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 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		.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);
152