arch/sparc/kernel/auxio_32.c

// SPDX-License-Identifier: GPL-2.0
/* auxio.c: Probing for the Sparc AUXIO register at boot time.
 *
 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
 */

#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/export.h>

#include <asm/oplib.h>
#include <asm/io.h>
#include <asm/auxio.h>
#include <asm/string.h>		/* memset(), Linux has no bzero() */
#include <asm/cpu_type.h>

#include "kernel.h"

/* Probe and map in the Auxiliary I/O register */

/* auxio_register is not static because it is referenced 
 * in entry.S::floppy_tdone
 */
void __iomem *auxio_register = NULL;
static DEFINE_SPINLOCK(auxio_lock);

void __init auxio_probe(void)
{
	phandle node, auxio_nd;
	struct linux_prom_registers auxregs[1];
	struct resource r;

	switch (sparc_cpu_model) {
	case sparc_leon:
	case sun4d:
		return;
	default:
		break;
	}
	node = prom_getchild(prom_root_node);
	auxio_nd = prom_searchsiblings(node, "auxiliary-io");
	if(!auxio_nd) {
		node = prom_searchsiblings(node, "obio");
		node = prom_getchild(node);
		auxio_nd = prom_searchsiblings(node, "auxio");
		if(!auxio_nd) {
#ifdef CONFIG_PCI
			/* There may be auxio on Ebus */
			return;
#else
			if(prom_searchsiblings(node, "leds")) {
				/* VME chassis sun4m machine, no auxio exists. */
				return;
			}
			prom_printf("Cannot find auxio node, cannot continue...\n");
			prom_halt();
#endif
		}
	}
	if(prom_getproperty(auxio_nd, "reg", (char *) auxregs, sizeof(auxregs)) <= 0)
		return;
	prom_apply_obio_ranges(auxregs, 0x1);
	/* Map the register both read and write */
	r.flags = auxregs[0].which_io & 0xF;
	r.start = auxregs[0].phys_addr;
	r.end = auxregs[0].phys_addr + auxregs[0].reg_size - 1;
	auxio_register = of_ioremap(&r, 0, auxregs[0].reg_size, "auxio");
	/* Fix the address on sun4m. */
	if ((((unsigned long) auxregs[0].phys_addr) & 3) == 3)
		auxio_register += (3 - ((unsigned long)auxio_register & 3));

	set_auxio(AUXIO_LED, 0);
}

unsigned char get_auxio(void)
{
	if(auxio_register) 
		return sbus_readb(auxio_register);
	return 0;
}
EXPORT_SYMBOL(get_auxio);

void set_auxio(unsigned char bits_on, unsigned char bits_off)
{
	unsigned char regval;
	unsigned long flags;
	spin_lock_irqsave(&auxio_lock, flags);
	switch (sparc_cpu_model) {
	case sun4m:
		if(!auxio_register)
			break;     /* VME chassis sun4m, no auxio. */
		regval = sbus_readb(auxio_register);
		sbus_writeb(((regval | bits_on) & ~bits_off) | AUXIO_ORMEIN4M,
			auxio_register);
		break;
	case sun4d:
		break;
	default:
		panic("Can't set AUXIO register on this machine.");
	}
	spin_unlock_irqrestore(&auxio_lock, flags);
}
EXPORT_SYMBOL(set_auxio);

/* sun4m power control register (AUXIO2) */

volatile u8 __iomem *auxio_power_register = NULL;

void __init auxio_power_probe(void)
{
	struct linux_prom_registers regs;
	phandle node;
	struct resource r;

	/* Attempt to find the sun4m power control node. */
	node = prom_getchild(prom_root_node);
	node = prom_searchsiblings(node, "obio");
	node = prom_getchild(node);
	node = prom_searchsiblings(node, "power");
	if (node == 0 || (s32)node == -1)
		return;

	/* Map the power control register. */
	if (prom_getproperty(node, "reg", (char *)&regs, sizeof(regs)) <= 0)
		return;
	prom_apply_obio_ranges(&regs, 1);
	memset(&r, 0, sizeof(r));
	r.flags = regs.which_io & 0xF;
	r.start = regs.phys_addr;
	r.end = regs.phys_addr + regs.reg_size - 1;
	auxio_power_register =
		(u8 __iomem *)of_ioremap(&r, 0, regs.reg_size, "auxpower");

	/* Display a quick message on the console. */
	if (auxio_power_register)
		printk(KERN_INFO "Power off control detected.\n");
}