[PATCH 5.16 114/285] clk: si5341: fix reported clk_rate when output divider is 2

Greg Kroah-Hartman
2022-04-12T08:11:10Z

From: Adam Wujek <dev_public@wujek.eu>

[ Upstream commit 2a8b539433e111c4de364237627ef219d2f6350a ]

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@wujek.eu>
Link: https://lore.kernel.org/r/20211203141125.2447520-1-dev_public@wujek.eu
Reviewed-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 f7b41366666e..4de098b6b0d4 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;
}
--
2.35.1