Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753441Ab2BWVrS (ORCPT ); Thu, 23 Feb 2012 16:47:18 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:45438 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752288Ab2BWVrR (ORCPT ); Thu, 23 Feb 2012 16:47:17 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of rmallon@gmail.com designates 10.68.193.136 as permitted sender) smtp.mail=rmallon@gmail.com; dkim=pass header.i=rmallon@gmail.com Message-ID: <4F46B3DF.7010402@gmail.com> Date: Fri, 24 Feb 2012 08:47:11 +1100 From: Ryan Mallon User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.27) Gecko/20120216 Lightning/1.0b2 Thunderbird/3.1.19 MIME-Version: 1.0 To: Nicolas Ferre CC: plagnioj@jcrosoft.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux@arm.linux.org.uk, arnd@arndb.de Subject: Re: [PATCH v3 17/21] ARM: at91: merge SRAM Memory banks thanks to mirroring References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3438 Lines: 79 On 24/02/12 01:26, Nicolas Ferre wrote: > From: Jean-Christophe PLAGNIOL-VILLARD > > 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? ~Ryan > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD > Acked-by: Nicolas Ferre > --- > 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 */ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/