Thread (2 messages) 2 messages, 2 authors, 2011-08-23

Re: [RFC/PATCH v2 10/13] dt: omap4: panda board: set clock freq for i2c devices

From: G, Manjunath Kondaiah <hidden>
Date: 2011-08-23 19:15:13
Also in: linux-arm-kernel, linux-omap

Hi Benoit,

On Wed, Aug 24, 2011 at 12:33 AM, Cousson, Benoit [off-list ref] wrote:
quoted
From: G, Manjunath Kondaiah<redacted>
To: devicetree-discuss@lists.ozlabs.org
CC: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org


Update omap4 panda dts file with required clock frequencies
for the i2c client devices existing on panda board.

Signed-off-by: G, Manjunath Kondaiah<redacted>
---
  arch/arm/boot/dts/omap4-panda.dts |   16 ++++++++++++++++
  1 files changed, 16 insertions(+), 0 deletions(-)
diff --git a/arch/arm/boot/dts/omap4-panda.dts
b/arch/arm/boot/dts/omap4-panda.dts
index c28aa95..6b831ca 100644
--- a/arch/arm/boot/dts/omap4-panda.dts
+++ b/arch/arm/boot/dts/omap4-panda.dts
@@ -3,4 +3,20 @@
  / {
       model = "TI OMAP4 PandaBoard";
       compatible = "ti,omap4-panda", "ti,omap4430";
+
+       i2c1 {
+               clock-frequency =<400000>;
+       };
+
+       i2c2 {
+               clock-frequency =<400000>;
+       };
+
+       i2c3 {
+               clock-frequency =<400000>;
+       };
+
+       i2c4 {
+               clock-frequency =<400000>;
+       };
  };
Are you sure that this patch is setting the expected frequency?
I see 100kHz in the boot log even with that patch.

I took me some time to find the proper syntax, but in order to reference an
existing node, you have to use &i2c1 at the top level of the file. If you
check the output of the DTC compiler, you will see the property at the
proper node.
Thanks for bringing this issue. This was one of query I have asked to grant in
one of the e-mail threads. Even I noticed that, it used to fetch default speed
instead of speed assigned in dts file. Let me check with your suggestion.

-Manjunath
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