linux/drivers/watchdog/nic7018_wdt.c
Uwe Kleine-König 55b0fb4537 watchdog: nic7018: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230303213716.2123717-19-u.kleine-koenig@pengutronix.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2023-04-22 12:53:47 +02:00

251 lines
5.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 National Instruments Corp.
*/
#include <linux/acpi.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#define LOCK 0xA5
#define UNLOCK 0x5A
#define WDT_CTRL_RESET_EN BIT(7)
#define WDT_RELOAD_PORT_EN BIT(7)
#define WDT_CTRL 1
#define WDT_RELOAD_CTRL 2
#define WDT_PRESET_PRESCALE 4
#define WDT_REG_LOCK 5
#define WDT_COUNT 6
#define WDT_RELOAD_PORT 7
#define WDT_MIN_TIMEOUT 1
#define WDT_MAX_TIMEOUT 464
#define WDT_DEFAULT_TIMEOUT 80
#define WDT_MAX_COUNTER 15
static unsigned int timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. (default="
__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started. (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
struct nic7018_wdt {
u16 io_base;
u32 period;
struct watchdog_device wdd;
};
struct nic7018_config {
u32 period;
u8 divider;
};
static const struct nic7018_config nic7018_configs[] = {
{ 2, 4 },
{ 32, 5 },
};
static inline u32 nic7018_timeout(u32 period, u8 counter)
{
return period * counter - period / 2;
}
static const struct nic7018_config *nic7018_get_config(u32 timeout,
u8 *counter)
{
const struct nic7018_config *config;
u8 count;
if (timeout < 30 && timeout != 16) {
config = &nic7018_configs[0];
count = timeout / 2 + 1;
} else {
config = &nic7018_configs[1];
count = DIV_ROUND_UP(timeout + 16, 32);
if (count > WDT_MAX_COUNTER)
count = WDT_MAX_COUNTER;
}
*counter = count;
return config;
}
static int nic7018_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
const struct nic7018_config *config;
u8 counter;
config = nic7018_get_config(timeout, &counter);
outb(counter << 4 | config->divider,
wdt->io_base + WDT_PRESET_PRESCALE);
wdd->timeout = nic7018_timeout(config->period, counter);
wdt->period = config->period;
return 0;
}
static int nic7018_start(struct watchdog_device *wdd)
{
struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
u8 control;
nic7018_set_timeout(wdd, wdd->timeout);
control = inb(wdt->io_base + WDT_RELOAD_CTRL);
outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL);
outb(1, wdt->io_base + WDT_RELOAD_PORT);
control = inb(wdt->io_base + WDT_CTRL);
outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL);
return 0;
}
static int nic7018_stop(struct watchdog_device *wdd)
{
struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
outb(0, wdt->io_base + WDT_CTRL);
outb(0, wdt->io_base + WDT_RELOAD_CTRL);
outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);
return 0;
}
static int nic7018_ping(struct watchdog_device *wdd)
{
struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
outb(1, wdt->io_base + WDT_RELOAD_PORT);
return 0;
}
static unsigned int nic7018_get_timeleft(struct watchdog_device *wdd)
{
struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
u8 count;
count = inb(wdt->io_base + WDT_COUNT) & 0xF;
if (!count)
return 0;
return nic7018_timeout(wdt->period, count);
}
static const struct watchdog_info nic7018_wdd_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "NIC7018 Watchdog",
};
static const struct watchdog_ops nic7018_wdd_ops = {
.owner = THIS_MODULE,
.start = nic7018_start,
.stop = nic7018_stop,
.ping = nic7018_ping,
.set_timeout = nic7018_set_timeout,
.get_timeleft = nic7018_get_timeleft,
};
static int nic7018_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct watchdog_device *wdd;
struct nic7018_wdt *wdt;
struct resource *io_rc;
int ret;
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
platform_set_drvdata(pdev, wdt);
io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!io_rc) {
dev_err(dev, "missing IO resources\n");
return -EINVAL;
}
if (!devm_request_region(dev, io_rc->start, resource_size(io_rc),
KBUILD_MODNAME)) {
dev_err(dev, "failed to get IO region\n");
return -EBUSY;
}
wdt->io_base = io_rc->start;
wdd = &wdt->wdd;
wdd->info = &nic7018_wdd_info;
wdd->ops = &nic7018_wdd_ops;
wdd->min_timeout = WDT_MIN_TIMEOUT;
wdd->max_timeout = WDT_MAX_TIMEOUT;
wdd->timeout = WDT_DEFAULT_TIMEOUT;
wdd->parent = dev;
watchdog_set_drvdata(wdd, wdt);
watchdog_set_nowayout(wdd, nowayout);
watchdog_init_timeout(wdd, timeout, dev);
/* Unlock WDT register */
outb(UNLOCK, wdt->io_base + WDT_REG_LOCK);
ret = watchdog_register_device(wdd);
if (ret) {
outb(LOCK, wdt->io_base + WDT_REG_LOCK);
return ret;
}
dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
wdt->io_base, timeout, nowayout);
return 0;
}
static void nic7018_remove(struct platform_device *pdev)
{
struct nic7018_wdt *wdt = platform_get_drvdata(pdev);
watchdog_unregister_device(&wdt->wdd);
/* Lock WDT register */
outb(LOCK, wdt->io_base + WDT_REG_LOCK);
}
static const struct acpi_device_id nic7018_device_ids[] = {
{"NIC7018", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, nic7018_device_ids);
static struct platform_driver watchdog_driver = {
.probe = nic7018_probe,
.remove_new = nic7018_remove,
.driver = {
.name = KBUILD_MODNAME,
.acpi_match_table = ACPI_PTR(nic7018_device_ids),
},
};
module_platform_driver(watchdog_driver);
MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog driver");
MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
MODULE_LICENSE("GPL");