In the SpacemiT public document, when the FNCLKSEL field of
the APBC_SSPAX_CLK_RST register is 7 (3'b111),
which is a reserved value. And BIT3 of the same register is
a reserved bit.

But the documentation is incorrect. In reality, the value 7 (3'b111)
of FNCLKSEL is not reserved. Instead, it indicates that i2s_bclk is
selected as the parent clock. Similarly, bit 3 is not reserved either.
When FNCLKSEL is set to 7, bit 3 determines whether i2s_bclk is actually
enabled as the parent clock.

In all other cases (i.e., when FNCLKSEL is not 7), bit 3 has no effect.

Importantly, whenever FNCLKSEL is set to 7, bit 3 must also be set to 1,
otherwise the selection of i2s_bclk becomes invalid.

Fixes: 1b72c59db0add ("clk: spacemit: Add clock support for SpacemiT K1 SoC")
Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
I sent with a wrong email so resend.
---
Changes in v4:
  - add comments
  - add tags
  - Link to v3: https://lore.kernel.org/r/20250731-k1-clk-i2s-v3-0-2f655ddb0c6f@linux.spacemit.com

Changes in v3:
  - Fixing ABI-breaking behavior
  - Modify commit msgs
  - Link to v2: https://lore.kernel.org/r/20250722-k1-clk-i2s-v2-0-2f8edfe3dab4@linux.spacemit.com

Changes in v2:
  - Use virtual gate instead of new function for sspa
  - Add Suggested-by tag: Yao Zi
  - Add Fixes tag
  - Link to v1: https://lore.kernel.org/all/20250718-k1-clk-i2s-v1-1-e92c10fd0f60@linux.spacemit.com/

---
Troy Mitchell (2):
      dt-bindings: clock: spacemit: CLK_SSPA_I2S_BCLK for SSPA
      clk: spacemit: fix sspax_clk

 drivers/clk/spacemit/ccu-k1.c                  | 29 ++++++++++++++++++++++----
 include/dt-bindings/clock/spacemit,k1-syscon.h |  2 ++
 2 files changed, 27 insertions(+), 4 deletions(-)
---
base-commit: 733923397fd95405a48f165c9b1fbc8c4b0a4681
change-id: 20250717-k1-clk-i2s-e4272f1f915b

Best regards,
-- 
Troy Mitchell <troy.mitchell@linux.spacemit.com>

Hi Troy,

On 21:01 Tue 05 Aug     , Troy Mitchell wrote:
> In the SpacemiT public document, when the FNCLKSEL field of
> the APBC_SSPAX_CLK_RST register is 7 (3'b111),
> which is a reserved value. And BIT3 of the same register is
> a reserved bit.
> 
> But the documentation is incorrect. In reality, the value 7 (3'b111)
> of FNCLKSEL is not reserved. Instead, it indicates that i2s_bclk is
> selected as the parent clock. Similarly, bit 3 is not reserved either.
> When FNCLKSEL is set to 7, bit 3 determines whether i2s_bclk is actually
> enabled as the parent clock.
> 
> In all other cases (i.e., when FNCLKSEL is not 7), bit 3 has no effect.
> 
> Importantly, whenever FNCLKSEL is set to 7, bit 3 must also be set to 1,
> otherwise the selection of i2s_bclk becomes invalid.
> 
> Fixes: 1b72c59db0add ("clk: spacemit: Add clock support for SpacemiT K1 SoC")
Fixes tag get lost when applying this series, please move to patch [2/2]
or apply to both of the two patches? (I think it doesn't hurt)

also, please rebase this series once 6.17-rc1 tagged as currently patch [1/2]
can't be applied cleanly

> Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
> ---
> I sent with a wrong email so resend.
> ---
> Changes in v4:
>   - add comments
>   - add tags
>   - Link to v3: https://lore.kernel.org/r/20250731-k1-clk-i2s-v3-0-2f655ddb0c6f@linux.spacemit.com
> 
> Changes in v3:
>   - Fixing ABI-breaking behavior
>   - Modify commit msgs
>   - Link to v2: https://lore.kernel.org/r/20250722-k1-clk-i2s-v2-0-2f8edfe3dab4@linux.spacemit.com
> 
> Changes in v2:
>   - Use virtual gate instead of new function for sspa
>   - Add Suggested-by tag: Yao Zi
>   - Add Fixes tag
>   - Link to v1: https://lore.kernel.org/all/20250718-k1-clk-i2s-v1-1-e92c10fd0f60@linux.spacemit.com/
> 
> ---
> Troy Mitchell (2):
>       dt-bindings: clock: spacemit: CLK_SSPA_I2S_BCLK for SSPA
>       clk: spacemit: fix sspax_clk
> 
>  drivers/clk/spacemit/ccu-k1.c                  | 29 ++++++++++++++++++++++----
>  include/dt-bindings/clock/spacemit,k1-syscon.h |  2 ++
>  2 files changed, 27 insertions(+), 4 deletions(-)
> ---
> base-commit: 733923397fd95405a48f165c9b1fbc8c4b0a4681
> change-id: 20250717-k1-clk-i2s-e4272f1f915b
> 
> Best regards,
> -- 
> Troy Mitchell <troy.mitchell@linux.spacemit.com>
> 
> 

-- 
Yixun Lan (dlan)