From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: [RFC 5/5] [powerpc] Implement a p1010rdb clock source. Date: Mon, 08 Aug 2011 18:03:06 +0200 Message-ID: <4E4008BA.6030303@grandegger.com> References: <20110808113136.GS4926@sgi.com> <4E3FDFC9.7080508@grandegger.com> <20110808135630.GU4926@sgi.com> <4E3FEFBB.9050103@grandegger.com> <20110808142153.GW4926@sgi.com> <4E3FF4B8.2010603@grandegger.com> <20110808144424.GY4926@sgi.com> <4E3FF9EA.6030601@grandegger.com> <4E3FFD5B.7080000@pengutronix.de> <4E4001E1.3030508@grandegger.com> <20110808155540.GD4926@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Marc Kleine-Budde , U Bhaskar-B22300 To: Robin Holt Return-path: In-Reply-To: <20110808155540.GD4926-sJ/iWh9BUns@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org Errors-To: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org List-Id: netdev.vger.kernel.org On 08/08/2011 05:55 PM, Robin Holt wrote: > On Mon, Aug 08, 2011 at 05:33:53PM +0200, Wolfgang Grandegger wrote: >> On 08/08/2011 05:14 PM, Marc Kleine-Budde wrote: > ... > >>> On 08/08/2011 04:59 PM, Wolfgang Grandegger wrote: >>>> On 08/08/2011 04:44 PM, Robin Holt wrote: >>>>> On Mon, Aug 08, 2011 at 04:37:44PM +0200, Wolfgang Grandegger wrote: >>>>>> On 08/08/2011 04:21 PM, Robin Holt wrote: >>>>>>> On Mon, Aug 08, 2011 at 04:16:27PM +0200, Wolfgang Grandegger wrote: >>>>>>>> On 08/08/2011 03:56 PM, Robin Holt wrote: >>>>>>>>>> commit 65bb8b060a873fa4f5188f2951081f6011259614 >>>>>>>>>> Author: Bhaskar Upadhaya >>>>>>>>>> Date: Fri Mar 4 20:27:58 2011 +0530 >>>>>>>>> >>>>>>>>> On a side note, that commit fixes up "fsl,flexcan-v1.0" >>>>>>>>> ... >>>>>>>>> + do_fixup_by_compat_u32(blob, "fsl,flexcan-v1.0", >>>>>>>>> + "clock_freq", gd->bus_clk, 1); >>>>>>>>> >>>>>>>>> Should I go back to flexcan-v1.0 in my patches? >>>>>>>> >>>>>>>> Well, no. Let's wait. I don't think we need it. Also, it sets >>>>>>>> "clock_freq" while >>>>>>>> >>>>>>>> http://lxr.linux.no/#linux+v3.0.1/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt >>>>>>>> >>>>>>>> documents "clock-frequencies"... :-(. >>>>>>> >>>>>>> You answered a different question that I was asking. I was asking if >>>>>>> I should change fsl,flexcan back to fsl,flexcan-v1.0 as documented on >>>>>>> line 5. The clock_freq looks like a uboot change will need to be made >>>>>>> as well. >>>>>> >>>>>> Well, I wrote above: "Well, no. Let's wait. I don't think we need it." >>>>>> >>>>>> For the P1010 we can sinmply derive the clock frequency from >>>>>> "fsl_get_sys_freq()", which is fine for the time being. No extra >>>>>> properties, etc. The clk implemetation might go into >>>>>> >>>>>> http://lxr.linux.no/#linux+v3.0.1/arch/powerpc/platforms/85xx/clock.c >>>>>> >>>>>> or >>>>>> >>>>>> http://lxr.linux.no/#linux+v3.0.1/arch/powerpc/sysdev/fsl_soc.c >>>>>> >>>>>> And may depend on HAVE_CAN_FLEXCAN >>>>>> >>>>>> BTW, I have not found HAVE_CAN_FLEXCAN in your patch. What kernel are >>>>>> you using? >>>>> >>>>> I am starting with the v3.0 kernel, apply one patch from the freescale BSP >>>>> we receive under NDA which introduces the P1010RDB board into the QorIQ >>>>> platform, and then work from there for the flexcan stuff. That patch >>>>> introduces the HAVE_CAN_FLEXCAN. I do not like how freescale structured >>>>> that Kconfig bit, so I have tweaked it to be selected automatically >>>>> when P1010RDB, NET, and CAN are selected. That allows the CAN_FLEXCAN >>>>> selection to determine is we are going to build the flexcan.c file. >>>> >>>> ARM boards select HAVE_CAN_FLEXCAN and I do not see a good reason why >>>> we should do it differently for PowerPC. >>>> >>>> For mainline inclusion, you should provide your patches against the >>>> David Millers "net-next-2.6" tree, which already seems to have support >>>> for the P1010RDB: >>>> >>>> config P1010_RDB >>>> bool "Freescale P1010RDB" >>>> select DEFAULT_UIMAGE >>>> help >>>> This option enables support for the MPC85xx RDB (P1010 RDB) board >>>> >>>> P1010RDB contains P1010Si, which provides CPU performance up to 800 >>>> MHz and 1600 DMIPS, additional functionality and faster interfaces >>>> (DDR3/3L, SATA II, and PCI Express). >>>> >>>> >>>>> Our contact with Freescale would prefer that I not post that patch until >>>>> we get the OK from freescale to do so since we received it under NDA. >>>> >>>> I don't think we currently need it. I prefer dropping and cleaning up >>>> the device tree stuff as it is not needed for the P1010 anyway. If a >>>> new processor shows up with enhanced capabilities requiring >>>> configuration via device tree, we or somebody else can provide a patch. >>>> Marc, what do you think? >>> >>> ACK - The device tree bindings as in mainline's Documentation is a mess. >>> If the powerpc guys are happy with a clock interfaces based approach >>> somewhere in arch/ppc, I'm more than happy to remove: >>> - fsl,flexcan-clock-source (not implemented, even in the fsl driver) >>> >>> - fsl,flexcan-clock-divider \__ replace with code in arch/ppc, or >>> - clock-frequency / a single clock-frequency attribute >> >> In the "net-next-2.6" tree there is also: >> >> $ grep flexcan arch/powerpc/boots/dts/*.dts >> p1010rdb.dts: fsl,flexcan-clock-source = "platform"; >> p1010rdb.dts: fsl,flexcan-clock-source = "platform"; >> p1010si.dtsi: compatible = "fsl,flexcan-v1.0"; >> p1010si.dtsi: fsl,flexcan-clock-divider = <2>; >> p1010si.dtsi: compatible = "fsl,flexcan-v1.0"; >> p1010si.dtsi: fsl,flexcan-clock-divider = <2>; >> >> Especially the fsl,flexcan-clock-divider = <2>; might make people think, >> that they could set something else. > > I am currently lost on the direction. I think I need something like: > > 1) Patch 1/5 removing the "#include " stays. OK. > 2) Patch 2/5 abstracting readl/writel stays. OK. > 3) Patch 3/5 of_match for ppc and the match string is "fsl,flexcan" stays. Yep. > 4) Patch 4/5 I have not been given clear direction to not do it but have > not gotten a favorable response. Please drop this one for mainline. > 5) Patch 5/5 goes from being a powerpc patch back to being a flexcan.c No, I just would prefer a more general place, e.g.: http://lxr.linux.no/#linux+v3.0.1/arch/powerpc/platforms/85xx/clock.c Furthermore you need patches to cleanup some DTS and platform files and the Documentation. Wolfgang.