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/smp_lock.h>
14 #include <linux/pm.h>
15 #include <linux/of.h>
16 #include <linux/of_device.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 of_device * op)72 static inline void apc_free(struct of_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 cycle_kernel_lock();
80 return 0;
81 }
82
apc_release(struct inode * inode,struct file * f)83 static int apc_release(struct inode *inode, struct file *f)
84 {
85 return 0;
86 }
87
apc_ioctl(struct file * f,unsigned int cmd,unsigned long __arg)88 static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg)
89 {
90 __u8 inarg, __user *arg;
91
92 arg = (__u8 __user *) __arg;
93
94 lock_kernel();
95
96 switch (cmd) {
97 case APCIOCGFANCTL:
98 if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg)) {
99 unlock_kernel();
100 return -EFAULT;
101 }
102 break;
103
104 case APCIOCGCPWR:
105 if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg)) {
106 unlock_kernel();
107 return -EFAULT;
108 }
109 break;
110
111 case APCIOCGBPORT:
112 if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg)) {
113 unlock_kernel();
114 return -EFAULT;
115 }
116 break;
117
118 case APCIOCSFANCTL:
119 if (get_user(inarg, arg)) {
120 unlock_kernel();
121 return -EFAULT;
122 }
123 apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG);
124 break;
125 case APCIOCSCPWR:
126 if (get_user(inarg, arg)) {
127 unlock_kernel();
128 return -EFAULT;
129 }
130 apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
131 break;
132 case APCIOCSBPORT:
133 if (get_user(inarg, arg)) {
134 unlock_kernel();
135 return -EFAULT;
136 }
137 apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
138 break;
139 default:
140 unlock_kernel();
141 return -EINVAL;
142 };
143
144 unlock_kernel();
145 return 0;
146 }
147
148 static const struct file_operations apc_fops = {
149 .unlocked_ioctl = apc_ioctl,
150 .open = apc_open,
151 .release = apc_release,
152 };
153
154 static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
155
apc_probe(struct of_device * op,const struct of_device_id * match)156 static int __devinit apc_probe(struct of_device *op,
157 const struct of_device_id *match)
158 {
159 int err;
160
161 regs = of_ioremap(&op->resource[0], 0,
162 resource_size(&op->resource[0]), APC_OBPNAME);
163 if (!regs) {
164 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
165 return -ENODEV;
166 }
167
168 err = misc_register(&apc_miscdev);
169 if (err) {
170 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
171 apc_free(op);
172 return -ENODEV;
173 }
174
175 /* Assign power management IDLE handler */
176 if (!apc_no_idle)
177 pm_idle = apc_swift_idle;
178
179 printk(KERN_INFO "%s: power management initialized%s\n",
180 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");
181
182 return 0;
183 }
184
185 static struct of_device_id __initdata apc_match[] = {
186 {
187 .name = APC_OBPNAME,
188 },
189 {},
190 };
191 MODULE_DEVICE_TABLE(of, apc_match);
192
193 static struct of_platform_driver apc_driver = {
194 .name = "apc",
195 .match_table = apc_match,
196 .probe = apc_probe,
197 };
198
apc_init(void)199 static int __init apc_init(void)
200 {
201 return of_register_driver(&apc_driver, &of_bus_type);
202 }
203
204 /* This driver is not critical to the boot process
205 * and is easiest to ioremap when SBus is already
206 * initialized, so we install ourselves thusly:
207 */
208 __initcall(apc_init);
209