nvram.rar_nvram

/* * 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/spinlock.h> #include <asm/uaccess.h> #include <asm/prom.h> #include <asm/machdep.h> #include <asm/rtas.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 int done; unsigned long 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 ((rtas_call(rtas_token("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 int done; unsigned long 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 ((rtas_call(rtas_token("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; const __be32 *nbytes_p; unsigned int proplen; nvram = of_find_node_by_type(NULL, "nvram"); if (nvram == NULL) return; nbytes_p = of_get_property(nvram, "#bytes", &proplen); if (nbytes_p == NULL || proplen != sizeof(unsigned int)) { of_node_put(nvram); return; } nvram_size = be32_to_cpup(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; }