https://github.com/torvalds/linux
Tip revision: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c authored by Linus Torvalds on 18 July 2021, 21:13:49 UTC
Linux 5.14-rc2
Linux 5.14-rc2
Tip revision: 2734d6c
tqmx86_wdt.c
// SPDX-License-Identifier: GPL-2.0+
/*
* Watchdog driver for TQMx86 PLD.
*
* The watchdog supports power of 2 timeouts from 1 to 4096sec.
* Once started, it cannot be stopped.
*
* Based on the vendor code written by Vadim V.Vlasov
* <vvlasov@dev.rtsoft.ru>
*/
#include <linux/io.h>
#include <linux/log2.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/timer.h>
#include <linux/watchdog.h>
/* default timeout (secs) */
#define WDT_TIMEOUT 32
static unsigned int timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. (1<=timeout<=4096, default="
__MODULE_STRING(WDT_TIMEOUT) ")");
struct tqmx86_wdt {
struct watchdog_device wdd;
void __iomem *io_base;
};
#define TQMX86_WDCFG 0x00 /* Watchdog Configuration Register */
#define TQMX86_WDCS 0x01 /* Watchdog Config/Status Register */
static int tqmx86_wdt_start(struct watchdog_device *wdd)
{
struct tqmx86_wdt *priv = watchdog_get_drvdata(wdd);
iowrite8(0x81, priv->io_base + TQMX86_WDCS);
return 0;
}
static int tqmx86_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
{
struct tqmx86_wdt *priv = watchdog_get_drvdata(wdd);
u8 val;
t = roundup_pow_of_two(t);
val = ilog2(t) | 0x90;
val += 3; /* values 0,1,2 correspond to 0.125,0.25,0.5s timeouts */
iowrite8(val, priv->io_base + TQMX86_WDCFG);
wdd->timeout = t;
return 0;
}
static const struct watchdog_info tqmx86_wdt_info = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING,
.identity = "TQMx86 Watchdog",
};
static struct watchdog_ops tqmx86_wdt_ops = {
.owner = THIS_MODULE,
.start = tqmx86_wdt_start,
.set_timeout = tqmx86_wdt_set_timeout,
};
static int tqmx86_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct tqmx86_wdt *priv;
struct resource *res;
int err;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!res)
return -ENODEV;
priv->io_base = devm_ioport_map(dev, res->start, resource_size(res));
if (!priv->io_base)
return -ENOMEM;
watchdog_set_drvdata(&priv->wdd, priv);
priv->wdd.parent = dev;
priv->wdd.info = &tqmx86_wdt_info;
priv->wdd.ops = &tqmx86_wdt_ops;
priv->wdd.min_timeout = 1;
priv->wdd.max_timeout = 4096;
priv->wdd.max_hw_heartbeat_ms = 4096*1000;
priv->wdd.timeout = WDT_TIMEOUT;
watchdog_init_timeout(&priv->wdd, timeout, dev);
watchdog_set_nowayout(&priv->wdd, WATCHDOG_NOWAYOUT);
tqmx86_wdt_set_timeout(&priv->wdd, priv->wdd.timeout);
err = devm_watchdog_register_device(dev, &priv->wdd);
if (err)
return err;
dev_info(dev, "TQMx86 watchdog\n");
return 0;
}
static struct platform_driver tqmx86_wdt_driver = {
.driver = {
.name = "tqmx86-wdt",
},
.probe = tqmx86_wdt_probe,
};
module_platform_driver(tqmx86_wdt_driver);
MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
MODULE_DESCRIPTION("TQMx86 Watchdog");
MODULE_ALIAS("platform:tqmx86-wdt");
MODULE_LICENSE("GPL");