From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Thu, 07 Feb 2013 11:07:14 -0700 Subject: [U-Boot] [PATCH v2 2/3] Tegra114: fdt: Update DT files with I2C info for T114/Dalmore In-Reply-To: References: <1360193208-16055-1-git-send-email-twarren@nvidia.com> <1360193208-16055-3-git-send-email-twarren@nvidia.com> <5113C0C7.8010404@nvidia.com> Message-ID: <5113ED52.4040306@wwwdotorg.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 02/07/2013 09:17 AM, Tom Warren wrote: > Laxman, > > On Thu, Feb 7, 2013 at 7:57 AM, Laxman Dewangan wrote: >> On Thursday 07 February 2013 04:56 AM, 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). >>> >>> Signed-off-by: Tom Warren >>> --- >> >> >> >>> diff --git a/board/nvidia/dts/tegra114-dalmore.dts >>> b/board/nvidia/dts/tegra114-dalmore.dts >>> index 7315577..13b07f3 100644 >>> --- a/board/nvidia/dts/tegra114-dalmore.dts >>> +++ b/board/nvidia/dts/tegra114-dalmore.dts >>> @@ -6,8 +6,41 @@ >>> model =NVIDIA Dalmore"; >>> compatible =nvidia,dalmore", "nvidia,tegra114"; >>> >>> + aliases { >>> + i2c0 =/i2c at 7000d000"; >>> + i2c1 =/i2c at 7000c000"; >>> + i2c2 =/i2c at 7000c400"; >>> + i2c3 =/i2c at 7000c500"; >>> + i2c4 =/i2c at 7000c700"; >>> + }; >> >> >> Can we move this to tegar114.dtsi file. > > I could, but why? Most, if not all, of the U-Boot boards that use DT > are putting their aliases in the .dts file in the board directory. Laxman, the issue here is that right now in U-Boot, I believe, if a particular board only uses I2C adapters 0, 2, and 4, then only U-Boot device IDs 0, 1, and 2 are defined, rather than IDs 0, 2, and 4. That's why the aliases are in the per-board file for now, because the actual set of I2C adapters enabled is board-specific. Tom, as background for Laxman's request, for other devices (e.g. serial ports), customer engineers have pushed back on that naming scheme, and always want a specific HW device to end up with a static name, irrespective of which other devices of the same type are used, if any. For that reason, in the kernel, we have aliases for the serial ports in tegra*.dtsi rather than in per-board files, and the names are static. So I wonder if in U-Boot we really have to have IDs 0..n rather than e.g. IDs 0, 2, 4 for the I2C ports (when some aren't used). Then, we could just put the aliases in tegra*.dtsi, which makes life simpler when creating board .dts files...