From mboxrd@z Thu Jan  1 00:00:00 1970
From: dev@lynxeye.de (Lucas Stach)
Date: Thu, 19 Dec 2013 12:43:28 +0100
Subject: [PATCH 2/4] clk: tegra: add EMC clock driver
In-Reply-To: <20131219100557.GE17188@tbergstrom-lnx.Nvidia.com>
References: <1387272400-4689-1-git-send-email-josephl@nvidia.com>
 <1387272400-4689-3-git-send-email-josephl@nvidia.com>
 <52B0D6FA.2060101@wwwdotorg.org>
 <1387359758.2576.38.camel@jlo-ubuntu-64.nvidia.com>
 <52B1E950.1040001@wwwdotorg.org>
 <20131219100557.GE17188@tbergstrom-lnx.Nvidia.com>
Message-ID: <1387453408.1712.3.camel@tellur>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Am Donnerstag, den 19.12.2013, 12:05 +0200 schrieb Peter De Schrijver:
[...]
> 
> > funny tricks like running from IRAM since we can't access SDRAM during
> > the clock change? If so, I'm not sure how having the EMC clock changing
> > code is going to help your case (2) anyway, since we'll presumably have
> > to code up a custom stub in assembly for the part of the code that runs
> > from IRAM...
> > 
> 
> There is no need for assembler or running from IRAM (at least from Tegra30
> onwards, I don't know about Tegra20).
> 
Tegra20 doesn't need any IRAM trickery, the sequence is just:
1. set up EMC shadow registers for new clock frequency
2. change EMC divider in CAR module

This was known working on Colibri T20 before the CCF change.

Regards,
Lucas