> >On Fri, Nov 17, 2023 at 08:30:21PM +0800, Inochi Amaoto wrote: >>> >>> On 17/11/2023 06:07, Inochi Amaoto wrote: >>>> The timer registers of aclint don't follow the clint layout and can >>>> be mapped on any different offset. As sg2042 uses separated timer >>>> and mswi for its clint, it should follow the aclint spec and have >>>> separated registers. >>>> >>>> The previous patch introduced a new type of T-HEAD aclint timer which >>>> has clint timer layout. Although it has the clint timer layout, it >>>> should follow the aclint spec and uses the separated mtime and mtimecmp >>>> regs. So a ABI change is needed to make the timer fit the aclint spec. >>>> >>>> To make T-HEAD aclint timer more closer to the aclint spec, use >>>> regs-names to represent the mtimecmp register, which can avoid hack >>>> for unsupport mtime register of T-HEAD aclint timer. >>>> >>> >>> I don't understand this reasoning. You had one entry, you still have one >>> entry. Adding reg-names (not regs-names) does not change it. >>> >> >> If no "reg-names", all the register of ACLINT should be defined. However, >> T-HEAD aclint timer of sg2042 only supports mtimecmp register. If no extra >> prompt is provided for the SBI, it will fail to recognize aclint timer >> registers when parsing the aclint node with one reg entry. >> >> There is another way to avoid this by using an empty entry to identify >> unsupported mtime, but Conor have already rejected this. See [1]. >> >> Link: https://lore.kernel.org/all/20231114-skedaddle-precinct-66c8897227bb@squawk/ [1] > >Perhaps you misunderstood my suggestion. I was looking for _both_ >registers to be defined in the binding as well as adding reg-names as a >required property. Doing what you have here might work for your use >case, but does not make sense from a bindings point of view as there is >no way to describe the mtime register, should it exist in another SoC. > Thanks for your clarification. If I understand you correctly, the binding should have all registers that ACLINT has. But for specific use case, it should only contain supported registers and omit unsupported. Please correct me if I misunderstood. Thanks. >Cheers, >Conor >
