| Message ID | 1580272046-32101-2-git-send-email-Sandeep.Singh@amd.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | SFH: Add Support for AMD Sensor Fusion Hub | expand |
On Wed, 2020-01-29 at 09:57 +0530, Sandeep Singh wrote: > From: Sandeep Singh <sandeep.singh@amd.com> > > Add Maintainer list for AMD SFH SFH (SENSOR FUSION HUB) This way it will be clear what is SFH. > Solution and work flow > document. > > Signed-off-by: Nehal Shah <Nehal-bakulchandra.Shah@amd.com> > Signed-off-by: Sandeep Singh <sandeep.singh@amd.com> > --- > Documentation/hid/amd-sfh-hid.rst | 159 > ++++++++++++++++++++++++++++++++++++++ > MAINTAINERS | 8 ++ > 2 files changed, 167 insertions(+) > create mode 100644 Documentation/hid/amd-sfh-hid.rst > > diff --git a/Documentation/hid/amd-sfh-hid.rst > b/Documentation/hid/amd-sfh-hid.rst > new file mode 100644 > index 0000000..1183350 > --- /dev/null > +++ b/Documentation/hid/amd-sfh-hid.rst > @@ -0,0 +1,159 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +AMD Sensor Fusion Hub:- > +====================== > +AMD sensor fushion Hub is part of a SOC starting from ryzon based > platforms. > +The solution is working well on windows OS in several > +OEM products. AMD SFH uses HID over PCIe bus. In terms of > architecture > +it is much more resmebles like ISH .However the major diffrence is > all > +The hid reports are generated as part of kernel driver. > + > +Block Diagram:- > +============= > + ------------------------------- > + | HID User Space Applications | > + ------------------------------- > +--------------------------------------------- > + --------------------------------- > + | HID Core | > + --------------------------------- > + > + --------------------------------- > + | AMD HID Transport Driver | > + --------------------------------- > + > + -------------------------------- > + | AMD HID Client Driver | > + | with HID Report Generator| > + -------------------------------- > + > + -------------------------------- > + | AMD MP2 PCIe Driver | > + -------------------------------- > +--------------------------------------------- > + ------------------------------- > + | SFH MP2 Processor | > + -------------------------------- > + > + > +AMD HID Transport Layer :- > +*************************** > +AMD SFH transport is also implemented as a bus. Each client > application > +executing in the AMD MP2 is registered as a device on this bus. > +The driver, which binds each device (AMD SFH HID driver) identifies > +the device type and registers with the hid core. Transport drivers > +attach a constant "struct hid_ll_driver" object with each device. > +Once a device is registered with HID core, the callbacks provided > via > +this struct are used by HID core to communicate with the device. > +AMD HID Transport driver implements the synchronous calls. > + > +AMD HID Client Driver:- > +********************** > +This driver is responsible to implement HID request and descriptors. > +As firmware is OS agnostic, HID client driver fills the HID request > +structure and descriptors. HID client driver is in complex in nature > +as it is interface between MP2 PCIe driver and HID. HID client > driver > +initialized the MP2 PCIe driver and holds the instance of MP2 > driver. > +It identified the number of sensors connected using MP2- PCIe driver > and > +based on that allocate the DRAM address for each and every sensor > and > +pass it to MP2-PCIe driver. > +On enumeration of each sensor, client driver fills out the HID > Descriptor > +structure and HID input report structure. HID Feature report > structure can > +be optional. The report descriptor structure varies sensor to > sensor. > +Now on enumeration client driver does two major things > +1. Register the HID sensor client to virtual bus (Platform driver) > and bind it. > +2. Probes the AMD HID transport driver. Which in turns register > device to the core. > + > +AMD MP2 PCIe Driver:- > +******************** > +MP2 PCIe driver is responsible for making all transaction with the > firmware over > +PCIe.The connection establishment between firmware and MP2 PCIe > driver happens here. > + > +The communication between X86 and MP2 is spilt into three parts. > +1. Command Transfer => C2P Mailbox Register are used > +2. Data Transfer => DRAM > + > +Commands are sent to MP2 using C2P Mail Box registers. These > C2P registers > +are mapped in PCIe address space.Writing into C2P Message register > generate > +interrupt to MP2. The client driver allocates the physical memory > and send > +the same to MP2 for data transfer. MP2 firmware uses DRAM interface > registers > +to indirectly access DRAM memory. For Firmware always write minimum > 32 bytes > +into