linux-stable/drivers/watchdog/sama5d4_wdt.c
Bhumika Goyal b893e344bf 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>
2017-02-24 14:00:23 -08:00

280 lines
6.3 KiB
C

/*
* Driver for Atmel SAMA5D4 Watchdog Timer
*
* Copyright (C) 2015 Atmel Corporation
*
* Licensed under GPLv2.
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/watchdog.h>
#include "at91sam9_wdt.h"
/* minimum and maximum watchdog timeout, in seconds */
#define MIN_WDT_TIMEOUT 1
#define MAX_WDT_TIMEOUT 16
#define WDT_DEFAULT_TIMEOUT MAX_WDT_TIMEOUT
#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0)
struct sama5d4_wdt {
struct watchdog_device wdd;
void __iomem *reg_base;
u32 config;
};
static int wdt_timeout = WDT_DEFAULT_TIMEOUT;
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(wdt_timeout, int, 0);
MODULE_PARM_DESC(wdt_timeout,
"Watchdog timeout in seconds. (default = "
__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
#define wdt_read(wdt, field) \
readl_relaxed((wdt)->reg_base + (field))
#define wdt_write(wtd, field, val) \
writel_relaxed((val), (wdt)->reg_base + (field))
static int sama5d4_wdt_start(struct watchdog_device *wdd)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
u32 reg;
reg = wdt_read(wdt, AT91_WDT_MR);
reg &= ~AT91_WDT_WDDIS;
wdt_write(wdt, AT91_WDT_MR, reg);
return 0;
}
static int sama5d4_wdt_stop(struct watchdog_device *wdd)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
u32 reg;
reg = wdt_read(wdt, AT91_WDT_MR);
reg |= AT91_WDT_WDDIS;
wdt_write(wdt, AT91_WDT_MR, reg);
return 0;
}
static int sama5d4_wdt_ping(struct watchdog_device *wdd)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
return 0;
}
static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
u32 value = WDT_SEC2TICKS(timeout);
u32 reg;
reg = wdt_read(wdt, AT91_WDT_MR);
reg &= ~AT91_WDT_WDV;
reg &= ~AT91_WDT_WDD;
reg |= AT91_WDT_SET_WDV(value);
reg |= AT91_WDT_SET_WDD(value);
wdt_write(wdt, AT91_WDT_MR, reg);
wdd->timeout = timeout;
return 0;
}
static const struct watchdog_info sama5d4_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.identity = "Atmel SAMA5D4 Watchdog",
};
static const struct watchdog_ops sama5d4_wdt_ops = {
.owner = THIS_MODULE,
.start = sama5d4_wdt_start,
.stop = sama5d4_wdt_stop,
.ping = sama5d4_wdt_ping,
.set_timeout = sama5d4_wdt_set_timeout,
};
static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
{
struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
if (wdt_read(wdt, AT91_WDT_SR)) {
pr_crit("Atmel Watchdog Software Reset\n");
emergency_restart();
pr_crit("Reboot didn't succeed\n");
}
return IRQ_HANDLED;
}
static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
{
const char *tmp;
wdt->config = AT91_WDT_WDDIS;
if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
!strcmp(tmp, "software"))
wdt->config |= AT91_WDT_WDFIEN;
else
wdt->config |= AT91_WDT_WDRSTEN;
if (of_property_read_bool(np, "atmel,idle-halt"))
wdt->config |= AT91_WDT_WDIDLEHLT;
if (of_property_read_bool(np, "atmel,dbg-halt"))
wdt->config |= AT91_WDT_WDDBGHLT;
return 0;
}
static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
{
struct watchdog_device *wdd = &wdt->wdd;
u32 value = WDT_SEC2TICKS(wdd->timeout);
u32 reg;
/*
* Because the fields WDV and WDD must not be modified when the WDDIS
* bit is set, so clear the WDDIS bit before writing the WDT_MR.
*/
reg = wdt_read(wdt, AT91_WDT_MR);
reg &= ~AT91_WDT_WDDIS;
wdt_write(wdt, AT91_WDT_MR, reg);
reg = wdt->config;
reg |= AT91_WDT_SET_WDD(value);
reg |= AT91_WDT_SET_WDV(value);
wdt_write(wdt, AT91_WDT_MR, reg);
return 0;
}
static int sama5d4_wdt_probe(struct platform_device *pdev)
{
struct watchdog_device *wdd;
struct sama5d4_wdt *wdt;
struct resource *res;
void __iomem *regs;
u32 irq = 0;
int ret;
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdd = &wdt->wdd;
wdd->timeout = wdt_timeout;
wdd->info = &sama5d4_wdt_info;
wdd->ops = &sama5d4_wdt_ops;
wdd->min_timeout = MIN_WDT_TIMEOUT;
wdd->max_timeout = MAX_WDT_TIMEOUT;
watchdog_set_drvdata(wdd, wdt);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(regs))
return PTR_ERR(regs);
wdt->reg_base = regs;
if (pdev->dev.of_node) {
irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
if (!irq)
dev_warn(&pdev->dev, "failed to get IRQ from DT\n");
ret = of_sama5d4_wdt_init(pdev->dev.of_node, wdt);
if (ret)
return ret;
}
if ((wdt->config & AT91_WDT_WDFIEN) && irq) {
ret = devm_request_irq(&pdev->dev, irq, sama5d4_wdt_irq_handler,
IRQF_SHARED | IRQF_IRQPOLL |
IRQF_NO_SUSPEND, pdev->name, pdev);
if (ret) {
dev_err(&pdev->dev,
"cannot register interrupt handler\n");
return ret;
}
}
ret = watchdog_init_timeout(wdd, wdt_timeout, &pdev->dev);
if (ret) {
dev_err(&pdev->dev, "unable to set timeout value\n");
return ret;
}
ret = sama5d4_wdt_init(wdt);
if (ret)
return ret;
watchdog_set_nowayout(wdd, nowayout);
ret = watchdog_register_device(wdd);
if (ret) {
dev_err(&pdev->dev, "failed to register watchdog device\n");
return ret;
}
platform_set_drvdata(pdev, wdt);
dev_info(&pdev->dev, "initialized (timeout = %d sec, nowayout = %d)\n",
wdt_timeout, nowayout);
return 0;
}
static int sama5d4_wdt_remove(struct platform_device *pdev)
{
struct sama5d4_wdt *wdt = platform_get_drvdata(pdev);
sama5d4_wdt_stop(&wdt->wdd);
watchdog_unregister_device(&wdt->wdd);
return 0;
}
static const struct of_device_id sama5d4_wdt_of_match[] = {
{ .compatible = "atmel,sama5d4-wdt", },
{ }
};
MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
static struct platform_driver sama5d4_wdt_driver = {
.probe = sama5d4_wdt_probe,
.remove = sama5d4_wdt_remove,
.driver = {
.name = "sama5d4_wdt",
.of_match_table = sama5d4_wdt_of_match,
}
};
module_platform_driver(sama5d4_wdt_driver);
MODULE_AUTHOR("Atmel Corporation");
MODULE_DESCRIPTION("Atmel SAMA5D4 Watchdog Timer driver");
MODULE_LICENSE("GPL v2");