From mboxrd@z Thu Jan  1 00:00:00 1970
From: andy.green@linaro.org (Andy Green)
Date: Fri, 29 Jun 2012 17:13:27 +0800
Subject: [PATCH 1/3] OMAP2+: add cpu id register to MAC address helper
In-Reply-To: <20120629090515.GA4202@atomide.com>
References: <20120629054404.11091.31289.stgit@build.warmcat.com>
 <20120629055509.11091.2780.stgit@build.warmcat.com>
 <20120629090515.GA4202@atomide.com>
Message-ID: <4FED71B7.80308@linaro.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 06/29/12 17:05, the mail apparently from Tony Lindgren included:
> * Andy Green <andy.green@linaro.org> [120628 22:59]:
>>
>> Introduce a generic helper function that can generate a valid MAC
>> address using data from the OMAP unique CPU ID register.
> ...
>
>> --- a/arch/arm/mach-omap2/id.c
>> +++ b/arch/arm/mach-omap2/id.c
>> @@ -530,3 +530,42 @@ void __init omap2_set_globals_tap(struct omap_globals *omap2_globals)
>>   	else
>>   		tap_prod_id = 0x0208;
>>   }
>> +
>> +/*
>> + * this uses the unique per-cpu info from the cpu fuses set at factory to
>> + * generate a 6-byte MAC address.  Two bits in the generated code are used
>> + * to elaborate the generated address into four, so it can be used on multiple
>> + * network interfaces.
>> + */
>> +
>> +void omap2_die_id_to_ethernet_mac(u8 *mac, int subtype)
>> +{
>> +	struct omap_die_id odi;
>> +	u32 tap = read_tap_reg(OMAP_TAP_IDCODE);
>> +
>> +	omap_get_die_id(&odi);
>> +
>> +	mac[0] = odi.id_2;
>> +	mac[1] = odi.id_2 >> 8;
>> +	mac[2] = odi.id_1;
>> +	mac[3] = odi.id_1 >> 8;
>> +	mac[4] = odi.id_1 >> 16;
>> +	mac[5] = odi.id_1 >> 24;
>> +
>> +	/* XOR other chip-specific data with ID */
>> +
>> +	tap ^= odi.id_3;
>> +
>> +	mac[0] ^= tap;
>> +	mac[1] ^= tap >> 8;
>> +	mac[2] ^= tap >> 16;
>> +	mac[3] ^= tap >> 24;
>> +
>> +	/* allow four MACs from this same basic data */
>> +
>> +	mac[1] = (mac[1] & ~0xc0) | ((subtype & 3) << 6);
>> +
>> +	/* mark it as not multicast, and outside official 80211 MAC namespace */
>> +
>> +	mac[0] = (mac[0] & ~1) | 2;
>> +}
>
> Let's just make this omap_die_id_to_ethernet_mac, no need to keep the
> omap2 naming there as this should not conflict with any omap1 stuff.

Okay, will do thanks.

-Andy

-- 
Andy Green | TI Landing Team Leader
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