linux/drivers/watchdog/aspeed_wdt.c
Guenter Roeck 7db1634d62 watchdog: aspeed_wdt: Convert to use device managed functions
Use device managed functions to simplify error handling, reduce
source code size, improve readability, and reduce the likelyhood of bugs.

The conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts used
to generate this commit log are available at
https://github.com/groeck/coccinelle-patches

- Drop assignments to otherwise unused variables
- Drop remove function
- Drop platform_set_drvdata()
- Use devm_watchdog_register_driver() to register watchdog device

Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24 14:00:23 -08:00

201 lines
4.8 KiB
C

/*
* Copyright 2016 IBM Corporation
*
* Joel Stanley <joel@jms.id.au>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
struct aspeed_wdt {
struct watchdog_device wdd;
void __iomem *base;
u32 ctrl;
};
static const struct of_device_id aspeed_wdt_of_table[] = {
{ .compatible = "aspeed,ast2400-wdt" },
{ .compatible = "aspeed,ast2500-wdt" },
{ },
};
MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
#define WDT_STATUS 0x00
#define WDT_RELOAD_VALUE 0x04
#define WDT_RESTART 0x08
#define WDT_CTRL 0x0C
#define WDT_CTRL_RESET_MODE_SOC (0x00 << 5)
#define WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5)
#define WDT_CTRL_1MHZ_CLK BIT(4)
#define WDT_CTRL_WDT_EXT BIT(3)
#define WDT_CTRL_WDT_INTR BIT(2)
#define WDT_CTRL_RESET_SYSTEM BIT(1)
#define WDT_CTRL_ENABLE BIT(0)
#define WDT_RESTART_MAGIC 0x4755
/* 32 bits at 1MHz, in milliseconds */
#define WDT_MAX_TIMEOUT_MS 4294967
#define WDT_DEFAULT_TIMEOUT 30
#define WDT_RATE_1MHZ 1000000
static struct aspeed_wdt *to_aspeed_wdt(struct watchdog_device *wdd)
{
return container_of(wdd, struct aspeed_wdt, wdd);
}
static void aspeed_wdt_enable(struct aspeed_wdt *wdt, int count)
{
wdt->ctrl |= WDT_CTRL_ENABLE;
writel(0, wdt->base + WDT_CTRL);
writel(count, wdt->base + WDT_RELOAD_VALUE);
writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART);
writel(wdt->ctrl, wdt->base + WDT_CTRL);
}
static int aspeed_wdt_start(struct watchdog_device *wdd)
{
struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
aspeed_wdt_enable(wdt, wdd->timeout * WDT_RATE_1MHZ);
return 0;
}
static int aspeed_wdt_stop(struct watchdog_device *wdd)
{
struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
wdt->ctrl &= ~WDT_CTRL_ENABLE;
writel(wdt->ctrl, wdt->base + WDT_CTRL);
return 0;
}
static int aspeed_wdt_ping(struct watchdog_device *wdd)
{
struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART);
return 0;
}
static int aspeed_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
u32 actual;
wdd->timeout = timeout;
actual = min(timeout, wdd->max_hw_heartbeat_ms * 1000);
writel(actual * WDT_RATE_1MHZ, wdt->base + WDT_RELOAD_VALUE);
writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART);
return 0;
}
static int aspeed_wdt_restart(struct watchdog_device *wdd,
unsigned long action, void *data)
{
struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000);
mdelay(1000);
return 0;
}
static const struct watchdog_ops aspeed_wdt_ops = {
.start = aspeed_wdt_start,
.stop = aspeed_wdt_stop,
.ping = aspeed_wdt_ping,
.set_timeout = aspeed_wdt_set_timeout,
.restart = aspeed_wdt_restart,
.owner = THIS_MODULE,
};
static const struct watchdog_info aspeed_wdt_info = {
.options = WDIOF_KEEPALIVEPING
| WDIOF_MAGICCLOSE
| WDIOF_SETTIMEOUT,
.identity = KBUILD_MODNAME,
};
static int aspeed_wdt_probe(struct platform_device *pdev)
{
struct aspeed_wdt *wdt;
struct resource *res;
int ret;
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
wdt->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(wdt->base))
return PTR_ERR(wdt->base);
/*
* The ast2400 wdt can run at PCLK, or 1MHz. The ast2500 only
* runs at 1MHz. We chose to always run at 1MHz, as there's no
* good reason to have a faster watchdog counter.
*/
wdt->wdd.info = &aspeed_wdt_info;
wdt->wdd.ops = &aspeed_wdt_ops;
wdt->wdd.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT_MS;
wdt->wdd.parent = &pdev->dev;
wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT;
watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev);
/*
* Control reset on a per-device basis to ensure the
* host is not affected by a BMC reboot, so only reset
* the SOC and not the full chip
*/
wdt->ctrl = WDT_CTRL_RESET_MODE_SOC |
WDT_CTRL_1MHZ_CLK |
WDT_CTRL_RESET_SYSTEM;
if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE) {
aspeed_wdt_start(&wdt->wdd);
set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
}
ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdd);
if (ret) {
dev_err(&pdev->dev, "failed to register\n");
return ret;
}
return 0;
}
static struct platform_driver aspeed_watchdog_driver = {
.probe = aspeed_wdt_probe,
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = of_match_ptr(aspeed_wdt_of_table),
},
};
module_platform_driver(aspeed_watchdog_driver);
MODULE_DESCRIPTION("Aspeed Watchdog Driver");
MODULE_LICENSE("GPL");