diff options
Diffstat (limited to 'drivers/mtd/maps/sc520cdp.c')
| -rw-r--r-- | drivers/mtd/maps/sc520cdp.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/mtd/maps/sc520cdp.c b/drivers/mtd/maps/sc520cdp.c new file mode 100644 index 0000000000..8ef7aec634 --- /dev/null +++ b/drivers/mtd/maps/sc520cdp.c @@ -0,0 +1,294 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* sc520cdp.c -- MTD map driver for AMD SC520 Customer Development Platform + * + * Copyright (C) 2001 Sysgo Real-Time Solutions GmbH + * + * 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 https://www.amd.com/products/epd/desiging/evalboards/18.elansc520/520_cdp_brief/index.html + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <asm/io.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/map.h> +#include <linux/mtd/concat.h> + +/* +** 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) +{ + unsigned long __iomem *mmcr; + unsigned long mmcr_val; + int i, j; + + /* map in SC520's MMCR area */ + mmcr = ioremap(SC520_MMCR_BASE, SC520_MMCR_EXTENT); + if(!mmcr) { /* ioremap 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 = readl(&mmcr[SC520_PAR(j)]); + /* if target device field matches, reprogram the PAR */ + if((mmcr_val & SC520_PAR_TRGDEV) == par_table[i].trgdev) + { + writel(par_table[i].new_par, &mmcr[SC520_PAR(j)]); + 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, j, 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(sc520cdp_map[i].phys, sc520cdp_map[i].size); + + if (!sc520cdp_map[i].virt) { + printk("Failed to ioremap\n"); + for (j = 0; j < i; j++) { + if (mymtd[j]) { + map_destroy(mymtd[j]); + iounmap(sc520cdp_map[j].virt); + } + } + 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"); |