On Mon, Oct 26, 2015 at 02:25:10PM -0700, Stephen Boyd wrote:

Some qcom based bootloaders identify the dtb blob based on a set
of device properties like SoC, platform, PMIC, and revisions of
those components. In downstream kernels, these values are added
to the different component dtsi files (i.e. pmic dtsi file, SoC
dtsi file, board dtsi file, etc.) via qcom specific DT
properties. The dtb files are parsed by a program called dtbTool
that picks out these properties and creates a table of contents
binary blob with the property information and some offsets into
the concatenation of all the dtbs (termed a QCDT image).

Got a pointer to what these properties look like?

Why does all this need to be a single property?

+Each board must specify a top-level board compatible string with the following
+format:
+
+	compatible = "qcom,<SoC>(-<soc_version>)(-<foundry_id>)-<plat_type>(/<subtype>)(-<plat_version>)(-<mb>MB)(-<panel>-panel)(-boot-<boot>)(-<pmic>(-v<pmic_version>)){0-4}"
+
+where elements in parentheses "()" are optional and elements in brackets "<>"

[] brackets are more generally used for optional params.

+are names of elements. Meaning only the 'SoC' and 'plat_type' elements are
+required.
+
+The 'SoC' element must be one of the following strings:
+
+	apq8016
+	apq8074
+	apq8084
+	apq8096
+	msm8916
+	msm8974
+	msm8996
+
+The 'plat_type' element must be one of the following strings:
+
+	cdp
+	liquid
+	dragonboard
+	mtp sbc

Platform is pretty overloaded meaning. Perhaps board_type would be more 
clear.

+
+The 'soc_version', 'plat_version' and 'pmic_version' elements take the form of
+v<Major>.<Minor> where the minor number may be omitted when it's zero, i.e.
+v1.0 is the same as v1. If all versions of the 'plat_version' element's match,
+then a wildcard '*' should be used, e.g. 'v*'.
+
+The 'foundry_id', 'subtype', and 'mb' elements are one or more digits from 0
+to 9.

Can you define what these are exactly. I gather mb is RAM size.

+
+The 'panel' element must be one of the following strings:
+
+	720p
+	fWVGA
+	hd
+	qHD

How is this used?

+The 'boot' element must be one of the following strings:
+
+	emmc_sdc1
+	ufs
+
+The 'pmic' element must be one of the following strings:
+
+	pm8841
+	pm8019
+	pm8110
+	pma8084
+	pmi8962
+	pmd9635
+	pm8994
+	pmi8994
+	pm8916
+	pm8004
+	pm8909
+
+The 'pmic' element is specified in order of ascending USID. The PMIC in USID0
+goes first, and then USID2, USID4, and finally USID6. Up to four PMICs may be
+specified and no holes in the USID number space are allowed.

What is USID?

+
+Examples:
+
+	"qcom,msm8916-v1-cdp-pm8916-v2.1"
+
+A CDP board with an msm8916 SoC, version 1 paired with a pm8916 PMIC of version
+2.1.
+
+	"qcom,apq8074-v2.0-2-dragonboard/1-v0.1-512MB-panel-qHD-boot-emmc_sdc1-pm8941-v0.2-pm8909-v2.2-pma8084-v3-pm8110-v1"

Which example is more common?

+
+A dragonboard board v0.1 of subtype 1 with an apq8074 SoC version 2, made in
+foundry 2 with 512MB of memory and a qHD panel booting from emmc_sdc1, paired
+with a pm8941 PMIC version 0.2 at USID0, pm8909 PMIC version 2.2 at USID2,
+pma8084 version 3 at USID4 and a pm8110 version 1 at USID6.
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html