[PATCH] arm64: zynqmp: Add 'silabs, skip-recall' to all si570 clk nodes

[PATCH] arm64: zynqmp: Add 'silabs, skip-recall' to all si570 clk nodes

[Michal Simek]

From: Saeed Nowshadi <saeed.nowshadi@amd.com>

Without 'silabs,skip-recall' property, the driver on System Controller
re-calibrates the output clock frequency at probe() time based on the NVRAM
setting.  This re-calibration causes a glitch on the output clock.  At
power-on, Versal is also booting and expecting a glitch-free clock for
its correct operation.  System Controller should skip the re-calibration
step to prevent any clock instability for Versal.

Signed-off-by: Saeed Nowshadi <saeed.nowshadi@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
---

 arch/arm/dts/zynqmp-e-a2197-00-revA.dts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/dts/zynqmp-e-a2197-00-revA.dts b/arch/arm/dts/zynqmp-e-a2197-00-revA.dts
index f1b0a4aa65dd..0b97fa3f28ac 100644
--- a/arch/arm/dts/zynqmp-e-a2197-00-revA.dts
+++ b/arch/arm/dts/zynqmp-e-a2197-00-revA.dts
@@ -449,6 +449,7 @@
 				factory-fout = <156250000>;
 				clock-frequency = <156250000>;
 				clock-output-names = "si570_zsfp_clk";
+				silabs,skip-recall;
 			};
 		};
 		i2c@6 { /* USER_SI570_1 */
@@ -463,6 +464,7 @@
 				factory-fout = <100000000>;
 				clock-frequency = <100000000>;
 				clock-output-names = "si570_user1";
+				silabs,skip-recall;
 			};
 
 		};
@@ -560,6 +562,7 @@
 				factory-fout = <200000000>;
 				clock-frequency = <200000000>;
 				clock-output-names = "si570_lpddr4_clk2";
+				silabs,skip-recall;
 			};
 		};
 		i2c@5 { /* LPDDR4_SI570_CLK1 */
@@ -574,6 +577,7 @@
 				factory-fout = <200000000>;
 				clock-frequency = <200000000>;
 				clock-output-names = "si570_lpddr4_clk1";
+				silabs,skip-recall;
 			};
 		};
 		i2c@6 { /* HSDP_SI570 */
@@ -588,6 +592,7 @@
 				factory-fout = <156250000>;
 				clock-frequency = <156250000>;
 				clock-output-names = "si570_hsdp_clk";
+				silabs,skip-recall;
 			};
 		};
 		i2c@7 { /* 8A34001 - U219B and J310 connector */
-- 
2.36.1

Re: [PATCH] arm64: zynqmp: Add 'silabs, skip-recall' to all si570 clk nodes

[Michal Simek]

On 1/25/24 09:07, Michal Simek wrote:
> From: Saeed Nowshadi <saeed.nowshadi@amd.com>
> 
> Without 'silabs,skip-recall' property, the driver on System Controller
> re-calibrates the output clock frequency at probe() time based on the NVRAM
> setting.  This re-calibration causes a glitch on the output clock.  At
> power-on, Versal is also booting and expecting a glitch-free clock for
> its correct operation.  System Controller should skip the re-calibration
> step to prevent any clock instability for Versal.
> 
> Signed-off-by: Saeed Nowshadi <saeed.nowshadi@amd.com>
> Signed-off-by: Michal Simek <michal.simek@amd.com>
> ---
> 
>   arch/arm/dts/zynqmp-e-a2197-00-revA.dts | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm/dts/zynqmp-e-a2197-00-revA.dts b/arch/arm/dts/zynqmp-e-a2197-00-revA.dts
> index f1b0a4aa65dd..0b97fa3f28ac 100644
> --- a/arch/arm/dts/zynqmp-e-a2197-00-revA.dts
> +++ b/arch/arm/dts/zynqmp-e-a2197-00-revA.dts
> @@ -449,6 +449,7 @@
>   				factory-fout = <156250000>;
>   				clock-frequency = <156250000>;
>   				clock-output-names = "si570_zsfp_clk";
> +				silabs,skip-recall;
>   			};
>   		};
>   		i2c@6 { /* USER_SI570_1 */
> @@ -463,6 +464,7 @@
>   				factory-fout = <100000000>;
>   				clock-frequency = <100000000>;
>   				clock-output-names = "si570_user1";
> +				silabs,skip-recall;
>   			};
>   
>   		};
> @@ -560,6 +562,7 @@
>   				factory-fout = <200000000>;
>   				clock-frequency = <200000000>;
>   				clock-output-names = "si570_lpddr4_clk2";
> +				silabs,skip-recall;
>   			};
>   		};
>   		i2c@5 { /* LPDDR4_SI570_CLK1 */
> @@ -574,6 +577,7 @@
>   				factory-fout = <200000000>;
>   				clock-frequency = <200000000>;
>   				clock-output-names = "si570_lpddr4_clk1";
> +				silabs,skip-recall;
>   			};
>   		};
>   		i2c@6 { /* HSDP_SI570 */
> @@ -588,6 +592,7 @@
>   				factory-fout = <156250000>;
>   				clock-frequency = <156250000>;
>   				clock-output-names = "si570_hsdp_clk";
> +				silabs,skip-recall;
>   			};
>   		};
>   		i2c@7 { /* 8A34001 - U219B and J310 connector */

Applied.
M