Subject: Re: [PATCH v2 6/6] Documentation: coresight: docs for config load via configfs

From: Mathieu Poirier <[email-masked]>
Date: Wed, 12 Jan 2022 11:43:20 -0700

[...]

> > +
> > +CONFIG_ELEM element
> > +~~~~~~~~~~~~~~~~~~~
> > +
> > +::
> > +
> > +   [cscfg_file_elem_header]                // header length value to end of feature strings.
> > +   [cscfg_file_elem_str]                   // name of the configuration.
> > +   [cscfg_file_elem_str]                   // description of configuration.
> > +   [u16 value](nr_presets)                 // number of defined presets.
> > +   [u32 value](nr_total_params)            // total parameters defined by all used features.
> > +   [u16 value](nr_feat_refs)               // number of features referenced by the configuration
> > +   [u64 values] * (nr_presets * nr_total_params)     // the preset values.
> > +   [cscfg_file_elem_str] * (nr_feat_refs)  // the features used in the configurations.
> 
> There seems to be a discrepency between the above format and the afdo3 structure
> definition in sample file coresight-cfg-filegen.c. 
> 

Void that comment - the above and the struct cscfg_config_desc don't have a 1:1
mapping.

> More comments to come...
> 
> Thanks,
> Mathieu
> 
> > +
> > +FEATURE_ELEM element
> > +~~~~~~~~~~~~~~~~~~~~
> > +
> > +::
> > +
> > +   [cscfg_file_elem_header]                // header length is total bytes to end of param structures.
> > +   [cscfg_file_elem_str]                   // feature name.
> > +   [cscfg_file_elem_str]                   // feature description.
> > +   [u32 value](match_flags)                // flags to associate the feature with a device.
> > +   [u16 value](nr_regs)                    // number of registers.
> > +   [u16 value](nr_params)                  // number of parameters.
> > +   [cscfg_regval_desc struct] * (nr_regs)  // register definitions
> > +   [PARAM_ELEM] * (nr_params)              // parameters definitions
> > +
> > +PARAM_ELEM element
> > +~~~~~~~~~~~~~~~~~~
> > +
> > +::
> > +
> > +   [cscfg_file_elem_str]         // parameter name.
> > +   [u64 value](param_value]      // initial value.
> > +
> > +Additional definitions.
> > +~~~~~~~~~~~~~~~~~~~~~~~
> > +
> > +The following structures are defined in **coresight-config-file.h**
> > +
> > + * **struct cscfg_file_header** : This structure contains an initial magic number, the total
> > +   length of the file, and the number of features in the file.
> > + * **struct cscfg_file_elem_header**: This defines the total length and type of a CONFIG_ELEM
> > +   or a FEATURE_ELEM.
> > + * **struct cscfg_file_elem_str**: This defines a string and its length.
> > +
> > +The magic number in cscfg_file_header is defined as two bitfields::
> > +
> > +   [31:8] Fixed magic number to identify file type.
> > +   [7:0]  Current file format version.
> > +
> > +The following defines determine the maximum overall file size and maximum individual
> > +string size::
> > +
> > +   CSCFG_FILE_MAXSIZE       // maximum overall file size.
> > +   CSCFG_FILE_STR_MAXSIZE   // maximum individual string size.
> > -- 
> > 2.17.1
> > 

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