* [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
@ 2022-04-06 13:05 Tudor Ambarus
2022-04-07 6:26 ` Claudiu.Beznea
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Tudor Ambarus @ 2022-04-06 13:05 UTC (permalink / raw)
To: nicolas.ferre, claudiu.beznea
Cc: alexandre.belloni, devicetree, linux-arm-kernel, linux-kernel,
Tudor Ambarus, Mihai Sain
The impedance of the QSPI PCB lines on the sama7g5ek is 50 Ohms.
Align the output impedance of the QSPI0 HSIOs by setting a medium drive
strength which corresponds to an impedance of 56 Ohms when VDD is in the
3.0V - 3.6V range. The high drive strength setting corresponds to an
output impedance of 42 Ohms on the QSPI0 HSIOs.
Suggested-by: Mihai Sain <mihai.sain@microchip.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
index 08685a10eda1..8f9643170ba3 100644
--- a/arch/arm/boot/dts/at91-sama7g5ek.dts
+++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
@@ -655,7 +655,7 @@ pinctrl_qspi: qspi {
<PIN_PB21__QSPI0_INT>;
bias-disable;
slew-rate = <0>;
- atmel,drive-strength = <ATMEL_PIO_DRVSTR_HI>;
+ atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
};
pinctrl_sdmmc0_default: sdmmc0_default {
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
2022-04-06 13:05 [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines Tudor Ambarus
@ 2022-04-07 6:26 ` Claudiu.Beznea
2022-04-07 7:51 ` Tudor.Ambarus
2022-04-13 12:40 ` Nicolas Ferre
2022-04-13 12:43 ` Nicolas Ferre
2 siblings, 1 reply; 6+ messages in thread
From: Claudiu.Beznea @ 2022-04-07 6:26 UTC (permalink / raw)
To: Tudor.Ambarus, Nicolas.Ferre
Cc: alexandre.belloni, devicetree, linux-arm-kernel, linux-kernel,
Mihai.Sain
Hi, Tudor,
On 06.04.2022 16:05, Tudor Ambarus wrote:
> The impedance of the QSPI PCB lines on the sama7g5ek is 50 Ohms.
> Align the output impedance of the QSPI0 HSIOs by setting a medium drive
> strength which corresponds to an impedance of 56 Ohms when VDD is in the
> 3.0V - 3.6V range. The high drive strength setting corresponds to an
> output impedance of 42 Ohms on the QSPI0 HSIOs.
>
> Suggested-by: Mihai Sain <mihai.sain@microchip.com>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Is it necessary a fixes tag here?
Thank you,
Claudiu Beznea
> ---
> arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
> index 08685a10eda1..8f9643170ba3 100644
> --- a/arch/arm/boot/dts/at91-sama7g5ek.dts
> +++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
> @@ -655,7 +655,7 @@ pinctrl_qspi: qspi {
> <PIN_PB21__QSPI0_INT>;
> bias-disable;
> slew-rate = <0>;
> - atmel,drive-strength = <ATMEL_PIO_DRVSTR_HI>;
> + atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
> };
>
> pinctrl_sdmmc0_default: sdmmc0_default {
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
2022-04-07 6:26 ` Claudiu.Beznea
@ 2022-04-07 7:51 ` Tudor.Ambarus
2022-04-07 8:24 ` Claudiu.Beznea
0 siblings, 1 reply; 6+ messages in thread
From: Tudor.Ambarus @ 2022-04-07 7:51 UTC (permalink / raw)
To: Claudiu.Beznea, Nicolas.Ferre
Cc: alexandre.belloni, devicetree, linux-arm-kernel, linux-kernel,
Mihai.Sain
On 4/7/22 09:26, Claudiu Beznea - M18063 wrote:
> Hi, Tudor,
>
> On 06.04.2022 16:05, Tudor Ambarus wrote:
>> The impedance of the QSPI PCB lines on the sama7g5ek is 50 Ohms.
>> Align the output impedance of the QSPI0 HSIOs by setting a medium drive
>> strength which corresponds to an impedance of 56 Ohms when VDD is in the
>> 3.0V - 3.6V range. The high drive strength setting corresponds to an
>> output impedance of 42 Ohms on the QSPI0 HSIOs.
>>
>> Suggested-by: Mihai Sain <mihai.sain@microchip.com>
>> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
>
> Is it necessary a fixes tag here?
>
It's not a fix per se, it's just a fine tuning that's why I chose to don't add
the fixes tag. The memory that we have populated on sama7g5ek works fine even
with high drive strength, but it's better to adjust it and use medium instead,
in case some other flashes with higher frequencies are tested. If you think a
fixes tag is needed, give me a sign and I'll resubmit.
>
>> ---
>> arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
>> index 08685a10eda1..8f9643170ba3 100644
>> --- a/arch/arm/boot/dts/at91-sama7g5ek.dts
>> +++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
>> @@ -655,7 +655,7 @@ pinctrl_qspi: qspi {
>> <PIN_PB21__QSPI0_INT>;
>> bias-disable;
>> slew-rate = <0>;
>> - atmel,drive-strength = <ATMEL_PIO_DRVSTR_HI>;
>> + atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
>> };
>>
>> pinctrl_sdmmc0_default: sdmmc0_default {
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
2022-04-07 7:51 ` Tudor.Ambarus
@ 2022-04-07 8:24 ` Claudiu.Beznea
0 siblings, 0 replies; 6+ messages in thread
From: Claudiu.Beznea @ 2022-04-07 8:24 UTC (permalink / raw)
To: Tudor.Ambarus, Nicolas.Ferre
Cc: alexandre.belloni, devicetree, linux-arm-kernel, linux-kernel,
Mihai.Sain
On 07.04.2022 10:51, Tudor Ambarus - M18064 wrote:
> On 4/7/22 09:26, Claudiu Beznea - M18063 wrote:
>> Hi, Tudor,
>>
>> On 06.04.2022 16:05, Tudor Ambarus wrote:
>>> The impedance of the QSPI PCB lines on the sama7g5ek is 50 Ohms.
