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#include <asm/processor.h>
  24
  25/* Debugging
  26 * 
  27 * #define APC_DEBUG_LED
  28 */
  29
  30#define APC_MINOR       MISC_DYNAMIC_MINOR
  31#define APC_OBPNAME     "power-management"
  32#define APC_DEVNAME "apc"
  33
  34static u8 __iomem *regs;
  35static int apc_no_idle = 0;
  36
  37#define apc_readb(offs)         (sbus_readb(regs+offs))
  38#define apc_writeb(val, offs)   (sbus_writeb(val, regs+offs))
  39
  40/* Specify "apc=noidle" on the kernel command line to 
  41 * disable APC CPU standby support.  Certain prototype
  42 * systems (SPARCstation-Fox) do not play well with APC
  43 * CPU idle, so disable this if your system has APC and 
  44 * crashes randomly.
  45 */
  46static int __init apc_setup(char *str) 
  47{
  48        if(!strncmp(str, "noidle", strlen("noidle"))) {
  49                apc_no_idle = 1;
  50                return 1;
  51        }
  52        return 0;
  53}
  54__setup("apc=", apc_setup);
  55
  56/* 
  57 * CPU idle callback function
  58 * See .../arch/sparc/kernel/process.c
  59 */
  60static void apc_swift_idle(void)
  61{
  62#ifdef APC_DEBUG_LED
  63        set_auxio(0x00, AUXIO_LED); 
  64#endif
  65
  66        apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG);
  67
  68#ifdef APC_DEBUG_LED
  69        set_auxio(AUXIO_LED, 0x00); 
  70#endif
  71} 
  72
  73static inline void apc_free(struct platform_device *op)
  74{
  75        of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0]));
  76}
  77
  78static int apc_open(struct inode *inode, struct file *f)
  79{
  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 = (__u8 __user *) __arg;
  91
  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
 114        case APCIOCSCPWR:
 115                if (get_user(inarg, arg))
 116                        return -EFAULT;
 117                apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
 118                break;
 119
 120        case APCIOCSBPORT:
 121                if (get_user(inarg, arg))
 122                        return -EFAULT;
 123                apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
 124                break;
 125
 126        default:
 127                return -EINVAL;
 128        }
 129
 130        return 0;
 131}
 132
 133static const struct file_operations apc_fops = {
 134        .unlocked_ioctl =       apc_ioctl,
 135        .open =                 apc_open,
 136        .release =              apc_release,
 137        .llseek =               noop_llseek,
 138};
 139
 140static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
 141
 142static int apc_probe(struct platform_device *op)
 143{
 144        int err;
 145
 146        regs = of_ioremap(&op->resource[0], 0,
 147                          resource_size(&op->resource[0]), APC_OBPNAME);
 148        if (!regs) {
 149                printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
 150                return -ENODEV;
 151        }
 152
 153        err = misc_register(&apc_miscdev);
 154        if (err) {
 155                printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
 156                apc_free(op);
 157                return -ENODEV;
 158        }
 159
 160        /* Assign power management IDLE handler */
 161        if (!apc_no_idle)
 162                sparc_idle = apc_swift_idle;
 163
 164        printk(KERN_INFO "%s: power management initialized%s\n", 
 165               APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");
 166
 167        return 0;
 168}
 169
 170static struct of_device_id apc_match[] = {
 171        {
 172                .name = APC_OBPNAME,
 173        },
 174        {},
 175};
 176MODULE_DEVICE_TABLE(of, apc_match);
 177
 178static struct platform_driver apc_driver = {
 179        .driver = {
 180                .name = "apc",
 181                .owner = THIS_MODULE,
 182                .of_match_table = apc_match,
 183        },
 184        .probe          = apc_probe,
 185};
 186
 187static int __init apc_init(void)
 188{
 189        return platform_driver_register(&apc_driver);
 190}
 191
 192/* This driver is not critical to the boot process
 193 * and is easiest to ioremap when SBus is already
 194 * initialized, so we install ourselves thusly:
 195 */
 196__initcall(apc_init);
 197