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
34 static 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 */
pmc_swift_idle(void)43 static 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
pmc_probe(struct platform_device * op)56 static 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
74 static struct of_device_id pmc_match[] = {
75 {
76 .name = PMC_OBPNAME,
77 },
78 {},
79 };
80 MODULE_DEVICE_TABLE(of, pmc_match);
81
82 static struct platform_driver pmc_driver = {
83 .driver = {
84 .name = "pmc",
85 .owner = THIS_MODULE,
86 .of_match_table = pmc_match,
87 },
88 .probe = pmc_probe,
89 };
90
pmc_init(void)91 static int __init pmc_init(void)
92 {
93 return platform_driver_register(&pmc_driver);
94 }
95
96 /* This driver is not critical to the boot process
97 * and is easiest to ioremap when SBus is already
98 * initialized, so we install ourselves thusly:
99 */
100 __initcall(pmc_init);
101