>>> Align the output impedance of the QSPI0 HSIOs by setting a medium drive
>>> strength which corresponds to an impedance of 56 Ohms when VDD is in the
>>> 3.0V - 3.6V range. The high drive strength setting corresponds to an
>>> output impedance of 42 Ohms on the QSPI0 HSIOs.
>>>
>>> Suggested-by: Mihai Sain <mihai.sain@microchip.com>
>>> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
>>
>> Is it necessary a fixes tag here?
>>
>
> It's not a fix per se, it's just a fine tuning that's why I chose to don't add
> the fixes tag. The memory that we have populated on sama7g5ek works fine even
> with high drive strength, but it's better to adjust it and use medium instead,
> in case some other flashes with higher frequencies are tested. If you think a
> fixes tag is needed, give me a sign and I'll resubmit.
Its good for me as is. Just wanted to be sure it hasn't been forgotten.
Thank you!
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>
>>
>>> ---
>>> arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
>>> index 08685a10eda1..8f9643170ba3 100644
>>> --- a/arch/arm/boot/dts/at91-sama7g5ek.dts
>>> +++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
>>> @@ -655,7 +655,7 @@ pinctrl_qspi: qspi {
>>> <PIN_PB21__QSPI0_INT>;
>>> bias-disable;
>>> slew-rate = <0>;
>>> - atmel,drive-strength = <ATMEL_PIO_DRVSTR_HI>;
>>> + atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
>>> };
>>>
>>> pinctrl_sdmmc0_default: sdmmc0_default {
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
2022-04-06 13:05 [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines Tudor Ambarus
2022-04-07 6:26 ` Claudiu.Beznea
@ 2022-04-13 12:40 ` Nicolas Ferre
2022-04-13 12:43 ` Nicolas Ferre
2 siblings, 0 replies; 6+ messages in thread
From: Nicolas Ferre @ 2022-04-13 12:40 UTC (permalink / raw)
To: Tudor Ambarus, claudiu.beznea
Cc: alexandre.belloni, devicetree, linux-arm-kernel, linux-kernel,
Mihai Sain
On 06/04/2022 at 15:05, Tudor Ambarus wrote:
> The impedance of the QSPI PCB lines on the sama7g5ek is 50 Ohms.
> Align the output impedance of the QSPI0 HSIOs by setting a medium drive
> strength which corresponds to an impedance of 56 Ohms when VDD is in the
> 3.0V - 3.6V range. The high drive strength setting corresponds to an
> output impedance of 42 Ohms on the QSPI0 HSIOs.
>
> Suggested-by: Mihai Sain <mihai.sain@microchip.com>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
And queued in "fixes" branch for 5.18.
Thanks, best regards,
Nicolas
> ---
> arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
> index 08685a10eda1..8f9643170ba3 100644
> --- a/arch/arm/boot/dts/at91-sama7g5ek.dts
> +++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
> @@ -655,7 +655,7 @@ pinctrl_qspi: qspi {
> <PIN_PB21__QSPI0_INT>;
> bias-disable;
> slew-rate = <0>;
> - atmel,drive-strength = <ATMEL_PIO_DRVSTR_HI>;
> + atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
> };
>
> pinctrl_sdmmc0_default: sdmmc0_default {
--
Nicolas Ferre
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines
2022-04-06 13:05 [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines Tudor Ambarus
2022-04-07 6:26 ` Claudiu.Beznea
2022-04-13 12:40 ` Nicolas Ferre
@ 2022-04-13 12:43 ` Nicolas Ferre
2 siblings, 0 replies; 6+ messages in thread
From: Nicolas Ferre @ 2022-04-13 12:43 UTC (permalink / raw)
To: Tudor Ambarus, claudiu.beznea
Cc: alexandre.belloni, devicetree, linux-arm-kernel, linux-kernel,
Mihai Sain
On 06/04/2022 at 15:05, Tudor Ambarus wrote:
> The impedance of the QSPI PCB lines on the sama7g5ek is 50 Ohms.
> Align the output impedance of the QSPI0 HSIOs by setting a medium drive
> strength which corresponds to an impedance of 56 Ohms when VDD is in the
> 3.0V - 3.6V range. The high drive strength setting corresponds to an
> output impedance of 42 Ohms on the QSPI0 HSIOs.
>
> Suggested-by: Mihai Sain <mihai.sain@microchip.com>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Queued in fixes branch for 5.18. Thanks!
Best regards,
Nicolas
> ---
> arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
> index 08685a10eda1..8f9643170ba3 100644
> --- a/arch/arm/boot/dts/at91-sama7g5ek.dts
> +++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
> @@ -655,7 +655,7 @@ pinctrl_qspi: qspi {
> <PIN_PB21__QSPI0_INT>;
> bias-disable;
> slew-rate = <0>;
> - atmel,drive-strength = <ATMEL_PIO_DRVSTR_HI>;
> + atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
> };
>
> pinctrl_sdmmc0_default: sdmmc0_default {
--
Nicolas Ferre
^ permalink raw reply [flat|nested] 6+ messages in thread
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2022-04-06 13:05 [PATCH] ARM: dts: at91: sama7g5ek: Align the impedance of the QSPI0's HSIO and PCB lines Tudor Ambarus
2022-04-07 6:26 ` Claudiu.Beznea
2022-04-07 7:51 ` Tudor.Ambarus
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