diff mbox

[3/3] ARM64: dts: meson: fix clock source of the pclk for UART_AO

Message ID 20180326081809.49493-4-yixun.lan@amlogic.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Yixun Lan March 26, 2018, 8:18 a.m. UTC
From the hardware perspective, the clk81 is the parent of
the UART_AO clocks. So it make more sense to mark
the CLKID_AO_UART1/2 as the pclk.

Previous we had flag=CLK_IGNORE_UNUSED in AO clock driver.
This will make kernel leave clock as it is while bootloader
set the clock on.

Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
---
 arch/arm64/boot/dts/amlogic/meson-axg.dtsi  | 4 ++--
 arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 4 ++--
 arch/arm64/boot/dts/amlogic/meson-gxl.dtsi  | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

Comments

Jerome Brunet March 27, 2018, 9:20 a.m. UTC | #1
On Mon, 2018-03-26 at 16:18 +0800, Yixun Lan wrote:
> From the hardware perspective, the clk81 is the parent of
> the UART_AO clocks. So it make more sense to mark
> the CLKID_AO_UART1/2 as the pclk.
> 
> Previous we had flag=CLK_IGNORE_UNUSED in AO clock driver.
> This will make kernel leave clock as it is while bootloader
> set the clock on.
> 

Hi Yixun,

I'm not sure I understand your description correctly so I'll phrase. Please tell
me if I misunderstood something

The actual pclk of the AO uarts is the corresponding clkc_ao uart gate, not the
main clock controller clk81. This was not problem so far, because the uart_gate
had the CLK_IGNORE_UNUSED flag, which kept the gate open.

In another patch, you removed this flag, so you need to give the correct clock
in DT to make things work again ? right ?

If I got it correctly, please rephrase the description a bit.
Also you need to be careful in which order patches get merged.

1. You need the clkc_ao in place, exporting CLKID_AO_UARTx with
CLK_IGNORE_UNUSED.

2. This patch can be merged (still with CLK_IGNORE_UNUSED)

3. Once the DT patch have reached mainline, you should a patch to remove to
CLK_IGNORE_UNUSED flag

This way, we avoid breaking bisect, with revision where CLKID_AO_UARTx would get
disabled by the CCF clk_disable_unused() mechanism while the UART driver does
not claim the appropriate clock.


> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> ---
>  arch/arm64/boot/dts/amlogic/meson-axg.dtsi  | 4 ++--
>  arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 4 ++--
>  arch/arm64/boot/dts/amlogic/meson-gxl.dtsi  | 4 ++--
>  3 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
> index 48584d5a329b..e538e2448bb5 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
> @@ -533,7 +533,7 @@
>  				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
>  				reg = <0x0 0x3000 0x0 0x18>;
>  				interrupts = <GIC_SPI 193 IRQ_TYPE_EDGE_RISING>;
> -				clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
> +				clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
>  				clock-names = "xtal", "pclk", "baud";
>  				status = "disabled";
>  			};
> @@ -542,7 +542,7 @@
>  				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
>  				reg = <0x0 0x4000 0x0 0x18>;
>  				interrupts = <GIC_SPI 197 IRQ_TYPE_EDGE_RISING>;
> -				clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
> +				clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
>  				clock-names = "xtal", "pclk", "baud";
>  				status = "disabled";
>  			};
> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
> index 3290a4dc3522..a458ea50c2ef 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
> @@ -783,12 +783,12 @@
>  };
>  
>  &uart_AO {
> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
>  	clock-names = "xtal", "pclk", "baud";
>  };
>  
>  &uart_AO_B {
> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
>  	clock-names = "xtal", "pclk", "baud";
>  };
>  
> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
> index 4f355f17eed6..474f4f9630e4 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
> @@ -733,12 +733,12 @@
>  };
>  
>  &uart_AO {
> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
>  	clock-names = "xtal", "pclk", "baud";
>  };
>  
>  &uart_AO_B {
> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
>  	clock-names = "xtal", "pclk", "baud";
>  };
>
Yixun Lan March 27, 2018, 12:35 p.m. UTC | #2
On 03/27/2018 05:20 PM, Jerome Brunet wrote:
> On Mon, 2018-03-26 at 16:18 +0800, Yixun Lan wrote:
>> From the hardware perspective, the clk81 is the parent of
>> the UART_AO clocks. So it make more sense to mark
>> the CLKID_AO_UART1/2 as the pclk.
>>
>> Previous we had flag=CLK_IGNORE_UNUSED in AO clock driver.
>> This will make kernel leave clock as it is while bootloader
>> set the clock on.
>>
> 
> Hi Yixun,
> 
> I'm not sure I understand your description correctly so I'll phrase. Please tell
> me if I misunderstood something
> 
> The actual pclk of the AO uarts is the corresponding clkc_ao uart gate, not the
> main clock controller clk81. This was not problem so far, because the uart_gate
> had the CLK_IGNORE_UNUSED flag, which kept the gate open.
> 
Yes, exactly

> In another patch, you removed this flag, so you need to give the correct clock
> in DT to make things work again ? right ?
> 
Yes, right.


