[Letux-kernel] SGX530/540/544 integration and reset-controller

H. Nikolaus Schaller hns at goldelico.com
Thu Nov 3 10:00:53 CET 2016


Hi,
I have some progress but no breakthrough.

1. reset-controller

using of_reset_control_get_shared() makes the driver
initialize and make the OMAP3 kernel no longer panic
during boot (have not tried on OMAP5).

There is still a -EBUSY issue in reset_control_deassert
so that the resets are not really done.

2. reset-controller + SGX530/40 driver

a) compile error (missing __get_user_pages)

MM API suggests to use one of the other more specific
get_user_pages functions.

The one that has the most comparable parameter list
is get_user_pages_remote() and with that we get the
sgx530 code compiled.

What I am not at all sure about is what "remote" means
and if it is the right thing to do.

b) locating the SGX reset controller

Although I have added a "gpu" node to omap3.dtsi the new
reset controller is still not found.

That has likely its reason in that there is no
ti,hwmods = "gpu" like Jonathan has added for the SGX544.
We probably have to add something similar to omap3/4
hwmods.

c) clock setup

And what we are most likely completely missing is clock
setup for the SGX530.

3. code

here is the latest merged tree with SGX530/540 and 544
patches:

http://git.goldelico.com/?p=gta04-kernel.git;a=shortlog;h=refs/heads/letux-4.9-rc3%2Breset-controller%2Bpvr

BR,
Nikolaus



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