linux/arch/sparc/kernel/apc.c
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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/smp_lock.h>
  14#include <linux/pm.h>
  15
  16#include <asm/io.h>
  17#include <asm/sbus.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
  32volatile static u8 __iomem *regs; 
  33static int apc_regsize;
  34static int apc_no_idle __initdata = 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 */
  45static 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 */
  59static 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
  72static inline void apc_free(void)
  73{
  74        sbus_iounmap(regs, apc_regsize);
  75}
  76
  77static int apc_open(struct inode *inode, struct file *f)
  78{
  79        cycle_kernel_lock();
  80        return 0;
  81}
  82
  83static int apc_release(struct inode *inode, struct file *f)
  84{
  85        return 0;
  86}
  87
  88static 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
 148static const struct file_operations apc_fops = {
 149        .unlocked_ioctl =       apc_ioctl,
 150        .open =                 apc_open,
 151        .release =              apc_release,
 152};
 153
 154static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
 155
 156static int __init apc_probe(void)
 157{
 158        struct sbus_bus *sbus = NULL;
 159        struct sbus_dev *sdev = NULL;
 160        int iTmp = 0;
 161
 162        for_each_sbus(sbus) {
 163                for_each_sbusdev(sdev, sbus) {
 164                        if (!strcmp(sdev->prom_name, APC_OBPNAME)) {
 165                                goto sbus_done;
 166                        }
 167                }
 168        }
 169
 170sbus_done:
 171        if (!sdev) {
 172                return -ENODEV;
 173        }
 174
 175        apc_regsize = sdev->reg_addrs[0].reg_size;
 176        regs = sbus_ioremap(&sdev->resource[0], 0, 
 177                                   apc_regsize, APC_OBPNAME);
 178        if(!regs) {
 179                printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
 180                return -ENODEV;
 181        }
 182
 183        iTmp = misc_register(&apc_miscdev);
 184        if (iTmp != 0) {
 185                printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
 186                apc_free();
 187                return -ENODEV;
 188        }
 189
 190        /* Assign power management IDLE handler */
 191        if(!apc_no_idle)
 192                pm_idle = apc_swift_idle;       
 193
 194        printk(KERN_INFO "%s: power management initialized%s\n", 
 195                APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");
 196        return 0;
 197}
 198
 199/* This driver is not critical to the boot process
 200 * and is easiest to ioremap when SBus is already
 201 * initialized, so we install ourselves thusly:
 202 */
 203__initcall(apc_probe);
 204
 205