Re: [PATCH v4 4/9] tegra: fdt: i2c: Add extra I2C bindings for U-Boot

Hi Stephen,

On Wed, Feb 29, 2012 at 12:36 PM, Stephen Warren [off-list ref] wrote:

On 02/29/2012 01:32 PM, Simon Glass wrote:

quoted

Hi Stephen,

On Wed, Feb 29, 2012 at 12:21 PM, Stephen Warren [off-list ref] wrote:

quoted

On 02/29/2012 10:31 AM, Simon Glass wrote:

quoted

Add U-Boot's peripheral clock information to the Tegra20 device tree file.

quoted

diff --git a/arch/arm/dts/tegra20.dtsi b/arch/arm/dts/tegra20.dtsi

quoted

              compatible = "nvidia,tegra20-i2c";
              reg = <0x7000C000 0x100>;
              interrupts = < 70 >;
+             clocks = <&tegra_car 12>;       /* PERIPH_ID_I2C1 */
      };

The I2C modules all require 2 clocks; the one you've added in this patch
and a second reference to pll_p_out3. Can you please list both of these
here, and update the I2C binding to describe the set of clocks that it
requires. Thanks.

OK - do you have a pointer to the kernel commit please? I always seem
to have trouble tracking this stuff down.

The clock stuff isn't in the kernel yet, so there's no commit to point
to. The commit I asked you to create would update the bindings to define
which clocks the I2C node needs, and would then go into U-Boot and the
kernel.

Which binding should I update? I have had a look through Olof's trees at:

git://git.kernel.org/pub/scm/linux/kernel/git/olof/tegra.git

I would expect to find the Tegra i2c binding file in
Documentation/devicetree/bindings/i2c, but all I see is:

arm-versatile.txt  fsl-i2c.txt      i2c-designware.txt  samsung-i2c.txt
ce4100-i2c.txt     fsl-imx-i2c.txt  omap-i2c.txt        trivial-devices.txt

I have looked through the device tree mailing list, and I have
searched using my favourite search engine, but I honestly cannot find
anything. Are you sure that this has been done?

If it is not available anywhere, please can you email me the current
binding file that you want me to update and I will send out a patch
with the binding, and then a separate patch with the clock update.

As a reference though, look at the kernel I2C driver and see that it
performs two clk_get() calls, and then look into tegra2_clocks.c to see
the two clocks it matches.

OK I think you want something like:

 clocks = <&tegra_car 12>, <&tegra_car 124>;       /* PERIPH_ID_I2C1,
PLL_P_OUT3 */

I will update this patch to do that, at least, while I wait for
information about the binding.

Regards,
Simon

--
nvpublic
--
To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html