 02, 2016 at 10:18:20AM +0000, kernel@xxxxxxxxxxxxxxxx wrote: > From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> > > Add a thermal driver for the TSENSE device of the bcm2835/6/7 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) > > Note: > No support for 32-bit arm bcm2837, as there is no > arch/arm/boot/dts/bcm2836.dtsi upstream as of now. > 64-bit arm support is not tested > > 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) > V4 -> V5: use correct compatiblity for different soc versions in dt > support ARM64 for bcm2837 in devicetree and defconfig > V5 -> V6: incorporated changes recommended by Stefan Wahren > V6 -> V7: removed depends on ARCH_BCM2836 || ARCH_BCM2837 in Kconfig > V7 -> V8: rebased > Despite the minor questions on patch 2, specially on the request to use existing slope and offset properties, I am ok with the other DT changes. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
