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/*
* Watchdog driver for Technologic Systems TS-72xx based SBCs
* (TS-7200, TS-7250 and TS-7260). These boards have external
* glue logic CPLD chip, which includes programmable watchdog
* timer.
*
* Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi>
*
* This driver is based on ep93xx_wdt and wm831x_wdt drivers.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/io.h>
#define TS72XX_WDT_DEFAULT_TIMEOUT 30
static int timeout;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
/* priv->control_reg */
#define TS72XX_WDT_CTRL_DISABLE 0x00
#define TS72XX_WDT_CTRL_250MS 0x01
#define TS72XX_WDT_CTRL_500MS 0x02
#define TS72XX_WDT_CTRL_1SEC 0x03
#define TS72XX_WDT_CTRL_RESERVED 0x04
#define TS72XX_WDT_CTRL_2SEC 0x05
#define TS72XX_WDT_CTRL_4SEC 0x06
#define TS72XX_WDT_CTRL_8SEC 0x07
/* priv->feed_reg */
#define TS72XX_WDT_FEED_VAL 0x05
struct ts72xx_wdt_priv {
void __iomem *control_reg;
void __iomem *feed_reg;
struct watchdog_device wdd;
unsigned char regval;
};
static int ts72xx_wdt_start(struct watchdog_device *wdd)
{
struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
writeb(priv->regval, priv->control_reg);
return 0;
}
static int ts72xx_wdt_stop(struct watchdog_device *wdd)
{
struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg);
return 0;
}
static int ts72xx_wdt_ping(struct watchdog_device *wdd)
{
struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
return 0;
}
static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
{
struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
if (to == 1) {
priv->regval = TS72XX_WDT_CTRL_1SEC;
} else if (to == 2) {
priv->regval = TS72XX_WDT_CTRL_2SEC;
} else if (to <= 4) {
priv->regval = TS72XX_WDT_CTRL_4SEC;
to = 4;
} else {
priv->regval = TS72XX_WDT_CTRL_8SEC;
if (to <= 8)
to = 8;
}
wdd->timeout = to;
if (watchdog_active(wdd)) {
ts72xx_wdt_stop(wdd);
ts72xx_wdt_start(wdd);
}
return 0;
}
static const struct watchdog_info ts72xx_wdt_ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "TS-72XX WDT",
};
static const struct watchdog_ops ts72xx_wdt_ops = {
.owner = THIS_MODULE,
.start = ts72xx_wdt_start,
.stop = ts72xx_wdt_stop,
.ping = ts72xx_wdt_ping,
.set_timeout = ts72xx_wdt_settimeout,
};
static int ts72xx_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ts72xx_wdt_priv *priv;
struct watchdog_device *wdd;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->control_reg = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->control_reg))
return PTR_ERR(priv->control_reg);
priv->feed_reg = devm_platform_ioremap_resource(pdev, 1);
if (IS_ERR(priv->feed_reg))
return PTR_ERR(priv->feed_reg);
wdd = &priv->wdd;
wdd->info = &ts72xx_wdt_ident;
wdd->ops = &ts72xx_wdt_ops;
wdd->min_timeout = 1;
wdd->max_hw_heartbeat_ms = 8000;
wdd->parent = dev;
watchdog_set_nowayout(wdd, nowayout);
wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT;
watchdog_init_timeout(wdd, timeout, dev);
watchdog_set_drvdata(wdd, priv);
ret = devm_watchdog_register_device(dev, wdd);
if (ret)
return ret;
dev_info(dev, "TS-72xx Watchdog driver\n");
return 0;
}
static struct platform_driver ts72xx_wdt_driver = {
.probe = ts72xx_wdt_probe,
.driver = {
.name = "ts72xx-wdt",
},
};
module_platform_driver(ts72xx_wdt_driver);
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
MODULE_DESCRIPTION("TS-72xx SBC Watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ts72xx-wdt");
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