[PATCH] rockchip: boot_mode: fix download key detection

[PATCH] rockchip: boot_mode: fix download key detection

[Tianling Shen]

rockchip_dnl_key_pressed() looks for the ADC device by checking
whether the device name starts with "saradc".

On RK3328, RK3576, RK3588 etc., the SARADC node is named "adc@...",
so the device name no longer has the "saradc" prefix. As a result,
U-Boot fails to find the SARADC device and does not sample the
download key state.

Do not rely on the DT node name. Match the bound Rockchip SARADC
driver instead, which works for both "saradc@..." and "adc@..."
node names.

Signed-off-by: Tianling Shen <cnsztl@gmail.com>
---
 arch/arm/mach-rockchip/boot_mode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-rockchip/boot_mode.c b/arch/arm/mach-rockchip/boot_mode.c
index 55e9456668ae..363fad523cbd 100644
--- a/arch/arm/mach-rockchip/boot_mode.c
+++ b/arch/arm/mach-rockchip/boot_mode.c
@@ -51,7 +51,7 @@ __weak int rockchip_dnl_key_pressed(void)
 
 	ret = -ENODEV;
 	uclass_foreach_dev(dev, uc) {
-		if (!strncmp(dev->name, "saradc", 6)) {
+		if (!strcmp(dev->driver->name, "rockchip_saradc")) {
 			ret = adc_channel_single_shot(dev->name, 1, &val);
 			break;
 		}
-- 
2.54.0

Re: [PATCH] rockchip: boot_mode: fix download key detection

[Jonas Karlman]

Hi Tianling,

On 6/10/2026 5:01 AM, Tianling Shen wrote:
> rockchip_dnl_key_pressed() looks for the ADC device by checking
> whether the device name starts with "saradc".
> 
> On RK3328, RK3576, RK3588 etc., the SARADC node is named "adc@...",
> so the device name no longer has the "saradc" prefix. As a result,
> U-Boot fails to find the SARADC device and does not sample the
> download key state.
> 
> Do not rely on the DT node name. Match the bound Rockchip SARADC
> driver instead, which works for both "saradc@..." and "adc@..."
> node names.
> 
> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> ---
>  arch/arm/mach-rockchip/boot_mode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-rockchip/boot_mode.c b/arch/arm/mach-rockchip/boot_mode.c
> index 55e9456668ae..363fad523cbd 100644
> --- a/arch/arm/mach-rockchip/boot_mode.c
> +++ b/arch/arm/mach-rockchip/boot_mode.c
> @@ -51,7 +51,7 @@ __weak int rockchip_dnl_key_pressed(void)
>  
>  	ret = -ENODEV;
>  	uclass_foreach_dev(dev, uc) {
> -		if (!strncmp(dev->name, "saradc", 6)) {
> +		if (!strcmp(dev->driver->name, "rockchip_saradc")) {

The adc channel used below may not fit all boards/SoCs, so this change
may have unintended consequences.

I have previously avoided "fixing"/enable this code path for RK35xx
because the download key selection should really be improved when this
is fixed/expanded to more boards/SoCs.

E.g. maybe add support to declare a recovery button in u-boot,config
node and use UCLASS_BUTTON to check if such button was pressed or
something similar?

Regards,
Jonas

>  			ret = adc_channel_single_shot(dev->name, 1, &val);
>  			break;
>  		}

Re: [PATCH] rockchip: boot_mode: fix download key detection

[Tianling Shen]

Hi Jonas,

On 2026/6/10 21:25, Jonas Karlman wrote:
> Hi Tianling,
> 
> On 6/10/2026 5:01 AM, Tianling Shen wrote:
>> rockchip_dnl_key_pressed() looks for the ADC device by checking
>> whether the device name starts with "saradc".
>>
>> On RK3328, RK3576, RK3588 etc., the SARADC node is named "adc@...",
>> so the device name no longer has the "saradc" prefix. As a result,
>> U-Boot fails to find the SARADC device and does not sample the
>> download key state.
>>
>> Do not rely on the DT node name. Match the bound Rockchip SARADC
>> driver instead, which works for both "saradc@..." and "adc@..."
>> node names.
>>
>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
>> ---
>>   arch/arm/mach-rockchip/boot_mode.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/mach-rockchip/boot_mode.c b/arch/arm/mach-rockchip/boot_mode.c
>> index 55e9456668ae..363fad523cbd 100644
>> --- a/arch/arm/mach-rockchip/boot_mode.c
>> +++ b/arch/arm/mach-rockchip/boot_mode.c
>> @@ -51,7 +51,7 @@ __weak int rockchip_dnl_key_pressed(void)
>>   
>>   	ret = -ENODEV;
>>   	uclass_foreach_dev(dev, uc) {
>> -		if (!strncmp(dev->name, "saradc", 6)) {
>> +		if (!strcmp(dev->driver->name, "rockchip_saradc")) {
> 
> The adc channel used below may not fit all boards/SoCs, so this change
> may have unintended consequences.
> 
> I have previously avoided "fixing"/enable this code path for RK35xx
> because the download key selection should really be improved when this
> is fixed/expanded to more boards/SoCs.
> 
> E.g. maybe add support to declare a recovery button in u-boot,config
> node and use UCLASS_BUTTON to check if such button was pressed or
> something similar?

