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-rw-r--r--arch/sh/drivers/heartbeat.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/sh/drivers/heartbeat.c b/arch/sh/drivers/heartbeat.c
new file mode 100644
index 000000000000..bc59cb6cd78b
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+++ b/arch/sh/drivers/heartbeat.c
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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
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);
43 if (up)
44 if (bit == (ARRAY_SIZE(hd->bit_pos) - 1)) {
45 bit--;
46 up = 0;
47 } else
48 bit++;
49 else if (bit == 0)
50 up = 1;
51 else
52 bit--;
53
54 mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) /
55 ((avenrun[0] / 5) + (3 << FSHIFT)))));
56}
57
58static int heartbeat_drv_probe(struct platform_device *pdev)
59{
60 struct resource *res;
61 struct heartbeat_data *hd;
62
63 if (unlikely(pdev->num_resources != 1)) {
64 dev_err(&pdev->dev, "invalid number of resources\n");
65 return -EINVAL;
66 }
67
68 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
69 if (unlikely(res == NULL)) {
70 dev_err(&pdev->dev, "invalid resource\n");
71 return -EINVAL;
72 }
73
74 hd = kmalloc(sizeof(struct heartbeat_data), GFP_KERNEL);
75 if (unlikely(!hd))
76 return -ENOMEM;
77
78 if (pdev->dev.platform_data) {
79 memcpy(hd->bit_pos, pdev->dev.platform_data,
80 ARRAY_SIZE(hd->bit_pos));
81 } else {
82 int i;
83
84 for (i = 0; i < ARRAY_SIZE(hd->bit_pos); i++)
85 hd->bit_pos[i] = i;
86 }
87
88 hd->base = (void __iomem *)res->start;
89
90 setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd);
91 platform_set_drvdata(pdev, hd);
92
93 return mod_timer(&hd->timer, jiffies + 1);
94}
95
96static int heartbeat_drv_remove(struct platform_device *pdev)
97{
98 struct heartbeat_data *hd = platform_get_drvdata(pdev);
99
100 del_timer_sync(&hd->timer);
101
102 platform_set_drvdata(pdev, NULL);
103
104 kfree(hd);
105
106 return 0;
107}
108
109static struct platform_driver heartbeat_driver = {
110 .probe = heartbeat_drv_probe,
111 .remove = heartbeat_drv_remove,
112 .driver = {
113 .name = DRV_NAME,
114 },
115};
116
117static int __init heartbeat_init(void)
118{
119 printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
120 return platform_driver_register(&heartbeat_driver);
121}
122
123static void __exit heartbeat_exit(void)
124{
125 platform_driver_unregister(&heartbeat_driver);
126}
127module_init(heartbeat_init);
128module_exit(heartbeat_exit);
129
130MODULE_VERSION(DRV_VERSION);
131MODULE_AUTHOR("Paul Mundt");
132MODULE_LICENSE("GPLv2");