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Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/sysdev/mmio_nvram.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/mmio_nvram.c b/arch/powerpc/sysdev/mmio_nvram.c new file mode 100644 index 000000000..c31f634f1 --- /dev/null +++ b/arch/powerpc/sysdev/mmio_nvram.c @@ -0,0 +1,158 @@ +/* + * memory mapped NVRAM + * + * (C) Copyright IBM Corp. 2005 + * + * Authors : Utz Bacher <utz.bacher@de.ibm.com> + * + * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include <asm/machdep.h> +#include <asm/nvram.h> +#include <asm/prom.h> + +static void __iomem *mmio_nvram_start; +static long mmio_nvram_len; +static DEFINE_SPINLOCK(mmio_nvram_lock); + +static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index) +{ + unsigned long flags; + + if (*index >= mmio_nvram_len) + return 0; + if (*index + count > mmio_nvram_len) + count = mmio_nvram_len - *index; + + spin_lock_irqsave(&mmio_nvram_lock, flags); + + memcpy_fromio(buf, mmio_nvram_start + *index, count); + + spin_unlock_irqrestore(&mmio_nvram_lock, flags); + + *index += count; + return count; +} + +static unsigned char mmio_nvram_read_val(int addr) +{ + unsigned long flags; + unsigned char val; + + if (addr >= mmio_nvram_len) + return 0xff; + + spin_lock_irqsave(&mmio_nvram_lock, flags); + + val = ioread8(mmio_nvram_start + addr); + + spin_unlock_irqrestore(&mmio_nvram_lock, flags); + + return val; +} + +static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index) +{ + unsigned long flags; + + if (*index >= mmio_nvram_len) + return 0; + if (*index + count > mmio_nvram_len) + count = mmio_nvram_len - *index; + + spin_lock_irqsave(&mmio_nvram_lock, flags); + + memcpy_toio(mmio_nvram_start + *index, buf, count); + + spin_unlock_irqrestore(&mmio_nvram_lock, flags); + + *index += count; + return count; +} + +static void mmio_nvram_write_val(int addr, unsigned char val) +{ + unsigned long flags; + + if (addr < mmio_nvram_len) { + spin_lock_irqsave(&mmio_nvram_lock, flags); + + iowrite8(val, mmio_nvram_start + addr); + + spin_unlock_irqrestore(&mmio_nvram_lock, flags); + } +} + +static ssize_t mmio_nvram_get_size(void) +{ + return mmio_nvram_len; +} + +int __init mmio_nvram_init(void) +{ + struct device_node *nvram_node; + unsigned long nvram_addr; + struct resource r; + int ret; + + nvram_node = of_find_node_by_type(NULL, "nvram"); + if (!nvram_node) + nvram_node = of_find_compatible_node(NULL, NULL, "nvram"); + if (!nvram_node) { + printk(KERN_WARNING "nvram: no node found in device-tree\n"); + return -ENODEV; + } + + ret = of_address_to_resource(nvram_node, 0, &r); + if (ret) { + printk(KERN_WARNING "nvram: failed to get address (err %d)\n", + ret); + goto out; + } + nvram_addr = r.start; + mmio_nvram_len = resource_size(&r); + if ( (!mmio_nvram_len) || (!nvram_addr) ) { + printk(KERN_WARNING "nvram: address or length is 0\n"); + ret = -EIO; + goto out; + } + + mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len); + if (!mmio_nvram_start) { + printk(KERN_WARNING "nvram: failed to ioremap\n"); + ret = -ENOMEM; + goto out; + } + + printk(KERN_INFO "mmio NVRAM, %luk at 0x%lx mapped to %p\n", + mmio_nvram_len >> 10, nvram_addr, mmio_nvram_start); + + ppc_md.nvram_read_val = mmio_nvram_read_val; + ppc_md.nvram_write_val = mmio_nvram_write_val; + ppc_md.nvram_read = mmio_nvram_read; + ppc_md.nvram_write = mmio_nvram_write; + ppc_md.nvram_size = mmio_nvram_get_size; + +out: + of_node_put(nvram_node); + return ret; +} |