Yes this is much better than evaluating raw ADC values, but BUTTON is 
not available in SPL so we cannot have this functionality in SPL (though 
this idea was already rejected :P).

I have made an initial version that use UCLASS_BUTTON:

```
__weak int rockchip_dnl_key_pressed(void)
{
#if CONFIG_IS_ENABLED(BUTTON)
	const char *path;
	struct udevice *button;
	ofnode node;
	int ret;

	path = ofnode_options_read_str("recovery-key");
	if (!path)
		path = ofnode_conf_read_str("u-boot,recovery-key");
	if (!path)
		return false;

	if (path[0] == '/')
		node = ofnode_path(path);
	else
		node = ofnode_get_aliases_node(path);

	if (!ofnode_valid(node)) {
		pr_err("%s: invalid recovery key '%s'\n", __func__, path);
		return false;
	}

	ret = uclass_get_device_by_ofnode(UCLASS_BUTTON, node, &button);
	if (ret) {
		pr_err("%s: recovery key is not a button: %d\n", __func__, ret);
		return false;
	}

	ret = button_get_state(button);
	if (ret < 0) {
		pr_err("%s: failed to read recovery key: %d\n", __func__, ret);
		return false;
	}

	return ret == BUTTON_ON;
#else
	return false;
#endif
}
```

... so it can be configured in u-boot.dtsi like this:
```
/ {
	options {
		u-boot {
			recovery-key = "/keys-1/button-recovery";
		};
	};
};
```

I have tested this on my DshanPi A1 board and it seems to work okay.

Is this an acceptable way to configure recovery key? I'm also wondering 
if it's necessary to keep compatibility with old adc_channel_single_shot 
implementation.

Thanks,
Tianling.

> 
> Regards,
> Jonas
> 
>>   			ret = adc_channel_single_shot(dev->name, 1, &val);
>>   			break;
>>   		}
> 

Re: [PATCH] rockchip: boot_mode: fix download key detection

[Quentin Schulz]

Hi Tianling, Jonas,

On 6/11/26 9:45 AM, Tianling Shen wrote:
> Hi Jonas,
> 
> On 2026/6/10 21:25, Jonas Karlman wrote:
>> Hi Tianling,
>>
>> On 6/10/2026 5:01 AM, Tianling Shen wrote:
>>> rockchip_dnl_key_pressed() looks for the ADC device by checking
>>> whether the device name starts with "saradc".
>>>
>>> On RK3328, RK3576, RK3588 etc., the SARADC node is named "adc@...",
>>> so the device name no longer has the "saradc" prefix. As a result,
>>> U-Boot fails to find the SARADC device and does not sample the
>>> download key state.
>>>
>>> Do not rely on the DT node name. Match the bound Rockchip SARADC
>>> driver instead, which works for both "saradc@..." and "adc@..."
>>> node names.
>>>
>>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
>>> ---
>>>   arch/arm/mach-rockchip/boot_mode.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/mach-rockchip/boot_mode.c b/arch/arm/mach- 
>>> rockchip/boot_mode.c
>>> index 55e9456668ae..363fad523cbd 100644
>>> --- a/arch/arm/mach-rockchip/boot_mode.c
>>> +++ b/arch/arm/mach-rockchip/boot_mode.c
>>> @@ -51,7 +51,7 @@ __weak int rockchip_dnl_key_pressed(void)
>>>       ret = -ENODEV;
>>>       uclass_foreach_dev(dev, uc) {
>>> -        if (!strncmp(dev->name, "saradc", 6)) {
>>> +        if (!strcmp(dev->driver->name, "rockchip_saradc")) {
>>
>> The adc channel used below may not fit all boards/SoCs, so this change
>> may have unintended consequences.
>>
>> I have previously avoided "fixing"/enable this code path for RK35xx
>> because the download key selection should really be improved when this
>> is fixed/expanded to more boards/SoCs.
>>
>> E.g. maybe add support to declare a recovery button in u-boot,config
>> node and use UCLASS_BUTTON to check if such button was pressed or
>> something similar?
> 
> Yes this is much better than evaluating raw ADC values, but BUTTON is 
> not available in SPL so we cannot have this functionality in SPL (though 
> this idea was already rejected :P).
> 

I'm sorry my memory is failing me, do you have a link maybe to that 
discussion?

