Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* apc - Driver implementation for power management functions

 * of Aurora Personality Chip (APC) on SPARCstation-4/5 and

 * derivatives.

 *

 * Copyright (c) 2002 Eric Brower (ebrower@usa.net)

 */

#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/errno.h>

#include <linux/init.h>

#include <linux/miscdevice.h>

#include <linux/pm.h>

#include <asm/io.h>

#include <asm/sbus.h>

#include <asm/oplib.h>

#include <asm/uaccess.h>

#include <asm/auxio.h>

#include <asm/apc.h>

/* Debugging

 *

 * #define APC_DEBUG_LED

 */

#define APC_MINOR       MISC_DYNAMIC_MINOR

#define APC_OBPNAME     "power-management"

#define APC_DEVNAME "apc"

volatile static u8 __iomem *regs;

static int apc_regsize;

static int apc_no_idle __initdata = 0;

#define apc_readb(offs)                 (sbus_readb(regs+offs))

#define apc_writeb(val, offs)   (sbus_writeb(val, regs+offs))

/* Specify "apc=noidle" on the kernel command line to

 * disable APC CPU standby support.  Certain prototype

 * systems (SPARCstation-Fox) do not play well with APC

 * CPU idle, so disable this if your system has APC and

 * crashes randomly.

 */

static int __init apc_setup(char *str)

{

        if(!strncmp(str, "noidle", strlen("noidle"))) {

                apc_no_idle = 1;

                return 1;

        }

        return 0;

}

__setup("apc=", apc_setup);

/*

 * CPU idle callback function

 * See .../arch/sparc/kernel/process.c

 */

void apc_swift_idle(void)

{

#ifdef APC_DEBUG_LED

        set_auxio(0x00, AUXIO_LED);

#endif

        apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG);

#ifdef APC_DEBUG_LED

        set_auxio(AUXIO_LED, 0x00);

#endif

}

static inline void apc_free(void)

{

        sbus_iounmap(regs, apc_regsize);

}

static int apc_open(struct inode *inode, struct file *f)

{

        return 0;

}

static int apc_release(struct inode *inode, struct file *f)

{

        return 0;

}

static int apc_ioctl(struct inode *inode, struct file *f,

                     unsigned int cmd, unsigned long __arg)

{

        __u8 inarg, __user *arg;

        arg = (__u8 __user *) __arg;

        switch (cmd) {

        case APCIOCGFANCTL:

                if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg))

                                return -EFAULT;

                break;

        case APCIOCGCPWR:

                if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg))

                        return -EFAULT;

                break;

        case APCIOCGBPORT:

                if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg))

                        return -EFAULT;

                break;

        case APCIOCSFANCTL:

                if (get_user(inarg, arg))

                        return -EFAULT;

                apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG);

                break;

        case APCIOCSCPWR:

                if (get_user(inarg, arg))

                        return -EFAULT;

                apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);

                break;

        case APCIOCSBPORT:

                if (get_user(inarg, arg))

                        return -EFAULT;

                apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);

                break;

        default:

                return -EINVAL;

        };

        return 0;

}

static const struct file_operations apc_fops = {

        .ioctl =        apc_ioctl,

        .open =         apc_open,

        .release =      apc_release,

};

static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };

static int __init apc_probe(void)

{

        struct sbus_bus *sbus = NULL;

        struct sbus_dev *sdev = NULL;

        int iTmp = 0;

        for_each_sbus(sbus) {

                for_each_sbusdev(sdev, sbus) {

                        if (!strcmp(sdev->prom_name, APC_OBPNAME)) {

                                goto sbus_done;

                        }

                }

        }

sbus_done:

        if (!sdev) {

                return -ENODEV;

        }

        apc_regsize = sdev->reg_addrs[0].reg_size;

        regs = sbus_ioremap(&sdev->resource[0], 0,

                                   apc_regsize, APC_OBPNAME);

        if(!regs) {

                printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);

                return -ENODEV;

        }

        iTmp = misc_register(&apc_miscdev);

        if (iTmp != 0) {

                printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);

                apc_free();

                return -ENODEV;

        }

        /* Assign power management IDLE handler */

        if(!apc_no_idle)

                pm_idle = apc_swift_idle;

        printk(KERN_INFO "%s: power management initialized%s\n",

                APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");

        return 0;

}

/* This driver is not critical to the boot process

 * and is easiest to ioremap when SBus is already

 * initialized, so we install ourselves thusly:

 */

__initcall(apc_probe);