Messages in this thread | | | Date | Mon, 19 May 2014 15:29:35 +0300 | From | Tero Kristo <> | Subject | Re: [PATCH] clk: ti: clk-7xx: Correct ABE DPLL configuration |
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On 05/06/2014 04:39 PM, Peter Ujfalusi wrote: > Mike, > > On 04/24/2014 06:03 PM, Tero Kristo wrote: >> On 04/24/2014 12:11 PM, Peter Ujfalusi wrote: >>> Mike, Tero, >>> >>> On 04/03/2014 09:29 AM, Peter Ujfalusi wrote: >>>> On 04/02/2014 05:12 PM, Tero Kristo wrote: >>>>> On 04/02/2014 04:48 PM, Peter Ujfalusi wrote: >>>>>> ABE DPLL frequency need to be lowered from 361267200 >>>>>> to 180633600 to facilitate the ATL requironments. >>>>>> The dpll_abe_m2x2_ck clock need to be set to double >>>>>> of ABE DPLL rate in order to have correct clocks >>>>>> for audio. >>>>> >>>>> Do you have some sort of TRM reference for this? >>>> >>>> The ATL's max divider is 32. >>>> For audio purpose the clock coming out from the ATL instance should be >>>> 128 * fs. It is only possible to have 44.1KHz sampling rate with ABE DPLL set >>>> to 361267200 or 180633600. Which means: >>>> The atl generated clock should be 128 * 44100 = 5644800 >>>> From ABE_DPLL 361267200 we would need to have 64 as divider (ATL can't do >>>> this). >>>> From the suggested ABE_DPLL of 180633600 we can use ATL divider of 32, which >>>> is the maximum it can do. >>>> >>>> So the reason for the change is to have ATLPCLK clock which can be used for >>>> audio in the future, the 361267200 is just too high. >>> >>> Tero: can I have your ack for this patch or do you have further concerns? >> >> Yea looks good to me, except for the fact that there is some work on getting >> default rate/parent support through DT. I would like a comment from Mike about >> the estimate when this can get in, and whether we should merge intermediate >> solutions still like this. >> >> Anyway, you can consider this patch acked by me, I'll let Mike to decide what >> to do with it though. > > Do you have anything against this patch? Since right now there is no other > ways to fix the ABE DPLL for dra7 it would be great if we could have this in > till we have the final solution. Also I'd like to point out that the original > frequency the ABE DPLL was not correct and renders the audio to be not usable > on the platform. > > Thanks, > Péter
Thanks, queued for 3.16/ti-clk-drv.
-Tero
> >> >> -Tero >> >>> Mike: do you want me to resend this patch? >>> >>> Thanks, >>> Péter >>> >>>> >>>>> >>>>> -Tero >>>>> >>>>>> >>>>>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> >>>>>> --- >>>>>> drivers/clk/ti/clk-7xx.c | 7 ++++++- >>>>>> 1 file changed, 6 insertions(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/drivers/clk/ti/clk-7xx.c b/drivers/clk/ti/clk-7xx.c >>>>>> index f7e40734c819..19a55bf407dd 100644 >>>>>> --- a/drivers/clk/ti/clk-7xx.c >>>>>> +++ b/drivers/clk/ti/clk-7xx.c >>>>>> @@ -16,7 +16,7 @@ >>>>>> #include <linux/clkdev.h> >>>>>> #include <linux/clk/ti.h> >>>>>> >>>>>> -#define DRA7_DPLL_ABE_DEFFREQ 361267200 >>>>>> +#define DRA7_DPLL_ABE_DEFFREQ 180633600 >>>>>> #define DRA7_DPLL_GMAC_DEFFREQ 1000000000 >>>>>> >>>>>> >>>>>> @@ -322,6 +322,11 @@ int __init dra7xx_dt_clk_init(void) >>>>>> if (rc) >>>>>> pr_err("%s: failed to configure ABE DPLL!\n", __func__); >>>>>> >>>>>> + dpll_ck = clk_get_sys(NULL, "dpll_abe_m2x2_ck"); >>>>>> + rc = clk_set_rate(dpll_ck, DRA7_DPLL_ABE_DEFFREQ * 2); >>>>>> + if (rc) >>>>>> + pr_err("%s: failed to configure ABE DPLL m2x2!\n", __func__); >>>>>> + >>>>>> dpll_ck = clk_get_sys(NULL, "dpll_gmac_ck"); >>>>>> rc = clk_set_rate(dpll_ck, DRA7_DPLL_GMAC_DEFFREQ); >>>>>> if (rc) >>>>>> >>>>> >>>> >>>> >>> >> >
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