> I have made an initial version that use UCLASS_BUTTON:
> 
> ```
> __weak int rockchip_dnl_key_pressed(void)
> {
> #if CONFIG_IS_ENABLED(BUTTON)
>      const char *path;
>      struct udevice *button;
>      ofnode node;
>      int ret;
> 
>      path = ofnode_options_read_str("recovery-key");
>      if (!path)
>          path = ofnode_conf_read_str("u-boot,recovery-key");
>      if (!path)
>          return false;
> 
>      if (path[0] == '/')
>          node = ofnode_path(path);
>      else
>          node = ofnode_get_aliases_node(path);
> 
>      if (!ofnode_valid(node)) {
>          pr_err("%s: invalid recovery key '%s'\n", __func__, path);
>          return false;
>      }
> 
>      ret = uclass_get_device_by_ofnode(UCLASS_BUTTON, node, &button);
>      if (ret) {
>          pr_err("%s: recovery key is not a button: %d\n", __func__, ret);
>          return false;
>      }
> 
>      ret = button_get_state(button);
>      if (ret < 0) {
>          pr_err("%s: failed to read recovery key: %d\n", __func__, ret);
>          return false;
>      }
> 
>      return ret == BUTTON_ON;
> #else
>      return false;
> #endif
> }
> ```
> 
> ... so it can be configured in u-boot.dtsi like this:
> ```
> / {
>      options {
>          u-boot {
>              recovery-key = "/keys-1/button-recovery";

This should absolutely be a phandle and not a path.

>          };
>      };
> };
> ```
> 
> I have tested this on my DshanPi A1 board and it seems to work okay.
> 
> Is this an acceptable way to configure recovery key? I'm also wondering 

It could be. Typically, when a new property makes it to the device tree, 
it must be documented in the binding. Here it would be part of a 
u-boot,config node, but I couldn't find a binding in U-Boot, Linux 
kernel or the Device Tree spec, so I don't know what we're supposed to 
do here. The button itself will need to be part of the Linux kernel 
upstream DTS, the difficult part will be which event code it needs to 
return and will be board-specific.

> if it's necessary to keep compatibility with old adc_channel_single_shot 
> implementation.
> 

Not necessarily, but we absolutely need all boards using this old 
mechanism to be supported by the new mechanism, which may be difficult 
since we don't necessarily have access to their schematics.

I think we can maybe compromise for now on a Kconfig symbol for the 
channel to use? What do you think? We would still need to check the 
schematics of all boards that exercise this path and check if fixing the 
condition won't cause side effects (because it now is reading the ADC 
channel while it wasn't before due to the typo). The other option is to 
explicitly disable it for all devices that could never meet the 
condition with the typo (so even at SoC level since SARADC is an 
SoC-specific IP) such that it can only be enabled if someone tests it on 
their board.

Cheers,
Quentin

Re: [PATCH] rockchip: boot_mode: fix download key detection

[Tianling Shen]

Hi Quentin,

On 2026/6/26 19:52, Quentin Schulz wrote:
> Hi Tianling, Jonas,
> 
> On 6/11/26 9:45 AM, Tianling Shen wrote:
>> Hi Jonas,
>>
>> On 2026/6/10 21:25, Jonas Karlman wrote:
>>> Hi Tianling,
>>>
>>> On 6/10/2026 5:01 AM, Tianling Shen wrote:
>>>> rockchip_dnl_key_pressed() looks for the ADC device by checking
>>>> whether the device name starts with "saradc".
>>>>
>>>> On RK3328, RK3576, RK3588 etc., the SARADC node is named "adc@...",
>>>> so the device name no longer has the "saradc" prefix. As a result,
>>>> U-Boot fails to find the SARADC device and does not sample the
>>>> download key state.
>>>>
>>>> Do not rely on the DT node name. Match the bound Rockchip SARADC
>>>> driver instead, which works for both "saradc@..." and "adc@..."
>>>> node names.
>>>>
>>>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
>>>> ---
>>>>   arch/arm/mach-rockchip/boot_mode.c | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm/mach-rockchip/boot_mode.c b/arch/arm/mach- 
>>>> rockchip/boot_mode.c
>>>> index 55e9456668ae..363fad523cbd 100644
>>>> --- a/arch/arm/mach-rockchip/boot_mode.c
>>>> +++ b/arch/arm/mach-rockchip/boot_mode.c
>>>> @@ -51,7 +51,7 @@ __weak int rockchip_dnl_key_pressed(void)
>>>>       ret = -ENODEV;
>>>>       uclass_foreach_dev(dev, uc) {
>>>> -        if (!strncmp(dev->name, "saradc", 6)) {
>>>> +        if (!strcmp(dev->driver->name, "rockchip_saradc")) {
>>>
>>> The adc channel used below may not fit all boards/SoCs, so this change
>>> may have unintended consequences.
>>>
>>> I have previously avoided "fixing"/enable this code path for RK35xx
>>> because the download key selection should really be improved when this
>>> is fixed/expanded to more boards/SoCs.
>>>
>>> E.g. maybe add support to declare a recovery button in u-boot,config
>>> node and use UCLASS_BUTTON to check if such button was pressed or
>>> something similar?
>>
>> Yes this is much better than evaluating raw ADC values, but BUTTON is 
>> not available in SPL so we cannot have this functionality in SPL 
>> (though this idea was already rejected :P).
>>
> 
> I'm sorry my memory is failing me, do you have a link maybe to that 
> discussion?

