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/*
* Generic heartbeat driver for regular LED banks
*
* Copyright (C) 2007 Paul Mundt
*
* Most SH reference boards include a number of individual LEDs that can
* be independently controlled (either via a pre-defined hardware
* function or via the LED class, if desired -- the hardware tends to
* encapsulate some of the same "triggers" that the LED class supports,
* so there's not too much value in it).
*
* Additionally, most of these boards also have a LED bank that we've
* traditionally used for strobing the load average. This use case is
* handled by this driver, rather than giving each LED bit position its
* own struct device.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/io.h>
#define DRV_NAME "heartbeat"
#define DRV_VERSION "0.1.0"
struct heartbeat_data {
void __iomem *base;
unsigned char bit_pos[8];
struct timer_list timer;
};
static void heartbeat_timer(unsigned long data)
{
struct heartbeat_data *hd = (struct heartbeat_data *)data;
static unsigned bit = 0, up = 1;
ctrl_outw(1 << hd->bit_pos[bit], (unsigned long)hd->base);
bit += up;
if ((bit == 0) || (bit == ARRAY_SIZE(hd->bit_pos)-1))
up = -up;
mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) /
((avenrun[0] / 5) + (3 << FSHIFT)))));
}
static int heartbeat_drv_probe(struct platform_device *pdev)
{
struct resource *res;
struct heartbeat_data *hd;
if (unlikely(pdev->num_resources != 1)) {
dev_err(&pdev->dev, "invalid number of resources\n");
return -EINVAL;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(res == NULL)) {
dev_err(&pdev->dev, "invalid resource\n");
return -EINVAL;
}
hd = kmalloc(sizeof(struct heartbeat_data), GFP_KERNEL);
if (unlikely(!hd))
return -ENOMEM;
if (pdev->dev.platform_data) {
memcpy(hd->bit_pos, pdev->dev.platform_data,
ARRAY_SIZE(hd->bit_pos));
} else {
int i;
for (i = 0; i < ARRAY_SIZE(hd->bit_pos); i++)
hd->bit_pos[i] = i;
}
hd->base = (void __iomem *)(unsigned long)res->start;
setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd);
platform_set_drvdata(pdev, hd);
return mod_timer(&hd->timer, jiffies + 1);
}
static int heartbeat_drv_remove(struct platform_device *pdev)
{
struct heartbeat_data *hd = platform_get_drvdata(pdev);
del_timer_sync(&hd->timer);
platform_set_drvdata(pdev, NULL);
kfree(hd);
return 0;
}
static struct platform_driver heartbeat_driver = {
.probe = heartbeat_drv_probe,
.remove = heartbeat_drv_remove,
.driver = {
.name = DRV_NAME,
},
};
static int __init heartbeat_init(void)
{
printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
return platform_driver_register(&heartbeat_driver);
}
static void __exit heartbeat_exit(void)
{
platform_driver_unregister(&heartbeat_driver);
}
module_init(heartbeat_init);
module_exit(heartbeat_exit);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("Paul Mundt");
MODULE_LICENSE("GPLv2");
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