LXR linux/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#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
  33static u8 __iomem *regs;
  34static 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 */
  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(struct platform_device *op)
  73{
  74        of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0]));
  75}
  76
  77static int apc_open(struct inode *inode, struct file *f)
  78{
  79        return 0;
  80}
  81
  82static int apc_release(struct inode *inode, struct file *f)
  83{
  84        return 0;
  85}
  86
  87static 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
 132static 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
 139static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
 140
 141static 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
 169static struct of_device_id apc_match[] = {
 170        {
 171                .name = APC_OBPNAME,
 172        },
 173        {},
 174};
 175MODULE_DEVICE_TABLE(of, apc_match);
 176
 177static 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
 186static 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