Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  c 2001 PPC 64 Team, IBM Corp
 *
 * /dev/nvram driver for PPC
 */
 
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/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_val(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_val(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);
}
 
static ssize_t chrp_nvram_size(void)
{
<------>return nvram_size;
}
 
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_val;
<------>ppc_md.nvram_write_val = chrp_nvram_write_val;
<------>ppc_md.nvram_size      = chrp_nvram_size;
 
<------>return;
}
 
MODULE_LICENSE("GPL v2");