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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
17 #include <asm/io.h>
18 #include <asm/oplib.h>
19 #include <asm/uaccess.h>
20 #include <asm/auxio.h>
21 #include <asm/apc.h>
22
23 /* Debugging
24 *
25 * #define APC_DEBUG_LED
26 */
27
28 #define APC_MINOR MISC_DYNAMIC_MINOR
29 #define APC_OBPNAME "power-management"
30 #define APC_DEVNAME "apc"
31
32 static u8 __iomem *regs;
33 static int apc_no_idle __devinitdata = 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 */
44 static 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 */
58 static void 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
71 static inline void apc_free(struct platform_device *op)
72 {
73 of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0]));
74 }
75
76 static int apc_open(struct inode *inode, struct file *f)
77 {
78 return 0;
79 }
80
81 static int apc_release(struct inode *inode, struct file *f)
82 {
83 return 0;
84 }
85
86 static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg)
87 {
88 __u8 inarg, __user *arg = (__u8 __user *) __arg;
89
90 switch (cmd) {
91 case APCIOCGFANCTL:
92 if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg))
93 return -EFAULT;
94 break;
95
96 case APCIOCGCPWR:
97 if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg))
98 return -EFAULT;
99 break;
100
101 case APCIOCGBPORT:
102 if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg))
103 return -EFAULT;
104 break;
105
106 case APCIOCSFANCTL:
107 if (get_user(inarg, arg))
108 return -EFAULT;
109 apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG);
110 break;
111
112 case APCIOCSCPWR:
113 if (get_user(inarg, arg))
114 return -EFAULT;
115 apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
116 break;
117
118 case APCIOCSBPORT:
119 if (get_user(inarg, arg))
120 return -EFAULT;
121 apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
122 break;
123
124 default:
125 return -EINVAL;
126 };
127
128 return 0;
129 }
130
131 static const struct file_operations apc_fops = {
132 .unlocked_ioctl = apc_ioctl,
133 .open = apc_open,
134 .release = apc_release,
135 .llseek = noop_llseek,
136 };
137
138 static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
139
140 static int __devinit apc_probe(struct platform_device *op)
141 {
142 int err;
143
144 regs = of_ioremap(&op->resource[0], 0,
145 resource_size(&op->resource[0]), APC_OBPNAME);
146 if (!regs) {
147 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
148 return -ENODEV;
149 }
150
151 err = misc_register(&apc_miscdev);
152 if (err) {
153 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
154 apc_free(op);
155 return -ENODEV;
156 }
157
158 /* Assign power management IDLE handler */
159 if (!apc_no_idle)
160 pm_idle = apc_swift_idle;
161
162 printk(KERN_INFO "%s: power management initialized%s\n",
163 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");
164
165 return 0;
166 }
167
168 static struct of_device_id apc_match[] = {
169 {
170 .name = APC_OBPNAME,
171 },
172 {},
173 };
174 MODULE_DEVICE_TABLE(of, apc_match);
175
176 static struct platform_driver apc_driver = {
177 .driver = {
178 .name = "apc",
179 .owner = THIS_MODULE,
180 .of_match_table = apc_match,
181 },
182 .probe = apc_probe,
183 };
184
185 static int __init apc_init(void)
186 {
187 return platform_driver_register(&apc_driver);
188 }
189
190 /* This driver is not critical to the boot process
191 * and is easiest to ioremap when SBus is already
192 * initialized, so we install ourselves thusly:
193 */
194 __initcall(apc_init);