+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
