From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 1/3] OMAP2+: add cpu id register to MAC address helper Date: Fri, 29 Jun 2012 02:05:16 -0700 Message-ID: <20120629090515.GA4202@atomide.com> References: <20120629054404.11091.31289.stgit@build.warmcat.com> <20120629055509.11091.2780.stgit@build.warmcat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-ewr.mailhop.org ([204.13.248.71]:14819 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752045Ab2F2JFV (ORCPT ); Fri, 29 Jun 2012 05:05:21 -0400 Content-Disposition: inline In-Reply-To: <20120629055509.11091.2780.stgit@build.warmcat.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Andy Green Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, nicolas.pitre@linaro.org, s-jan@ti.com, arnd@arndb.de, patches@linaro.org, rostedt@goodmis.org * Andy Green [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. Tony