[PATCH 1/2] drm/tegra: Set the dsi lp clk parent and rate

[Thierry Reding]

On Mon, Sep 22, 2014 at 11:00:56AM +0200, Lucas Stach wrote:
> Am Freitag, den 19.09.2014, 15:53 -0400 schrieb Sean Paul:
> > Per NVidia, this clock rate should be around 70MHz in
> > order to properly sample reads on data lane 0. In order
> > to achieve this rate, we need to reparent the clock from
> > clk_m which can only achieve 12MHz. Add parent_lp to the
> > dts bindings and set the parent & rate on init.
> > 
> > Signed-off-by: Sean Paul <seanpaul at chromium.org>
> 
> NACK
> 
> You are pushing SoC integration details into the binding of the device.
> 
> You have two reasonable routes to go here: either the clock driver needs
> to be made smarter to reparent the clock in case the required clock rate
> could not be achieved with the current parent or you go the easy route
> and reparent the clock as part of the initial configuration.

Agreed. There doesn't seem to be a case where it would make sense to
have this configurable per-board. Can you achieve the same effect by
adding this to the clock initialization table?

Oh, I just see that we have this in the Tegra124 clock initialization
table:

	{TEGRA114_CLK_DSIALP, TEGRA114_CLK_PLL_P, 68000000, 0},
	{TEGRA114_CLK_DSIBLP, TEGRA114_CLK_PLL_P, 68000000, 0},

Doesn't that work for you already? If not that'd be a bug that should be
fixed in the clock driver.

Thierry
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