linux-stable/drivers/watchdog/sama5d4_wdt.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for Atmel SAMA5D4 Watchdog Timer
*
* Copyright (C) 2015-2019 Microchip Technology Inc. and its subsidiaries
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.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 mr;
u32 ir;
unsigned long last_ping;
bool need_irq;
bool sam9x60_support;
};
static int wdt_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_enabled (!(wdt->mr & AT91_WDT_WDDIS))
#define wdt_read(wdt, field) \
readl_relaxed((wdt)->reg_base + (field))
/* 4 slow clock periods is 4/32768 = 122.07µs*/
#define WDT_DELAY usecs_to_jiffies(123)
static void wdt_write(struct sama5d4_wdt *wdt, u32 field, u32 val)
{
/*
* WDT_CR and WDT_MR must not be modified within three slow clock
* periods following a restart of the watchdog performed by a write
* access in WDT_CR.
*/
while (time_before(jiffies, wdt->last_ping + WDT_DELAY))
usleep_range(30, 125);
writel_relaxed(val, wdt->reg_base + field);
wdt->last_ping = jiffies;
}
static void wdt_write_nosleep(struct sama5d4_wdt *wdt, u32 field, u32 val)
{
if (time_before(jiffies, wdt->last_ping + WDT_DELAY))
udelay(123);
writel_relaxed(val, wdt->reg_base + field);
wdt->last_ping = jiffies;
}
static int sama5d4_wdt_start(struct watchdog_device *wdd)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
if (wdt->sam9x60_support) {
writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IER);
wdt->mr &= ~AT91_SAM9X60_WDDIS;
} else {
wdt->mr &= ~AT91_WDT_WDDIS;
}
wdt_write(wdt, AT91_WDT_MR, wdt->mr);
return 0;
}
static int sama5d4_wdt_stop(struct watchdog_device *wdd)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
if (wdt->sam9x60_support) {
writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IDR);
wdt->mr |= AT91_SAM9X60_WDDIS;
} else {
wdt->mr |= AT91_WDT_WDDIS;
}
wdt_write(wdt, AT91_WDT_MR, wdt->mr);
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);
if (wdt->sam9x60_support) {
wdt_write(wdt, AT91_SAM9X60_WLR,
AT91_SAM9X60_SET_COUNTER(value));
wdd->timeout = timeout;
return 0;
}
wdt->mr &= ~AT91_WDT_WDV;
wdt->mr |= AT91_WDT_SET_WDV(value);
/*
* WDDIS has to be 0 when updating WDD/WDV. The datasheet states: When
* setting the WDDIS bit, and while it is set, the fields WDV and WDD
* must not be modified.
* If the watchdog is enabled, then the timeout can be updated. Else,
* wait that the user enables it.
*/
if (wdt_enabled)
wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS);
wdd->timeout = timeout;
return 0;
}
static const struct watchdog_info sama5d4_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.identity = "Atmel SAMA5D4 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 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);
u32 reg;
if (wdt->sam9x60_support)
reg = wdt_read(wdt, AT91_SAM9X60_ISR);
else
reg = wdt_read(wdt, AT91_WDT_SR);
if (reg) {
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;
if (wdt->sam9x60_support)
wdt->mr = AT91_SAM9X60_WDDIS;
else
wdt->mr = AT91_WDT_WDDIS;
if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
!strcmp(tmp, "software"))
wdt->need_irq = true;
if (of_property_read_bool(np, "atmel,idle-halt"))
wdt->mr |= AT91_WDT_WDIDLEHLT;
if (of_property_read_bool(np, "atmel,dbg-halt"))
wdt->mr |= AT91_WDT_WDDBGHLT;
return 0;
}
static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
{
u32 reg, val;
val = WDT_SEC2TICKS(WDT_DEFAULT_TIMEOUT);
/*
* When booting and resuming, the bootloader may have changed the
* watchdog configuration.
* If the watchdog is already running, we can safely update it.
* Else, we have to disable it properly.
