From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <4.2.2.20000308153704.00a601f0@mail.kerbango.com> Date: Wed, 08 Mar 2000 15:53:16 -0800 To: Björn Lundberg , "linuxppc-embedded@lists.linuxppc.org" From: Steve Calfee Subject: Re: USB driver for MPC850/823 In-Reply-To: <38C61ED8.E77126FB@inu.se> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: At 10:35 AM 3/8/00 +0100, Björn Lundberg wrote: >The driver is developed under Malek's 2.2.5 for embedded PPC. >Since the documentation has been a bit poor for the USB host mode, much >had to be done with trial and error. Some of which is left in the >source. >Most changes are in new source files but some changes has been done in >commproc.c and .h to support RISC timers and more DPRAM (microcode >alert). >For some reason I couldn't use USB buffers in SDRAM, only DPRAM!? >As stated earlier on the list it's developed on an 850, but I haven't >found anything that says it won't work on an 823. I have started looking at your code to try understand some of the roadblocks that I have hit. I have ISOC in/out working on the 823 USB. My IN and OUT packets are from main system Dram. You dont say what the problem was, but if the problem is; the data sent was garbage, not what you prepared, the problem may be memory mapping. The CPM wants to access physical memory addresses. You use a macro __pa for this, but I dont think that works for all cases of user and kernel memory. I grepped and found: #define PAGE_OFFSET 0xc0000000 #define __pa(x) ((unsigned long)(x)-PAGE_OFFSET) Look at virt_to_phys(x); but that only does kmalloc'ed memory. There seems to be many mapping macros/routines but I don't know if one works for ANY virtual address to its physical address. Does anyone have a pointer to a document that thoroughly describes memory mapping, both for the x86 and the ppc? Steve Calfee -- embedded systems consultant calfee@home.com cell phone: (510) 468-5837 Kerbango phone: (408) 517-3355 home office ph: (510) 657-6039 ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/