From: tony@atomide•com (Tony Lindgren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 02/11] omap2/3: Fix DEBUG_LL for omap zoom2/3
Date: Fri, 30 Apr 2010 16:30:02 -0700 [thread overview]
Message-ID: <20100430233002.GJ29604@atomide.com> (raw)
In-Reply-To: <87y6g4d2ic.fsf@deeprootsystems.com>
* Kevin Hilman <khilman@deeprootsystems•com> [100430 14:56]:
> "Pandita, Vikram" <vikram.pandita@ti•com> writes:
>
> [...]
>
> >>>> > --- a/arch/arm/kernel/head.S
> >>>> > +++ b/arch/arm/kernel/head.S
> >>>> > @@ -328,6 +328,16 @@ __create_page_tables:
> >>>> > add r0, r4, #0xd8000000 >> 18
> >>>> > str r3, [r0]
> >>>> > #endif
> >>>> > +#if defined(CONFIG_MACH_OMAP_ZOOM2) ||
> >>defined(CONFIG_MACH_OMAP_ZOOM3)
> >>>> > + /*
> >>>> > + * Zoom2 and Zoom3 have UARTs only on the debug board.
> >>>> > + * The debug board is connected to the GPMC.
> >>>> > + */
> >>>> > + add r0, r4, #0xfa000000 >> 18
> >>>> > + orr r0, r0, #0x00400000 >> 18 @ ZOOM_UART_VIRT
> >>>> > + orr r3, r7, #0x10000000 @ ZOOM_UART_BASE
> >>>> > + str r3, [r0]
> >>>> > +#endif
> >>>>
> >>>> I don't see why this part is needed. The same mapping is done using
> >>>> the .io_pg_offset in the machine description which is done just before
> >>>> this in head.S
> >>>
> >>> That mapping does not cover the GPMC area where this UART is.
> >>
> >>Hmm, then shouldn't that be fixed? I understood the .phys_io and and
> >>.io_pg_offset fields of the mach_desc to be specifically for mapping
> >>the early UART, and nothing else.
> >
> > Here is the problem - with current approach we need two mappings to
> > happen and the MACHINE_START() code allows for only one via
> > .io_pg_offset and .phys_io
> >
> > Why:
>
> > Tony's approach is to pass the information about the debug uart
> > number from the UART1 Scratchpad register.
> >
> > this introduces a dependency that
> > UART1 registers also be mapped (virt<->phy).
> >
> > So for Tony's approach to work, .phys_io/.io_pg_offset continued to
> > have 0x4800000 based mapping and for external uart zoom3 port,
> > create this extra mapping.
> >
> > So find a better way from compressed.S to pass the uart number to
> > kernel, and we can solve the problem.
>
> Ah, yet another reason to use a memory location instead of UART1 SCR
> to pass the UART info (c.f. [1])
That should work if we don't need to access any L4 registers
early on before .map_io.
Regards,
Tony
> Kevin
>
> [1] http://marc.info/?l=linux-omap&m=127266219130713&w=2
next prev parent reply other threads:[~2010-04-30 23:30 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-30 20:33 [PATCH 00/11] omap2/3/4: Multi-omap updates to boot test with omap3_defconfig Tony Lindgren
2010-04-30 20:33 ` [PATCH 01/11] omap2/3/4: Fix multi.h when omap3 and omap4 are selected without omap2 Tony Lindgren
2010-04-30 20:33 ` [PATCH 02/11] omap2/3: Fix DEBUG_LL for omap zoom2/3 Tony Lindgren
2010-04-30 20:55 ` Kevin Hilman
2010-04-30 21:02 ` Tony Lindgren
2010-04-30 21:20 ` Kevin Hilman
2010-04-30 21:37 ` Pandita, Vikram
2010-04-30 21:53 ` Pandita, Vikram
2010-04-30 22:00 ` Kevin Hilman
2010-04-30 23:30 ` Tony Lindgren [this message]
2010-05-01 0:10 ` Kevin Hilman
2010-05-01 1:37 ` Tony Lindgren
2010-05-01 1:50 ` Tony Lindgren
2010-05-03 22:10 ` Pandita, Vikram
2010-05-04 0:40 ` Tony Lindgren
2010-05-04 0:57 ` [PATCH 02a/11] omap: Use a memory address for storing the debug port info instead of UART1 scratchpad Tony Lindgren
2010-05-04 0:58 ` [PATCH 02b/11] omap2/3: Fix DEBUG_LL for omap zoom2/3 Tony Lindgren
2010-05-04 17:33 ` Pandita, Vikram
2010-05-04 23:09 ` Tony Lindgren
2010-04-30 20:33 ` [PATCH 03/11] omap3: Fix compile for board-cm-t35 Tony Lindgren
2010-04-30 20:33 ` [PATCH 04/11] omap3: Remove non-muxable ball entries for 3630 Tony Lindgren
2010-04-30 20:33 ` [PATCH 05/11] omap4: Fix multiboot with CONFIG_PM and CONFIG_ARCH_OMAP3 selected Tony Lindgren
2010-04-30 20:33 ` [PATCH 06/11] omap4: Fix omap_l2_cache_init not to run for other omaps Tony Lindgren
2010-05-01 6:18 ` Shilimkar, Santosh
2010-05-01 17:46 ` Tony Lindgren
2010-04-30 20:34 ` [PATCH 07/11] omap2/3/4: Add new boards to omap3_defconfig Tony Lindgren
2010-04-30 20:34 ` [PATCH 08/11] omap2/3/4: Make omap3_defconfig usable on Nokia boards Tony Lindgren
2010-04-30 20:34 ` [PATCH 09/11] omap2/3/4: Update PMIC options for TWL and Menelaus chips Tony Lindgren
2010-04-30 20:34 ` [PATCH 10/11] omap2/3/4: Dissable CONFIG_PM_VERBOSE in omap3_defconfig Tony Lindgren
2010-04-30 20:34 ` [PATCH 11/11] omap2/3/4: Disable CONFIG_FB_OMAP " Tony Lindgren
2010-04-30 20:50 ` Tony Lindgren
2010-05-04 0:52 ` Tony Lindgren
2010-05-04 7:26 ` Tomi Valkeinen
2010-05-04 14:40 ` Tony Lindgren
2010-05-04 14:50 ` Tomi Valkeinen
2010-05-04 19:23 ` Tony Lindgren
2010-05-05 17:32 ` Old DSS code broken as module (was "RE: [PATCH 11/11] omap2/3/4: Disable CONFIG_FB_OMAP in omap3_defconfig") Aguirre, Sergio
2010-05-05 17:43 ` Tony Lindgren
2010-05-05 18:23 ` Aguirre, Sergio
2010-05-06 8:07 ` Tomi Valkeinen
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