Hi, On 11/16/21 12:18, Andy Shevchenko wrote: > On Sun, Nov 14, 2021 at 7:04 PM Hans de Goede <hdegoede@xxxxxxxxxx> 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 > > does not > >> 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 helper function for this >> and make this id 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. > > ... > >> + /* >> + * Note this may not seem like a very unique match, but in the >> + * 24000+ DMI decode dumps from linux-hardware.org only 42 have > > Can you add https:// (or is it gopher? :) linux-hardware.org is intended here as an identifier of the projects, not an URL. The DMI decode database lives here: https://github.com/linuxhw/DMI.git But I don't believe that adding the exact URL in the comment is important, esp. since that may change over time. > >> + * a board_vendor value of "AMI Corporation" and of those 42 >> + * only 1 (the GPD win/pocket entry) has a board_name of >> + * "Default string". Also very few devices have both board_ and >> + * product_name not set. >> + */ > > ... > >> +enum intel_cht_wc_models intel_cht_wc_get_model(void) >> +{ >> + const struct dmi_system_id *id; >> + >> + id = dmi_first_match(cht_wc_model_dmi_ids); >> + if (!id) >> + return INTEL_CHT_WC_UNKNOWN; >> + >> + return (long)id->driver_data; > > Why not proper casting, i.e. (enum intel_...)? Because sizeof(enum) != sizeof(void *) so then the compiler will complain. Where as sizeof(long) == sizeof(void *) > >> +} >> +EXPORT_SYMBOL_GPL(intel_cht_wc_get_model); > > Are you planning to use EXPORT_SYMBOL_GPL_NS()? If not, please consider it. No I was not planning on this and it seems overkill for just a single exported symbol. Regards, Hans
