[PATCH 05/11] sysreset: qcom-pshold: PM8916 PON reset type support

[Casey Connolly]

Hi Sam,

On 06/06/2026 10:47, Sam Day via B4 Relay wrote:
> From: Sam Day <me at samcday.com>
> 
> Before de-asserting PS_HOLD, PM8916 PMIC can be informed of what kind of
> reset should take place.
> 
> This might seem a little hacky/weird, but it's a byproduct of how the DT
> nodes are structured, and the way u-boot handles sysreset.

ahh yeah this is annoying that there's no DT link between these, this is
probably the best approach.

The way this is implemented right now means a board that doesn't have a
pm8916 will get at least a warning and an error on reset due to the pmic
device being missing.

Could you demote the error here to a dev_dbg() at least for the expected
-ENODEV case, and do the same in the previous patch.

> 
> The qcom,pshold node does not belong to the PMIC hierarchy. If U-Boot's
> sysreset infra was a little more flexible, we might be able to model the
> qcom,pm8916-pon driver as UCLASS_SYSRESET in order to catch the sysreset
> type and set the appropriate bits in the PMIC, before chaining to the
> pshold driver to de-assert PS_HOLD (which actually triggers the reset
> type that was written in the previous step).

I think an approach that could work better here would be to have the
pm8916-pon driver instead get a reference to the qcom,pshold in its
probe function and then have an exported qcom_pshold_register_pmic()
function. This way we keep the reset path simple and avoid the
unnecessary device lookup on platforms that don't have pm8916.

That said, I'm happy to defer something like that to a future
optimisation and get this merged more or less as-is.

Thanks and kind regards,


> 
> Signed-off-by: Sam Day <me at samcday.com>
> ---
>  drivers/sysreset/sysreset_qcom-pshold.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/sysreset/sysreset_qcom-pshold.c b/drivers/sysreset/sysreset_qcom-pshold.c
> index 45290478536..20ddb4ae4ec 100644
> --- a/drivers/sysreset/sysreset_qcom-pshold.c
> +++ b/drivers/sysreset/sysreset_qcom-pshold.c
> @@ -13,6 +13,8 @@
>  #include <sysreset.h>
>  #include <asm/io.h>
>  #include <linux/delay.h>
> +#include <dm/device_compat.h>
> +#include "pm8916_pon.h"
>  
>  struct qcom_pshold_priv {
>  	phys_addr_t base;
> @@ -22,6 +24,13 @@ static int qcom_pshold_request(struct udevice *dev, enum sysreset_t type)
>  {
>  	struct qcom_pshold_priv *priv = dev_get_priv(dev);
>  
> +	if (CONFIG_IS_ENABLED(PM8916_PON)) {
> +		int ret = pm8916_pon_set_reboot_type(type);
> +
> +		if (ret)
> +			dev_err(dev, "Failed to set reboot type: %d\n", ret);
> +	}
> +
>  	writel(0, priv->base);
>  	mdelay(10000);
>  
> 

-- 
// Casey (she/her)