LXR linux/arch/sparc/kernel/pmc.c

   1/* pmc - Driver implementation for power management functions
   2 * of Power Management Controller (PMC) on SPARCstation-Voyager.
   3 *
   4 * Copyright (c) 2002 Eric Brower (ebrower@usa.net)
   5 */
   6
   7#include <linux/kernel.h>
   8#include <linux/fs.h>
   9#include <linux/errno.h>
  10#include <linux/init.h>
  11#include <linux/miscdevice.h>
  12#include <linux/pm.h>
  13
  14#include <asm/io.h>
  15#include <asm/sbus.h>
  16#include <asm/oplib.h>
  17#include <asm/uaccess.h>
  18#include <asm/auxio.h>
  19
  20/* Debug
  21 *
  22 * #define PMC_DEBUG_LED
  23 * #define PMC_NO_IDLE
  24 */
  25
  26#define PMC_MINOR       MISC_DYNAMIC_MINOR
  27#define PMC_OBPNAME     "SUNW,pmc"
  28#define PMC_DEVNAME "pmc"
  29
  30#define PMC_IDLE_REG    0x00
  31#define PMC_IDLE_ON             0x01
  32
  33volatile static u8 __iomem *regs; 
  34static int pmc_regsize;
  35
  36#define pmc_readb(offs)                 (sbus_readb(regs+offs))
  37#define pmc_writeb(val, offs)   (sbus_writeb(val, regs+offs))
  38
  39/* 
  40 * CPU idle callback function
  41 * See .../arch/sparc/kernel/process.c
  42 */
  43void pmc_swift_idle(void)
  44{
  45#ifdef PMC_DEBUG_LED
  46        set_auxio(0x00, AUXIO_LED); 
  47#endif
  48
  49        pmc_writeb(pmc_readb(PMC_IDLE_REG) | PMC_IDLE_ON, PMC_IDLE_REG);
  50
  51#ifdef PMC_DEBUG_LED
  52        set_auxio(AUXIO_LED, 0x00); 
  53#endif
  54} 
  55
  56static inline void pmc_free(void)
  57{
  58        sbus_iounmap(regs, pmc_regsize);
  59}
  60
  61static int __init pmc_probe(void)
  62{
  63        struct sbus_bus *sbus = NULL;
  64        struct sbus_dev *sdev = NULL;
  65        for_each_sbus(sbus) {
  66                for_each_sbusdev(sdev, sbus) {
  67                        if (!strcmp(sdev->prom_name, PMC_OBPNAME)) {
  68                                goto sbus_done;
  69                        }
  70                }
  71        }
  72
  73sbus_done:
  74        if (!sdev) {
  75                return -ENODEV;
  76        }
  77
  78        pmc_regsize = sdev->reg_addrs[0].reg_size;
  79        regs = sbus_ioremap(&sdev->resource[0], 0, 
  80                                   pmc_regsize, PMC_OBPNAME);
  81        if (!regs) {
  82                printk(KERN_ERR "%s: unable to map registers\n", PMC_DEVNAME);
  83                return -ENODEV;
  84        }
  85
  86#ifndef PMC_NO_IDLE
  87        /* Assign power management IDLE handler */
  88        pm_idle = pmc_swift_idle;       
  89#endif
  90
  91        printk(KERN_INFO "%s: power management initialized\n", PMC_DEVNAME);
  92        return 0;
  93}
  94
  95/* This driver is not critical to the boot process
  96 * and is easiest to ioremap when SBus is already
  97 * initialized, so we install ourselves thusly:
  98 */
  99__initcall(pmc_probe);
 100