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[1/2] dt-bindings: i2c: designware: allow fine tuning tuning waveform from device tree

Message ID 20240201044623.374389-1-aahila@google.com
State New
Headers
Series [1/2] dt-bindings: i2c: designware: allow fine tuning tuning waveform from device tree |

Commit Message

Aahil Awatramani Feb. 1, 2024, 4:46 a.m. UTC 
  The Synopsys i2c driver allows a user to override the parameters
controlling the waveform using ACPI; this is useful for fine tuning when
needed to make spec compliance. Extend this support to the device tree to
allow non-ACPI platforms the same capabilities.

Signed-off-by: Aahil Awatramani <aahila@google.com>
---
 Documentation/devicetree/bindings/i2c/i2c.txt | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Comments

Krzysztof Kozlowski Feb. 1, 2024, 7:33 a.m. UTC | #1 
On 01/02/2024 05:46, Aahil Awatramani wrote:
> The Synopsys i2c driver allows a user to override the parameters

Driver? That already suggests it is not suitable for binding...

> controlling the waveform using ACPI; this is useful for fine tuning when
> needed to make spec compliance. Extend this support to the device tree to
> allow non-ACPI platforms the same capabilities.
> 
> Signed-off-by: Aahil Awatramani <aahila@google.com>
> ---
>  Documentation/devicetree/bindings/i2c/i2c.txt | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> index fc3dd7ec0445..3c33c36571f9 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> @@ -45,6 +45,24 @@ wants to support one of the below features, it should adapt these bindings.
>  	Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C
>  	specification.
>  
> +- i2c-scl-ss-hcnt
> +	HCNT value for standard speed mode in I2C Controller.

I have no clue what is HCNT, so I expect you to help us understand what
is this and why this is suitable for DT. Your reference to driver
suggests it is not suitable for DT.

Best regards,
Krzysztof
Andy Shevchenko Feb. 1, 2024, 11:46 a.m. UTC | #2 
On Thu, Feb 01, 2024 at 04:46:22AM +0000, Aahil Awatramani wrote:
> The Synopsys i2c driver allows a user to override the parameters
> controlling the waveform using ACPI; this is useful for fine tuning when
> needed to make spec compliance. Extend this support to the device tree to
> allow non-ACPI platforms the same capabilities.

DT has different counters from which one should derive these ones.
Can you explain why existing bindings may _not_ be utilised?

Without this very justification, NAK.
Aahil Awatramani Feb. 9, 2024, 9:05 p.m. UTC | #3 
Thank you Andy and Krzysztof,

I think you are right and I can use the other DT counter, I am
currently trying to test if they work for me.

Best,
Aahil

On Thu, Feb 1, 2024 at 3:49 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Thu, Feb 01, 2024 at 04:46:22AM +0000, Aahil Awatramani wrote:
> > The Synopsys i2c driver allows a user to override the parameters
> > controlling the waveform using ACPI; this is useful for fine tuning when
> > needed to make spec compliance. Extend this support to the device tree to
> > allow non-ACPI platforms the same capabilities.
>
> DT has different counters from which one should derive these ones.
> Can you explain why existing bindings may _not_ be utilised?
>
> Without this very justification, NAK.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
index fc3dd7ec0445..3c33c36571f9 100644
--- a/Documentation/devicetree/bindings/i2c/i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c.txt
@@ -45,6 +45,24 @@  wants to support one of the below features, it should adapt these bindings.
 	Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C
 	specification.
 
+- i2c-scl-ss-hcnt
+	HCNT value for standard speed mode in I2C Controller.
+
+- i2c-scl-ss-lcnt
+	LCNT value for standard speed mode in I2C Controller.
+
+- i2c-scl-fs-hcnt
+	HCNT value for fast speed mode in I2C Controller.
+
+- i2c-scl-fs-lcnt
+	LCNT value for fast speed mode in I2C Controller.
+
+- i2c-scl-hs-hcnt
+	HCNT value for high speed mode in I2C Controller.
+
+- i2c-scl-hs-lcnt
+	LCNT value for high speed mode in I2C Controller.
+
 - i2c-sda-falling-time-ns
 	Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C
 	specification.