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
15#include <asm/io.h>
16#include <asm/sbus.h>
17#include <asm/oplib.h>
18#include <asm/uaccess.h>
19#include <asm/auxio.h>
20#include <asm/apc.h>
21
22/* Debugging
23 *
24 * #define APC_DEBUG_LED
25 */
26
27#define APC_MINOR	MISC_DYNAMIC_MINOR
28#define APC_OBPNAME	"power-management"
29#define APC_DEVNAME "apc"
30
31volatile static u8 __iomem *regs;
32static int apc_regsize;
33static int apc_no_idle __initdata = 0;
34
35#define apc_readb(offs)			(sbus_readb(regs+offs))
36#define apc_writeb(val, offs) 	(sbus_writeb(val, regs+offs))
37
38/* Specify "apc=noidle" on the kernel command line to
39 * disable APC CPU standby support.  Certain prototype
40 * systems (SPARCstation-Fox) do not play well with APC
41 * CPU idle, so disable this if your system has APC and
42 * crashes randomly.
43 */
44static int __init apc_setup(char *str)
45{
46	if(!strncmp(str, "noidle", strlen("noidle"))) {
47		apc_no_idle = 1;
48		return 1;
49	}
50	return 0;
51}
52__setup("apc=", apc_setup);
53
54/*
55 * CPU idle callback function
56 * See .../arch/sparc/kernel/process.c
57 */
58void apc_swift_idle(void)
59{
60#ifdef APC_DEBUG_LED
61	set_auxio(0x00, AUXIO_LED);
62#endif
63
64	apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG);
65
66#ifdef APC_DEBUG_LED
67	set_auxio(AUXIO_LED, 0x00);
68#endif
69}
70
71static inline void apc_free(void)
72{
73	sbus_iounmap(regs, apc_regsize);
74}
75
76static int apc_open(struct inode *inode, struct file *f)
77{
78	return 0;
79}
80
81static int apc_release(struct inode *inode, struct file *f)
82{
83	return 0;
84}
85
86static int apc_ioctl(struct inode *inode, struct file *f,
87		     unsigned int cmd, unsigned long __arg)
88{
89	__u8 inarg, __user *arg;
90
91	arg = (__u8 __user *) __arg;
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	case APCIOCSCPWR:
114		if (get_user(inarg, arg))
115			return -EFAULT;
116		apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
117		break;
118	case APCIOCSBPORT:
119		if (get_user(inarg, arg))
120			return -EFAULT;
121		apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
122		break;
123	default:
124		return -EINVAL;
125	};
126
127	return 0;
128}
129
130static const struct file_operations apc_fops = {
131	.ioctl =	apc_ioctl,
132	.open =		apc_open,
133	.release =	apc_release,
134};
135
136static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
137
138static int __init apc_probe(void)
139{
140	struct sbus_bus *sbus = NULL;
141	struct sbus_dev *sdev = NULL;
142	int iTmp = 0;
143
144	for_each_sbus(sbus) {
145		for_each_sbusdev(sdev, sbus) {
146			if (!strcmp(sdev->prom_name, APC_OBPNAME)) {
147				goto sbus_done;
148			}
149		}
150	}
151
152sbus_done:
153	if (!sdev) {
154		return -ENODEV;
155	}
156
157	apc_regsize = sdev->reg_addrs[0].reg_size;
158	regs = sbus_ioremap(&sdev->resource[0], 0,
159				   apc_regsize, APC_OBPNAME);
160	if(!regs) {
161		printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
162		return -ENODEV;
163	}
164
165	iTmp = misc_register(&apc_miscdev);
166	if (iTmp != 0) {
167		printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
168		apc_free();
169		return -ENODEV;
170	}
171
172	/* Assign power management IDLE handler */
173	if(!apc_no_idle)
174		pm_idle = apc_swift_idle;
175
176	printk(KERN_INFO "%s: power management initialized%s\n",
177		APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");
178	return 0;
179}
180
181/* This driver is not critical to the boot process
182 * and is easiest to ioremap when SBus is already
183 * initialized, so we install ourselves thusly:
184 */
185__initcall(apc_probe);
186