From mboxrd@z Thu Jan 1 00:00:00 1970 From: LW@KARO-electronics.de (=?utf-8?Q?Lothar_Wa=C3=9Fmann?=) Date: Tue, 20 Mar 2012 14:17:48 +0100 Subject: [PATCH v1 1/5] ARM: imx28: add basic dt support In-Reply-To: References: <1331628428-24017-1-git-send-email-b29396@freescale.com> <1331628428-24017-2-git-send-email-b29396@freescale.com> <20120313172351.97C5E3E053B@localhost> <20120314124512.GG1180@shlinux2.ap.freescale.net> <20120314141643.GP3852@pengutronix.de> <20120315030206.GB13022@shlinux2.ap.freescale.net> <20321.37353.63115.664975@ipc1.ka-ro> <20120315105927.GE13022@shlinux2.ap.freescale.net> <20321.53468.310199.875966@ipc1.ka-ro> <20120316030134.GA5161@shlinux2.ap.freescale.net> <20120318184749.BB15D3E07BF@localhost> <20326.55337.249575.289067@ipc1.ka-ro> <20120319150601.B783A3E05A5@localhost> <20327.25470.723875.916422@ipc1.ka-ro> <20120319220224.ABF5A3E0A04@localhost> Message-ID: <20328.33660.472382.117901@ipc1.ka-ro> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, Dong Aisheng writes: > On Mon, Mar 19, 2012 at 3:02 PM, Grant Likely wrote: > > On Mon, 19 Mar 2012 17:49:02 +0100, Lothar Wa?mann wrote: > >> Hi, > >> > >> Grant Likely writes: > >> > On Mon, 19 Mar 2012 07:54:33 +0100, Lothar Wa?mann wrote: > >> > > Grant Likely writes: > >> > > > On Fri, 16 Mar 2012 11:01:35 +0800, Dong Aisheng wrote: > >> > > > > On Thu, Mar 15, 2012 at 07:22:04PM +0800, Lothar Wa?mann wrote: > >> > > > > > Dong Aisheng writes: > >> > > > > > > On Thu, Mar 15, 2012 at 02:53:29PM +0800, Lothar Wa?mann wrote: > >> > > > > > Anyway there is no definite spec how the MAC address(es) are stored > >> > > > > > in the fuse map. Thus reading the MAC from there is more or less > >> > > > > > platform specific. > >> > > > > > > >> > > > > It's just provide one more option since there are customers storing the MAC > >> > > > > in the fuse map. > >> > > > > >> > > > That should be straight forward to support; have a property that > >> > > > specifies the method used for fetching/calculating the MAC. > >> > > > > >> > > Executable code stored inside a DT blob? ;) > >> > > >> > I know you're joking here, but I'm going to answer seriously > >> > anyway... Absolutely not. ?What I'm suggesting is a property that > >> > specifies the method used to determine the mac address. ?Something > >> > like (off the top of my head): > >> > > >> > ? ? local-mac-address = [01 02 03 00 00 00]; > >> > ? ? local-mac-mask = [0xff 0xff 0xff 0 0 0]; > >> > ? ? mac-encoding = "append-serial-number"; > >> > > >> That still does not specify where the remaining part of the MAC is > >> stored and how it should be retrieved. > > > > I'm suggesting that you define a string that means something specific; > > that hopefully can be shared by multiple platforms. ?For example, > > "append-serial-number" might mean start with the values selected by > > AND of local-mac-address and local-mac-mask, and OR in the board's > > serial number. ?You would need to define something that worked if this > > was the solution you used. > > > I'm intend to Grant's this suggestion. > This can be shared by all other imx platforms which stores mac address in > fuse map and this is commonly used by customer. > Then we do not need keep writing repeat code for different platforms > via platform > data. > > For Lothar's question, we can add a property fuse_mac_offset to indicate > read mac from fuse map and where to read it. > That's not really enough. The format (big-endian vs. little-endian) may also differ. But it's not really necessary, if the solution with prom_update_property() works, since then platform code has full control over the MAC. > For how many bytes to read, we can calculate it from the local-mac-mask. > For example, local-mac-mask = [0xff 0xff 0xff 0 0 0], we can get the size > as 3 bypes. > > Then we have three properties: > local-mac-address = [01 02 03 00 00 00]; > local-mac-mask = [0xff 0xff 0xff 0 0 0]; > fuse_mac_offset = <1>; > > In fec driver, the final mac address can be got by: > local-mac-address & local-mac-mask | (read_fuse(1) & 0xffffff) > > Lathar, > Do you think if this is ok? > No. IMO the FEC driver itself should not read any fuses. Reading fuses is a SoC specific thing and the FEC driver should not depend on the idiosyncrasies of some SoC wrt. anything else but the implementation of the FEC itself. Lothar Wa?mann -- ___________________________________________________________ Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10 Gesch?ftsf?hrer: Matthias Kaussen Handelsregistereintrag: Amtsgericht Aachen, HRB 4996 www.karo-electronics.de | info at karo-electronics.de ___________________________________________________________