diff options
Diffstat (limited to 'drivers/mtd/maps/dc21285.c')
| -rw-r--r-- | drivers/mtd/maps/dc21285.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/mtd/maps/dc21285.c b/drivers/mtd/maps/dc21285.c new file mode 100644 index 000000000..70a3db3ab --- /dev/null +++ b/drivers/mtd/maps/dc21285.c @@ -0,0 +1,231 @@ +/* + * MTD map driver for flash on the DC21285 (the StrongARM-110 companion chip) + * + * (C) 2000 Nicolas Pitre <nico@fluxnic.net> + * + * This code is GPL + */ +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/slab.h> + +#include <linux/mtd/mtd.h> +#include <linux/mtd/map.h> +#include <linux/mtd/partitions.h> + +#include <asm/io.h> +#include <asm/hardware/dec21285.h> +#include <asm/mach-types.h> + + +static struct mtd_info *dc21285_mtd; + +#ifdef CONFIG_ARCH_NETWINDER +/* + * This is really ugly, but it seams to be the only + * realiable way to do it, as the cpld state machine + * is unpredictible. So we have a 25us penalty per + * write access. + */ +static void nw_en_write(void) +{ + unsigned long flags; + + /* + * we want to write a bit pattern XXX1 to Xilinx to enable + * the write gate, which will be open for about the next 2ms. + */ + raw_spin_lock_irqsave(&nw_gpio_lock, flags); + nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE); + raw_spin_unlock_irqrestore(&nw_gpio_lock, flags); + + /* + * let the ISA bus to catch on... + */ + udelay(25); +} +#else +#define nw_en_write() do { } while (0) +#endif + +static map_word dc21285_read8(struct map_info *map, unsigned long ofs) +{ + map_word val; + val.x[0] = *(uint8_t*)(map->virt + ofs); + return val; +} + +static map_word dc21285_read16(struct map_info *map, unsigned long ofs) +{ + map_word val; + val.x[0] = *(uint16_t*)(map->virt + ofs); + return val; +} + +static map_word dc21285_read32(struct map_info *map, unsigned long ofs) +{ + map_word val; + val.x[0] = *(uint32_t*)(map->virt + ofs); + return val; +} + +static void dc21285_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len) +{ + memcpy(to, (void*)(map->virt + from), len); +} + +static void dc21285_write8(struct map_info *map, const map_word d, unsigned long adr) +{ + if (machine_is_netwinder()) + nw_en_write(); + *CSR_ROMWRITEREG = adr & 3; + adr &= ~3; + *(uint8_t*)(map->virt + adr) = d.x[0]; +} + +static void dc21285_write16(struct map_info *map, const map_word d, unsigned long adr) +{ + if (machine_is_netwinder()) + nw_en_write(); + *CSR_ROMWRITEREG = adr & 3; + adr &= ~3; + *(uint16_t*)(map->virt + adr) = d.x[0]; +} + +static void dc21285_write32(struct map_info *map, const map_word d, unsigned long adr) +{ + if (machine_is_netwinder()) + nw_en_write(); + *(uint32_t*)(map->virt + adr) = d.x[0]; +} + +static void dc21285_copy_to_32(struct map_info *map, unsigned long to, const void *from, ssize_t len) +{ + while (len > 0) { + map_word d; + d.x[0] = *((uint32_t*)from); + dc21285_write32(map, d, to); + from += 4; + to += 4; + len -= 4; + } +} + +static void dc21285_copy_to_16(struct map_info *map, unsigned long to, const void *from, ssize_t len) +{ + while (len > 0) { + map_word d; + d.x[0] = *((uint16_t*)from); + dc21285_write16(map, d, to); + from += 2; + to += 2; + len -= 2; + } +} + +static void dc21285_copy_to_8(struct map_info *map, unsigned long to, const void *from, ssize_t len) +{ + map_word d; + d.x[0] = *((uint8_t*)from); + dc21285_write8(map, d, to); + from++; + to++; + len--; +} + +static struct map_info dc21285_map = { + .name = "DC21285 flash", + .phys = NO_XIP, + .size = 16*1024*1024, + .copy_from = dc21285_copy_from, +}; + +/* Partition stuff */ +static const char * const probes[] = { "RedBoot", "cmdlinepart", NULL }; + +static int __init init_dc21285(void) +{ + /* Determine bankwidth */ + switch (*CSR_SA110_CNTL & (3<<14)) { + case SA110_CNTL_ROMWIDTH_8: + dc21285_map.bankwidth = 1; + dc21285_map.read = dc21285_read8; + dc21285_map.write = dc21285_write8; + dc21285_map.copy_to = dc21285_copy_to_8; + break; + case SA110_CNTL_ROMWIDTH_16: + dc21285_map.bankwidth = 2; + dc21285_map.read = dc21285_read16; + dc21285_map.write = dc21285_write16; + dc21285_map.copy_to = dc21285_copy_to_16; + break; + case SA110_CNTL_ROMWIDTH_32: + dc21285_map.bankwidth = 4; + dc21285_map.read = dc21285_read32; + dc21285_map.write = dc21285_write32; + dc21285_map.copy_to = dc21285_copy_to_32; + break; + default: + printk (KERN_ERR "DC21285 flash: undefined bankwidth\n"); + return -ENXIO; + } + printk (KERN_NOTICE "DC21285 flash support (%d-bit bankwidth)\n", + dc21285_map.bankwidth*8); + + /* Let's map the flash area */ + dc21285_map.virt = ioremap(DC21285_FLASH, 16*1024*1024); + if (!dc21285_map.virt) { + printk("Failed to ioremap\n"); + return -EIO; + } + + if (machine_is_ebsa285()) { + dc21285_mtd = do_map_probe("cfi_probe", &dc21285_map); + } else { + dc21285_mtd = do_map_probe("jedec_probe", &dc21285_map); + } + + if (!dc21285_mtd) { + iounmap(dc21285_map.virt); + return -ENXIO; + } + + dc21285_mtd->owner = THIS_MODULE; + + mtd_device_parse_register(dc21285_mtd, probes, NULL, NULL, 0); + + if(machine_is_ebsa285()) { + /* + * Flash timing is determined with bits 19-16 of the + * CSR_SA110_CNTL. The value is the number of wait cycles, or + * 0 for 16 cycles (the default). Cycles are 20 ns. + * Here we use 7 for 140 ns flash chips. + */ + /* access time */ + *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16)); + /* burst time */ + *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20)); + /* tristate time */ + *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24)); + } + + return 0; +} + +static void __exit cleanup_dc21285(void) +{ + mtd_device_unregister(dc21285_mtd); + map_destroy(dc21285_mtd); + iounmap(dc21285_map.virt); +} + +module_init(init_dc21285); +module_exit(cleanup_dc21285); + + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Nicolas Pitre <nico@fluxnic.net>"); +MODULE_DESCRIPTION("MTD map driver for DC21285 boards"); |