Re: [PATCH v3 09/16] reset: starfive-jh7100: Add StarFive JH7100 reset driver

[Andy Shevchenko]

+Cc: Yury (bitmap expert)

On Tue, Nov 2, 2021 at 6:50 PM Emil Renner Berthing <kernel@xxxxxxxx> wrote:
>
> Add a driver for the StarFive JH7100 reset controller.

...

> +#define BIT_MASK32(x) BIT((x) % 32)

Possible namespace collision.

...

> +/*
> + * the registers work like a 32bit bitmap, so writing a 1 to the m'th bit of
> + * the n'th ASSERT register asserts line 32n + m, and writing a 0 deasserts the
> + * same line.
> + * most reset lines have their status inverted so a 0 in the STATUS register
> + * means the line is asserted and a 1 means it's deasserted. a few lines don't
> + * though, so store the expected value of the status registers when all lines
> + * are asserted.
> + */

Besides missing capitalization, if it sounds like bitmap, use bitmap.
I have checked DT definitions and it seems you don't even need the
BIT_MASK() macro,

> +static const u32 jh7100_reset_asserted[4] = {
> +       /* STATUS0 register */
> +       BIT_MASK32(JH7100_RST_U74) |
> +       BIT_MASK32(JH7100_RST_VP6_DRESET) |
> +       BIT_MASK32(JH7100_RST_VP6_BRESET),
> +       /* STATUS1 register */
> +       BIT_MASK32(JH7100_RST_HIFI4_DRESET) |
> +       BIT_MASK32(JH7100_RST_HIFI4_BRESET),
> +       /* STATUS2 register */
> +       BIT_MASK32(JH7100_RST_E24),
> +       /* STATUS3 register */
> +       0,
> +};

Yury, do we have any clever (clean) way to initialize a bitmap with
particular bits so that it will be a constant from the beginning? If
no, any suggestion what we can provide to such users?

...

> +       dev_dbg(rcdev->dev, "reset(%lu)\n", id);

These debug messages are useless since one should use ftrace facility instead,

-- 
With Best Regards,
Andy Shevchenko