aboutsummaryrefslogtreecommitdiff
path: root/arch/sparc/kernel/apc.c
blob: caef9deb5866f6d87a6fd3d72cb0bc4b25719080 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/* apc - Driver implementation for power management functions
 * of Aurora Personality Chip (APC) on SPARCstation-4/5 and
 * derivatives.
 *
 * Copyright (c) 2002 Eric Brower (ebrower@usa.net)
 */

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/pm.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <asm/io.h>
#include <asm/oplib.h>
#include <asm/uaccess.h>
#include <asm/auxio.h>
#include <asm/apc.h>

/* Debugging
 * 
 * #define APC_DEBUG_LED
 */

#define APC_MINOR	MISC_DYNAMIC_MINOR
#define APC_OBPNAME	"power-management"
#define APC_DEVNAME "apc"

static u8 __iomem *regs;
static int apc_no_idle __devinitdata = 0;

#define apc_readb(offs)		(sbus_readb(regs+offs))
#define apc_writeb(val, offs) 	(sbus_writeb(val, regs+offs))

/* Specify "apc=noidle" on the kernel command line to 
 * disable APC CPU standby support.  Certain prototype
 * systems (SPARCstation-Fox) do not play well with APC
 * CPU idle, so disable this if your system has APC and 
 * crashes randomly.
 */
static int __init apc_setup(char *str) 
{
	if(!strncmp(str, "noidle", strlen("noidle"))) {
		apc_no_idle = 1;
		return 1;
	}
	return 0;
}
__setup("apc=", apc_setup);

/* 
 * CPU idle callback function
 * See .../arch/sparc/kernel/process.c
 */
static void apc_swift_idle(void)
{
#ifdef APC_DEBUG_LED
	set_auxio(0x00, AUXIO_LED); 
#endif

	apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG);

#ifdef APC_DEBUG_LED
	set_auxio(AUXIO_LED, 0x00); 
#endif
} 

static inline void apc_free(struct platform_device *op)
{
	of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0]));
}

static int apc_open(struct inode *inode, struct file *f)
{
	return 0;
}

static int apc_release(struct inode *inode, struct file *f)
{
	return 0;
}

static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg)
{
	__u8 inarg, __user *arg = (__u8 __user *) __arg;

	switch (cmd) {
	case APCIOCGFANCTL:
		if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg))
			return -EFAULT;
		break;

	case APCIOCGCPWR:
		if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg))
			return -EFAULT;
		break;

	case APCIOCGBPORT:
		if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg))
			return -EFAULT;
		break;

	case APCIOCSFANCTL:
		if (get_user(inarg, arg))
			return -EFAULT;
		apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG);
		break;

	case APCIOCSCPWR:
		if (get_user(inarg, arg))
			return -EFAULT;
		apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
		break;

	case APCIOCSBPORT:
		if (get_user(inarg, arg))
			return -EFAULT;
		apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static const struct file_operations apc_fops = {
	.unlocked_ioctl =	apc_ioctl,
	.open =			apc_open,
	.release =		apc_release,
	.llseek =		noop_llseek,
};

static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };

static int __devinit apc_probe(struct platform_device *op)
{
	int err;

	regs = of_ioremap(&op->resource[0], 0,
			  resource_size(&op->resource[0]), APC_OBPNAME);
	if (!regs) {
		printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
		return -ENODEV;
	}

	err = misc_register(&apc_miscdev);
	if (err) {
		printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
		apc_free(op);
		return -ENODEV;
	}

	/* Assign power management IDLE handler */
	if (!apc_no_idle)
		pm_idle = apc_swift_idle;	

	printk(KERN_INFO "%s: power management initialized%s\n", 
	       APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");

	return 0;
}

static struct of_device_id apc_match[] = {
	{
		.name = APC_OBPNAME,
	},
	{},
};
MODULE_DEVICE_TABLE(of, apc_match);

static struct platform_driver apc_driver = {
	.driver = {
		.name = "apc",
		.owner = THIS_MODULE,
		.of_match_table = apc_match,
	},
	.probe		= apc_probe,
};

static int __init apc_init(void)
{
	return platform_driver_register(&apc_driver);
}

/* This driver is not critical to the boot process
 * and is easiest to ioremap when SBus is already
 * initialized, so we install ourselves thusly:
 */
__initcall(apc_init);