arch/sparc/kernel/apc.c

   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  */
  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  */
  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
  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
  77 static int apc_open(struct inode *inode, struct file *f)
  78 {
  79         cycle_kernel_lock();
  80         return 0;
  81 }
  82
  83 static int apc_release(struct inode *inode, struct file *f)
  84 {
  85         return 0;
  86 }
  87
  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
 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
 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);