Re: [PATCH v4 2/2] power: supply: qcom_smbx: add SMB5 support

[David Heidelberg]

On 20/08/2026 12:03, Robin Snyders via B4 Relay wrote:
> From: Casey Connolly <casey.connolly@xxxxxxxxxx>
>
> Introduce support for the SMB5 charger found on PM7250B, PM8150B and
> related Qualcomm PMICs.
>
> SMB5 uses different DCDC status offsets, charger-state encodings and
> electrical ranges. Select these from per-PMIC match data, with PM7250B
> using the PM8150B compatible fallback and parameter block. Read
> overvoltage from the SMB5 status bit, use the already-prescaled IIO
> voltage reading, and convert the SMB5 current-sense voltage to microamps.
> Use battery-info property presence when selecting voltage and current
> targets.
>
> Keep Type-C power-role and VBUS control with the dedicated TCPM and
> regulator drivers. Clear the unsupported HVDCP negotiation modes so stale
> firmware settings cannot raise VBUS. Leave the firmware recharge policy
> unchanged and match the downstream default of ADC-based AICL disabled,
> while enabling periodic hardware AICL with its twelve-second SMB5 rerun
> interval. Preserve the existing three-second SMB2 interval.
>
> PM8150B places the charger and VBUS regulator in the same DCDC peripheral,
> but the SMB5 path does not write the regulator registers. qcom_smbx reads
> 0x1108 and 0x110b, while qcom_usb_vbus-regulator writes 0x1140, 0x1152
> and 0x1153. The SMB2-only OTG configuration write to 0x1153 is not part
> of the SMB5 initialization sequence. The TCPM port and PD PHY use the
> separate 0x15xx and 0x17xx peripherals. Name the USBIN BC1.2 integration
> register and SMB2-only OTG definitions accordingly to make this ownership
> boundary explicit.
>
> Program the battery limits and complete SMB5 input and charging setup
> from the power-supply registration init callback before device_add
> publishes the properties. This makes all public callbacks safe without
> driver-specific probe synchronization.
>
> Suspend USB input and charging before SMB5 initialization. On a later
> failure, restore the original charging-enable state before the
> input-suspend state; leave the input suspended if charging cannot be
> restored. Cancel status work before unregistering the power supply during
> managed teardown. Update the Kconfig description to cover both charger
> generations.
>
> On a OnePlus 7T Pro, register reads from the initial implementation
> confirmed the programmed 4.40 V, 1.50 A and 500 mA limits. A 180-second
> guarded charging trace and a subsequent 600-second runtime trace
> completed without crossing the voltage guard.
>
> Signed-off-by: Casey Connolly <casey.connolly@xxxxxxxxxx>
> Co-developed-by: Joel Selvaraj <foss@xxxxxxxxxxxxxxxx>
> Signed-off-by: Joel Selvaraj <foss@xxxxxxxxxxxxxxxx>
> Co-developed-by: Robin Snyders <robin@xxxxxxxxxxx>
> Signed-off-by: Robin Snyders <robin@xxxxxxxxxxx>
> ---
>   drivers/power/supply/Kconfig     |   8 +-
>   drivers/power/supply/qcom_smbx.c | 757 ++++++++++++++++++++++++++++++---------
>   2 files changed, 598 insertions(+), 167 deletions(-)
>
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index b89ef40df7f8..1159a7711919 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -1173,13 +1173,13 @@ config BATTERY_CHARGER_SURFACE_RT
>   	  will be called surface-rt-ec.
>   
>   config CHARGER_QCOM_SMB2
> -	tristate "Qualcomm PMI8998 PMIC charger driver"
> +	tristate "Qualcomm SMB2 and SMB5 charger driver"
>   	depends on MFD_SPMI_PMIC
>   	depends on IIO
>   	help
> -	  Say Y here to enable the Qualcomm PMIC Charger driver. This
> -	  adds support for the SMB2 switch mode battery charger found
> -	  in PMI8998 and related PMICs.
> +	  Say Y here to enable the Qualcomm PMIC charger driver. This adds
> +	  support for the SMB2 and SMB5 switch-mode battery chargers found
> +	  in PMI8998, PM660, PM7250B and PM8150B PMICs.
>   
>   config FUEL_GAUGE_MM8013
>   	tristate "Mitsumi MM8013 fuel gauge driver"
> diff --git a/drivers/power/supply/qcom_smbx.c b/drivers/power/supply/qcom_smbx.c
> index 71f5a4859412..bc2b1cd3ed68 100644
> --- a/drivers/power/supply/qcom_smbx.c
> +++ b/drivers/power/supply/qcom_smbx.c
> @@ -23,6 +23,13 @@
>   #include <linux/types.h>
>   #include <linux/workqueue.h>
>   
> +enum smb_generation {
> +	SMB2,
> +	SMB5,
> +};
> +
> +#define SMB_REG_OFFSET(smb) ((smb)->gen == SMB2 ? 0x600 : 0x100)
> +

More and more as I look at it, this shouldn't be here, but within the 
device-tree as
charger@1000 {
    reg = <0x1000>, <0x1600>;  # SMB2, or
    reg = <0x1000>, <0x1100>;  # SMB5
};

But see also:
https://lore.kernel.org/all/eodzuccugtdn42basgpczett4yatyirog4nxwe5rhg5xf46ibp@jzcjmje4aqc3/

I'll try to do some basic separation so we know what bits belongs into which 
blog, keep you in CC.

David


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