This patch moves ARM core and DRAM timing functions around to simplify
the dependencies for system_clock_init().
The original code was architected such that the system_clock_init()
function called other functions to obtain core and memory timings.
Due to the way memory timing information must be obtained on Snow,
which entails decoding platform-specific board straps, the bottom-
up approach resulted in having the low-level clock init code
implicitly depend on board and vendor-specific info:
main()
->system_clock_init()
-> get_arm_ratios()
-> CPU-specific code
-> clock_get_mem_timings()
-> board_get_revision()
-> read GPIOs (3-state logic)
-> Decode GPIOs in a vendor-specific manner
-> Choose memory timings from module-specific look-up table
...then proceed to init clocks
...come back to main()
The new approach gathers all board and vendor-specific info in a
more appropriate location and passes it into system_clock_init():
main()
-> get_arm_ratios()
-> CPU-specific code
-> get_mem_timings()
-> board_get_config()
-> read GPIOs (3-state logic)
-> Decode GPIOs in a vendor-specific manner
-> Choose memory timings from module-specific look-up table
-> system_clock_init()
...back to main()
Change-Id: Ie237ebff76fc2d8a4d2f4577a226ac3909e4d4e8
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/2271
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>