> From: AKASHI Takahiro <takahiro.aka...@linaro.org> > Sent: Wednesday, July 26, 2023 10:38 > > This is a help text for scmi command. > > Signed-off-by: AKASHI Takahiro <takahiro.aka...@linaro.org> > --- > v2 > * add more descriptions about SCMI
Reviewed-by: Etienne Carriere <etienne.carri...@foss.st.com> > --- > doc/usage/cmd/scmi.rst | 126 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 126 insertions(+) > create mode 100644 doc/usage/cmd/scmi.rst > > diff --git a/doc/usage/cmd/scmi.rst b/doc/usage/cmd/scmi.rst > new file mode 100644 > index 000000000000..aebcfe95101d > --- /dev/null > +++ b/doc/usage/cmd/scmi.rst > @@ -0,0 +1,126 @@ > +.. SPDX-License-Identifier: GPL-2.0+: > + > +scmi command > +============ > + > +Synopsis > +-------- > + > +:: > + > + scmi info > + scmi perm_dev <agent id> <device id> <flags> > + scmi perm_proto <agent id> <device id> <protocol id> <flags> > + scmi reset <agent id> <flags> > + > +Description > +----------- > + > +Arm System Control and Management Interface (SCMI hereafter) is a set of > +standardised interfaces to manage system resources, like clocks, power > +domains, pin controls, reset and so on, in a system-wide manner. > + > +An entity which provides those services is called a SCMI firmware (or > +SCMI server if you like) may be placed/implemented by EL3 software or > +by a dedicated system control processor (SCP) or else. > + > +A user of SCMI interfaces, including U-Boot, is called a SCMI agent and > +may issues commands, which are defined in each protocol for specific system > +resources, to SCMI server via a communication channel, called a transport. > +Those interfaces are independent from the server's implementation thanks to > +a tranport layer. > + > +For more details, see the `SCMI specification`_. > + > +While most of system resources managed under SCMI protocols are implemented > +and handled as standard U-Boot devices, for example clk_scmi, scmi command > +provides additional management functionality against SCMI server. > + > +scmi info > +~~~~~~~~~ > + Show base information about SCMI server and supported protocols > + > +scmi perm_dev > +~~~~~~~~~~~~~ > + Allow or deny access permission to the device > + > +scmi perm_proto > +~~~~~~~~~~~~~~~ > + Allow or deny access to the protocol on the device > + > +scmi reset > +~~~~~~~~~~ > + Reset the already-configured permissions against the device > + > +Parameters are used as follows: > + > +<agent id> > + SCMI Agent ID, hex value By the way, this documentation states hexadecimal value are awaited but not the embedded doc (patch v2 10/12). Would it be worth it? > + > +<device id> > + SCMI Device ID, hex value > + > + Please note that what a device means is not defined > + in the specification. > + > +<protocol id> > + SCMI Protocol ID, hex value > + > + It must not be 0x10 (base protocol) > + > +<flags> > + Flags to control the action, hex value > + > + 0 to deny, 1 to allow. The other values are reserved and allowed > + values may depend on the implemented version of SCMI server in > + the future. See SCMI specification for more details. > + > +Example > +------- > + > +Obtain basic information about SCMI server: > + > +:: > + > + => scmi info > + SCMI device: scmi > + protocol version: 0x20000 > + # of agents: 3 > + 0: platform > + > 1: OSPM > + 2: PSCI > + # of protocols: 4 > + Power domain management > + Performance domain management > + Clock management > + Sensor management > + vendor: Linaro > + sub vendor: PMWG > + impl version: 0x20b0000 > + > +Ask for access permission to device#0: > + > +:: > + > + => scmi perm_dev 1 0 1 > + > +Reset configurations with all access permission settings retained: > + > +:: > + > + => scmi reset 1 0 > + > +Configuration > +------------- > + > +The scmi command is only available if CONFIG_CMD_SCMI=y. > +Default n because this command is mainly for debug purpose. > + > +Return value > +------------ > + > +The return value ($?) is set to 0 if the operation succeeded, > +1 if the operation failed or -1 if the operation failed due to > +a syntax error. > + > +.. _`SCMI specification`: > https://developer.arm.com/documentation/den0056/e/?lang=en > -- > 2.41.0 >