Please refer 
https://lore.kernel.org/u-boot/fd15b6e4-5525-4ce5-a145-ceb47d44c40e@rock-chips.com/

> 
>> I have made an initial version that use UCLASS_BUTTON:
>>
>> ```
>> __weak int rockchip_dnl_key_pressed(void)
>> {
>> #if CONFIG_IS_ENABLED(BUTTON)
>>      const char *path;
>>      struct udevice *button;
>>      ofnode node;
>>      int ret;
>>
>>      path = ofnode_options_read_str("recovery-key");
>>      if (!path)
>>          path = ofnode_conf_read_str("u-boot,recovery-key");
>>      if (!path)
>>          return false;
>>
>>      if (path[0] == '/')
>>          node = ofnode_path(path);
>>      else
>>          node = ofnode_get_aliases_node(path);
>>
>>      if (!ofnode_valid(node)) {
>>          pr_err("%s: invalid recovery key '%s'\n", __func__, path);
>>          return false;
>>      }
>>
>>      ret = uclass_get_device_by_ofnode(UCLASS_BUTTON, node, &button);
>>      if (ret) {
>>          pr_err("%s: recovery key is not a button: %d\n", __func__, ret);
>>          return false;
>>      }
>>
>>      ret = button_get_state(button);
>>      if (ret < 0) {
>>          pr_err("%s: failed to read recovery key: %d\n", __func__, ret);
>>          return false;
>>      }
>>
>>      return ret == BUTTON_ON;
>> #else
>>      return false;
>> #endif
>> }
>> ```
>>
>> ... so it can be configured in u-boot.dtsi like this:
>> ```
>> / {
>>      options {
>>          u-boot {
>>              recovery-key = "/keys-1/button-recovery";
> 
> This should absolutely be a phandle and not a path.

This prop also works with phandle. However most dts from upstream kernel 
does not have aliases for button, I have no idea how to refer them by 
phandle without modifying original copy.

> 
>>          };
>>      };
>> };
>> ```
>>
>> I have tested this on my DshanPi A1 board and it seems to work okay.
>>
>> Is this an acceptable way to configure recovery key? I'm also wondering 
> 
> It could be. Typically, when a new property makes it to the device tree, 
> it must be documented in the binding. Here it would be part of a u- 
> boot,config node, but I couldn't find a binding in U-Boot, Linux kernel 
> or the Device Tree spec, so I don't know what we're supposed to do here. 
> The button itself will need to be part of the Linux kernel upstream DTS, 
> the difficult part will be which event code it needs to return and will 
> be board-specific.

So recovery-key prop is added to detect if that button is pressed only. 
We don't care the event code.

> 
>> if it's necessary to keep compatibility with old 
>> adc_channel_single_shot implementation.
>>
> 
> Not necessarily, but we absolutely need all boards using this old 
> mechanism to be supported by the new mechanism, which may be difficult 
> since we don't necessarily have access to their schematics.

I'm not sure how many users are there. This code has been broken for a 
long time. I can see a few boards implement their own download key 
detection by similar (old) code.

> 
> I think we can maybe compromise for now on a Kconfig symbol for the 
> channel to use? What do you think? We would still need to check the 
> schematics of all boards that exercise this path and check if fixing the 
> condition won't cause side effects (because it now is reading the ADC 
> channel while it wasn't before due to the typo). The other option is to 
> explicitly disable it for all devices that could never meet the 
> condition with the typo (so even at SoC level since SARADC is an SoC- 
> specific IP) such that it can only be enabled if someone tests it on 
> their board.

Honestly I don't want to "improve" this old path if we decide to use the 
new config prop. KEY_DOWN_MAX_VAL=30 is also too strict for some boards 
(for example the ADC value on DshanPi A1 can be up to 45~47 when the 
button is pressed).

Thanks,
Tianling.

> 
> Cheers,
> Quentin