[PATCH v3 17/21] ARM: at91: merge SRAM Memory banks thanks to mirroring
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Fri Feb 24 11:54:43 EST 2012
On 08:47 Fri 24 Feb , Ryan Mallon wrote:
> On 24/02/12 01:26, Nicolas Ferre wrote:
>
> > From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> >
> > On at91sam9260 and at91sam9g20 the SRAM banks are mirrored. We can
> > merge them together to be able to have bigger and continuous
> > internal RAM.
>
> I think this patch needs some comments in the code. As mentioned in the
> last round, this functionality is not documented, so it is not obvious
> how/why this works. This is especially true for any user who has
> problems with this code and then tries to look up those addresses in
> their at91 manual only to find the regions are reserved.
>
> Nicolas, are you able to give an official Atmel stance on this?
you have the ack from Nico and he send the e-mail
Best Regards,
J.
>
> ~Ryan
>
> > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> > Acked-by: Nicolas Ferre <nicolas.ferre at atmel.com>
> > ---
> > arch/arm/mach-at91/at91sam9260.c | 13 +++++--------
> > arch/arm/mach-at91/include/mach/at91sam9260.h | 4 ++++
> > 2 files changed, 9 insertions(+), 8 deletions(-)
> >
> > diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c
> > index 14882ae..4ade265 100644
> > --- a/arch/arm/mach-at91/at91sam9260.c
> > +++ b/arch/arm/mach-at91/at91sam9260.c
> > @@ -310,15 +310,12 @@ static void __init at91sam9xe_map_io(void)
> >
> > static void __init at91sam9260_map_io(void)
> > {
> > - if (cpu_is_at91sam9xe()) {
> > + if (cpu_is_at91sam9xe())
> > at91sam9xe_map_io();
> > - } else if (cpu_is_at91sam9g20()) {
> > - at91_init_sram(0, AT91SAM9G20_SRAM0_BASE, AT91SAM9G20_SRAM0_SIZE);
> > - at91_init_sram(1, AT91SAM9G20_SRAM1_BASE, AT91SAM9G20_SRAM1_SIZE);
> > - } else {
> > - at91_init_sram(0, AT91SAM9260_SRAM0_BASE, AT91SAM9260_SRAM0_SIZE);
> > - at91_init_sram(1, AT91SAM9260_SRAM1_BASE, AT91SAM9260_SRAM1_SIZE);
> > - }
> > + else if (cpu_is_at91sam9g20())
> > + at91_init_sram(0, AT91SAM9G20_SRAM_BASE, AT91SAM9G20_SRAM_SIZE);
> > + else
> > + at91_init_sram(0, AT91SAM9260_SRAM_BASE, AT91SAM9260_SRAM_SIZE);
> > }
> >
> > static void __init at91sam9260_ioremap_registers(void)
> > diff --git a/arch/arm/mach-at91/include/mach/at91sam9260.h b/arch/arm/mach-at91/include/mach/at91sam9260.h
> > index 2e47b6d..08ae9af 100644
> > --- a/arch/arm/mach-at91/include/mach/at91sam9260.h
> > +++ b/arch/arm/mach-at91/include/mach/at91sam9260.h
> > @@ -113,6 +113,8 @@
> > #define AT91SAM9260_SRAM0_SIZE SZ_4K /* Internal SRAM 0 size (4Kb) */
> > #define AT91SAM9260_SRAM1_BASE 0x00300000 /* Internal SRAM 1 base address */
> > #define AT91SAM9260_SRAM1_SIZE SZ_4K /* Internal SRAM 1 size (4Kb) */
> > +#define AT91SAM9260_SRAM_BASE 0x002FF000 /* Internal SRAM base address */
> > +#define AT91SAM9260_SRAM_SIZE SZ_8K /* Internal SRAM size (8Kb) */
> >
> > #define AT91SAM9260_UHP_BASE 0x00500000 /* USB Host controller */
> >
> > @@ -126,6 +128,8 @@
> > #define AT91SAM9G20_SRAM0_SIZE SZ_16K /* Internal SRAM 0 size (16Kb) */
> > #define AT91SAM9G20_SRAM1_BASE 0x00300000 /* Internal SRAM 1 base address */
> > #define AT91SAM9G20_SRAM1_SIZE SZ_16K /* Internal SRAM 1 size (16Kb) */
> > +#define AT91SAM9G20_SRAM_BASE 0x002FC000 /* Internal SRAM base address */
> > +#define AT91SAM9G20_SRAM_SIZE SZ_32K /* Internal SRAM size (32Kb) */
> >
> > #define AT91SAM9G20_UHP_BASE 0x00500000 /* USB Host controller */
> >
>
>
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