DRAM.So it is expected that driver shall allocate minimum 32 > bytes DRAM space. > + > +Enumeration and Probing flow:- > +***************************** > + HID AMD AMD AMD > -PCIe MP2 > + Core Transport Client > Driver Driver FW > + | | | | > | > + | | on Boot Driver Loaded | > | > + | | | | > | > + | | |----MP2-PCIe Int---------> > | | > + | | | | > | > + | | |---Get Number of sensors-> > | | > + | | | Read > P2C | > + | | | Register > | > + | | | | > | > + | | | Loop(for No of > Sensors) | | > + | | |-------------------- > --| | | > + | | | Create HID > Descriptor| | | > + | | | Create Input report > | | | > + | | | Descriptor > Map | | | > + | | | the MP2 FW Index to > | | | > + | | | HID > Index | | | > + | | | Allocate the > DRAM | Enable | > + | | | address | Sensors > | > + | | |-------------------- > --| | | > + | | HID > transport| | Enable | > + | |<--Probe------| |---Sensor > CMD--> | > + | | Create the | | > | > + | | HID > device | | | > + | | (MFD) | | > | > + | | by Populating| | > | > + | | the > HID | | | > + | | ll_driver | | > | > + | HID | | | > | > + | add | | | > | > + |Device | | | > | > + |<------------- | | | > | > + > + > +Data Flow from Application to the AMD SFH Driver:- > +************************************************* > + > + | | | | > | > +Get | | | | > | > +Input | | | | > | > +Report | | | > | | > +---> | | | > | | > + |HID_req | | | > | > + |get_report | | | > | > + |------------- > >| | | | > + | | > HID_get_input| | | > + | | report | | > | > + | |------------->|---------------------- > --| | | > + | | | Read the DRAM data > for| | | > + | | | requsted sensor > and | | | > + | | | create the HID > input | | | > + | | | report | | > | > + | | |---------------------- > --| | | > + | |Data received > | | | > + | | in HID > report| | | > + To |<-------------|<------------- > | | | > +Applications | | | > | > +<------- > | | | | > | > + > + > +Data Flow from AMD SFH Driver to Application:- > +********************************************** > + | | | > | | > + | | |---------------------- > --| | | > + | | |Periodically > Read | | | > + | | |the data for > all | | | > + | | |enumerated > sensors | | | > + | | |from the dram and > create| | | > + | | | HID Input > reports | | | > + | | |---------------------- > --| | | > + | |HID > Input | | | > + | |Input > report | | | > + <----submit to Application----- > | | | > + | | | | > | > diff --git a/MAINTAINERS b/MAINTAINERS > index 56765f5..7cfeb5a 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -884,6 +884,14 @@ S: Supported > F: drivers/net/ethernet/amd/xgbe/ > F: arch/arm64/boot/dts/amd/amd-seattle-xgbe*.dtsi > > +AMD SENSOR FUSION HUB DRIVER > +M: Nehal Shah <nehal-bakulchandra.shah@amd.com> > +M: Sandeep Singh <sandeep.singh@amd.com> > +L: linux-input@vger.kernel.org > +S: Maintained > +F: Documentation/hid/amd-sfh* > +F: drivers/hid/amd-sfh-hid/ > + > ANALOG DEVICES INC AD5686 DRIVER > M: Stefan Popa <stefan.popa@analog.com> > L: linux-pm@vger.kernel.org
diff --git a/Documentation/hid/amd-sfh-hid.rst b/Documentation/hid/amd-sfh-hid.rst new file mode 100644 index 0000000..1183350 --- /dev/null +++ b/Documentation/hid/amd-sfh-hid.rst @@ -0,0 +1,159 @@ +.. SPDX-License-Identifier: GPL-2.0 + +AMD Sensor Fusion Hub:- +====================== +AMD sensor fushion Hub is part of a SOC starting from ryzon based platforms. +The solution is working well on windows OS in several +OEM products. AMD SFH uses HID over PCIe bus. In terms of architecture +it is much more resmebles like ISH .However the major diffrence is all +The hid reports are generated as part of kernel driver. + +Block Diagram:- +============= + ------------------------------- + | HID User Space Applications | + ------------------------------- +--------------------------------------------- + --------------------------------- + | HID Core | + --------------------------------- + + --------------------------------- + | AMD HID Transport Driver | + --------------------------------- + + -------------------------------- + | AMD HID Client Driver | + | with HID Report Generator| + -------------------------------- + + -------------------------------- + | AMD MP2 PCIe Driver | + -------------------------------- +--------------------------------------------- + ------------------------------- + | SFH MP2 Processor | + -------------------------------- + + +AMD HID Transport Layer :- +*************************** +AMD SFH transport is also implemented as a bus. Each client application +executing in the AMD MP2 is registered as a device on this bus. +The driver, which binds each device (AMD SFH HID driver) identifies +the device type and registers with the hid core. Transport drivers +attach a constant "struct hid_ll_driver" object with each device. +Once a device is registered with HID core, the callbacks provided via +this struct are used by HID core to communicate with the device. +AMD HID Transport driver implements the synchronous calls. + +AMD HID Client Driver:- +********************** +This driver is responsible to implement HID request and descriptors. +As firmware is OS agnostic, HID client driver fills the HID request +structure and descriptors. HID client driver is in complex in nature +as it is interface between MP2 PCIe driver and HID. HID client driver +initialized the MP2 PCIe driver and holds the instance of MP2 driver. +It identified the number of sensors connected using MP2- PCIe driver and +based on that allocate the DRAM address for each and every sensor and +pass it to MP2-PCIe driver. +On enumeration of each sensor, client driver fills out the HID Descriptor +structure and HID input report structure. HID Feature report structure can +be optional. The report descriptor structure varies sensor to sensor. +Now on enumeration client driver does two major things +1. Register the HID sensor client to virtual bus (Platform driver) and bind it. +2. Probes the AMD HID transport driver. Which in turns register device to the core. + +AMD MP2 PCIe Driver:- +******************** +MP2 PCIe driver is responsible for making all transaction with the firmware over +PCIe.The connection establishment between firmware and MP2 PCIe driver happens here. + +The communication between X86 and MP2 is spilt into three parts. +1. Command Transfer => C2P Mailbox Register are used +2. Data Transfer => DRAM + +Commands are sent to MP2 using C2P Mail Box registers. These C2P registers +are mapped in PCIe address space.Writing into C2P Message register generate +interrupt to MP2. The client driver allocates the physical memory and send +the same to MP2 for data transfer. MP2 firmware uses DRAM interface registers +to indirectly access DRAM memory. For Firmware always write minimum 32 bytes +into DRAM.So it is expected that driver shall allocate minimum 32 bytes DRAM space. + +Enumeration and Probing flow:- +***************************** + HID AMD AMD AMD -PCIe MP2 + Core Transport Client Driver Driver FW + | | | | | + | | on Boot Driver Loaded | | + | | | | | + | | |----MP2-PCIe Int---------> | | + | | | | | + | | |---Get Number of sensors-> | | + | | | Read P2C | + | | | Register | + | | | | | + | | | Loop(for No of Sensors) | | + | | |----------------------| | | + | | | Create HID Descriptor| | | + | | | Create Input report | | | + | | | Descriptor Map | | | + | | | the MP2 FW Index to | | | + | | | HID Index | | | + | | | Allocate the DRAM | Enable | + | | | address | Sensors | + | | |----------------------| | | + | | HID transport| | Enable | + | |<--Probe------| |---Sensor CMD--> | + | | Create the | | | + | | HID device | | | + | | (MFD) | | | + | | by Populating| | | + | | the HID | | | + | | ll_driver | | | + | HID | | | | + | add | | | | + |Device | | | | + |<------------- | | | | + + +Data Flow from Application to the AMD SFH Driver:- +************************************************* + + | | | | | +Get | | | | | +Input | | | | | +Report | | | | | +---> | | | | | + |HID_req | | | | + |get_report | | | | + |------------->| | | | + | | HID_get_input| | | + | | report | | | + | |------------->|------------------------| | | + | | | Read the DRAM data for| | | + | | | requsted sensor and | | | + | | | create the HID input | | | + | | | report | | | + | | |------------------------| | | + | |Data received | | | + | | in HID report| | | + To |<-------------|<-------------| | | +Applications | | | | +<-------| | | | | + + +Data Flow from AMD SFH Driver to Application:- +********************************************** + | | | | | + | | |------------------------| | | + | | |Periodically Read | | | + | | |the data for all | | | + | | |enumerated sensors | | | + | | |from the dram and create| | | + | | | HID Input reports | | | + | | |------------------------| | | + | |HID Input | | | + | |Input report | | | + <----submit to Application-----| | | + | | | | | diff --git a/MAINTAINERS b/MAINTAINERS index 56765f5..7cfeb5a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -884,6 +884,14 @@ S: Supported F: drivers/net/ethernet/amd/xgbe/ F: arch/arm64/boot/dts/amd/amd-seattle-xgbe*.dtsi +AMD SENSOR FUSION HUB DRIVER +M: Nehal Shah <nehal-bakulchandra.shah@amd.com> +M: Sandeep Singh <sandeep.singh@amd.com> +L: linux-input@vger.kernel.org +S: Maintained +F: Documentation/hid/amd-sfh* +F: drivers/hid/amd-sfh-hid/ + ANALOG DEVICES INC AD5686 DRIVER M: Stefan Popa <stefan.popa@analog.com> L: linux-pm@vger.kernel.org