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