when writing Linux VINO driver i followed documentation found at: ftp://oss.sgi.com/pub/linux/mips/doc/indy/vino/vino.ps shortly (if someone is interested, i can send whole code): /* array of allocated pages */ unsigned long *pages; /* same as above, but contains physical addresses */ unsigned long *buf_desc; /* i hope page starts at 4k boundary ;) */ /* i also know that GFP_DMA is useless for MIPS */ buf_desc = (unsigned long *) __get_free_pages(GFP_KERNEL | GFP_DMA, 0); pages = (unsigned long*) kmalloc(npage * sizeof(unsigned long), GFP_KERNEL)); for (i = 0; i < npage; i++) { pages[i] = __get_free_pages(GFP_KERNEL | GFP_DMA, 0); /* fill with something to see if vino writes data */ memset((void *) pages[i], i, PAGE_SIZE); /* virt_to_bus returns PHYSADDR */ buf_desc[i] = virt_to_bus((void *)pages[i]); mem_map_reserve(virt_to_page(pages[i])); } buf_desc[npage] = VINO_DESC_STOP; /* here set all things according doc (page_index to zero and so on...) ... /* write descriptor table pointer to vino */ vino_reg_write(virt_to_bus(buf_desc), VINO_A_DESC_TLB_PTR); vino_reg_write(virt_to_bus(buf_desc), VINO_A_DESC_PTR); /* and now start DMA */ vino_reg_or(VINO_CTRL_A_DMA_ENBL, VINO_CTRL); after that memory stays untouched, no data are trasferred. any ideas how to make DMA working? or better where to get more complete vino documentation? regards, ladislav michl
