From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Mon, 12 Sep 2011 09:41:47 +0200 Subject: [PATCH 2/6] arm/imx6q: add core definitions and low-level debug uart In-Reply-To: <20110912023000.GC1258@S2100-06.ap.freescale.net> References: <1315303120-24203-1-git-send-email-shawn.guo@linaro.org> <1315303120-24203-3-git-send-email-shawn.guo@linaro.org> <20110906202555.GQ28816@pengutronix.de> <20110907110001.GI8148@S2100-06.ap.freescale.net> <20110907123635.GT28816@pengutronix.de> <20110912023000.GC1258@S2100-06.ap.freescale.net> Message-ID: <20110912074147.GE28624@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Shawn, On Mon, Sep 12, 2011 at 10:30:01AM +0800, Shawn Guo wrote: > On Wed, Sep 07, 2011 at 02:36:35PM +0200, Uwe Kleine-K?nig wrote: > > On Wed, Sep 07, 2011 at 07:00:02PM +0800, Shawn Guo wrote: > > > On Tue, Sep 06, 2011 at 10:25:55PM +0200, Uwe Kleine-K?nig wrote: > > > > On Tue, Sep 06, 2011 at 05:58:36PM +0800, Shawn Guo wrote: > > [...] > > > > > > diff --git a/arch/arm/plat-mxc/include/mach/mx6q.h b/arch/arm/plat-mxc/include/mach/mx6q.h > > > > > new file mode 100644 > > > > > index 0000000..7432310 > > > > > --- /dev/null > > > > > +++ b/arch/arm/plat-mxc/include/mach/mx6q.h > > > > > @@ -0,0 +1,29 @@ > > > > > +/* > > > > > + * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved. > > > > > + * Copyright 2011 Linaro Ltd. > > > > > + * > > > > > + * The code contained herein is licensed under the GNU General Public > > > > > + * License. You may obtain a copy of the GNU General Public License > > > > > + * Version 2 or later at the following locations: > > > > > + * > > > > > + * http://www.opensource.org/licenses/gpl-license.html > > > > > + * http://www.gnu.org/copyleft/gpl.html > > > > > + */ > > > > > + > > > > > +#ifndef __MACH_MX6Q_H__ > > > > > +#define __MACH_MX6Q_H__ > > > > > + > > > > > +/* static mappings */ > > > > > +#define IMX6Q_VA(x) (0xf4000000 + (x)) > > > > > + > > > > > +#define MX6Q_SCU_BASE_ADDR 0x00a00000 > > > > > +#define MX6Q_CCM_BASE_ADDR 0x020c4000 > > > > > +#define MX6Q_ANATOP_BASE_ADDR 0x020c8000 > > > > > +#define MX6Q_UART4_BASE_ADDR 0x021f0000 > > > > > + > > > > > +#define MX6Q_SCU_BASE_VADDR IMX6Q_VA(MX6Q_SCU_BASE_ADDR) > > > > > +#define MX6Q_CCM_BASE_VADDR IMX6Q_VA(MX6Q_CCM_BASE_ADDR) > > > > > +#define MX6Q_ANATOP_BASE_VADDR IMX6Q_VA(MX6Q_ANATOP_BASE_ADDR) > > > > > +#define MX6Q_UART4_BASE_VADDR IMX6Q_VA(MX6Q_UART4_BASE_ADDR) > > > > Depending on the sizes of these memory regions you can use the existing > > > > IMX_IO_P2V here. The conditions are: > > > > > > > > SCU_SIZE <= 0x200000 > > Actually this should be 0x100000 as this is the size that is mapped in a > > continous chunk. > > > > > > CCM_SIZE <= 0x4000 > > > > ANATOP_SIZE <= 0x28000 > > > > UART4 <= 0x100000 > > > > > > > This is exactly what I dislike about IMX_IO_P2V(). We have to verify > > > all these conditions manually. Looking at the static mapping below > > I did it semi-manual, I just put your constants for imx6q into my script > > (all with size=0x4000 for now) and it told me: > > > > ... > > * mx6q: > > * SCU 0x00a00000+0x004000 -> 0xf4000000+0x004000 > > * CCM 0x020c4000+0x004000 -> 0xf42c4000+0x004000 > > * ANATOP 0x020c8000+0x004000 -> 0xf42c8000+0x004000 > > * UART4 0x021f0000+0x004000 -> 0xf42f0000+0x004000 > > ... > > > > > (copied from arch/arm/plat-mxc/include/mach/hardware.h), do you think > > > it's really scalable and easy to maintain for the long run? > > At least it provides a way to verify the correctness of the mapping. > > Before I introduced the mapping function there was a conflict IIRC. > > > > > /* > > > * This is rather complicated for humans and ugly to verify, but for a machine > > > * it's OK. Still more as it is usually only applied to constants. The upsides > > > * on using this approach are: > > > * > > > * - same mapping on all i.MX machines > > > * - works for assembler, too > > > * - no need to nurture #defines for virtual addresses > > > * > > > * The downside it, it's hard to verify (but I have a script for that). > > If you want I can provide you that script. > > > Yes, please. I would use IMX_IO_P2V() in the next post. I just found a bug in the conflict detection code, so I put it in a repository to prevent the broken script to enter the archives. You can find it on git://git.pengutronix.de/git/ukl/imx-iop2v.git > [...] > > > > #define IMX_IO_P2V(x) ( \ > > > 0xf4000000 + \ > > > (((x) & 0x50000000) >> 6) + \ > > > (((x) & 0x0b000000) >> 4) + \ > > > (((x) & 0x000fffff))) > > > > > > > hmm, looking at patch 4 SCU_BASE is determined by a coprocessor > > > > instruction?! > > > > > > Ah, yes. The SCU physical base address can be retrieved from > > > coprocessor. > > Is there an advantage in autodetecting the base address? > > > Any disadvantage for doing so? It makes #define MX6Q_SCU_BASE_ADDR 0x00a00000 superfluous. And in case the real address is different it might make IMX_IO_P2V(real scu address) != scu_io_desc.virtual which makes the scriptable check for conflicts kind of useless and might come as a surprise. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |