Commit Graph

4 Commits

Author SHA1 Message Date
Daniel Drake 012a121184 viafb: don't touch clock state on OLPC XO-1.5
As detailed in the thread titled "viafb PLL/clock tweaking causes XO-1.5
instability," enabling or disabling the IGA1/IGA2 clocks causes occasional
stability problems during suspend/resume cycles on this platform.

This is rather odd, as the documentation suggests that clocks have two
states (on/off) and the default (stable) configuration is configured to
enable the clock only when it is needed. However, explicitly enabling *or*
disabling the clock triggers this system instability, suggesting that there
is a 3rd state at play here.

Leaving the clock enable/disable registers alone solves this problem.
This fixes spurious reboots during suspend/resume behaviour introduced by
commit b692a63a.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: stable@vger.kernel.org
2012-09-22 21:31:01 +00:00
Florian Tobias Schandinat bea02e4587 viafb: add engine clock support
This patch adds support for enabling and configuring the engine on
VIAs IGPs. This is the main clock used for everything but pixel
output.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
2011-03-26 02:53:21 +00:00
Florian Tobias Schandinat b692a63af8 viafb: add VIA slapping capability
This patch introduces dummy functions to execute when we don't know
what we should do (due to missing documentation). They do nothing
but print a nice message in the log explaining the situation.
To trigger this message initial power management support is
activated which might save a bit energy by disabling PLL and clock
if no device is configured to use them.

Note: The message is only shown for the oldest IGPs CLE266 and K400
      as for the other platforms there are reasonable assumptions
      how it does (hopefully) work.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
2011-03-24 21:17:52 +00:00
Florian Tobias Schandinat 2c536f84c1 viafb: split clock and PLL code to an extra file
This patch is a huge move operation with some rename and introduces
an interface to still use the functions. This should be a step in
the right direction to reuse the code whenever possible but cleanly
separate code that differs on different platform and keeping the
complexity as low as possible.
pll_config was renamed to via_pll_config to keep the naming scheme.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
2011-03-24 13:30:09 +00:00