[PATCH 19/21] regulator: fixed/gpio: Update device tree bindings

From: Linus Walleij <linus.walleij@linaro.org>
To: Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
	Linus Walleij <linus.walleij@linaro.org>,
	devicetree@vger.kernel.org
Subject: [PATCH 19/21] regulator: fixed/gpio: Update device tree bindings
Date: Mon, 12 Feb 2018 14:17:15 +0100	[thread overview]
Message-ID: <20180212131717.27193-20-linus.walleij@linaro.org> (raw)
In-Reply-To: <20180212131717.27193-1-linus.walleij@linaro.org>

Deprecate the open drain binding for fixed regulator and indicate
that we prefer this to be passed in the GPIO phandle flags.

Clarify that the line inversion semantics for fixed and GPIO
regulators completely overrides the active low flags in the
phandle flags.

Unfortunately this can not be changed to prefer that we pass
the flags in the phandle: the bindings have been specified and
deployed such that the presence/absence of this flag and only
that controls the line inversion semantics. The crucial semantic
is that the absence of the flag means the core will assume
the line is active low, which in GPIO terms is an exception,
as GPIO lines are normally assumed to be active high.

This special device tree semantic cannot be changed without
introducing a whole new compatible string for the fixed and
GPIO regulators, so we just contain the situation.

Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 .../devicetree/bindings/regulator/fixed-regulator.txt       | 13 +++++++++++--
 .../devicetree/bindings/regulator/gpio-regulator.txt        |  4 ++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/regulator/fixed-regulator.txt b/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
index 4fae41d54798..60ce9cb8f891 100644
--- a/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
@@ -7,10 +7,19 @@ Optional properties:
 - gpio: gpio to use for enable control
 - startup-delay-us: startup time in microseconds
 - enable-active-high: Polarity of GPIO is Active high
-If this property is missing, the default assumed is Active low.
+  If this property is missing, the default assumed is Active low.
+  If the phandle flags to the GPIO handle also flag the line as active
+  low or high, that will be ignored for fixed regulators and the
+  presence or absence of this flag solely controls the inversion
+  semantics.
+-vin-supply: Input supply name.
+
+Deprecated properties:
 - gpio-open-drain: GPIO is open drain type.
   If this property is missing then default assumption is false.
--vin-supply: Input supply name.
+  Do not use this property in new device trees: instead use the
+  phandle flag to indicate to the GPIO provider that the line
+  should be handled as open drain.
 
 Any property defined as part of the core regulator
 binding, defined in regulator.txt, can also be used.
diff --git a/Documentation/devicetree/bindings/regulator/gpio-regulator.txt b/Documentation/devicetree/bindings/regulator/gpio-regulator.txt
index dd1ed789728e..06f5cb4af052 100644
--- a/Documentation/devicetree/bindings/regulator/gpio-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/gpio-regulator.txt
@@ -12,6 +12,10 @@ Optional properties:
 			  defualt is LOW if nothing is specified.
 - startup-delay-us	: Startup time in microseconds.
 - enable-active-high	: Polarity of GPIO is active high (default is low).
+			  If the phandle flags to the GPIO handle also flag the line as
+			  active low or high, that will be ignored for fixed regulators
+			  and the presence or absence of this flag solely controls the
+			  inversion semantics.
 - regulator-type	: Specifies what is being regulated, must be either
 			  "voltage" or "current", defaults to voltage.
 
-- 
2.14.3
