u-boot-brain/arch
Fabio Estevam 41c881c0ca mx53: Turn off child clocks before reconfigure perclk_root
In addition to ensuring that PERCLK remains at least 2.5 times slower
than the AHB clock, certain steps need to be followed to ensure robust
operation of PERCLK when reconfiguring the PERCLK clock source.

To properly configure the PERCLK clock source, the following steps are
required:

1.In the CCGR registers, gate the clocks to all PERCLK-dependent
  modules.
2.Select the desired input clock for the PERCLK root clock (to be either
  source from the peripherals main source clock or the
  lp_apm clock source). Refer to the CMCBR register,  perclk_lp_apm_sel bit.
3.Configure the perclk_pred1, perclk_pred2, and perclk_podf dividers
  to the desired setting.  Refer to the CBCDR register for details.
4.In the CCGR registers, enable the desired clocks for the
  PERCLK-dependent module clocks.

If these steps aren't followed, GPT timer may stop and the kernel stops
at "Calibrating delay loop".

Signed-off-by: Terry Lv <r65388@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
2011-11-04 22:06:37 +01:00
..
arm mx53: Turn off child clocks before reconfigure perclk_root 2011-11-04 22:06:37 +01:00
avr32 avr32: Use getenv_ulong() in place of getenv(), strtoul 2011-10-23 23:33:17 +02:00
blackfin blackfin: Use getenv_ulong() in place of getenv(), strtoul 2011-10-23 23:33:18 +02:00
m68k m68k: Use getenv_ulong() in place of getenv(), strtoul 2011-10-23 23:33:18 +02:00
microblaze microblaze: Fix strict-aliasing rules for in_be32 2011-10-24 07:57:03 +02:00
mips mips: Use getenv_ulong() in place of getenv(), strtoul 2011-10-23 23:33:19 +02:00
nds32 nds32: asm/io.h: add __iormb __iowmb and inline io support 2011-11-01 12:47:30 +08:00
nios2 nios2: cache: define ARCH_DMA_MINALIGN for DMA buffer alignment 2011-10-23 20:50:42 +02:00
powerpc Reduce build times 2011-11-03 20:44:58 +01:00
sandbox sandbox: drop unused return 2011-11-03 22:35:25 +01:00
sh cosmetic: s/BOARD_LATE_INIT/CONFIG_BOARD_LATE_INIT 2011-10-27 23:53:59 +02:00
sparc sparc: Use getenv_ulong() in place of getenv(), strtoul 2011-10-23 23:33:19 +02:00
x86 Reduce build times 2011-11-03 20:44:58 +01:00
.gitignore update include/asm/ gitignore after move 2010-05-07 00:17:30 +02:00