From mboxrd@z Thu Jan  1 00:00:00 1970
From: plagnioj@jcrosoft.com (Jean-Christophe PLAGNIOL-VILLARD)
Date: Wed, 27 Apr 2011 01:45:14 +0200
Subject: [PATCH 05/14] at91: use structure to store the current soc
In-Reply-To: <4DB7299D.80308@bluewatersys.com>
References: <20110425180847.GA12904@game.jcrosoft.org>
	<1303756284-26529-5-git-send-email-plagnioj@jcrosoft.com>
	<4DB5F0C7.2070903@bluewatersys.com>
	<20110426042131.GD12904@game.jcrosoft.org>
	<4DB64DC3.70609@bluewatersys.com>
	<20110426064216.GJ12904@game.jcrosoft.org>
	<4DB7299D.80308@bluewatersys.com>
Message-ID: <20110426234514.GC29103@game.jcrosoft.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

> > yes it's for now we can use one soc at a time I'm working to remove those
> > issue and make then soc specific
> > before doint this I need to fix pm, interrupt, earlyprintk, ll_debug, etc...
> >
> > for gpio and timers it's already fix so one by one and it will be clean
> > in those 2 we can now specify on the soc the resource so we do not need to
> > have the same AT91_PIOx, AT91_ST and AT91_PIT for all soc
> > they can have their own.
> >
> > When this cleanup will be finished we will have
> > AT91SAM9263_PIOx AT91SAM9263_PIT etc...
> > and only common define when they are really common
> >>> all of this work is in preparation to allow multiple soc in the same kernel
> >>> that's also why I map the system controller the same way on all at91 arm9
> >> If the __cpu_is macros, which read the registers directly, remain then I
> >> don't see how this can be generic between the various SoCs?
> > because they will be use only at the begenning before any drivers or other ip
> > enable so we can use them later it will not be the case anymore
> >
> > Best Regards,
> > J.
> I think that a better approach is to have only the cpu_is_ macros which
> read the shadow value and then have at91_initialize (or some other
> function which is init called before anything needs the cpu_is_ macros)
> which just directly reads the cpu id registers and fills in the
> structure. You won't need a structure that way either, just an id.
> Something like:
> 
> /* include/mach/cpu.h */
> 
> /* Base SoC types */
> 
> #define AT91_SOC_AT91RM9200	0x1
> #define AT91_SOC_AT91SAM9260	0x2
> 
> /* Extended SoC types */
> #define AT91_SOC_AT91SAM9XE	(0x1 << 16)
> 
> /* Accessor macros */
> #define AT91_SOC_TYPE(x)	((x) & 0xffff)
> #define AT91_SOC_EXT_TYPE(x)	(((x) >> 16) & 0xffff)
> 
> extern unsigned long at91_soc_id;
> 
> #define cpu_is_at91rm9200()	(AT91_SOC_TYPE(at91_soc_id) == AT91_SOC_AT91RM9200)
> #define cpu_is_at91sam9260()	(AT91_SOC_TYPE(at91_soc_id) == AT91_SOC_AT91SAM9260)
> #define cpu_is_at91sam9xe()	(AT91_SOC_EXT_TYPE(at91_soc_id) == AT91_SOC_AT91SAM9XE)
> 
> /* soc.c */
> unsigned long at91_soc_id = 0;
> 
> static void at91_detect_cpu(void)
> {
> 	unsigned long cpu_id, full_id, arch_id, exid;
> 
> 
> 	full_id = at91_sys_read(AT91_DBGU_CIDR);
> 	cpu_id  = full_id & !AT91_CIDR_VERSION);
> 	arch_id = full_id & AT91_CIDR_ARCH;
> 	exid    = at91_sys_read(AT91_DBGU_EXID);
> 
> 	switch (cpu_id) {
> 	case ARCH_ID_AT91RM9200:
> 		at91_soc_id = AT91_SOC_AT91RM9200;
> 		current_soc = at91rm9200_soc;
> 		break;
> 
> 	case ARCH_ID_AT91SAM9260:
> 		at91_soc_id = AT91_SOC_AT91SAM9260;
> 		if (arch_id == ARCH_FAMILY_AT91SAM9XE)
> 			at91_soc_id |= AT91_SOC_AT91SAM9XE;
> 		current_soc = at91sam9260_soc;
> 		break;
> 	...
> 	
> 	default:
> 		panic("Unknown AT91 SoC type\n");
> 	}
> } 
> 
> 
> This way the cpu detection code is much clearer and easier to read and
> only one set of __cpu_is macros are needed. The values for
> ARCH_ID_AT91RM9200, etc can be moved into soc.c since they are not
> needed elsewhere.
This will never work you do not listen

the DBUG is at DIFFERENT base address on the AT91
you need to check them one by one

I keep the structure to keep more imformation inside and do not want to be
limited by a 32bit and complex encoding to maintain

Best Regards,
J.