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// SPDX-License-Identifier: GPL-2.0
/*
* Generic heartbeat driver for regular LED banks
*
* Copyright (C) 2007 - 2010 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.
*/
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/timer.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <asm/heartbeat.h>
#define DRV_NAME "heartbeat"
#define DRV_VERSION "0.1.2"
static unsigned char default_bit_pos[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
static inline void heartbeat_toggle_bit(struct heartbeat_data *hd,
unsigned bit, unsigned int inverted)
{
unsigned int new;
new = (1 << hd->bit_pos[bit]);
if (inverted)
new = ~new;
new &= hd->mask;
switch (hd->regsize) {
case 32:
new |= ioread32(hd->base) & ~hd->mask;
iowrite32(new, hd->base);
break;
case 16:
new |= ioread16(hd->base) & ~hd->mask;
iowrite16(new, hd->base);
break;
default:
new |= ioread8(hd->base) & ~hd->mask;
iowrite8(new, hd->base);
break;
}
}
static void heartbeat_timer(struct timer_list *t)
{
struct heartbeat_data *hd = from_timer(hd, t, timer);
static unsigned bit = 0, up = 1;
heartbeat_toggle_bit(hd, bit, hd->flags & HEARTBEAT_INVERTED);
bit += up;
if ((bit == 0) || (bit == (hd->nr_bits)-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;
int i;
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;
}
if (pdev->dev.platform_data) {
hd = pdev->dev.platform_data;
} else {
hd = kzalloc(sizeof(struct heartbeat_data), GFP_KERNEL);
if (unlikely(!hd))
return -ENOMEM;
}
hd->base = ioremap_nocache(res->start, resource_size(res));
if (unlikely(!hd->base)) {
dev_err(&pdev->dev, "ioremap failed\n");
if (!pdev->dev.platform_data)
kfree(hd);
return -ENXIO;
}
if (!hd->nr_bits) {
hd->bit_pos = default_bit_pos;
hd->nr_bits = ARRAY_SIZE(default_bit_pos);
}
hd->mask = 0;
for (i = 0; i < hd->nr_bits; i++)
hd->mask |= (1 << hd->bit_pos[i]);
if (!hd->regsize) {
switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
case IORESOURCE_MEM_32BIT:
hd->regsize = 32;
break;
case IORESOURCE_MEM_16BIT:
hd->regsize = 16;
break;
case IORESOURCE_MEM_8BIT:
default:
hd->regsize = 8;
break;
}
}
timer_setup(&hd->timer, heartbeat_timer, 0);
platform_set_drvdata(pdev, hd);
return mod_timer(&hd->timer, jiffies + 1);
}
static struct platform_driver heartbeat_driver = {
.probe = heartbeat_drv_probe,
.driver = {
.name = DRV_NAME,
.suppress_bind_attrs = true,
},
};
static int __init heartbeat_init(void)
{
printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
return platform_driver_register(&heartbeat_driver);
}
device_initcall(heartbeat_init);
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