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>
This patch adds a board command to configure the I2C bootstrap EEPROM
values. Right now 533 and 667MHz are supported for booting either via NOR
or NAND FLASH. Here the usage:
=> bootstrap 533 nor ;to configure the board for 533MHz NOR booting
=> bootstrap 667 nand ;to configure the board for 667MHz NNAND booting
Signed-off-by: Stefan Roese <sr@denx.de>