1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* pmc - Driver implementation for power management functions |
3 | * of Power Management Controller (PMC) on SPARCstation-Voyager. |
4 | * |
5 | * Copyright (c) 2002 Eric Brower (ebrower@usa.net) |
6 | */ |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/fs.h> |
10 | #include <linux/errno.h> |
11 | #include <linux/init.h> |
12 | #include <linux/pm.h> |
13 | #include <linux/of.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/module.h> |
16 | |
17 | #include <asm/io.h> |
18 | #include <asm/oplib.h> |
19 | #include <linux/uaccess.h> |
20 | #include <asm/auxio.h> |
21 | #include <asm/processor.h> |
22 | |
23 | /* Debug |
24 | * |
25 | * #define PMC_DEBUG_LED |
26 | * #define PMC_NO_IDLE |
27 | */ |
28 | |
29 | #define PMC_OBPNAME "SUNW,pmc" |
30 | #define PMC_DEVNAME "pmc" |
31 | |
32 | #define PMC_IDLE_REG 0x00 |
33 | #define PMC_IDLE_ON 0x01 |
34 | |
35 | static u8 __iomem *regs; |
36 | |
37 | #define pmc_readb(offs) (sbus_readb(regs+offs)) |
38 | #define pmc_writeb(val, offs) (sbus_writeb(val, regs+offs)) |
39 | |
40 | /* |
41 | * CPU idle callback function |
42 | * See .../arch/sparc/kernel/process.c |
43 | */ |
44 | static void pmc_swift_idle(void) |
45 | { |
46 | #ifdef PMC_DEBUG_LED |
47 | set_auxio(0x00, AUXIO_LED); |
48 | #endif |
49 | |
50 | pmc_writeb(pmc_readb(PMC_IDLE_REG) | PMC_IDLE_ON, PMC_IDLE_REG); |
51 | |
52 | #ifdef PMC_DEBUG_LED |
53 | set_auxio(AUXIO_LED, 0x00); |
54 | #endif |
55 | } |
56 | |
57 | static int pmc_probe(struct platform_device *op) |
58 | { |
59 | regs = of_ioremap(&op->resource[0], 0, |
60 | resource_size(res: &op->resource[0]), PMC_OBPNAME); |
61 | if (!regs) { |
62 | printk(KERN_ERR "%s: unable to map registers\n" , PMC_DEVNAME); |
63 | return -ENODEV; |
64 | } |
65 | |
66 | #ifndef PMC_NO_IDLE |
67 | /* Assign power management IDLE handler */ |
68 | sparc_idle = pmc_swift_idle; |
69 | #endif |
70 | |
71 | printk(KERN_INFO "%s: power management initialized\n" , PMC_DEVNAME); |
72 | return 0; |
73 | } |
74 | |
75 | static const struct of_device_id pmc_match[] = { |
76 | { |
77 | .name = PMC_OBPNAME, |
78 | }, |
79 | {}, |
80 | }; |
81 | MODULE_DEVICE_TABLE(of, pmc_match); |
82 | |
83 | static struct platform_driver pmc_driver = { |
84 | .driver = { |
85 | .name = "pmc" , |
86 | .of_match_table = pmc_match, |
87 | }, |
88 | .probe = pmc_probe, |
89 | }; |
90 | |
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 | |