1/* auxio.c: Probing for the Sparc AUXIO register at boot time.
  2 *
  3 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
  4 *
  5 * Refactoring for unified NCR/PCIO support 2002 Eric Brower (ebrower@usa.net)
  6 */
  7
  8#include <linux/module.h>
  9#include <linux/kernel.h>
 10#include <linux/init.h>
 11#include <linux/ioport.h>
 12#include <linux/of_device.h>
 13
 14#include <asm/prom.h>
 15#include <asm/io.h>
 16#include <asm/auxio.h>
 17
 18void __iomem *auxio_register = NULL;
 19EXPORT_SYMBOL(auxio_register);
 20
 21enum auxio_type {
 22	AUXIO_TYPE_NODEV,
 23	AUXIO_TYPE_SBUS,
 24	AUXIO_TYPE_EBUS
 25};
 26
 27static enum auxio_type auxio_devtype = AUXIO_TYPE_NODEV;
 28static DEFINE_SPINLOCK(auxio_lock);
 29
 30static void __auxio_rmw(u8 bits_on, u8 bits_off, int ebus)
 31{
 32	if (auxio_register) {
 33		unsigned long flags;
 34		u8 regval, newval;
 35
 36		spin_lock_irqsave(&auxio_lock, flags);
 37
 38		regval = (ebus ?
 39			  (u8) readl(auxio_register) :
 40			  sbus_readb(auxio_register));
 41		newval =  regval | bits_on;
 42		newval &= ~bits_off;
 43		if (!ebus)
 44			newval &= ~AUXIO_AUX1_MASK;
 45		if (ebus)
 46			writel((u32) newval, auxio_register);
 47		else
 48			sbus_writeb(newval, auxio_register);
 49		
 50		spin_unlock_irqrestore(&auxio_lock, flags);
 51	}
 52}
 53
 54static void __auxio_set_bit(u8 bit, int on, int ebus)
 55{
 56	u8 bits_on = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
 57	u8 bits_off = 0;
 58
 59	if (!on) {
 60		u8 tmp = bits_off;
 61		bits_off = bits_on;
 62		bits_on = tmp;
 63	}
 64	__auxio_rmw(bits_on, bits_off, ebus);
 65}
 66
 67void auxio_set_led(int on)
 68{
 69	int ebus = auxio_devtype == AUXIO_TYPE_EBUS;
 70	u8 bit;
 71
 72	bit = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
 73	__auxio_set_bit(bit, on, ebus);
 74}
 75EXPORT_SYMBOL(auxio_set_led);
 76
 77static void __auxio_sbus_set_lte(int on)
 78{
 79	__auxio_set_bit(AUXIO_AUX1_LTE, on, 0);
 80}
 81
 82void auxio_set_lte(int on)
 83{
 84	switch(auxio_devtype) {
 85	case AUXIO_TYPE_SBUS:
 86		__auxio_sbus_set_lte(on);
 87		break;
 88	case AUXIO_TYPE_EBUS:
 89		/* FALL-THROUGH */
 90	default:
 91		break;
 92	}
 93}
 94EXPORT_SYMBOL(auxio_set_lte);
 95
 96static const struct of_device_id auxio_match[] = {
 97	{
 98		.name = "auxio",
 99	},
100	{},
101};
102
103MODULE_DEVICE_TABLE(of, auxio_match);
104
105static int __devinit auxio_probe(struct platform_device *dev)
106{
107	struct device_node *dp = dev->dev.of_node;
108	unsigned long size;
109
110	if (!strcmp(dp->parent->name, "ebus")) {
111		auxio_devtype = AUXIO_TYPE_EBUS;
112		size = sizeof(u32);
113	} else if (!strcmp(dp->parent->name, "sbus")) {
114		auxio_devtype = AUXIO_TYPE_SBUS;
115		size = 1;
116	} else {
117		printk("auxio: Unknown parent bus type [%s]\n",
118		       dp->parent->name);
119		return -ENODEV;
120	}
121	auxio_register = of_ioremap(&dev->resource[0], 0, size, "auxio");
122	if (!auxio_register)
123		return -ENODEV;
124
125	printk(KERN_INFO "AUXIO: Found device at %s\n",
126	       dp->full_name);
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		.owner = THIS_MODULE,
139		.of_match_table = auxio_match,
140	},
141};
142
143static int __init auxio_init(void)
144{
145	return platform_driver_register(&auxio_driver);
146}
147
148/* Must be after subsys_initcall() so that busses are probed.  Must
149 * be before device_initcall() because things like the floppy driver
150 * need to use the AUXIO register.
151 */
152fs_initcall(auxio_init);