/* sc520cdp.c -- MTD map driver for AMD SC520 Customer Development Platform * * Copyright (C) 2001 Sysgo Real-Time Solutions GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * * * The SC520CDP is an evaluation board for the Elan SC520 processor available * from AMD. It has two banks of 32-bit Flash ROM, each 8 Megabytes in size, * and up to 512 KiB of 8-bit DIL Flash ROM. * For details see http://www.amd.com/products/epd/desiging/evalboards/18.elansc520/520_cdp_brief/index.html */ #include #include #include #include #include #include #include #include /* ** The Embedded Systems BIOS decodes the first FLASH starting at ** 0x8400000. This is a *terrible* place for it because accessing ** the flash at this location causes the A22 address line to be high ** (that's what 0x8400000 binary's ought to be). But this is the highest ** order address line on the raw flash devices themselves!! ** This causes the top HALF of the flash to be accessed first. Beyond ** the physical limits of the flash, the flash chip aliases over (to ** 0x880000 which causes the bottom half to be accessed. This splits the ** flash into two and inverts it! If you then try to access this from another ** program that does NOT do this insanity, then you *will* access the ** first half of the flash, but not find what you expect there. That ** stuff is in the *second* half! Similarly, the address used by the ** BIOS for the second FLASH bank is also quite a bad choice. ** If REPROGRAM_PAR is defined below (the default), then this driver will ** choose more useful addresses for the FLASH banks by reprogramming the ** responsible PARxx registers in the SC520's MMCR region. This will ** cause the settings to be incompatible with the BIOS's settings, which ** shouldn't be a problem since you are running Linux, (i.e. the BIOS is ** not much use anyway). However, if you need to be compatible with ** the BIOS for some reason, just undefine REPROGRAM_PAR. */ #define REPROGRAM_PAR #ifdef REPROGRAM_PAR /* These are the addresses we want.. */ #define WINDOW_ADDR_0 0x08800000 #define WINDOW_ADDR_1 0x09000000 #define WINDOW_ADDR_2 0x09800000 /* .. and these are the addresses the BIOS gives us */ #define WINDOW_ADDR_0_BIOS 0x08400000 #define WINDOW_ADDR_1_BIOS 0x08c00000 #define WINDOW_ADDR_2_BIOS 0x09400000 #else #define WINDOW_ADDR_0 0x08400000 #define WINDOW_ADDR_1 0x08C00000 #define WINDOW_ADDR_2 0x09400000 #endif #define WINDOW_SIZE_0 0x00800000 #define WINDOW_SIZE_1 0x00800000 #define WINDOW_SIZE_2 0x00080000 static struct map_info sc520cdp_map[] = { { .name = "SC520CDP Flash Bank #0", .size = WINDOW_SIZE_0, .bankwidth = 4, .phys = WINDOW_ADDR_0 }, { .name = "SC520CDP Flash Bank #1", .size = WINDOW_SIZE_1, .bankwidth = 4, .phys = WINDOW_ADDR_1 }, { .name = "SC520CDP DIL Flash", .size = WINDOW_SIZE_2, .bankwidth = 1, .phys = WINDOW_ADDR_2 }, }; #define NUM_FLASH_BANKS ARRAY_SIZE(sc520cdp_map) static struct mtd_info *mymtd[NUM_FLASH_BANKS]; static struct mtd_info *merged_mtd; #ifdef REPROGRAM_PAR /* ** The SC520 MMCR (memory mapped control register) region resides ** at 0xFFFEF000. The 16 Programmable Address Region (PAR) registers ** are at offset 0x88 in the MMCR: */ #define SC520_MMCR_BASE 0xFFFEF000 #define SC520_MMCR_EXTENT 0x1000 #define SC520_PAR(x) ((0x88/sizeof(unsigned long)) + (x)) #define NUM_SC520_PAR 16 /* total number of PAR registers */ /* ** The highest three bits in a PAR register determine what target ** device is controlled by this PAR. Here, only ROMCS? and BOOTCS ** devices are of interest. */ #define SC520_PAR_BOOTCS (0x4<<29) #define SC520_PAR_ROMCS0 (0x5<<29) #define SC520_PAR_ROMCS1 (0x6<<29) #define SC520_PAR_TRGDEV (0x7<<29) /* ** Bits 28 thru 26 determine some attributes for the ** region controlled by the PAR. (We only use non-cacheable) */ #define SC520_PAR_WRPROT (1<<26) /* write protected */ #define SC520_PAR_NOCACHE (1<<27) /* non-cacheable */ #define SC520_PAR_NOEXEC (1<<28) /* code execution denied */ /* ** Bit 25 determines the granularity: 4K or 64K */ #define