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![Thomas Gleixner](/assets/img/avatar_default.png)
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 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 77 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.837555891@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
145 lines
3.1 KiB
C
145 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* memory mapped NVRAM
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*
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* (C) Copyright IBM Corp. 2005
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*
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* Authors : Utz Bacher <utz.bacher@de.ibm.com>
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*/
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/spinlock.h>
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#include <linux/types.h>
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#include <asm/machdep.h>
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#include <asm/nvram.h>
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#include <asm/prom.h>
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static void __iomem *mmio_nvram_start;
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static long mmio_nvram_len;
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static DEFINE_SPINLOCK(mmio_nvram_lock);
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static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index)
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{
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unsigned long flags;
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if (*index >= mmio_nvram_len)
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return 0;
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if (*index + count > mmio_nvram_len)
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count = mmio_nvram_len - *index;
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spin_lock_irqsave(&mmio_nvram_lock, flags);
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memcpy_fromio(buf, mmio_nvram_start + *index, count);
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spin_unlock_irqrestore(&mmio_nvram_lock, flags);
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*index += count;
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return count;
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}
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static unsigned char mmio_nvram_read_val(int addr)
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{
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unsigned long flags;
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unsigned char val;
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if (addr >= mmio_nvram_len)
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return 0xff;
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spin_lock_irqsave(&mmio_nvram_lock, flags);
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val = ioread8(mmio_nvram_start + addr);
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spin_unlock_irqrestore(&mmio_nvram_lock, flags);
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return val;
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}
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static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index)
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{
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unsigned long flags;
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if (*index >= mmio_nvram_len)
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return 0;
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if (*index + count > mmio_nvram_len)
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count = mmio_nvram_len - *index;
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spin_lock_irqsave(&mmio_nvram_lock, flags);
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memcpy_toio(mmio_nvram_start + *index, buf, count);
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spin_unlock_irqrestore(&mmio_nvram_lock, flags);
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*index += count;
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return count;
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}
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static void mmio_nvram_write_val(int addr, unsigned char val)
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{
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unsigned long flags;
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if (addr < mmio_nvram_len) {
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spin_lock_irqsave(&mmio_nvram_lock, flags);
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iowrite8(val, mmio_nvram_start + addr);
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spin_unlock_irqrestore(&mmio_nvram_lock, flags);
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}
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}
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static ssize_t mmio_nvram_get_size(void)
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{
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return mmio_nvram_len;
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}
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int __init mmio_nvram_init(void)
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{
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struct device_node *nvram_node;
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unsigned long nvram_addr;
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struct resource r;
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int ret;
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nvram_node = of_find_node_by_type(NULL, "nvram");
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if (!nvram_node)
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nvram_node = of_find_compatible_node(NULL, NULL, "nvram");
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if (!nvram_node) {
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printk(KERN_WARNING "nvram: no node found in device-tree\n");
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return -ENODEV;
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}
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ret = of_address_to_resource(nvram_node, 0, &r);
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if (ret) {
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printk(KERN_WARNING "nvram: failed to get address (err %d)\n",
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ret);
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goto out;
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}
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nvram_addr = r.start;
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mmio_nvram_len = resource_size(&r);
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if ( (!mmio_nvram_len) || (!nvram_addr) ) {
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printk(KERN_WARNING "nvram: address or length is 0\n");
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ret = -EIO;
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goto out;
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}
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mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len);
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if (!mmio_nvram_start) {
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printk(KERN_WARNING "nvram: failed to ioremap\n");
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ret = -ENOMEM;
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goto out;
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}
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printk(KERN_INFO "mmio NVRAM, %luk at 0x%lx mapped to %p\n",
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mmio_nvram_len >> 10, nvram_addr, mmio_nvram_start);
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ppc_md.nvram_read_val = mmio_nvram_read_val;
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ppc_md.nvram_write_val = mmio_nvram_write_val;
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ppc_md.nvram_read = mmio_nvram_read;
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ppc_md.nvram_write = mmio_nvram_write;
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ppc_md.nvram_size = mmio_nvram_get_size;
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out:
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of_node_put(nvram_node);
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return ret;
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}
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