> If I got it correctly, please rephrase the description a bit.
> Also you need to be careful in which order patches get merged.
> 
> 1. You need the clkc_ao in place, exporting CLKID_AO_UARTx with
> CLK_IGNORE_UNUSED.
> 
> 2. This patch can be merged (still with CLK_IGNORE_UNUSED)
> 
> 3. Once the DT patch have reached mainline, you should a patch to remove to
> CLK_IGNORE_UNUSED flag
> 
> This way, we avoid breaking bisect, with revision where CLKID_AO_UARTx would get
> disabled by the CCF clk_disable_unused() mechanism while the UART driver does
> not claim the appropriate clock.
> 
I wasn't sure about what's the best approach
I just gave a warning about that patch 2 (removing CLK_IGNORE_UNUSED)
and patch 3 (fix the DTS) should be merged together

and your suggestion sounds good, I will adjust

> 
>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>> ---
>>  arch/arm64/boot/dts/amlogic/meson-axg.dtsi  | 4 ++--
>>  arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 4 ++--
>>  arch/arm64/boot/dts/amlogic/meson-gxl.dtsi  | 4 ++--
>>  3 files changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
>> index 48584d5a329b..e538e2448bb5 100644
>> --- a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
>> +++ b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
>> @@ -533,7 +533,7 @@
>>  				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
>>  				reg = <0x0 0x3000 0x0 0x18>;
>>  				interrupts = <GIC_SPI 193 IRQ_TYPE_EDGE_RISING>;
>> -				clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
>> +				clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
>>  				clock-names = "xtal", "pclk", "baud";
>>  				status = "disabled";
>>  			};
>> @@ -542,7 +542,7 @@
>>  				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
>>  				reg = <0x0 0x4000 0x0 0x18>;
>>  				interrupts = <GIC_SPI 197 IRQ_TYPE_EDGE_RISING>;
>> -				clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
>> +				clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
>>  				clock-names = "xtal", "pclk", "baud";
>>  				status = "disabled";
>>  			};
>> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
>> index 3290a4dc3522..a458ea50c2ef 100644
>> --- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
>> +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
>> @@ -783,12 +783,12 @@
>>  };
>>  
>>  &uart_AO {
>> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
>> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
>>  	clock-names = "xtal", "pclk", "baud";
>>  };
>>  
>>  &uart_AO_B {
>> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
>> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
>>  	clock-names = "xtal", "pclk", "baud";
>>  };
>>  
>> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
>> index 4f355f17eed6..474f4f9630e4 100644
>> --- a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
>> +++ b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
>> @@ -733,12 +733,12 @@
>>  };
>>  
>>  &uart_AO {
>> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
>> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
>>  	clock-names = "xtal", "pclk", "baud";
>>  };
>>  
>>  &uart_AO_B {
>> -	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
>> +	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
>>  	clock-names = "xtal", "pclk", "baud";
>>  };
>>  
> 
> .
>
diff mbox

Patch

diff --git a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
index 48584d5a329b..e538e2448bb5 100644
--- a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi
@@ -533,7 +533,7 @@ 
 				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
 				reg = <0x0 0x3000 0x0 0x18>;
 				interrupts = <GIC_SPI 193 IRQ_TYPE_EDGE_RISING>;
-				clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
+				clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
 				clock-names = "xtal", "pclk", "baud";
 				status = "disabled";
 			};
@@ -542,7 +542,7 @@ 
 				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
 				reg = <0x0 0x4000 0x0 0x18>;
 				interrupts = <GIC_SPI 197 IRQ_TYPE_EDGE_RISING>;
-				clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
+				clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
 				clock-names = "xtal", "pclk", "baud";
 				status = "disabled";
 			};
diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
index 3290a4dc3522..a458ea50c2ef 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
@@ -783,12 +783,12 @@ 
 };
 
 &uart_AO {
-	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
+	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
 	clock-names = "xtal", "pclk", "baud";
 };
 
 &uart_AO_B {
-	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
+	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
 	clock-names = "xtal", "pclk", "baud";
 };
 
diff --git a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
index 4f355f17eed6..474f4f9630e4 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
@@ -733,12 +733,12 @@ 
 };
 
 &uart_AO {
-	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
+	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART1>, <&xtal>;
 	clock-names = "xtal", "pclk", "baud";
 };
 
 &uart_AO_B {
-	clocks = <&xtal>, <&clkc CLKID_CLK81>, <&xtal>;
+	clocks = <&xtal>, <&clkc_AO CLKID_AO_UART2>, <&xtal>;
 	clock-names = "xtal", "pclk", "baud";
 };