[U-Boot] [PATCH 2/4] MX5: Add AHB clock reporting and fix IPG clock reporting

Jason Hui
2011-09-22T04:46:58Z

Hi, Marek,

On Thu, Sep 22, 2011 at 11:41 AM, Marek Vasut <marek.vasut@gmail.com> wrote:
> On Thursday, September 22, 2011 05:05:43 AM Jason Hui wrote:
>> Hi, Marek
>>
>> On Thu, Sep 15, 2011 at 8:09 AM, Marek Vasut <marek.vasut@gmail.com> wrote:
>> > Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
>> > ---
>> > ?arch/arm/cpu/armv7/mx5/clock.c | ? 36
>> > +++++++++++++++++++++++++++--------- 1 files changed, 27 insertions(+),
>> > 9 deletions(-)
>> >
>> > diff --git a/arch/arm/cpu/armv7/mx5/clock.c
>> > b/arch/arm/cpu/armv7/mx5/clock.c index 9f37f7f..a9fe81c 100644
>> > --- a/arch/arm/cpu/armv7/mx5/clock.c
>> > +++ b/arch/arm/cpu/armv7/mx5/clock.c
>> > @@ -152,18 +152,35 @@ static u32 get_periph_clk(void)
>> > ?}
>> >
>> > ?/*
>> > + * Get the rate of ahb clock.
>> > + */
>> > +static u32 get_ahb_clk(void)
>> > +{
>> > + ? ? ? uint32_t freq, div, reg;
>> > +
>> > + ? ? ? freq = decode_pll(mxc_plls[PLL2_CLOCK], CONFIG_SYS_MX5_HCLK);
>> > +
>> > + ? ? ? reg = __raw_readl(&mxc_ccm->cbcdr);
>> > + ? ? ? div = ((reg & MXC_CCM_CBCDR_AHB_PODF_MASK) >>
>> > + ? ? ? ? ? ? ? ? ? ? ? MXC_CCM_CBCDR_AHB_PODF_OFFSET) + 1;
>> > +
>> > + ? ? ? return freq / div;
>> > +}
>>
>> This is not correct, ahb clock is not fixed-source from PLL2.
>>
>> Currently implementation,we did not take care the ahb_bypass clock setting
>> and don't consider the lp-apm mode for main-bus clock input.
>
> There is no "current implementation".

The current implementation is for the get_periph_clk(..), anyway, the
abh clock should be:

ahb_clk = get_periph_clk()/ahb_pdof,
ipg_clk = ahb_clk/ipg_podf,

> Besides, that's how the BootROM sets it up
> so until someone needs it, this is ok.

u-boot still can change the BootROM setting.

Jason Liu
>
>>
>> Jason Liu
>