On Tue, Apr 09, 2024 at 09:13:33AM +0000, Peng Fan wrote: > Hi Sudeep, > > > Subject: Re: [PATCH v2 3/6] firmware: arm_scmi: add initial support for i.MX > > BBM protocol > > > > On Mon, Apr 08, 2024 at 07:04:43PM +0100, Cristian Marussi wrote: > > > On Fri, Apr 05, 2024 at 08:39:25PM +0800, Peng Fan (OSS) wrote: > > > > From: Peng Fan <peng.fan@xxxxxxx> > > > > > > > > The i.MX BBM protocol is for managing i.MX BBM module which provides > > > > RTC and BUTTON feature. > > > > > > > > > > I appreciate that you added versioning but I think a bit of > > > documentation about what the protocol and its comamnds purpose is > > > still lacking, as asked by Sudeep previously > > > > > > > > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore > > > .kernel.org%2Flinux-arm- > > kernel%2FZeGtoJ7ztSe8Kg8R%40bogus%2F%23t&data= > > > > > 05%7C02%7Cpeng.fan%40nxp.com%7Ce92ff78b9126447afe9708dc587358d > > 4%7C686e > > > > > a1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C638482499632395762%7C > > Unknown%7C > > > > > TWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiL > > CJXVC > > > > > I6Mn0%3D%7C0%7C%7C%7C&sdata=7QP%2BkkjHA3Sa0CdcbbObGG4kgYYK > > XAGA2r%2F%2F > > > x0MogqU%3D&reserved=0 > > > > > > > I have decided to ignore all these vendor protocol patches until they have > > some documentation to understand what these protocol are for, what are the > > commands, their input/output parameter details, any conditions are the > > caller and callee,..etc very similar to SCMI spec. > > Where do you expect the documentation to be put? > To begin with, we need all these vendor protocols in a directory say vendors/nxp under drivers/firmware/arm_scmi. It can be a simple text file under that. We can see later if we need any more formal version elsewhere but that shouldn't be a blocker for these changes. > similar as scmi_protocol.h, put in scmi_imx_protcol.h? > > > > To start with can you please expand what is BBM or MISC protocol is ? > > ok. Sorry for missing your previous comment in v1. Let me write here briefly > first. > Thanks > The Battery Backup (BB) Domain contains the Battery Backed Security > Module (BBSM) and the Battery Backed Non-Secure Module (BBNSM). > BBM protocol is to manage i.MX BBSM and BBNSM. This protocol supports > #define COMMAND_PROTOCOL_VERSION 0x0U > #define COMMAND_PROTOCOL_ATTRIBUTES 0x1U > #define COMMAND_PROTOCOL_MESSAGE_ATTRIBUTES 0x2U > #define COMMAND_BBM_GPR_SET 0x3U > #define COMMAND_BBM_GPR_GET 0x4U > #define COMMAND_BBM_RTC_ATTRIBUTES 0x5U > #define COMMAND_BBM_RTC_TIME_SET 0x6U > #define COMMAND_BBM_RTC_TIME_GET 0x7U > #define COMMAND_BBM_RTC_ALARM_SET 0x8U > #define COMMAND_BBM_BUTTON_GET 0x9U > #define COMMAND_BBM_RTC_NOTIFY 0xAU > #define COMMAND_BBM_BUTTON_NOTIFY 0xBU > #define COMMAND_NEGOTIATE_PROTOCOL_VERSION 0x10U > Hopefully description of each of these commands cover what GPR above means really. > For now in this patchset for linux, we only use RTC, and BUTTON > for system wakeup > > For MISC protocol, it is for various misc things, such as discover > build info, get rom passed data, get reset reason, get i.mx > cfg name, control set(for gpio expander under m33 control and > etc). The command as below: > #define COMMAND_PROTOCOL_VERSION 0x0U > #define COMMAND_PROTOCOL_ATTRIBUTES 0x1U > #define COMMAND_PROTOCOL_MESSAGE_ATTRIBUTES 0x2U > #define COMMAND_MISC_CONTROL_SET 0x3U > #define COMMAND_MISC_CONTROL_GET 0x4U > #define COMMAND_MISC_CONTROL_ACTION 0x5U > #define COMMAND_MISC_DISCOVER_BUILD_INFO 0x6U > #define COMMAND_MISC_ROM_PASSOVER_GET 0x7U > #define COMMAND_MISC_CONTROL_NOTIFY 0x8U > #define COMMAND_MISC_REASON_ATTRIBUTES 0x9U > #define COMMAND_MISC_RESET_REASON 0xAU > #define COMMAND_MISC_SI_INFO 0xBU > #define COMMAND_MISC_CFG_INFO 0xCU > #define COMMAND_MISC_SYSLOG 0xDU > #define COMMAND_NEGOTIATE_PROTOCOL_VERSION 0x10U > And same here. Just as an example what BUILD_INFO ? There will be 10s if not 100s of different image in the system. What does this BUILD_INFO provide ? And why is this important over version or release info ? These are simple pointers, expect more questions like this if the document is not self sufficient in explaining such details. -- Regards, Sudeep
