Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755599AbaDXJLZ (ORCPT ); Thu, 24 Apr 2014 05:11:25 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:55346 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754182AbaDXJLU (ORCPT ); Thu, 24 Apr 2014 05:11:20 -0400 Message-ID: <5358D534.2070205@ti.com> Date: Thu, 24 Apr 2014 12:11:16 +0300 From: Peter Ujfalusi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Tero Kristo , Mike Turquette CC: Tony Lindgren , , Subject: Re: [PATCH] clk: ti: clk-7xx: Correct ABE DPLL configuration References: <1396446525-20302-1-git-send-email-peter.ujfalusi@ti.com> <533C1AC2.1000307@ti.com> <533CFFB3.9070201@ti.com> In-Reply-To: <533CFFB3.9070201@ti.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? Mike: do you want me to resend this patch? Thanks, P?ter > >> >> -Tero >> >>> >>> Signed-off-by: Peter Ujfalusi >>> --- >>> 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 >>> #include >>> >>> -#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) >>> >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/