On Mon, 06 Dec 2021, Hans de Goede wrote:
> Tablet / laptop designs using an Intel Cherry Trail x86 main SoC with
> an Intel Whiskey Cove PMIC do not use a single standard setup for
> the charger, fuel-gauge and other chips surrounding the PMIC /
> charging+data USB port.
>
> Unlike what is normal on x86 this diversity in designs is not handled
> by the ACPI tables. On 2 of the 3 known designs there are no standard
> (PNP0C0A) ACPI battery devices and on the 3th design the ACPI battery
> device does not work under Linux due to it requiring non-standard
> and undocumented ACPI behavior.
>
> So to make things work under Linux we use native charger and fuel-gauge
> drivers on these devices, re-using the native drivers used on ARM boards
> with the same charger / fuel-gauge ICs.
>
> This requires various MFD-cell drivers for the CHT-WC PMIC cells to
> know which model they are exactly running on so that they can e.g.
> instantiate an I2C-client for the right model charger-IC (the charger
> is connected to an I2C-controller which is part of the PMIC).
>
> Rather then duplicating DMI-id matching to check which model we are
> running on in each MFD-cell driver, add a check for this to the
> shared drivers/mfd/intel_soc_pmic_chtwc.c code by using a
> DMI table for all 3 known models:
>
> 1. The GPD Win and GPD Pocket mini-laptops, these are really 2 models
> but the Pocket re-uses the GPD Win's design in a different housing:
>
> The WC PMIC is connected to a TI BQ24292i charger, paired with
> a Maxim MAX17047 fuelgauge + a FUSB302 USB Type-C Controller +
> a PI3USB30532 USB switch, for a fully functional Type-C port.
>
> 2. The Xiaomi Mi Pad 2:
>
> The WC PMIC is connected to a TI BQ25890 charger, paired with
> a TI BQ27520 fuelgauge, using the TI BQ25890 for BC1.2 charger type
> detection, for a USB-2 only Type-C port without PD.
>
> 3. The Lenovo Yoga Book YB1-X90 / Lenovo Yoga Book YB1-X91 series:
>
> The WC PMIC is connected to a TI BQ25892 charger, paired with
> a TI BQ27542 fuelgauge, using the WC PMIC for BC1.2 charger type
> detection and using the BQ25892's Mediatek Pump Express+ (1.0)
> support to enable charging with up to 12V through a micro-USB port.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> Changes in v4:
> - Put '{' and comment of DMI entries on separate lines (requested by Lee)
> - Drop comment on terminating empty entry in DMI table
>
> Changes in v3:
> - Store the model in struct intel_soc_pmic instead of adding a helper
> function to retreive it
>
> Changes in v2:
> - New patch in v2 of this patch-set
> ---
> drivers/mfd/intel_soc_pmic_chtwc.c | 40 ++++++++++++++++++++++++++++++
> include/linux/mfd/intel_soc_pmic.h | 8 ++++++
> 2 files changed, 48 insertions(+)
Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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