126 строки
3.1 KiB
C
126 строки
3.1 KiB
C
/*
|
|
* 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 *)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");
|