SC520_PAR_PG_SIZ4 (0<<25) #define SC520_PAR_PG_SIZ64 (1<<25) /* ** Build a value to be written into a PAR register. ** We only need ROM entries, 64K page size: */ #define SC520_PAR_ENTRY(trgdev, address, size) \ ((trgdev) | SC520_PAR_NOCACHE | SC520_PAR_PG_SIZ64 | \ (address) >> 16 | (((size) >> 16) - 1) << 14) struct sc520_par_table { unsigned long trgdev; unsigned long new_par; unsigned long default_address; }; static const struct sc520_par_table par_table[NUM_FLASH_BANKS] = { { /* Flash Bank #0: selected by ROMCS0 */ SC520_PAR_ROMCS0, SC520_PAR_ENTRY(SC520_PAR_ROMCS0, WINDOW_ADDR_0, WINDOW_SIZE_0), WINDOW_ADDR_0_BIOS }, { /* Flash Bank #1: selected by ROMCS1 */ SC520_PAR_ROMCS1, SC520_PAR_ENTRY(SC520_PAR_ROMCS1, WINDOW_ADDR_1, WINDOW_SIZE_1), WINDOW_ADDR_1_BIOS }, { /* DIL (BIOS) Flash: selected by BOOTCS */ SC520_PAR_BOOTCS, SC520_PAR_ENTRY(SC520_PAR_BOOTCS, WINDOW_ADDR_2, WINDOW_SIZE_2), WINDOW_ADDR_2_BIOS } }; static void sc520cdp_setup_par(void) { volatile unsigned long __iomem *mmcr; unsigned long mmcr_val; int i, j; /* map in SC520's MMCR area */ mmcr = ioremap_nocache(SC520_MMCR_BASE, SC520_MMCR_EXTENT); if(!mmcr) { /* ioremap_nocache failed: skip the PAR reprogramming */ /* force physical address fields to BIOS defaults: */ for(i = 0; i < NUM_FLASH_BANKS; i++) sc520cdp_map[i].phys = par_table[i].default_address; return; } /* ** Find the PARxx registers that are responsible for activating ** ROMCS0, ROMCS1 and BOOTCS. Reprogram each of these with a ** new value from the table. */ for(i = 0; i < NUM_FLASH_BANKS; i++) { /* for each par_table entry */ for(j = 0; j < NUM_SC520_PAR; j++) { /* for each PAR register */ mmcr_val = mmcr[SC520_PAR(j)]; /* if target device field matches, reprogram the PAR */ if((mmcr_val & SC520_PAR_TRGDEV) == par_table[i].trgdev) { mmcr[SC520_PAR(j)] = par_table[i].new_par; break; } } if(j == NUM_SC520_PAR) { /* no matching PAR found: try default BIOS address */ printk(KERN_NOTICE "Could not find PAR responsible for %s\n", sc520cdp_map[i].name); printk(KERN_NOTICE "Trying default address 0x%lx\n", par_table[i].default_address); sc520cdp_map[i].phys = par_table[i].default_address; } } iounmap(mmcr); } #endif static int __init init_sc520cdp(void) { int i, devices_found = 0; #ifdef REPROGRAM_PAR /* reprogram PAR registers so flash appears at the desired addresses */ sc520cdp_setup_par(); #endif for (i = 0; i < NUM_FLASH_BANKS; i++) { printk(KERN_NOTICE "SC520 CDP flash device: 0x%Lx at 0x%Lx\n", (unsigned long long)sc520cdp_map[i].size, (unsigned long long)sc520cdp_map[i].phys); sc520cdp_map[i].virt = ioremap_nocache(sc520cdp_map[i].phys, sc520cdp_map[i].size); if (!sc520cdp_map[i].virt) { printk("Failed to ioremap_nocache\n"); return -EIO; } simple_map_init(&sc520cdp_map[i]); mymtd[i] = do_map_probe("cfi_probe", &sc520cdp_map[i]); if(!mymtd[i]) mymtd[i] = do_map_probe("jedec_probe", &sc520cdp_map[i]); if(!mymtd[i]) mymtd[i] = do_map_probe("map_rom", &sc520cdp_map[i]); if (mymtd[i]) { mymtd[i]->owner = THIS_MODULE; ++devices_found; } else { iounmap(sc520cdp_map[i].virt); } } if(devices_found >= 2) { /* Combine the two flash banks into a single MTD device & register it: */ merged_mtd = mtd_concat_create(mymtd, 2, "SC520CDP Flash Banks #0 and #1"); if(merged_mtd) mtd_device_register(merged_mtd, NULL, 0); } if(devices_found == 3) /* register the third (DIL-Flash) device */ mtd_device_register(mymtd[2], NULL, 0); return(devices_found ? 0 : -ENXIO); } static void __exit cleanup_sc520cdp(void) { int i; if (merged_mtd) { mtd_device_unregister(merged_mtd); mtd_concat_destroy(merged_mtd); } if (mymtd[2]) mtd_device_unregister(mymtd[2]); for (i = 0; i < NUM_FLASH_BANKS; i++) { if (mymtd[i]) map_destroy(mymtd[i]); if (sc520cdp_map[i].virt) { iounmap(sc520cdp_map[i].virt); sc520cdp_map[i].virt = NULL; } } } module_init(init_sc520cdp); module_exit(cleanup_sc520cdp); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Sysgo Real-Time Solutions GmbH"); MODULE_DESCRIPTION("MTD map driver for AMD SC520 Customer Development Platform");