Commit Graph

3 Commits

Author SHA1 Message Date
maxims@google.com
99f8ad7321 aspeed: Refactor AST2500 RAM Driver and Sysreset Driver
This change switches all existing users of ast2500 Watchdog to Driver
Model based Watchdog driver.

To perform system reset Sysreset Driver uses first Watchdog device found
via uclass_first_device call. Since the system is going to be reset
anyway it does not make much difference which watchdog is used.

Instead of using Watchdog to reset itself, SDRAM driver now uses Reset
driver to do that.

These were the only users of the old Watchdog API, so that API is
removed.

This all is done in one change to avoid having to maintain dual API for
watchdog in between.

Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-08 11:57:32 -04:00
maxims@google.com
14e4b14979 aspeed: Add basic ast2500-specific drivers and configuration
Clock Driver

This driver is ast2500-specific and is not compatible with earlier
versions of this chip. The differences are not that big, but they are
in somewhat random places, so making it compatible with ast2400 is not
worth the effort at the moment.

SDRAM MC driver

The driver is very ast2500-specific and is completely incompatible
with previous versions of the chip.

The memory controller is very poorly documented by Aspeed in the
datasheet, with any mention of the whole range of registers missing. The
initialization procedure has been basically taken from Aspeed SDK, where
it is implemented in assembly. Here it is rewritten in C, with very limited
understanding of what exactly it is doing.
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-01-28 14:04:29 -05:00
maxims@google.com
4697abea62 aspeed: Add drivers common to all Aspeed SoCs
Add support for Watchdog Timer, which is compatible with AST2400 and
AST2500 watchdogs. There is no uclass for Watchdog yet, so the driver
does not follow the driver model. It also uses fixed clock, so no clock
driver is needed.

Add support for timer for Aspeed ast2400/ast2500 devices.
The driver actually controls several devices, but because all devices
share the same Control Register, it is somewhat difficult to completely
decouple them. Since only one timer is needed at the moment, this should
be OK. The timer uses fixed clock, so does not rely on a clock driver.

Add sysreset driver, which uses watchdog timer to do resets and particular
watchdog device to use is hardcoded (0)
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-01-28 14:04:27 -05:00