blob: 23dd6080422f155cdb422b7f373e2964eedf41d6 [file] [log] [blame]
Paul Mundt401e9092007-02-13 15:46:39 +09001/*
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
31struct heartbeat_data {
32 void __iomem *base;
33 unsigned char bit_pos[8];
34 struct timer_list timer;
35};
36
37static 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);
Takashi YOSHIIf6072892007-03-12 15:33:22 +090043 bit += up;
44 if ((bit == 0) || (bit == ARRAY_SIZE(hd->bit_pos)-1))
45 up = -up;
Paul Mundt401e9092007-02-13 15:46:39 +090046
47 mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) /
48 ((avenrun[0] / 5) + (3 << FSHIFT)))));
49}
50
51static 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
81 hd->base = (void __iomem *)res->start;
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
89static 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
102static struct platform_driver heartbeat_driver = {
103 .probe = heartbeat_drv_probe,
104 .remove = heartbeat_drv_remove,
105 .driver = {
106 .name = DRV_NAME,
107 },
108};
109
110static 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
116static void __exit heartbeat_exit(void)
117{
118 platform_driver_unregister(&heartbeat_driver);
119}
120module_init(heartbeat_init);
121module_exit(heartbeat_exit);
122
123MODULE_VERSION(DRV_VERSION);
124MODULE_AUTHOR("Paul Mundt");
125MODULE_LICENSE("GPLv2");