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diff --git a/Documentation/driver-api/xilinx/eemi.rst b/Documentation/driver-api/xilinx/eemi.rst new file mode 100644 index 000000000000..9dcbc6f18d75 --- /dev/null +++ b/Documentation/driver-api/xilinx/eemi.rst @@ -0,0 +1,67 @@ +==================================== +Xilinx Zynq MPSoC EEMI Documentation +==================================== + +Xilinx Zynq MPSoC Firmware Interface +------------------------------------- +The zynqmp-firmware node describes the interface to platform firmware. +ZynqMP has an interface to communicate with secure firmware. Firmware +driver provides an interface to firmware APIs. Interface APIs can be +used by any driver to communicate with PMC(Platform Management Controller). + +Embedded Energy Management Interface (EEMI) +---------------------------------------------- +The embedded energy management interface is used to allow software +components running across different processing clusters on a chip or +device to communicate with a power management controller (PMC) on a +device to issue or respond to power management requests. + +EEMI ops is a structure containing all eemi APIs supported by Zynq MPSoC. +The zynqmp-firmware driver maintain all EEMI APIs in zynqmp_eemi_ops +structure. Any driver who want to communicate with PMC using EEMI APIs +can call zynqmp_pm_get_eemi_ops(). + +Example of EEMI ops:: + + /* zynqmp-firmware driver maintain all EEMI APIs */ + struct zynqmp_eemi_ops { + int (*get_api_version)(u32 *version); + int (*query_data)(struct zynqmp_pm_query_data qdata, u32 *out); + }; + + static const struct zynqmp_eemi_ops eemi_ops = { + .get_api_version = zynqmp_pm_get_api_version, + .query_data = zynqmp_pm_query_data, + }; + +Example of EEMI ops usage:: + + static const struct zynqmp_eemi_ops *eemi_ops; + u32 ret_payload[PAYLOAD_ARG_CNT]; + int ret; + + eemi_ops = zynqmp_pm_get_eemi_ops(); + if (IS_ERR(eemi_ops)) + return PTR_ERR(eemi_ops); + + ret = eemi_ops->query_data(qdata, ret_payload); + +IOCTL +------ +IOCTL API is for device control and configuration. It is not a system +IOCTL but it is an EEMI API. This API can be used by master to control +any device specific configuration. IOCTL definitions can be platform +specific. This API also manage shared device configuration. + +The following IOCTL IDs are valid for device control: +- IOCTL_SET_PLL_FRAC_MODE 8 +- IOCTL_GET_PLL_FRAC_MODE 9 +- IOCTL_SET_PLL_FRAC_DATA 10 +- IOCTL_GET_PLL_FRAC_DATA 11 + +Refer EEMI API guide [0] for IOCTL specific parameters and other EEMI APIs. + +References +---------- +[0] Embedded Energy Management Interface (EEMI) API guide: + https://www.xilinx.com/support/documentation/user_guides/ug1200-eemi-api.pdf |