X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2FDocumentation%2Fdevicetree%2Fbindings%2Fregulator%2Fpwm-regulator.txt;h=ed936f0f34f28446e5151e238b7bf31161658b0c;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=ce91f61feb12554e0d62d84ebe93d13e9e6fbf59;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git

diff --git a/kernel/Documentation/devicetree/bindings/regulator/pwm-regulator.txt b/kernel/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
index ce91f61fe..ed936f0f3 100644
--- a/kernel/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
+++ b/kernel/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
@@ -1,27 +1,68 @@
-pwm regulator bindings
+Bindings for the Generic PWM Regulator
+======================================
+
+Currently supports 2 modes of operation:
+
+Voltage Table:		When in this mode, a voltage table (See below) of
+			predefined voltage <=> duty-cycle values must be
+			provided via DT. Limitations are that the regulator can
+			only operate at the voltages supplied in the table.
+			Intermediary duty-cycle values which would normally
+			allow finer grained voltage selection are ignored and
+			rendered useless.  Although more control is given to
+			the user if the assumptions made in continuous-voltage
+			mode do not reign true.
+
+Continuous Voltage:	This mode uses the regulator's maximum and minimum
+			supplied voltages specified in the
+			regulator-{min,max}-microvolt properties to calculate
+			appropriate duty-cycle values.  This allows for a much
+			more fine grained solution when compared with
+			voltage-table mode above.  This solution does make an
+			assumption that a %50 duty-cycle value will cause the
+			regulator voltage to run at half way between the
+			supplied max_uV and min_uV values.
 
 Required properties:
-- compatible: Should be "pwm-regulator"
-- pwms: OF device-tree PWM specification (see PWM binding pwm.txt)
-- voltage-table: voltage and duty table, include 2 members in each set of
-  brackets, first one is voltage(unit: uv), the next is duty(unit: percent)
+--------------------
+- compatible:		Should be "pwm-regulator"
+
+- pwms:			PWM specification (See: ../pwm/pwm.txt)
+
+Only required for Voltage Table Mode:
+- voltage-table: 	Voltage and Duty-Cycle table consisting of 2 cells
+			    First cell is voltage in microvolts (uV)
+			    Second cell is duty-cycle in percent (%)
+
+NB: To be clear, if voltage-table is provided, then the device will be used
+in Voltage Table Mode.  If no voltage-table is provided, then the device will
+be used in Continuous Voltage Mode.
 
-Any property defined as part of the core regulator binding defined in
-regulator.txt can also be used.
+Any property defined as part of the core regulator binding can also be used.
+(See: ../regulator/regulator.txt)
 
-Example:
+Continuous Voltage Example:
 	pwm_regulator {
 		compatible = "pwm-regulator;
 		pwms = <&pwm1 0 8448 0>;
+		regulator-min-microvolt = <1016000>;
+		regulator-max-microvolt = <1114000>;
+		regulator-name = "vdd_logic";
+	};
 
+Voltage Table Example:
+	pwm_regulator {
+		compatible = "pwm-regulator;
+		pwms = <&pwm1 0 8448 0>;
+		regulator-min-microvolt = <1016000>;
+		regulator-max-microvolt = <1114000>;
+		regulator-name = "vdd_logic";
+
+			      /* Voltage Duty-Cycle */
 		voltage-table = <1114000 0>,
 				<1095000 10>,
 				<1076000 20>,
 				<1056000 30>,
 				<1036000 40>,
 				<1016000 50>;
-
-		regulator-min-microvolt = <1016000>;
-		regulator-max-microvolt = <1114000>;
-		regulator-name = "vdd_logic";
 	};