From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH 1/2] i2c: designware: device tree bindings for i2c speed mode Date: Wed, 20 Aug 2014 10:34:59 +0100 Message-ID: <20140820093459.GB21174@leverpostej> References: <1408473276-10847-1-git-send-email-atull@opensource.altera.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1408473276-10847-1-git-send-email-atull@opensource.altera.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: "atull@opensource.altera.com" Cc: "wsa@the-dreams.de" , "baruch@tkos.co.il" , "mika.westerberg@linux.intel.com" , "grant.likely@linaro.org" , "robh+dt@kernel.org" , "skuribay@pobox.com" , "Romain.Baeriswyl@abilis.com" , "rafael.j.wysocki@intel.com" , "alan@linux.intel.com" , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "delicious.quinoa@gmail.com" , "dinguyen@opensource.altera.com" , "yvanderv@opensource.altera.com" List-Id: devicetree@vger.kernel.org On Tue, Aug 19, 2014 at 07:34:35PM +0100, atull@opensource.altera.com wrote: > From: Alan Tull > > Add "speed-mode" Device Tree property to select between > standard and fast i2c mode. Previously, driver was hardwired > as fast mode. Default to fast mode if property is not > present. > > Signed-off-by: Alan Tull > --- > .../devicetree/bindings/i2c/i2c-designware.txt | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt > index 5199b0c..0e4cd21 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt > @@ -9,6 +9,8 @@ Required properties : > Recommended properties : > > - clock-frequency : desired I2C bus clock frequency in Hz. > + - speed-mode : 0 = standard (0 - 100Kb/s) > + : 1 = fast (<= 400Kb/s) <== default This is a bit opaque. Is this a limit on the max bit-rate the device should operate at? Why not just have an optional boolean property to limit to standard speed? Thanks, Mark. > > Optional properties : > - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds. > @@ -29,6 +31,7 @@ Example : > reg = <0xf0000 0x1000>; > interrupts = <11>; > clock-frequency = <400000>; > + speed-mode = <0>; > }; > > i2c@1120000 { > -- > 1.7.9.5 > > -- > 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 >