From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Thomas Zimmermann <tzimmermann@suse.de>,
Javier Martinez Canillas <javierm@redhat.com>,
airlied@linux.ie, daniel@ffwll.ch, deller@gmx.de,
maxime@cerno.tech, sam@ravnborg.org, msuchanek@suse.de,
mpe@ellerman.id.au, paulus@samba.org, geert@linux-m68k.org,
mark.cave-ayland@ilande.co.uk
Cc: linux-fbdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v2 10/10] drm/ofdrm: Support color management
Date: Fri, 05 Aug 2022 10:29:01 +1000 [thread overview]
Message-ID: <e92ea74fefd5110d2c1dbcea454d5ec8d2cadcf8.camel@kernel.crashing.org> (raw)
In-Reply-To: <05511c35-da46-aefd-3e03-364b7311284c@suse.de>
On Wed, 2022-07-27 at 10:41 +0200, Thomas Zimmermann wrote:
>
> > > +static void __iomem *ofdrm_mach64_cmap_ioremap(struct ofdrm_device *odev,
> > > + struct device_node *of_node,
> > > + u64 fb_base)
> > > +{
> > > + struct drm_device *dev = &odev->dev;
> > > + u64 address;
> > > + void __iomem *cmap_base;
> > > +
> > > + address = fb_base & 0xff000000ul;
> > > + address += 0x7ff000;
> > > +
> >
> > It would be good to know where these addresses are coming from. Maybe some
> > constant macros or a comment ? Same for the other places where addresses
> > and offsets are used.
>
> I have no idea where these values come from. I took them from offb. And
> I suspect that some of these CMAP helpers could be further merged if
> only it was clear where the numbers come from. But as i don't have the
> equipment for testing, I took most of this literally as-is from offb.
Ancient black magic :-) Old ATI mach64 chips had the registers sitting
at the end of the framebuffer. You can find an equivalent in
drivers/video/aty/atyfb_base.c:atyfb_setup_generic():
raddr = addr + 0x7ff000UL;
Cheers,
Ben.
next prev parent reply other threads:[~2022-08-05 0:39 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-20 14:27 [PATCH v2 00/10] drm: Add driver for PowerPC OF displays Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 01/10] drm/simpledrm: Remove mem field from device structure Thomas Zimmermann
2022-07-25 14:48 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 02/10] drm/simpledrm: Inline device-init helpers Thomas Zimmermann
2022-07-25 15:01 ` Javier Martinez Canillas
2022-07-27 7:50 ` Thomas Zimmermann
2022-07-27 9:30 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 03/10] drm/simpledrm: Remove pdev field from device structure Thomas Zimmermann
2022-07-25 15:02 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 04/10] drm/simpledrm: Compute framebuffer stride if not set Thomas Zimmermann
2022-07-21 14:46 ` Geert Uytterhoeven
2022-07-25 15:13 ` Javier Martinez Canillas
2022-07-27 7:53 ` Thomas Zimmermann
2022-08-11 17:23 ` Daniel Vetter
2022-08-11 18:26 ` Thomas Zimmermann
2022-08-11 18:27 ` Thomas Zimmermann
2022-09-06 19:16 ` Daniel Vetter
2022-07-20 14:27 ` [PATCH v2 05/10] drm/simpledrm: Convert to atomic helpers Thomas Zimmermann
2022-07-25 15:46 ` Javier Martinez Canillas
2022-07-27 7:58 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 06/10] drm/simpledrm: Move some functionality into fwfb helper library Thomas Zimmermann
2022-07-25 16:23 ` Javier Martinez Canillas
2022-07-27 8:24 ` Thomas Zimmermann
2022-07-27 9:39 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 07/10] drm/ofdrm: Add ofdrm for Open Firmware framebuffers Thomas Zimmermann
2022-07-26 13:17 ` Javier Martinez Canillas
2022-09-21 11:41 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 08/10] drm/ofdrm: Add CRTC state Thomas Zimmermann
2022-07-26 13:36 ` Javier Martinez Canillas
2022-09-21 11:45 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 09/10] drm/ofdrm: Add per-model device function Thomas Zimmermann
2022-07-26 13:38 ` Javier Martinez Canillas
2022-07-26 14:40 ` Michal Suchánek
2022-07-26 19:22 ` Javier Martinez Canillas
2022-07-27 8:33 ` Thomas Zimmermann
2022-08-05 0:22 ` Benjamin Herrenschmidt
2022-09-21 12:37 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 10/10] drm/ofdrm: Support color management Thomas Zimmermann
2022-07-26 13:49 ` Javier Martinez Canillas
2022-07-27 8:41 ` Thomas Zimmermann
2022-07-27 9:45 ` Javier Martinez Canillas
2022-08-05 0:29 ` Benjamin Herrenschmidt [this message]
2022-08-05 0:19 ` Benjamin Herrenschmidt
2022-09-21 12:55 ` Thomas Zimmermann
2022-09-21 16:48 ` Geert Uytterhoeven
2022-09-22 6:42 ` Thomas Zimmermann
2022-09-22 7:28 ` Maxime Ripard
2022-09-22 8:06 ` Thomas Zimmermann
2022-07-28 11:13 ` [PATCH v2 00/10] drm: Add driver for PowerPC OF displays Michael Ellerman
2022-07-28 11:31 ` Michal Suchánek
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