Re: [PATCH 1/6] platform/surface: Set up Surface Aggregator device registry
On 2/8/21 8:35 PM, Maximilian Luz wrote: The Surface System Aggregator Module (SSAM) subsystem provides various functionalities, which are separated by spreading them across multiple devices and corresponding drivers. Parts of that functionality / some of those devices, however, can (as far as we currently know) not be auto-detected by conventional means. While older (specifically 5th- and 6th-)generation models do advertise most of their functionality via standard platform devices in ACPI, newer generations do not. As we are currently also not aware of any feasible way to query said functionalities dynamically, this poses a problem. There is, however, a device in ACPI that seems to be used by Windows for identifying different Surface models: The Windows Surface Integration Device (WSID). This device seems to have a HID corresponding to the overall set of functionalities SSAM provides for the associated model. This commit introduces a registry providing non-detectable device information via software nodes. In addition, a SSAM platform hub driver is introduced, which takes care of creating and managing the SSAM devices specified in this registry. This approach allows for a hierarchical setup akin to ACPI and is easily extendable, e.g. via firmware node properties. Note that this commit only provides the basis for the platform hub and registry, and does not add any content to it. The registry will be expanded in subsequent commits. Signed-off-by: Maximilian Luz --- MAINTAINERS | 1 + drivers/platform/surface/Kconfig | 26 ++ drivers/platform/surface/Makefile | 1 + .../surface/surface_aggregator_registry.c | 284 ++ 4 files changed, 312 insertions(+) create mode 100644 drivers/platform/surface/surface_aggregator_registry.c diff --git a/MAINTAINERS b/MAINTAINERS index 4fcf3df517a8..000a82f59c76 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11826,6 +11826,7 @@ F: Documentation/driver-api/surface_aggregator/ F:drivers/platform/surface/aggregator/ F:drivers/platform/surface/surface_acpi_notify.c F:drivers/platform/surface/surface_aggregator_cdev.c +F: drivers/platform/surface/surface_aggregator_registry.c F:include/linux/surface_acpi_notify.h F:include/linux/surface_aggregator/ F:include/uapi/linux/surface_aggregator/ diff --git a/drivers/platform/surface/Kconfig b/drivers/platform/surface/Kconfig index 0847b2dc97bf..1cd37c041710 100644 --- a/drivers/platform/surface/Kconfig +++ b/drivers/platform/surface/Kconfig @@ -77,6 +77,32 @@ config SURFACE_AGGREGATOR_CDEV The provided interface is intended for debugging and development only, and should not be used otherwise. +config SURFACE_AGGREGATOR_REGISTRY + tristate "Surface System Aggregator Module Device Registry" + depends on SURFACE_AGGREGATOR_BUS Just noticed that there should also be a depends on SURFACE_AGGREGATOR here as SURFACE_AGGREGATOR_BUS is a bool. Without that, one could set CONFIG_SURFACE_AGGREGATOR=m CONFIG_SURFACE_AGGREGATOR_BUS=y CONFIG_SURFACE_AGGREGATOR_REGISTRY=y which will probably cause the compiler to complain that it can't find the functions from the Aggregator module. I'll leave it up as-is for a bit longer to maybe gather a couple more comments before I send out a v2 with this fixed. + help + Device-registry and device-hubs for Surface System Aggregator Module + (SSAM) devices. + + Provides a module and driver which act as a device-registry for SSAM + client devices that cannot be detected automatically, e.g. via ACPI. + Such devices are instead provided via this registry and attached via + device hubs, also provided in this module. + + Devices provided via this registry are: + - Platform profile (performance-/cooling-mode) device (5th- and later + generations). + - Battery/AC devices (7th-generation). + - HID input devices (7th-generation). + + Select M (recommended) or Y here if you want support for the above + mentioned devices on the corresponding Surface models. Without this + module, the respective devices will not be instantiated and thus any + functionality provided by them will be missing, even when drivers for + these devices are present. In other words, this module only provides + the respective client devices. Drivers for these devices still need to + be selected via the other options. + config SURFACE_GPE tristate "Surface GPE/Lid Support Driver" depends on DMI diff --git a/drivers/platform/surface/Makefile b/drivers/platform/surface/Makefile index 990424c5f0c9..80035ee540bf 100644 --- a/drivers/platform/surface/Makefile +++ b/drivers/platform/surface/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_SURFACE_3_POWER_OPREGION)+= surface3_power.o
