Hi, On 02/28/18 02:24, Maxime Ripard wrote: > On Tue, Feb 27, 2018 at 08:27:11PM -0600, Samuel Holland wrote: >> This series adds support for the "hardware message box" in recent >> Allwinner sunxi SoCs, used for communication with the ARISC management >> processor (the platform's equivalent of the ARM SCP). The end goal is to >> use the arm_scpi driver as a client, communicating with firmware running >> on the ARISC CPU. >> >> This driver has been tested with the base arm_scpi driver (which sends >> the SCPI_CMD_SCPI_CAPABILITIES command at probe time) and an in-progress >> firmware application running on the ARISC CPU. Because no firmware for >> the other end of the mailbox is complete at the moment, I have not >> included changes to the SoC device trees. > > This is not directly related to this series, but what is your end goal > with regard to SCPI? What features do you expect to have there? Current plans are to support in SCPI: - SMP bringup and CPU hotplug (via PSCI in ATF) - System reset and poweroff (via PSCI in ATF) - System standby and suspend (via PSCI in ATF) - DVFS for ARM CPUs - Clock control for clocks in R_PRCM (e.g. R_CIR_RX) - Thermal sensor reading Other planned features of the firmware: - System wakeup from poweroff (via GPIO or interrupt to firmware) - System power/suspend LED control (connected to GPIO or PMIC GPIO) - Polling of thermal sensor in firmware for thermal throttling > I'm asking because last time we discussed this, SCPI wasn't able to abstract > all the features the PMIC provides, and thus Linux needed to still be able to > access it. This should only be an issue for devices with AXP PMICs. Other devices with GPIO or simple I²C regulator control, such as H3 and H5 boards, can have all necessary features described with standard SCPI commands. SCPI provides for 127 vendor-defined "extended" commands, which could be used to build a full AXP PMIC driver, or simply provide commands to read/write PMIC registers. For the moment I'm not concerned with battery powered devices. So right now the relevant boards either a) don't have a PMIC, or b) can have everything but DVFS voltage hard-coded in the firmware. > Thanks! > Maxime Regards, Samuel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
