auxio_64.c

  1// SPDX-License-Identifier: GPL-2.0
  2/* auxio.c: Probing for the Sparc AUXIO register at boot time.
  3 *
  4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
  5 *
  6 * Refactoring for unified NCR/PCIO support 2002 Eric Brower (ebrower@usa.net)
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/kernel.h>
 11#include <linux/init.h>
 12#include <linux/ioport.h>
 13#include <linux/of.h>
 14#include <linux/platform_device.h>
 15
 16#include <asm/prom.h>
 17#include <asm/io.h>
 18#include <asm/auxio.h>
 19
 20void __iomem *auxio_register = NULL;
 21EXPORT_SYMBOL(auxio_register);
 22
 23enum auxio_type {
 24	AUXIO_TYPE_NODEV,
 25	AUXIO_TYPE_SBUS,
 26	AUXIO_TYPE_EBUS
 27};
 28
 29static enum auxio_type auxio_devtype = AUXIO_TYPE_NODEV;
 30static DEFINE_SPINLOCK(auxio_lock);
 31
 32static void __auxio_rmw(u8 bits_on, u8 bits_off, int ebus)
 33{
 34	if (auxio_register) {
 35		unsigned long flags;
 36		u8 regval, newval;
 37
 38		spin_lock_irqsave(&auxio_lock, flags);
 39
 40		regval = (ebus ?
 41			  (u8) readl(auxio_register) :
 42			  sbus_readb(auxio_register));
 43		newval =  regval | bits_on;
 44		newval &= ~bits_off;
 45		if (!ebus)
 46			newval &= ~AUXIO_AUX1_MASK;
 47		if (ebus)
 48			writel((u32) newval, auxio_register);
 49		else
 50			sbus_writeb(newval, auxio_register);
 51		
 52		spin_unlock_irqrestore(&auxio_lock, flags);
 53	}
 54}
 55
 56static void __auxio_set_bit(u8 bit, int on, int ebus)
 57{
 58	u8 bits_on = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
 59	u8 bits_off = 0;
 60
 61	if (!on) {
 62		u8 tmp = bits_off;
 63		bits_off = bits_on;
 64		bits_on = tmp;
 65	}
 66	__auxio_rmw(bits_on, bits_off, ebus);
 67}
 68
 69void auxio_set_led(int on)
 70{
 71	int ebus = auxio_devtype == AUXIO_TYPE_EBUS;
 72	u8 bit;
 73
 74	bit = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
 75	__auxio_set_bit(bit, on, ebus);
 76}
 77EXPORT_SYMBOL(auxio_set_led);
 78
 79static void __auxio_sbus_set_lte(int on)
 80{
 81	__auxio_set_bit(AUXIO_AUX1_LTE, on, 0);
 82}
 83
 84void auxio_set_lte(int on)
 85{
 86	switch(auxio_devtype) {
 87	case AUXIO_TYPE_SBUS:
 88		__auxio_sbus_set_lte(on);
 89		break;
 90	case AUXIO_TYPE_EBUS:
 91	default:
 92		break;
 93	}
 94}
 95EXPORT_SYMBOL(auxio_set_lte);
 96
 97static const struct of_device_id auxio_match[] = {
 98	{
 99		.name = "auxio",
100	},
101	{},
102};
103
104MODULE_DEVICE_TABLE(of, auxio_match);
105
106static int auxio_probe(struct platform_device *dev)
107{
108	struct device_node *dp = dev->dev.of_node;
109	unsigned long size;
110
111	if (of_node_name_eq(dp->parent, "ebus")) {
112		auxio_devtype = AUXIO_TYPE_EBUS;
113		size = sizeof(u32);
114	} else if (of_node_name_eq(dp->parent, "sbus")) {
115		auxio_devtype = AUXIO_TYPE_SBUS;
116		size = 1;
117	} else {
118		printk("auxio: Unknown parent bus type [%pOFn]\n",
119		       dp->parent);
120		return -ENODEV;
121	}
122	auxio_register = of_ioremap(&dev->resource[0], 0, size, "auxio");
123	if (!auxio_register)
124		return -ENODEV;
125
126	printk(KERN_INFO "AUXIO: Found device at %pOF\n", dp);
127
128	if (auxio_devtype == AUXIO_TYPE_EBUS)
129		auxio_set_led(AUXIO_LED_ON);
130
131	return 0;
132}
133
134static struct platform_driver auxio_driver = {
135	.probe		= auxio_probe,
136	.driver = {
137		.name = "auxio",
138		.of_match_table = auxio_match,
139	},
140};
141
142static int __init auxio_init(void)
143{
144	return platform_driver_register(&auxio_driver);
145}
146
147/* Must be after subsys_initcall() so that busses are probed.  Must
148 * be before device_initcall() because things like the floppy driver
149 * need to use the AUXIO register.
150 */
151fs_initcall(auxio_init);