dt-bindings: thermal: Add driver to modify thermal zone based on efuse

Add dt-bindings for driver to enable/disable pre-configured thermal
zones selectively at runtime based on efuse value. It uses QFPROM
nvmem cell interface to read efuse data. It supports multiple
efuse condtion.

Change-Id: I711e8aba423eaa95a2a2c4d5f9755bfc61850b6d

1 files changed, 73 insertions, 0 deletions

diff --git a/bindings/thermal/qcom-thermal-efprom.txt b/bindings/thermal/qcom-thermal-efprom.txt
new file mode 100644
index 00000000..d9e50103
--- /dev/null
+++ b/bindings/thermal/qcom-thermal-efprom.txt
@@ -0,0 +1,73 @@
+Modify Thermal Zone based on efuse data
+
+This driver is to enable/disable pre-configured thermal
+zones selectively at runtime based on efuse data. It uses QFPROM
+nvmem cell interface to read efuse data. It supports multiple
+efuse condition. If any of the efuse condition fails, driver just
+exits with default enabled thermal zones.
+
+Properties:
+
+- compatible:
+	Usage: Required
+	Value type: <string>
+	Definition: shall be "qcom,thermal-qfprom-device".
+
+- nvmem-cells:
+	Usage: Required
+	Value type: <array of phandle>
+	Definition: Array of phandles pointing to a nvmem-cells node
+		representing the efuse registers that has information that
+		is used to select the right thermal zone to enable.
+		Please refer nvmem-cells bindings
+		Documentation/devicetree/bindings/nvmem/nvmem.txt and also
+		example below.
+
+ nvmem-cell-names:
+	Usage: Required
+	Value type: <array of string>
+	Definition:  Should be array of name for each nvmem-cells phandle data.
+		Please refer nvmem-cells bindings
+		Documentation/devicetree/bindings/nvmem/nvmem.txt and also
+		example below.
+
+- qcom,thermal-qfprom-bit-values: It should be array of bit mask values to
+		match with each nvmem-cells bit value respectively. If all
+		nvmem-cells values are matching with respective bit mask value
+		from this property, then driver will update thermal zones as
+		per thermal zones mentioned in 'qcom,thermal-zone-enable-list'
+		and 'qcom,thermal-zone-disable-list'.
+
+- qcom,thermal-zone-enable-list:
+	Usage: Required
+	Value type: <array of strings>
+	Definition: Should define this property with list of thermal zone
+		names those need to be enabled if nvmem-cells condition is met.
+
+- qcom,thermal-zone-disable-list:
+	Usage: Required
+	Value type: <array of strings>
+	Definition: Should define this property with list of thermal zone
+		names those need to be disabled if nvmem-cells condition is met.
+
+Example:
+	qcom-thermal-qfprom {
+		compatible = "qcom,thermal-qfprom-device";
+		nvmem-cells = <&thermal_cpe>, <&thermal_revision>;
+		nvmem-cell-names = "cpe", "revision";
+		qcom,thermal-qfprom-bit-values = <0x1 0x3>
+		qcom,thermal-zone-enable-list = "mdm-core-0-cpe-step",
+					"mdm-core-1-cpe-step";
+		qcom,thermal-zone-disable-list = "mdm-core-0-step",
+					"mdm-core-1-step";
+	};
+
+	In this example, driver gets efuse bit values of nvmem-cell register
+	for both 'cpe' and 'revision' nvmem cells. It then compares these efuse
+	values with property 'qcom,thermal-qfprom-bit-values' values (0x1 and
+	0x3 here) respectively. If both efuse values are matching with this
+	property values, driver enables thermal zones listed in property
+	'qcom,thermal-zone-enable-list' and disables thermal zones listed in
+	property 'qcom,thermal-zone-disable-list'. If any of the efuse
+	value is not matching with respective 'qcom,thermal-qfprom-bit-values'
+	values, driver just exits without modifying any thermal zone.