1/* apc - Driver implementation for power management functions
2 * of Aurora Personality Chip (APC) on SPARCstation-4/5 and
3 * derivatives.
4 *
5 * Copyright (c) 2002 Eric Brower (ebrower@usa.net)
6 */
7
8#include <linux/kernel.h>
9#include <linux/fs.h>
10#include <linux/errno.h>
11#include <linux/init.h>
12#include <linux/miscdevice.h>
13#include <linux/pm.h>
14#include <linux/of.h>
15#include <linux/of_device.h>
16#include <linux/module.h>
17
18#include <asm/io.h>
19#include <asm/oplib.h>
20#include <asm/uaccess.h>
21#include <asm/auxio.h>
22#include <asm/apc.h>
23#include <asm/processor.h>
24
25/* Debugging
26 *
27 * #define APC_DEBUG_LED
28 */
29
30#define APC_MINOR	MISC_DYNAMIC_MINOR
31#define APC_OBPNAME	"power-management"
32#define APC_DEVNAME "apc"
33
34static u8 __iomem *regs;
35static int apc_no_idle = 0;
36
37#define apc_readb(offs)		(sbus_readb(regs+offs))
38#define apc_writeb(val, offs) 	(sbus_writeb(val, regs+offs))
39
40/* Specify "apc=noidle" on the kernel command line to
41 * disable APC CPU standby support.  Certain prototype
42 * systems (SPARCstation-Fox) do not play well with APC
43 * CPU idle, so disable this if your system has APC and
44 * crashes randomly.
45 */
46static int __init apc_setup(char *str)
47{
48	if(!strncmp(str, "noidle", strlen("noidle"))) {
49		apc_no_idle = 1;
50		return 1;
51	}
52	return 0;
53}
54__setup("apc=", apc_setup);
55
56/*
57 * CPU idle callback function
58 * See .../arch/sparc/kernel/process.c
59 */
60static void apc_swift_idle(void)
61{
62#ifdef APC_DEBUG_LED
63	set_auxio(0x00, AUXIO_LED);
64#endif
65
66	apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG);
67
68#ifdef APC_DEBUG_LED
69	set_auxio(AUXIO_LED, 0x00);
70#endif
71}
72
73static inline void apc_free(struct platform_device *op)
74{
75	of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0]));
76}
77
78static int apc_open(struct inode *inode, struct file *f)
79{
80	return 0;
81}
82
83static int apc_release(struct inode *inode, struct file *f)
84{
85	return 0;
86}
87
88static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg)
89{
90	__u8 inarg, __user *arg = (__u8 __user *) __arg;
91
92	switch (cmd) {
93	case APCIOCGFANCTL:
94		if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg))
95			return -EFAULT;
96		break;
97
98	case APCIOCGCPWR:
99		if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg))
100			return -EFAULT;
101		break;
102
103	case APCIOCGBPORT:
104		if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg))
105			return -EFAULT;
106		break;
107
108	case APCIOCSFANCTL:
109		if (get_user(inarg, arg))
110			return -EFAULT;
111		apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG);
112		break;
113
114	case APCIOCSCPWR:
115		if (get_user(inarg, arg))
116			return -EFAULT;
117		apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
118		break;
119
120	case APCIOCSBPORT:
121		if (get_user(inarg, arg))
122			return -EFAULT;
123		apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
124		break;
125
126	default:
127		return -EINVAL;
128	}
129
130	return 0;
131}
132
133static const struct file_operations apc_fops = {
134	.unlocked_ioctl =	apc_ioctl,
135	.open =			apc_open,
136	.release =		apc_release,
137	.llseek =		noop_llseek,
138};
139
140static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
141
142static int apc_probe(struct platform_device *op)
143{
144	int err;
145
146	regs = of_ioremap(&op->resource[0], 0,
147			  resource_size(&op->resource[0]), APC_OBPNAME);
148	if (!regs) {
149		printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
150		return -ENODEV;
151	}
152
153	err = misc_register(&apc_miscdev);
154	if (err) {
155		printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
156		apc_free(op);
157		return -ENODEV;
158	}
159
160	/* Assign power management IDLE handler */
161	if (!apc_no_idle)
162		sparc_idle = apc_swift_idle;
163
164	printk(KERN_INFO "%s: power management initialized%s\n",
165	       APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");
166
167	return 0;
168}
169
170static struct of_device_id apc_match[] = {
171	{
172		.name = APC_OBPNAME,
173	},
174	{},
175};
176MODULE_DEVICE_TABLE(of, apc_match);
177
178static struct platform_driver apc_driver = {
179	.driver = {
180		.name = "apc",
181		.of_match_table = apc_match,
182	},
183	.probe		= apc_probe,
184};
185
186static int __init apc_init(void)
187{
188	return platform_driver_register(&apc_driver);
189}
190
191/* This driver is not critical to the boot process
192 * and is easiest to ioremap when SBus is already
193 * initialized, so we install ourselves thusly:
194 */
195__initcall(apc_init);
196