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#include <linux/module.h>
  15
  16#include <asm/io.h>
  17#include <asm/oplib.h>
  18#include <asm/uaccess.h>
  19#include <asm/auxio.h>
  20#include <asm/processor.h>
  21
  22/* Debug
  23 *
  24 * #define PMC_DEBUG_LED
  25 * #define PMC_NO_IDLE
  26 */
  27
  28#define PMC_OBPNAME     "SUNW,pmc"
  29#define PMC_DEVNAME     "pmc"
  30
  31#define PMC_IDLE_REG    0x00
  32#define PMC_IDLE_ON     0x01
  33
  34static u8 __iomem *regs;
  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 */
  43static void 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 int pmc_probe(struct platform_device *op)
  57{
  58        regs = of_ioremap(&op->resource[0], 0,
  59                          resource_size(&op->resource[0]), PMC_OBPNAME);
  60        if (!regs) {
  61                printk(KERN_ERR "%s: unable to map registers\n", PMC_DEVNAME);
  62                return -ENODEV;
  63        }
  64
  65#ifndef PMC_NO_IDLE
  66        /* Assign power management IDLE handler */
  67        sparc_idle = pmc_swift_idle;
  68#endif
  69
  70        printk(KERN_INFO "%s: power management initialized\n", PMC_DEVNAME);
  71        return 0;
  72}
  73
  74static struct of_device_id pmc_match[] = {
  75        {
  76                .name = PMC_OBPNAME,
  77        },
  78        {},
  79};
  80MODULE_DEVICE_TABLE(of, pmc_match);
  81
  82static struct platform_driver pmc_driver = {
  83        .driver = {
  84                .name = "pmc",
  85                .of_match_table = pmc_match,
  86        },
  87        .probe          = pmc_probe,
  88};
  89
  90static int __init pmc_init(void)
  91{
  92        return platform_driver_register(&pmc_driver);
  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_init);
 100