u-boot-brain/board/amcc/sequoia
Stefan Roese e2e93442e5 ppc4xx: Fix bug in I2C bootstrap values for Sequoia/Rainier
The I2C bootstrap values that can be setup via the "bootstrap" command,
were setup incorrect regarding the generation of the internal sync PCI
clock. The values for PLB clock == 133MHz were slighly incorrect and the
values for PLB clock == 166MHz were totally incorrect. This could
lead to a hangup upon booting while PCI configuration scan.

This patch fixes this issue and configures valid PCI divisor values
for the sync PCI clock, with respect to the provided external async
PCI frequency.

Here the values of the formula in the chapter 14.2 "PCI clocking"
from the 440EPx users manual:

AsyncPCICLK - 1MHz <= SyncPCIClk <= (2 * AsyncPCIClk) - 1MHz

33MHz async PCI frequency:
PLB = 133:
=>      32 <= 44.3 <= 65        (div = 3)

PLB = 166:
=>      32 <= 55.3 <= 65        (div = 3)

66MHz async PCI frequency:
PLB = 133:
=>      65 <= 66.5 <= 132       (div = 2)

PLB = 166:
=>      65 <= 83 <= 132         (div = 2)

Signed-off-by: Stefan Roese <sr@denx.de>
2007-10-15 11:39:00 +02:00
..
cmd_sequoia.c ppc4xx: Fix bug in I2C bootstrap values for Sequoia/Rainier 2007-10-15 11:39:00 +02:00
config.mk Fix sequoia separate object direcory building problems. 2006-10-23 22:17:05 +02:00
init.S ppc4xx: (Re-)Enable CONFIG_PCI_PNP on AMCC 440EPx Sequoia 2007-08-31 15:21:46 +02:00
Makefile ppc4xx: Add bootstrap command for AMCC Sequoia (440EPx) eval board 2007-06-19 17:22:44 +02:00
sdram.c Merge with /home/stefan/git/u-boot/bamboo-nand 2007-06-01 16:15:34 +02:00
sdram.h Merge with /home/hs/SC3/u-boot 2007-01-15 13:41:04 +01:00
sequoia.c ppc4xx: Fix incorrect 33/66MHz PCI clock log-message on Sequoia & Yosemite 2007-10-15 11:29:33 +02:00
u-boot-nand.lds Add NAND environment support for PPC440EPx Sequoia NAND boot config 2006-09-12 20:19:10 +02:00
u-boot.lds Add support for AMCC Sequoia PPC440EPx eval board 2006-09-07 11:51:23 +02:00