mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-29 10:34:22 -04:00
b6e9fb7ac2
The BWMON hardware has two sets of registers: one for the monitor itself and one called "global". It has what seems to be some kind of a head switch and an interrupt control register. It's usually 0x200 in size. On fairly recent SoCs (with the starting point seemingly being moving the OSM programming to the firmware) these two register sets are contiguous and overlapping, like this (on sm8450): /* notice how base.start == global_base.start+0x100 */ reg = <0x90b6400 0x300>, <0x90b6300 0x200>; reg-names = "base", "global_base"; Which led to some confusion and the assumption that since the "interesting" global registers begin right after global_base+0x100, there's no need to map two separate regions and one can simply subtract 0x100 from the offsets. This is however not the case for anything older than SDM845, as the global region can appear in seemingly random spots on the register map. Handle the case where the global registers are mapped separately to allow proper functioning of BWMONv4 on MSM8998 and older. Add specific compatibles for 845, 8280xp, 7280 and 8550 (all of which use the single reg space scheme) to keep backwards compatibility with old DTs. Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20230304-topic-ddr_bwmon-v3-3-77a050c2fbda@linaro.org
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.