On Mon, Nov 03, 2014 at 01:30:38PM -0500, Sean Paul wrote:
On Mon, Nov 3, 2014 at 4:27 AM, Thierry Reding thierry.reding@gmail.com wrote:
From: Thierry Reding treding@nvidia.com
Implement ganged mode support for the Tegra DSI driver. The DSI host controller to gang up with is specified via a phandle in the device tree and the resolved DSI host controller used for the programming of the ganged-mode registers.
There's a lot in here that is not specifically ganging-support, such as adding the transfer callback and command mode, as well as pulling out functionality into helper functions. It might make things a little clearer to split this up into a few patches. I'll leave that up to you.
I think I tried to do that a while back, but things got really complicated so I abandonned that effort. I'll give it another shot and see what I can come up with.
diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
[...]
-static int tegra_output_dsi_enable(struct tegra_output *output) +static void tegra_dsi_ganged_enable(struct tegra_dsi *dsi, unsigned int start,
unsigned int size)+{
u32 value;tegra_dsi_writel(dsi, start, DSI_GANGED_MODE_START);tegra_dsi_writel(dsi, size << 16 | size, DSI_GANGED_MODE_SIZE);You might want to add "size = size & 0xFFFF;" before performing this write.
Actually according to register documentation the mask even needs to be 0x1fff, so that's a good idea. Alternatively I guess we could check the size earlier to make sure that we can actually support it.
Thierry