/* 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);
