From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH v5 1/4] hwmon: ltc2978: device tree bindings documentation Date: Fri, 03 Oct 2014 10:28:59 -0700 Message-ID: <542EDCDB.6040406@roeck-us.net> References: <1412275071-6417-1-git-send-email-atull@opensource.altera.com> <1412275071-6417-2-git-send-email-atull@opensource.altera.com> <20141003122736.GH26643@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20141003122736.GH26643@leverpostej> Sender: linux-kernel-owner@vger.kernel.org To: Mark Rutland , "atull@opensource.altera.com" , "broonie@kernel.org" Cc: "jdelvare@suse.de" , "lm-sensors@lm-sensors.org" , "lgirdwood@gmail.com" , "robh+dt@kernel.org" , Pawel Moll , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "delicious.quinoa@gmail.com" , "dinguyen@opensource.altera.com" , "yvanderv@opensource.altera.com" List-Id: devicetree@vger.kernel.org On 10/03/2014 05:27 AM, Mark Rutland wrote: > On Thu, Oct 02, 2014 at 07:37:48PM +0100, atull@opensource.altera.com wrote: >> From: Alan Tull >> >> Add device tree bindings documentation for ltc2978. >> >> Signed-off-by: Alan Tull >> --- >> v2: clean whitespace >> --- >> .../devicetree/bindings/hwmon/ltc2978.txt | 41 ++++++++++++++++++++ >> 1 file changed, 41 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/hwmon/ltc2978.txt >> >> diff --git a/Documentation/devicetree/bindings/hwmon/ltc2978.txt b/Documentation/devicetree/bindings/hwmon/ltc2978.txt >> new file mode 100644 >> index 0000000..b2d9c4d >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/hwmon/ltc2978.txt >> @@ -0,0 +1,41 @@ >> +ltc2978 >> + >> +Required properties: >> + - compatible: one of: ltc2974, ltc2977, ltc2978, ltc3880, ltc3883, ltm4676 > > Could we please format this like: > > - compatible: should contain one of: > * "ltc2974" > * "ltc2977" > * "ltc2978" > * "ltc3880" > * "ltc3883" > * "ltm4676" > > Given the file name, are these all variants of ltc2978? > >> + - reg: I2C address >> + >> +Optional properties: >> + Name of the optional regulator subnode must be "regulators". >> + - #address-cells must be 1. > > What's the single address cell used for? > I think this is required by the regulator bindings. Other regulators use the same, though they don't typically mention it in the properties list but only in the examples. >> + - #size-cells must be 0. >> + >> + For each regulator: >> + - reg: regulator number > > Which can be...? > > What does this correspond to in the HW? > Channel number or index. Pretty much the 0..7 from the name below. >> + - regulator-compatible: must be vout_en such as vout_en3 >> + valid range is: >> + ltc2977, ltc2978 : vout_en0 - vout_en7 >> + ltc2974 : vout_en0 - vout_en3 >> + ltc3880, ltm4676 : vout_en0 - vout_en1 >> + ltc3883 : vout_en0 only > > In other bindings I believe I've seen the node name used for this. > Seems like per-device names are chosen for other regulators. PMBus commonly uses the term "VOUT" for output voltages, so vout[0-7] should be ok. Which reminds me: We had earlier asked to drop the "_en" from the strings as unnecessary. > Mark, what's the preferred scheme for identifying regulators in a > container node? > >> + - regulator-name: arbitrary name for regulator > > Drop the 'aribtarary'. Either this should be the name of the regulator > on the board, or it shouldn't be necessary. > Not sure if it even needs to be documented here. It is already documented in Documentation/devicetree/bindings/regulator/regulator.txt. > Mark. > >> + >> +Example: >> +ltc2978@5e { >> + compatible = "ltc2978"; >> + reg = <0x5e>; >> + regulators { >> + #address-cells = <1>; >> + #size-cells = <0>; >> + >> + vdacp0_reg: regulator@0 { >> + reg = <0>; >> + regulator-compatible = "vout_en0"; >> + regulator-name = "FPGA-2.5V"; >> + }; >> + vdacp2_reg: regulator@2 { >> + reg = <2>; >> + regulator-compatible = "vout_en2"; >> + regulator-name = "FPGA-1.5V"; >> + }; >> + }; >> +}; >> -- >> 1.7.9.5 >> >> >