linux/drivers/watchdog/ep93xx_wdt.c

148 lines
3.7 KiB
C
Raw Normal View History

/*
* Watchdog driver for Cirrus Logic EP93xx family of devices.
*
* Copyright (c) 2004 Ray Lehtiniemi
* Copyright (c) 2006 Tower Technologies
* Based on ep93xx driver, bits from alim7101_wdt.c
*
* Authors: Ray Lehtiniemi <rayl@mail.com>,
* Alessandro Zummo <a.zummo@towertech.it>
*
* Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
* Convert to a platform device and use the watchdog framework API
*
* 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.
*
* This watchdog fires after 250msec, which is a too short interval
* for us to rely on the user space daemon alone. So we ping the
* wdt each ~200msec and eventually stop doing it if the user space
* daemon dies.
*/
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/io.h>
/* default timeout (secs) */
#define WDT_TIMEOUT 30
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
static unsigned int timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
#define EP93XX_WATCHDOG 0x00
#define EP93XX_WDSTATUS 0x04
struct ep93xx_wdt_priv {
void __iomem *mmio;
struct watchdog_device wdd;
};
static int ep93xx_wdt_start(struct watchdog_device *wdd)
{
struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
writel(0xaaaa, priv->mmio + EP93XX_WATCHDOG);
return 0;
}
static int ep93xx_wdt_stop(struct watchdog_device *wdd)
{
struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
writel(0xaa55, priv->mmio + EP93XX_WATCHDOG);
return 0;
}
static int ep93xx_wdt_ping(struct watchdog_device *wdd)
{
struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
writel(0x5555, priv->mmio + EP93XX_WATCHDOG);
return 0;
}
static const struct watchdog_info ep93xx_wdt_ident = {
.options = WDIOF_CARDRESET |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.identity = "EP93xx Watchdog",
};
watchdog: constify watchdog_ops structures Declare watchdog_ops structures as const as they are only stored in the ops field of a watchdog_device structure. This field is of type const, so watchdog_ops structures having this property can be made const too. Done using Coccinelle: @r disable optional_qualifier@ identifier x; position p; @@ static struct watchdog_ops x@p={...}; @ok@ struct watchdog_device w; identifier r.x; position p; @@ w.ops=&x@p; @bad@ position p != {r.p,ok.p}; identifier r.x; @@ x@p @depends on !bad disable optional_qualifier@ identifier r.x; @@ +const struct watchdog_ops x; File size details before and after patching. First line of every .o file shows the file size before patching and second line shows the size after patching. text data bss dec hex filename 1340 544 0 1884 75c drivers/watchdog/bcm_kona_wdt.o 1436 440 0 1876 754 drivers/watchdog/bcm_kona_wdt.o 1176 544 4 1724 6bc drivers/watchdog/digicolor_wdt.o 1272 440 4 1716 6b4 drivers/watchdog/digicolor_wdt.o 925 580 89 1594 63a drivers/watchdog/ep93xx_wdt.o 1021 476 89 1586 632 drivers/watchdog/ep93xx_wdt.o 4932 288 17 5237 1475 drivers/watchdog/s3c2410_wdt.o 5028 192 17 5237 1475 drivers/watchdog/s3c2410_wdt.o 1977 292 1 2270 8de drivers/watchdog/sama5d4_wdt.o 2073 196 1 2270 8de drivers/watchdog/sama5d4_wdt.o 1375 484 1 1860 744 drivers/watchdog/sirfsoc_wdt.o 1471 380 1 1852 73c drivers/watchdog/sirfsoc_wdt.o Size remains the same for the files drivers/watchdog/diag288_wdt.o drivers/watchdog/asm9260_wdt.o and drivers/watchdog/atlas7_wdt.o The following .o files did not compile: drivers/watchdog/sun4v_wdt.o, drivers/watchdog/sbsa_gwdt.o, drivers/watchdog/rt2880_wdt.o, drivers/watchdog/booke_wdt.o drivers/watchdog/mt7621_wdt.o Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-01-28 07:41:17 +00:00
static const struct watchdog_ops ep93xx_wdt_ops = {
.owner = THIS_MODULE,
.start = ep93xx_wdt_start,
.stop = ep93xx_wdt_stop,
.ping = ep93xx_wdt_ping,
};
static int ep93xx_wdt_probe(struct platform_device *pdev)
{
struct ep93xx_wdt_priv *priv;
struct watchdog_device *wdd;
struct resource *res;
unsigned long val;
int ret;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->mmio = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->mmio))
return PTR_ERR(priv->mmio);
val = readl(priv->mmio + EP93XX_WATCHDOG);
wdd = &priv->wdd;
wdd->bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
wdd->info = &ep93xx_wdt_ident;
wdd->ops = &ep93xx_wdt_ops;
wdd->min_timeout = 1;
wdd->max_hw_heartbeat_ms = 200;
wdd->parent = &pdev->dev;
watchdog_set_nowayout(wdd, nowayout);
wdd->timeout = WDT_TIMEOUT;
watchdog_init_timeout(wdd, timeout, &pdev->dev);
watchdog_set_drvdata(wdd, priv);
ret = devm_watchdog_register_device(&pdev->dev, wdd);
if (ret)
return ret;
dev_info(&pdev->dev, "EP93XX watchdog driver %s\n",
(val & 0x08) ? " (nCS1 disable detected)" : "");
return 0;
}
static struct platform_driver ep93xx_wdt_driver = {
.driver = {
.name = "ep93xx-wdt",
},
.probe = ep93xx_wdt_probe,
};
module_platform_driver(ep93xx_wdt_driver);
MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>");
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_DESCRIPTION("EP93xx Watchdog");
MODULE_LICENSE("GPL");