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401e9093 PM |
1 | /* |
2 | * Generic heartbeat driver for regular LED banks | |
3 | * | |
4 | * Copyright (C) 2007 Paul Mundt | |
5 | * | |
6 | * Most SH reference boards include a number of individual LEDs that can | |
7 | * be independently controlled (either via a pre-defined hardware | |
8 | * function or via the LED class, if desired -- the hardware tends to | |
9 | * encapsulate some of the same "triggers" that the LED class supports, | |
10 | * so there's not too much value in it). | |
11 | * | |
12 | * Additionally, most of these boards also have a LED bank that we've | |
13 | * traditionally used for strobing the load average. This use case is | |
14 | * handled by this driver, rather than giving each LED bit position its | |
15 | * own struct device. | |
16 | * | |
17 | * This file is subject to the terms and conditions of the GNU General Public | |
18 | * License. See the file "COPYING" in the main directory of this archive | |
19 | * for more details. | |
20 | */ | |
21 | #include <linux/init.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/sched.h> | |
25 | #include <linux/timer.h> | |
26 | #include <linux/io.h> | |
27 | ||
28 | #define DRV_NAME "heartbeat" | |
29 | #define DRV_VERSION "0.1.0" | |
30 | ||
31 | struct heartbeat_data { | |
32 | void __iomem *base; | |
33 | unsigned char bit_pos[8]; | |
34 | struct timer_list timer; | |
35 | }; | |
36 | ||
37 | static void heartbeat_timer(unsigned long data) | |
38 | { | |
39 | struct heartbeat_data *hd = (struct heartbeat_data *)data; | |
40 | static unsigned bit = 0, up = 1; | |
41 | ||
42 | ctrl_outw(1 << hd->bit_pos[bit], (unsigned long)hd->base); | |
f6072896 TY |
43 | bit += up; |
44 | if ((bit == 0) || (bit == ARRAY_SIZE(hd->bit_pos)-1)) | |
45 | up = -up; | |
401e9093 PM |
46 | |
47 | mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) / | |
48 | ((avenrun[0] / 5) + (3 << FSHIFT))))); | |
49 | } | |
50 | ||
51 | static int heartbeat_drv_probe(struct platform_device *pdev) | |
52 | { | |
53 | struct resource *res; | |
54 | struct heartbeat_data *hd; | |
55 | ||
56 | if (unlikely(pdev->num_resources != 1)) { | |
57 | dev_err(&pdev->dev, "invalid number of resources\n"); | |
58 | return -EINVAL; | |
59 | } | |
60 | ||
61 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
62 | if (unlikely(res == NULL)) { | |
63 | dev_err(&pdev->dev, "invalid resource\n"); | |
64 | return -EINVAL; | |
65 | } | |
66 | ||
67 | hd = kmalloc(sizeof(struct heartbeat_data), GFP_KERNEL); | |
68 | if (unlikely(!hd)) | |
69 | return -ENOMEM; | |
70 | ||
71 | if (pdev->dev.platform_data) { | |
72 | memcpy(hd->bit_pos, pdev->dev.platform_data, | |
73 | ARRAY_SIZE(hd->bit_pos)); | |
74 | } else { | |
75 | int i; | |
76 | ||
77 | for (i = 0; i < ARRAY_SIZE(hd->bit_pos); i++) | |
78 | hd->bit_pos[i] = i; | |
79 | } | |
80 | ||
bf73af23 | 81 | hd->base = (void __iomem *)(unsigned long)res->start; |
401e9093 PM |
82 | |
83 | setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd); | |
84 | platform_set_drvdata(pdev, hd); | |
85 | ||
86 | return mod_timer(&hd->timer, jiffies + 1); | |
87 | } | |
88 | ||
89 | static int heartbeat_drv_remove(struct platform_device *pdev) | |
90 | { | |
91 | struct heartbeat_data *hd = platform_get_drvdata(pdev); | |
92 | ||
93 | del_timer_sync(&hd->timer); | |
94 | ||
95 | platform_set_drvdata(pdev, NULL); | |
96 | ||
97 | kfree(hd); | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static struct platform_driver heartbeat_driver = { | |
103 | .probe = heartbeat_drv_probe, | |
104 | .remove = heartbeat_drv_remove, | |
105 | .driver = { | |
106 | .name = DRV_NAME, | |
107 | }, | |
108 | }; | |
109 | ||
110 | static int __init heartbeat_init(void) | |
111 | { | |
112 | printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION); | |
113 | return platform_driver_register(&heartbeat_driver); | |
114 | } | |
115 | ||
116 | static void __exit heartbeat_exit(void) | |
117 | { | |
118 | platform_driver_unregister(&heartbeat_driver); | |
119 | } | |
120 | module_init(heartbeat_init); | |
121 | module_exit(heartbeat_exit); | |
122 | ||
123 | MODULE_VERSION(DRV_VERSION); | |
124 | MODULE_AUTHOR("Paul Mundt"); | |
125 | MODULE_LICENSE("GPLv2"); |