On 01/29/2013 01:40 PM, Tom Warren wrote:
Stephen,
On Tue, Jan 29, 2013 at 1:09 PM, Stephen Warren swarren@wwwdotorg.org wrote:
On 01/29/2013 12:19 PM, Tom Warren wrote:
Note that T114 does not have a separate/different DVC (power I2C) controller like T20 - all 5 I2C controllers are identical, but I2C5 is used to designate the controller intended for power control (PWR_I2C in the schematics).
If you do keep this node, it needs the clocks property filled in.
i2c@7000c000 {compatible = "nvidia,tegra114-i2c", "nvidia,tegra20-i2c";The I2C nodes also aren't backwards-compatible.
They were on T30 (same compatible string there, except of course s/114/30/). And the tegra20-i2c is needed for fdtdec.c to find it (compat_names table).
Yes, I believe the HW changes between Tegra20 and Tegra30 were such that the Tegra20 driver would run unmodified on Tegra30 without issue. I don't believe that's the case for Tegra114 though. The solution would be to add the Tegra114 compatible value to the I2C driver so that it can search for both.
reg = <0x7000c000 0x100>;The interrupts property is missing here.
I didn't have an interrupts property for I2C on the T30 dts files, either.
That sounds like a bug in the DT.
What is it used for in U-Boot?
U-Boot doesn't use interrupts at least on Tegra, so it's not used. However, it'd be best to keep the U-Boot DT in line with the kernel DT so we can easily spot differences. There has been talk of trying to use the same DT for both too, although we're a long long way off from that.
If it's really needed, can I just crib it from the kernel dts file(s)?
Yes, but the Tegra114 patches aren't all checked in yet. See the following proposed patch for what you need:
https://lkml.org/lkml/2013/1/29/235
(note that patch is missing the clocks properties since the clock binding isn't finalized and checked in yet)
diff --git a/board/nvidia/dts/tegra114-dalmore.dts b/board/nvidia/dts/tegra114-dalmore.dts
Board changes would usually be a separate patch to an SoC change, but I guess not a big deal.
Actually, this is the way I've always done DT files (in a separate patch), and then the config files in a separate patch the enable the feature.
I meant that tegra114.dtsi and tegra114-dalmore.dts would usually be separate patches.
All 5 I2C ports are used on the board and only support 100KHz? That seems unusual, but I suppose it's possible.
That's the way I have it on T30, and looking at arch/arm/boot/dts/tegra30.dtsi in the kernel, all 5 ports are set to 100KHz.
But this is board-specific; it depends on which of the I2C controllers are actually pinmux'd out onto the board (-> which to enable), and which devices are attached to those buses (-> max I2C clock rate). I don't see how Tegra30 nor tegra30.dtsi are relevant here.