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/pm.h>
  12#include <linux/of.h>
  13#include <linux/of_device.h>
  14
  15#include <asm/io.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_OBPNAME     "SUNW,pmc"
  27#define PMC_DEVNAME     "pmc"
  28
  29#define PMC_IDLE_REG    0x00
  30#define PMC_IDLE_ON     0x01
  31
  32static u8 __iomem *regs;
  33
  34#define pmc_readb(offs)         (sbus_readb(regs+offs))
  35#define pmc_writeb(val, offs)   (sbus_writeb(val, regs+offs))
  36
  37/*
  38 * CPU idle callback function
  39 * See .../arch/sparc/kernel/process.c
  40 */
  41static void pmc_swift_idle(void)
  42{
  43#ifdef PMC_DEBUG_LED
  44        set_auxio(0x00, AUXIO_LED);
  45#endif
  46
  47        pmc_writeb(pmc_readb(PMC_IDLE_REG) | PMC_IDLE_ON, PMC_IDLE_REG);
  48
  49#ifdef PMC_DEBUG_LED
  50        set_auxio(AUXIO_LED, 0x00);
  51#endif
  52}
  53
  54static int __devinit pmc_probe(struct of_device *op,
  55                               const struct of_device_id *match)
  56{
  57        regs = of_ioremap(&op->resource[0], 0,
  58                          resource_size(&op->resource[0]), PMC_OBPNAME);
  59        if (!regs) {
  60                printk(KERN_ERR "%s: unable to map registers\n", PMC_DEVNAME);
  61                return -ENODEV;
  62        }
  63
  64#ifndef PMC_NO_IDLE
  65        /* Assign power management IDLE handler */
  66        pm_idle = pmc_swift_idle;
  67#endif
  68
  69        printk(KERN_INFO "%s: power management initialized\n", PMC_DEVNAME);
  70        return 0;
  71}
  72
  73static struct of_device_id __initdata pmc_match[] = {
  74        {
  75                .name = PMC_OBPNAME,
  76        },
  77        {},
  78};
  79MODULE_DEVICE_TABLE(of, pmc_match);
  80
  81static struct of_platform_driver pmc_driver = {
  82        .name           = "pmc",
  83        .match_table    = pmc_match,
  84        .probe          = pmc_probe,
  85};
  86
  87static int __init pmc_init(void)
  88{
  89        return of_register_driver(&pmc_driver, &of_bus_type);
  90}
  91
  92/* This driver is not critical to the boot process
  93 * and is easiest to ioremap when SBus is already
  94 * initialized, so we install ourselves thusly:
  95 */
  96__initcall(pmc_init);
  97