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