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2874c5fd28
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
95 lines
2.2 KiB
C
95 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* c 2001 PPC 64 Team, IBM Corp
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*
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* /dev/nvram driver for PPC
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/uaccess.h>
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#include <asm/prom.h>
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#include <asm/machdep.h>
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#include <asm/rtas.h>
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#include "chrp.h"
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static unsigned int nvram_size;
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static unsigned char nvram_buf[4];
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static DEFINE_SPINLOCK(nvram_lock);
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static unsigned char chrp_nvram_read_val(int addr)
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{
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unsigned int done;
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unsigned long flags;
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unsigned char ret;
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if (addr >= nvram_size) {
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printk(KERN_DEBUG "%s: read addr %d > nvram_size %u\n",
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current->comm, addr, nvram_size);
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return 0xff;
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}
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spin_lock_irqsave(&nvram_lock, flags);
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if ((rtas_call(rtas_token("nvram-fetch"), 3, 2, &done, addr,
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__pa(nvram_buf), 1) != 0) || 1 != done)
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ret = 0xff;
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else
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ret = nvram_buf[0];
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spin_unlock_irqrestore(&nvram_lock, flags);
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return ret;
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}
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static void chrp_nvram_write_val(int addr, unsigned char val)
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{
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unsigned int done;
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unsigned long flags;
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if (addr >= nvram_size) {
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printk(KERN_DEBUG "%s: write addr %d > nvram_size %u\n",
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current->comm, addr, nvram_size);
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return;
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}
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spin_lock_irqsave(&nvram_lock, flags);
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nvram_buf[0] = val;
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if ((rtas_call(rtas_token("nvram-store"), 3, 2, &done, addr,
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__pa(nvram_buf), 1) != 0) || 1 != done)
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printk(KERN_DEBUG "rtas IO error storing 0x%02x at %d", val, addr);
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spin_unlock_irqrestore(&nvram_lock, flags);
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}
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static ssize_t chrp_nvram_size(void)
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{
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return nvram_size;
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}
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void __init chrp_nvram_init(void)
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{
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struct device_node *nvram;
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const __be32 *nbytes_p;
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unsigned int proplen;
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nvram = of_find_node_by_type(NULL, "nvram");
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if (nvram == NULL)
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return;
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nbytes_p = of_get_property(nvram, "#bytes", &proplen);
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if (nbytes_p == NULL || proplen != sizeof(unsigned int)) {
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of_node_put(nvram);
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return;
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}
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nvram_size = be32_to_cpup(nbytes_p);
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printk(KERN_INFO "CHRP nvram contains %u bytes\n", nvram_size);
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of_node_put(nvram);
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ppc_md.nvram_read_val = chrp_nvram_read_val;
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ppc_md.nvram_write_val = chrp_nvram_write_val;
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ppc_md.nvram_size = chrp_nvram_size;
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return;
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}
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MODULE_LICENSE("GPL v2");
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