Re: [PATCH] clk: si5341: fix reported clk_rate when output divider is 2

From: Stephen Boyd
Date: Thu Jan 13 2022 - 16:23:15 EST


+Robert

Please review

Quoting Adam Wujek (2021-12-03 06:12:07)
> SI5341_OUT_CFG_RDIV_FORCE2 shall be checked first to distinguish whether
> a divider for a given output is set to 2 (SI5341_OUT_CFG_RDIV_FORCE2
> is set) or the output is disabled (SI5341_OUT_CFG_RDIV_FORCE2 not set,
> SI5341_OUT_R_REG is set 0).
> Before the change, divider set to 2 (SI5341_OUT_R_REG set to 0) was
> interpreted as output is disabled.
>
> Signed-off-by: Adam Wujek <dev_public@xxxxxxxx>
> ---
> drivers/clk/clk-si5341.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
> index b7641abe6747..15b1c90cafe5 100644
> --- a/drivers/clk/clk-si5341.c
> +++ b/drivers/clk/clk-si5341.c
> @@ -798,6 +798,15 @@ static unsigned long si5341_output_clk_recalc_rate(struct clk_hw *hw,
> u32 r_divider;
> u8 r[3];
>
> + err = regmap_read(output->data->regmap,
> + SI5341_OUT_CONFIG(output), &val);
> + if (err < 0)
> + return err;
> +
> + /* If SI5341_OUT_CFG_RDIV_FORCE2 is set, r_divider is 2 */
> + if (val & SI5341_OUT_CFG_RDIV_FORCE2)
> + return parent_rate / 2;
> +
> err = regmap_bulk_read(output->data->regmap,
> SI5341_OUT_R_REG(output), r, 3);
> if (err < 0)
> @@ -814,13 +823,6 @@ static unsigned long si5341_output_clk_recalc_rate(struct clk_hw *hw,
> r_divider += 1;
> r_divider <<= 1;
>
> - err = regmap_read(output->data->regmap,
> - SI5341_OUT_CONFIG(output), &val);
> - if (err < 0)
> - return err;
> -
> - if (val & SI5341_OUT_CFG_RDIV_FORCE2)
> - r_divider = 2;
>
> return parent_rate / r_divider;
> }