From mboxrd@z Thu Jan  1 00:00:00 1970
From: linus.ml.walleij@gmail.com (Linus Walleij)
Date: Tue, 23 Mar 2010 08:29:01 +0100
Subject: [PATCH 05/07] Basic IO mappings for mach-tcc8k
In-Reply-To: <20100322192748.GK2040@bluebox.local>
References: <20100322191900.GF2040@bluebox.local>
	<20100322192748.GK2040@bluebox.local>
Message-ID: <63386a3d1003230029r7ed7c4adm107298686aa14d5e@mail.gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

2010/3/22 Hans J. Koch <hjk@linutronix.de>:

> Map the IO ranges of TCC8xxx peripherals.
> + ? ? ? {
> + ? ? ? ? ? ? ? .virtual ? ? ? ?= INT_SRAM_BASE_VIRT, ? /* Internal SRAM */
> + ? ? ? ? ? ? ? .pfn ? ? ? ? ? ?= __phys_to_pfn(INT_SRAM_BASE),
> + ? ? ? ? ? ? ? .length ? ? ? ? = INT_SRAM_SIZE,
> + ? ? ? ? ? ? ? .type ? ? ? ? ? = MT_DEVICE
> + ? ? ? },

MT_DEVICE is probably inappropriate here as well.

> + ? ? ? {
> + ? ? ? ? ? ? ? .virtual ? ? ? ?= DATA_TCM_BASE_VIRT, ? /* Data TCM */
> + ? ? ? ? ? ? ? .pfn ? ? ? ? ? ?= __phys_to_pfn(DATA_TCM_BASE),
> + ? ? ? ? ? ? ? .length ? ? ? ? = DATA_TCM_SIZE,
> + ? ? ? ? ? ? ? .type ? ? ? ? ? = MT_DEVICE
> + ? ? ? },

Actually, look close at your specs here, because you seem to have both
SRAM and TCM, usually you have ITCM+DTCM, so the thing that is
called SRAM may be something else.

Looking at the .h file:

+#define INT_SRAM_BASE          0x30000000
+#define INT_SRAM_SIZE          SZ_32K
(...)
+#define DATA_TCM_BASE          0xa0000000
+#define DATA_TCM_SIZE          SZ_8K

Check if the SRAM is really an SRAM and not ITCM (which can be
suspected). Also check that the DTCM is really such a thing.
(The code in arch/arm/kernel/tcm.c does this once you enable it,
it will scream if the config of the system does not match what the
CPU register is saying about ITCM+DTCM.)

If the DTCM is really an embedded TCM you can move it wherever
you want, even i physical memory space. It doesn't have to be on
0xa0000000, this is probably only the place where your boot code
locates it.

Yours,
Linus Walleij