2 * Generic heartbeat driver for regular LED banks
4 * Copyright (C) 2007 - 2010 Paul Mundt
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).
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
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
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>
27 #include <asm/heartbeat.h>
29 #define DRV_NAME "heartbeat"
30 #define DRV_VERSION "0.1.2"
32 static unsigned char default_bit_pos[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
34 static inline void heartbeat_toggle_bit(struct heartbeat_data *hd,
35 unsigned bit, unsigned int inverted)
39 new = (1 << hd->bit_pos[bit]);
45 switch (hd->regsize) {
47 new |= ioread32(hd->base) & ~hd->mask;
48 iowrite32(new, hd->base);
51 new |= ioread16(hd->base) & ~hd->mask;
52 iowrite16(new, hd->base);
55 new |= ioread8(hd->base) & ~hd->mask;
56 iowrite8(new, hd->base);
61 static void heartbeat_timer(unsigned long data)
63 struct heartbeat_data *hd = (struct heartbeat_data *)data;
64 static unsigned bit = 0, up = 1;
66 heartbeat_toggle_bit(hd, bit, hd->flags & HEARTBEAT_INVERTED);
69 if ((bit == 0) || (bit == (hd->nr_bits)-1))
72 mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) /
73 ((avenrun[0] / 5) + (3 << FSHIFT)))));
76 static int heartbeat_drv_probe(struct platform_device *pdev)
79 struct heartbeat_data *hd;
82 if (unlikely(pdev->num_resources != 1)) {
83 dev_err(&pdev->dev, "invalid number of resources\n");
87 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
88 if (unlikely(res == NULL)) {
89 dev_err(&pdev->dev, "invalid resource\n");
93 if (pdev->dev.platform_data) {
94 hd = pdev->dev.platform_data;
96 hd = kzalloc(sizeof(struct heartbeat_data), GFP_KERNEL);
101 hd->base = ioremap_nocache(res->start, resource_size(res));
102 if (unlikely(!hd->base)) {
103 dev_err(&pdev->dev, "ioremap failed\n");
105 if (!pdev->dev.platform_data)
112 hd->bit_pos = default_bit_pos;
113 hd->nr_bits = ARRAY_SIZE(default_bit_pos);
117 for (i = 0; i < hd->nr_bits; i++)
118 hd->mask |= (1 << hd->bit_pos[i]);
121 switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
122 case IORESOURCE_MEM_32BIT:
125 case IORESOURCE_MEM_16BIT:
128 case IORESOURCE_MEM_8BIT:
135 setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd);
136 platform_set_drvdata(pdev, hd);
138 return mod_timer(&hd->timer, jiffies + 1);
141 static int heartbeat_drv_remove(struct platform_device *pdev)
143 struct heartbeat_data *hd = platform_get_drvdata(pdev);
145 del_timer_sync(&hd->timer);
148 platform_set_drvdata(pdev, NULL);
150 if (!pdev->dev.platform_data)
156 static struct platform_driver heartbeat_driver = {
157 .probe = heartbeat_drv_probe,
158 .remove = heartbeat_drv_remove,
164 static int __init heartbeat_init(void)
166 printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
167 return platform_driver_register(&heartbeat_driver);
170 static void __exit heartbeat_exit(void)
172 platform_driver_unregister(&heartbeat_driver);
174 module_init(heartbeat_init);
175 module_exit(heartbeat_exit);
177 MODULE_VERSION(DRV_VERSION);
178 MODULE_AUTHOR("Paul Mundt");
179 MODULE_LICENSE("GPL v2");