Messages in this thread | | | Date | Mon, 02 Oct 2023 20:55:23 +0200 | From | "Arnd Bergmann" <> | Subject | Re: [PATCH v5 1/3] debugfs_create_regset32() support 8/16 bit width registers |
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On Mon, Oct 2, 2023, at 20:37, Frank Li wrote: > Enhance the flexibility of `debugfs_create_regset32()` to support registers > of various bit widths. The key changes are as follows: > > 1. Renamed '*reg32' and '*regset32' to '*reg' and '*regset' in relevant > code to reflect that the register width is not limited to 32 bits. > > 2. Added 'size' and 'bigendian' fields to the `struct debugfs_reg` to allow > for specifying the size and endianness of registers. These additions > enable `debugfs_create_regset()` to support a wider range of register > types. > > 3. When 'size' is set to 0, it signifies a 32-bit register. This change > maintains compatibility with existing code that assumes 32-bit > registers. > > Improve the versatility of `debugfs_create_regset()` and enable it to > handle registers of different sizes and endianness, offering greater > flexibility for debugging and monitoring. > > Signed-off-by: Frank Li <Frank.Li@nxp.com>
This version looks correct to me, I see no fundamental problems with it. In fact, you could list "support for ioport_map() output" to the features above.
A few other thoughts from my side, all of which could be ignored:
- if the ioport access is not an important feature, we can instead support 64-bit readl() as I commented in a previous email. We just can't easily have both.
- instead of treating every value of "regs->size" other than 1 and 2 as meaning '32-bit read', I would explicitly check for 0 and 4 here
- Another more complicated but also more featureful variant would be to use the 'regmap' infrastructure as the abstraction, this would also provide access to big-endian, variable register width (including 64-bit), and pio, along with additional features and other bus types. Not sure it's worth it, but could be interesting to try out.
Arnd
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