linux/drivers/watchdog/mt7621_wdt.c

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/*
* Ralink MT7621/MT7628 built-in hardware watchdog timer
*
* Copyright (C) 2014 John Crispin <john@phrozen.org>
*
* This driver was based on: drivers/watchdog/rt2880_wdt.c
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/clk.h>
#include <linux/reset.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/watchdog.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <asm/mach-ralink/ralink_regs.h>
#define SYSC_RSTSTAT 0x38
#define WDT_RST_CAUSE BIT(1)
#define RALINK_WDT_TIMEOUT 30
#define TIMER_REG_TMRSTAT 0x00
#define TIMER_REG_TMR1LOAD 0x24
#define TIMER_REG_TMR1CTL 0x20
#define TMR1CTL_ENABLE BIT(7)
#define TMR1CTL_RESTART BIT(9)
#define TMR1CTL_PRESCALE_SHIFT 16
static void __iomem *mt7621_wdt_base;
static struct reset_control *mt7621_wdt_reset;
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) ")");
static inline void rt_wdt_w32(unsigned reg, u32 val)
{
iowrite32(val, mt7621_wdt_base + reg);
}
static inline u32 rt_wdt_r32(unsigned reg)
{
return ioread32(mt7621_wdt_base + reg);
}
static int mt7621_wdt_ping(struct watchdog_device *w)
{
rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART);
return 0;
}
static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
{
w->timeout = t;
rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000);
mt7621_wdt_ping(w);
return 0;
}
static int mt7621_wdt_start(struct watchdog_device *w)
{
u32 t;
/* set the prescaler to 1ms == 1000us */
rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT);
mt7621_wdt_set_timeout(w, w->timeout);
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
t |= TMR1CTL_ENABLE;
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
return 0;
}
static int mt7621_wdt_stop(struct watchdog_device *w)
{
u32 t;
mt7621_wdt_ping(w);
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
t &= ~TMR1CTL_ENABLE;
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
return 0;
}
static int mt7621_wdt_bootcause(void)
{
if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
return WDIOF_CARDRESET;
return 0;
}
static const struct watchdog_info mt7621_wdt_info = {
.identity = "Mediatek Watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
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 mt7621_wdt_ops = {
.owner = THIS_MODULE,
.start = mt7621_wdt_start,
.stop = mt7621_wdt_stop,
.ping = mt7621_wdt_ping,
.set_timeout = mt7621_wdt_set_timeout,
};
static struct watchdog_device mt7621_wdt_dev = {
.info = &mt7621_wdt_info,
.ops = &mt7621_wdt_ops,
.min_timeout = 1,
.max_timeout = 0xfffful / 1000,
};
static int mt7621_wdt_probe(struct platform_device *pdev)
{
struct resource *res;
int ret;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(mt7621_wdt_base))
return PTR_ERR(mt7621_wdt_base);
mt7621_wdt_reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (!IS_ERR(mt7621_wdt_reset))
reset_control_deassert(mt7621_wdt_reset);
mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause();
watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout,
&pdev->dev);
watchdog_set_nowayout(&mt7621_wdt_dev, nowayout);
ret = watchdog_register_device(&mt7621_wdt_dev);
return 0;
}
static int mt7621_wdt_remove(struct platform_device *pdev)
{
watchdog_unregister_device(&mt7621_wdt_dev);
return 0;
}
static void mt7621_wdt_shutdown(struct platform_device *pdev)
{
mt7621_wdt_stop(&mt7621_wdt_dev);
}
static const struct of_device_id mt7621_wdt_match[] = {
{ .compatible = "mediatek,mt7621-wdt" },
{},
};
MODULE_DEVICE_TABLE(of, mt7621_wdt_match);
static struct platform_driver mt7621_wdt_driver = {
.probe = mt7621_wdt_probe,
.remove = mt7621_wdt_remove,
.shutdown = mt7621_wdt_shutdown,
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = mt7621_wdt_match,
},
};
module_platform_driver(mt7621_wdt_driver);
MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver");
MODULE_AUTHOR("John Crispin <john@phrozen.org");
MODULE_LICENSE("GPL v2");