Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH 1/2] socfpga: hotplug: put cpu1 in wfi | Date | Thu, 02 Oct 2014 14:18:09 +0200 |
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On Thursday 02 October 2014 01:16:46 Pavel Machek wrote: > > > > > > struct socfpga_reset_manager { > > > u32 status; > > > u32 ctrl; > > > u32 counts; > > > u32 padding1; > > > u32 mpu_mod_reset; > > > u32 per_mod_reset; > > > u32 per2_mod_reset; > > > u32 brg_mod_reset; > > > }; > > > > > > from u-boot. Unlike macros, structs have advantages that typos lead to > > > easier-to-see failure modes... (And they are easier to read/parse, > > > too). > > > > > > > Copying from uboot sounds good, but I already know that the CPU reset > > offset is different for our next SOC, Arria 10. The Arria 10 SOC should > > still be able to use the same MSL as Cyclone5 and Arria5, but with a few > > differences. One of them being, the CPU1 reset offset is at 0x20 instead > > of 0x10. So I think having a macro for this one register is a bit > > cleaner than having to define a whole new struct for Arria10. > > I don't think "whole new struct" is a problem. At least it will be > plain to see what changed (which will get easily lost in ifdefs. > > struct cyclone5_reset_manager { > struct socfpga_reset_manager common; > u32 brg_mod_reset; > } > > struct aria10_reset_manager { > struct socfpga_reset_manager common; > char filler[0x10]; > u32 brg_mod_reset; > } > > if (of_machine_is_compatible("altr,socfpga-arria10")) > __raw_writel(0, (struct cyclone5_reset_manager *) rst_manager_base_addr->brg_mod_reset)); > else > __raw_writel(0, (struct aria10_reset_manager *) rst_manager_base_addr->brg_mod_reset)); > > ...does not sound that bad. (And you'll need some nice solution for > u-boot, anyway...)
I think it would be better to just add more fields and access a different field based on the SoC type than cast the structs around.
Also, never use __raw_writel unless you know exactly what you are doing. This should use writel, or possibly writel_relaxed.
Finally, don't sprinkle of_machine_is_compatible() checks all over the place. Make the decision once when you initially probe the machine.
Arnd
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