On Mon, 7 Sep 2020 at 08:50, Etienne Carriere etienne.carriere@linaro.org wrote:
This change introduces SCMI agent uclass to interact with a firmware using the SCMI protocols [1].
SCMI agent uclass currently supports a single method to request processing of the SCMI message by an identified server. A SCMI message is made of a byte payload associated to a protocol ID and a message ID, all defined by the SCMI specification [1]. On return from process_msg() method, the caller gets the service response.
SCMI agent uclass defines a post bind generic sequence for all devices. The sequence binds all the SCMI protocols listed in the FDT for that SCMI agent device. Currently none, but later change will introduce protocols.
This change implements a simple sandbox device for the SCMI agent uclass. The sandbox nicely answers SCMI_NOT_SUPPORTED to SCMI messages. To prepare for further test support, the sandbox exposes a architecture function for test application to read the sandbox emulated devices state. Currently supports 2 SCMI agents, identified by an ID in the FDT device name. The simplistic DM test does nothing yet.
SCMI agent uclass is designed for platforms that embed a SCMI server in a firmware hosted somewhere, for example in a companion co-processor or in the secure world of the executing processor. SCMI protocols allow an SCMI agent to discover and access external resources as clock, reset controllers and more. SCMI agent and server communicate following the SCMI specification [1]. This SCMI agent implementation complies with the DT bindings defined in the Linux kernel source tree regarding SCMI agent description since v5.8.
Links: [1] https://developer.arm.com/architectures/system-architectures/software-standa... Signed-off-by: Etienne Carriere etienne.carriere@linaro.org Cc: Simon Glass sjg@chromium.org Cc: Peng Fan peng.fan@nxp.com Cc: Sudeep Holla sudeep.holla@arm.com
Changes in v3:
- Address comments about adding a new uclass and some sandbox test from v2 in https://patchwork.ozlabs.org/project/uboot/list/?series=196253
- New directory drivers/firmware/scmi/. The path mimics Linux kernel source tree for the equivalent driver.
- Split scmi.h (patch v2) into scmi_protocols.h, scmi_agent.h and scmi_agent-uclass.h.
- Create new uclass UCLASS_SCMI_AGENT.
- Introduce a simple sandbox on that agent. Mailbox and smccc agents are moved to specific commits in the series.
Changes in v2:
- Fix CONFIG_SCMI_FIRMWARE description with explicit SCMI reference.
- Move struct, enum and macro definitions at source file top and add inline comment description for the structures and local functions.
- Replace rc with ret as return value local variable label.
- Use explicit return 0 on successful return paths.
- Replace EINVAL with more accurate error numbers.
- Use dev_read_u32() instead of ofnode_read_u32(dev_ofnode(), ...).
- Use memcpy_toio()/memcpy_fromio() when copying message payload to/from IO memory.
- Embed mailbox transport resources upon CONFIG_DM_MAILBOX and SMCCC transport resources upon CONFIG_ARM_SMCCC.
Note: review comments on defining a uclass and sandbox for SCMI transport drivers are NOT addressed in this v2. Main issue is that there is no driver/device defined for SCMI transport layer as well as and no defined compatible ID in the SCMI DT bindings documentation.
arch/sandbox/dts/test.dts | 16 +++ arch/sandbox/include/asm/scmi_test.h | 43 ++++++ configs/sandbox_defconfig | 2 + drivers/firmware/Kconfig | 2 + drivers/firmware/Makefile | 1 + drivers/firmware/scmi/Kconfig | 17 +++ drivers/firmware/scmi/Makefile | 2 + drivers/firmware/scmi/sandbox-scmi_agent.c | 147 +++++++++++++++++++++ drivers/firmware/scmi/scmi_agent-uclass.c | 107 +++++++++++++++ include/dm/uclass-id.h | 1 + include/scmi_agent-uclass.h | 24 ++++ include/scmi_agent.h | 68 ++++++++++ include/scmi_protocols.h | 41 ++++++ test/dm/Makefile | 1 + test/dm/scmi.c | 38 ++++++ 15 files changed, 510 insertions(+) create mode 100644 arch/sandbox/include/asm/scmi_test.h create mode 100644 drivers/firmware/scmi/Kconfig create mode 100644 drivers/firmware/scmi/Makefile create mode 100644 drivers/firmware/scmi/sandbox-scmi_agent.c create mode 100644 drivers/firmware/scmi/scmi_agent-uclass.c create mode 100644 include/scmi_agent-uclass.h create mode 100644 include/scmi_agent.h create mode 100644 include/scmi_protocols.h create mode 100644 test/dm/scmi.c
Reviewed-by: Simon Glass sjg@chromium.org