diff options
Diffstat (limited to 'arch/powerpc/platforms/chrp/nvram.c')
-rw-r--r-- | arch/powerpc/platforms/chrp/nvram.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/chrp/nvram.c b/arch/powerpc/platforms/chrp/nvram.c new file mode 100644 index 0000000..4ac7125 --- /dev/null +++ b/arch/powerpc/platforms/chrp/nvram.c @@ -0,0 +1,84 @@ +/* + * c 2001 PPC 64 Team, IBM Corp + * + * 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. + * + * /dev/nvram driver for PPC + * + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <asm/uaccess.h> +#include <asm/prom.h> +#include <asm/machdep.h> +#include "chrp.h" + +static unsigned int nvram_size; +static unsigned char nvram_buf[4]; +static DEFINE_SPINLOCK(nvram_lock); + +static unsigned char chrp_nvram_read(int addr) +{ + unsigned long done, flags; + unsigned char ret; + + if (addr >= nvram_size) { + printk(KERN_DEBUG "%s: read addr %d > nvram_size %u\n", + current->comm, addr, nvram_size); + return 0xff; + } + spin_lock_irqsave(&nvram_lock, flags); + if ((call_rtas("nvram-fetch", 3, 2, &done, addr, __pa(nvram_buf), 1) != 0) || 1 != done) + ret = 0xff; + else + ret = nvram_buf[0]; + spin_unlock_irqrestore(&nvram_lock, flags); + + return ret; +} + +static void chrp_nvram_write(int addr, unsigned char val) +{ + unsigned long done, flags; + + if (addr >= nvram_size) { + printk(KERN_DEBUG "%s: write addr %d > nvram_size %u\n", + current->comm, addr, nvram_size); + return; + } + spin_lock_irqsave(&nvram_lock, flags); + nvram_buf[0] = val; + if ((call_rtas("nvram-store", 3, 2, &done, addr, __pa(nvram_buf), 1) != 0) || 1 != done) + printk(KERN_DEBUG "rtas IO error storing 0x%02x at %d", val, addr); + spin_unlock_irqrestore(&nvram_lock, flags); +} + +void __init chrp_nvram_init(void) +{ + struct device_node *nvram; + unsigned int *nbytes_p, proplen; + + nvram = of_find_node_by_type(NULL, "nvram"); + if (nvram == NULL) + return; + + nbytes_p = (unsigned int *)get_property(nvram, "#bytes", &proplen); + if (nbytes_p == NULL || proplen != sizeof(unsigned int)) + return; + + nvram_size = *nbytes_p; + + printk(KERN_INFO "CHRP nvram contains %u bytes\n", nvram_size); + of_node_put(nvram); + + ppc_md.nvram_read_val = chrp_nvram_read; + ppc_md.nvram_write_val = chrp_nvram_write; + + return; +} |