From mboxrd@z Thu Jan 1 00:00:00 1970 From: w.sang@pengutronix.de (Wolfram Sang) Date: Mon, 20 Dec 2010 15:35:26 +0100 Subject: [PATCH v7 05/15] ARM: mxs: Add low-level debug UART support In-Reply-To: <20101220142516.GC16497@freescale.com> References: <1292679575-2635-1-git-send-email-shawn.guo@freescale.com> <1292679575-2635-4-git-send-email-shawn.guo@freescale.com> <20101220115059.GA8885@pengutronix.de> <20101220132147.GB16497@freescale.com> <20101220135535.GB8885@pengutronix.de> <20101220142516.GC16497@freescale.com> Message-ID: <20101220143526.GC8885@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Shawn, > > > I'm afraid not. How do you expect the detection is done, by reading > > > some register like we are doing in system.c? > > > > I am not sure which register you mean in system.c? > > > > > Which register specifically? > > > > The signature of the amba device (base + size - 0x20). You can check > > drivers/amba/bus.c how it checks for the signature. > > > > > If the register gets different address between > > > mx23 and mx28, we need to utilize the current mechanism to > > > distinguish the address anyway. > > > > We could simply test both locations and see where it is present? > > > Is there any problem of simply using arch_id here? I do not see > significant benefit of using the detection you suggest here > over the current way. Ah, sorry, I thought you meant auto-detection was not possible in debug.S as well (and there it is worthwhile so mx23 and mx28 can be built into one kernel). For uncompress.h, the gain is nothing major, true. One would save to add custom boards there just to match the base address, but well... Kind regards, Wolfram -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 198 bytes Desc: Digital signature URL: