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/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
  31 volatile static u8 __iomem *regs;
  32 static int apc_regsize;
  33 static 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  */
  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 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(void)
  72 {
  73         sbus_iounmap(regs, apc_regsize);
  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 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
 130 static const struct file_operations apc_fops = {
 131         .ioctl =        apc_ioctl,
 132         .open =         apc_open,
 133         .release =      apc_release,
 134 };
 135
 136 static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
 137
 138 static 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
 152 sbus_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