RE: [PATCH v2 3/6] firmware: arm_scmi: add initial support for i.MX BBM protocol

[Peng Fan]

Hi Sudeep,

> Subject: Re: [PATCH v2 3/6] firmware: arm_scmi: add initial support for iMX
> 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?

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.

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

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:
51 #define COMMAND_PROTOCOL_VERSION             0x0U                                                   
  52 #define COMMAND_PROTOCOL_ATTRIBUTES          0x1U                                                   
  53 #define COMMAND_PROTOCOL_MESSAGE_ATTRIBUTES  0x2U                                                   
  54 #define COMMAND_MISC_CONTROL_SET             0x3U                                                   
  55 #define COMMAND_MISC_CONTROL_GET             0x4U                                                   
  56 #define COMMAND_MISC_CONTROL_ACTION          0x5U                                                   
  57 #define COMMAND_MISC_DISCOVER_BUILD_INFO     0x6U                                                   
  58 #define COMMAND_MISC_ROM_PASSOVER_GET        0x7U                                                   
  59 #define COMMAND_MISC_CONTROL_NOTIFY          0x8U                                                   
  60 #define COMMAND_MISC_REASON_ATTRIBUTES       0x9U                                                   
  61 #define COMMAND_MISC_RESET_REASON            0xAU                                                   
  62 #define COMMAND_MISC_SI_INFO                 0xBU                                                   
  63 #define COMMAND_MISC_CFG_INFO                0xCU                                                   
  64 #define COMMAND_MISC_SYSLOG                  0xDU                                                   
  65 #define COMMAND_NEGOTIATE_PROTOCOL_VERSION   0x10U

I will add the information in v3.

But as of now I am not sure
how to proceed with dt-binding, add in vendor stuff
in arm,scmi.yaml or add imx,scmi.yaml

Thanks,
Peng.

> Don't expect me to respond if the requested details are still missing in the
> future versions, I am going to ignore it silently.
> 
> I have asked for these in atleast 2 different threads may be not just NXP
> patches but in one instance Qcom patches, but they apply equally here.
> 
> --
> Regards,
> Sudeep