[PATCH 1/6] platform/surface: Set up Surface Aggregator device registry
The Surface System Aggregator Module (SSAM) subsystem provides various functionalities, which are separated by spreading them across multiple devices and corresponding drivers. Parts of that functionality / some of those devices, however, can (as far as we currently know) not be auto-detected by conventional means. While older (specifically 5th- and 6th-)generation models do advertise most of their functionality via standard platform devices in ACPI, newer generations do not. As we are currently also not aware of any feasible way to query said functionalities dynamically, this poses a problem. There is, however, a device in ACPI that seems to be used by Windows for identifying different Surface models: The Windows Surface Integration Device (WSID). This device seems to have a HID corresponding to the overall set of functionalities SSAM provides for the associated model. This commit introduces a registry providing non-detectable device information via software nodes. In addition, a SSAM platform hub driver is introduced, which takes care of creating and managing the SSAM devices specified in this registry. This approach allows for a hierarchical setup akin to ACPI and is easily extendable, e.g. via firmware node properties. Note that this commit only provides the basis for the platform hub and registry, and does not add any content to it. The registry will be expanded in subsequent commits. Signed-off-by: Maximilian Luz --- MAINTAINERS | 1 + drivers/platform/surface/Kconfig | 26 ++ drivers/platform/surface/Makefile | 1 + .../surface/surface_aggregator_registry.c | 284 ++ 4 files changed, 312 insertions(+) create mode 100644 drivers/platform/surface/surface_aggregator_registry.c diff --git a/MAINTAINERS b/MAINTAINERS index 4fcf3df517a8..000a82f59c76 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11826,6 +11826,7 @@ F: Documentation/driver-api/surface_aggregator/ F: drivers/platform/surface/aggregator/ F: drivers/platform/surface/surface_acpi_notify.c F: drivers/platform/surface/surface_aggregator_cdev.c +F: drivers/platform/surface/surface_aggregator_registry.c F: include/linux/surface_acpi_notify.h F: include/linux/surface_aggregator/ F: include/uapi/linux/surface_aggregator/ diff --git a/drivers/platform/surface/Kconfig b/drivers/platform/surface/Kconfig index 0847b2dc97bf..1cd37c041710 100644 --- a/drivers/platform/surface/Kconfig +++ b/drivers/platform/surface/Kconfig @@ -77,6 +77,32 @@ config SURFACE_AGGREGATOR_CDEV The provided interface is intended for debugging and development only, and should not be used otherwise. +config SURFACE_AGGREGATOR_REGISTRY + tristate "Surface System Aggregator Module Device Registry" + depends on SURFACE_AGGREGATOR_BUS + help + Device-registry and device-hubs for Surface System Aggregator Module + (SSAM) devices. + + Provides a module and driver which act as a device-registry for SSAM + client devices that cannot be detected automatically, e.g. via ACPI. + Such devices are instead provided via this registry and attached via + device hubs, also provided in this module. + + Devices provided via this registry are: + - Platform profile (performance-/cooling-mode) device (5th- and later + generations). + - Battery/AC devices (7th-generation). + - HID input devices (7th-generation). + + Select M (recommended) or Y here if you want support for the above + mentioned devices on the corresponding Surface models. Without this + module, the respective devices will not be instantiated and thus any + functionality provided by them will be missing, even when drivers for + these devices are present. In other words, this module only provides + the respective client devices. Drivers for these devices still need to + be selected via the other options. + config SURFACE_GPE tristate "Surface GPE/Lid Support Driver" depends on DMI diff --git a/drivers/platform/surface/Makefile b/drivers/platform/surface/Makefile index 990424c5f0c9..80035ee540bf 100644 --- a/drivers/platform/surface/Makefile +++ b/drivers/platform/surface/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_SURFACE_3_POWER_OPREGION)+= surface3_power.o obj-$(CONFIG_SURFACE_ACPI_NOTIFY) += surface_acpi_notify.o obj-$(CONFIG_SURFACE_AGGREGATOR) += aggregator/ obj-$(CONFIG_SURFACE_AGGREGATOR_CDEV) += surface_aggregator_cdev.o +obj-$(CONFIG_SURFACE_AGGREGATOR_REGISTRY) += surface_aggregator_registry.o obj-$(CONFIG_SURFACE_GPE) += surface_gpe.o obj-$(CONFIG_SURFACE_HOTPLUG) += surface_hotplug.o obj-$(CONFIG_SURFACE_PRO3_BUTTON) += surfacepro3_button.o diff --git a/drivers/platform/surface/surface_aggregator_registry.c
