Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751896AbaA2LVw (ORCPT ); Wed, 29 Jan 2014 06:21:52 -0500 Received: from mail-lb0-f177.google.com ([209.85.217.177]:39134 "EHLO mail-lb0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbaA2LVu (ORCPT ); Wed, 29 Jan 2014 06:21:50 -0500 Subject: OMAP: clock DT conversion issues with omap36xx From: Christoph Fritz To: Tero Kristo Cc: Tomi Valkeinen , Ivaylo Dimitrov , "linux-omap@vger.kernel.org" , linux-kernel@vger.kernel.org, pali.rohar@gmail.com, pavel@ucw.cz, Nishanth Menon In-Reply-To: <1390928565.4904.88.camel@mars> References: <52E697C0.6000202@gmail.com> <1390848104.4936.62.camel@mars> <52E772A3.4090401@ti.com> <1390901735.2963.8.camel@lovely> <52E77D03.8090001@ti.com> <52E7B361.2030601@ti.com> <1390928565.4904.88.camel@mars> Content-Type: text/plain; charset="UTF-8" Date: Wed, 29 Jan 2014 12:21:45 +0100 Message-ID: <1390994505.5023.32.camel@mars> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2014-01-28 at 18:02 +0100, Christoph Fritz wrote: > On Tue, 2014-01-28 at 15:40 +0200, Tero Kristo wrote: > > > > >> Due to a regression since next-20140122 the following errors are present: > > >> > > >> - pin sys_clkout2, which gets configured to 24 Mhz by the fourth patch > > >> in this set, erroneously outputs only 12 Mhz. > > >> Just out of curiosity, configuring it to 48 Mhz puts out desired 24 Mhz. > > >> > > >> - omap_dss, which gets configured by the third patch in this set, fails > > >> to do 'dss_set_fck_rate(fck);' in > > >> drivers/video/omap2/dss/dss.c:dss_setup_default_clock() which leads to: > > >> > > >> | omapdss_dss: probe of omapdss_dss failed with error -22 > > >> | omapdss CORE error: Failed to initialize DSS platform driver > > >> | panel-dpi panel-dpi.0: failed to find video source 'dpi.0 > > >> > > >> Both regressions seem to have something to do with the clock framework. > > >> Could this be related to the DT clock conversion patches? > > > > > > > Yea its definitely possible, as the clock DT conversion touches pretty > > much everything. Have you tried whether this works properly with legacy > > boot? Personally I don't have access to any omap3 devices that would > > have display and have no possibility to check this out myself. Anyway, > > my initial guess is that some clock divider setup might be wrong with > > omap3, or we are missing some ti,set-rate-parent flag for some clock > > node which prevents escalating clk_set_rate properly. However, it should > > be easy to debug this by looking at the clock node in question, and its > > parent nodes to see if there are any problems. > > Currently I only analyzed sys_clkout2 (see attachments for full > clk_summary files): > > clk_summary__next-20140115__works_as_expected: > dpll4_m2_ck 1 1 96000000 > dpll4_m2x2_ck 1 1 96000000 > omap_192m_alwon_fck 1 1 96000000 > omap_96m_alwon_fck 1 2 96000000 > per_96m_fck 0 6 96000000 > mcbsp4_fck 0 1 96000000 > mcbsp3_fck 0 2 96000000 > mcbsp2_fck 0 2 96000000 > cm_96m_fck 2 3 96000000 > clkout2_src_ck 1 1 96000000 > sys_clkout2 1 1 24000000 > > For real, on pin sys_clkout2 are correctly 24 Mhz measured. > > clk_summary__next-20140124__sysclkout2_dss_fails: > dpll4_m2_ck 1 1 96000000 > dpll4_m2x2_mul_ck 1 1 192000000 > dpll4_m2x2_ck 1 1 192000000 > omap_192m_alwon_fck 0 0 192000000 > omap_96m_alwon_fck 1 2 192000000 > per_96m_fck 0 6 192000000 > mcbsp4_fck 0 1 192000000 > mcbsp3_fck 0 2 192000000 > mcbsp2_fck 0 2 192000000 > cm_96m_fck 2 3 192000000 > clkout2_src_ck 1 1 192000000 > sys_clkout2 1 1 24000000 > > For real, on pin sys_clkout2 are only ~12 Mhz measured. > > So I added this patch: > > Subject: [PATCH] ARM: dts: fix omap3 clock multiplier for dpll4_m2x2_ck > > Before DT clock conversion, there was no multiplier for dpll4_m2x2_ck. > So to be compatible again, set dpll4_m2x2_mul_ck multiplier back to 1. > --- > arch/arm/boot/dts/omap3xxx-clocks.dtsi | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/boot/dts/omap3xxx-clocks.dtsi b/arch/arm/boot/dts/omap3xxx-clocks.dtsi > index cb04d4b..b594050 100644 > --- a/arch/arm/boot/dts/omap3xxx-clocks.dtsi > +++ b/arch/arm/boot/dts/omap3xxx-clocks.dtsi > @@ -212,7 +212,7 @@ > #clock-cells = <0>; > compatible = "fixed-factor-clock"; > clocks = <&dpll4_m2_ck>; > - clock-mult = <2>; > + clock-mult = <1>; > clock-div = <1>; > }; > > And it works again. But due to the fact that sys_clkout2 was at 12 Mhz > instead of 24, shouldn't it have been at 48 caused by "clock-mult = 2 ? Any ideas on that? I reverted the patch above and added: From: Tero Kristo Date: Wed, 29 Jan 2014 11:03:46 +0200 Subject: [PATCH] ARM: dts: omap36xx: fix omap96m_alwon_fck OMAP36xx has different hardware implementation for the omap96m_alwon_fck compared to other OMAP3 variants. Reflect this properly in the dts file. Signed-off-by: Tero Kristo --- arch/arm/boot/dts/omap36xx-clocks.dtsi | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm/boot/dts/omap36xx-clocks.dtsi b/arch/arm/boot/dts/omap36xx-clocks.dtsi index 2fcf253..24ddf3f 100644 --- a/arch/arm/boot/dts/omap36xx-clocks.dtsi +++ b/arch/arm/boot/dts/omap36xx-clocks.dtsi @@ -88,3 +88,12 @@ <&mcbsp4_ick>, <&uart4_fck>; }; }; + +&omap_96m_alwon_fck { + compatible = "ti,divider-clock"; + clocks = <&omap_192m_alwon_fck>; + ti,bit-shift = <12>; + ti,max-div = <2>; + reg = <0x0a40>; + ti,index-starts-at-one; +}; But the output of sys_clkout2 is still wrong. clk_summary__next-20140124__patch_tero_fix_omap96m_alwon_fck dpll4_m2_ck 1 1 96000000 dpll4_m2x2_mul_ck 1 1 192000000 dpll4_m2x2_ck 1 1 192000000 omap_192m_alwon_fck 1 1 192000000 omap_96m_alwon_fck 1 2 192000000 per_96m_fck 0 6 192000000 mcbsp4_fck 0 1 192000000 mcbsp3_fck 0 2 192000000 mcbsp2_fck 0 2 192000000 cm_96m_fck 2 3 192000000 clkout2_src_ck 1 1 192000000 sys_clkout2 1 1 24000000 Thanks -- Christoph -- 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/