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