*/
if (!wdt_enabled) {
reg = wdt_read(wdt, AT91_WDT_MR);
if (wdt->sam9x60_support && (!(reg & AT91_SAM9X60_WDDIS)))
wdt_write_nosleep(wdt, AT91_WDT_MR,
reg | AT91_SAM9X60_WDDIS);
else if (!wdt->sam9x60_support &&
(!(reg & AT91_WDT_WDDIS)))
wdt_write_nosleep(wdt, AT91_WDT_MR,
reg | AT91_WDT_WDDIS);
}
if (wdt->sam9x60_support) {
if (wdt->need_irq)
wdt->ir = AT91_SAM9X60_PERINT;
else
wdt->mr |= AT91_SAM9X60_PERIODRST;
wdt_write(wdt, AT91_SAM9X60_IER, wdt->ir);
wdt_write(wdt, AT91_SAM9X60_WLR, AT91_SAM9X60_SET_COUNTER(val));
} else {
wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
wdt->mr |= AT91_WDT_SET_WDV(val);
if (wdt->need_irq)
wdt->mr |= AT91_WDT_WDFIEN;
else
wdt->mr |= AT91_WDT_WDRSTEN;
}
wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
return 0;
}
static int sama5d4_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct watchdog_device *wdd;
struct sama5d4_wdt *wdt;
void __iomem *regs;
u32 irq = 0;
int ret;
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdd = &wdt->wdd;
wdd->timeout = WDT_DEFAULT_TIMEOUT;
wdd->info = &sama5d4_wdt_info;
wdd->ops = &sama5d4_wdt_ops;
wdd->min_timeout = MIN_WDT_TIMEOUT;
wdd->max_timeout = MAX_WDT_TIMEOUT;
wdt->last_ping = jiffies;
if (of_device_is_compatible(dev->of_node, "microchip,sam9x60-wdt") ||
of_device_is_compatible(dev->of_node, "microchip,sama7g5-wdt"))
wdt->sam9x60_support = true;
watchdog_set_drvdata(wdd, wdt);
watchdog: Convert to use devm_platform_ioremap_resource Use devm_platform_ioremap_resource to reduce source code size, improve readability, and reduce the likelyhood of bugs. The conversion was done automatically with coccinelle using the following semantic patch. @r@ identifier res, pdev; expression a; expression index; expression e; @@ <+... - res = platform_get_resource(pdev, IORESOURCE_MEM, index); - a = devm_ioremap_resource(e, res); + a = devm_platform_ioremap_resource(pdev, index); ...+> @depends on r@ identifier r.res; @@ - struct resource *res; ... when != res @@ identifier res, pdev; expression index; expression a; @@ - struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, index); - a = devm_ioremap_resource(&pdev->dev, res); + a = devm_platform_ioremap_resource(pdev, index); Cc: Joel Stanley <joel@jms.id.au> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Keguang Zhang <keguang.zhang@gmail.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Avi Fishman <avifishman70@gmail.com> Cc: Nancy Yuen <yuenn@google.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Michal Simek <michal.simek@xilinx.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Kukjin Kim <kgene@kernel.org> Cc: Barry Song <baohua@kernel.org> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Maxime Ripard <maxime.ripard@bootlin.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Marc Gonzalez <marc.w.gonzalez@free.fr> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com> Acked-by: Michal Simek <michal.simek@xilinx.com> (cadence/xilinx wdts) Acked-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Patrice Chotard <patrice.chotard@st.com> Acked-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-04-02 19:01:53 +00:00
regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(regs))
return PTR_ERR(regs);
wdt->reg_base = regs;
ret = of_sama5d4_wdt_init(dev->of_node, wdt);
if (ret)
return ret;
if (wdt->need_irq) {
irq = irq_of_parse_and_map(dev->of_node, 0);
if (!irq) {
dev_warn(dev, "failed to get IRQ from DT\n");
wdt->need_irq = false;
}
}
if (wdt->need_irq) {
ret = devm_request_irq(dev, irq, sama5d4_wdt_irq_handler,
IRQF_SHARED | IRQF_IRQPOLL |
IRQF_NO_SUSPEND, pdev->name, pdev);
if (ret) {
dev_err(dev, "cannot register interrupt handler\n");
return ret;
}
}
watchdog_init_timeout(wdd, wdt_timeout, dev);
ret = sama5d4_wdt_init(wdt);
if (ret)
return ret;
watchdog_set_nowayout(wdd, nowayout);
watchdog_stop_on_unregister(wdd);
ret = devm_watchdog_register_device(dev, wdd);
if (ret)
return ret;
platform_set_drvdata(pdev, wdt);
dev_info(dev, "initialized (timeout = %d sec, nowayout = %d)\n",
wdd->timeout, nowayout);
return 0;
}
static const struct of_device_id sama5d4_wdt_of_match[] = {
{
.compatible = "atmel,sama5d4-wdt",
},
{
.compatible = "microchip,sam9x60-wdt",
},
{
.compatible = "microchip,sama7g5-wdt",
},
{ }
};
MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
#ifdef CONFIG_PM_SLEEP
static int sama5d4_wdt_suspend_late(struct device *dev)
{
struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
if (watchdog_active(&wdt->wdd))
sama5d4_wdt_stop(&wdt->wdd);
return 0;
}
static int sama5d4_wdt_resume_early(struct device *dev)
{
struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
/*
* FIXME: writing MR also pings the watchdog which may not be desired.
* This should only be done when the registers are lost on suspend but
* there is no way to get this information right now.
*/
sama5d4_wdt_init(wdt);
if (watchdog_active(&wdt->wdd))
sama5d4_wdt_start(&wdt->wdd);
return 0;
}
#endif
static const struct dev_pm_ops sama5d4_wdt_pm_ops = {
SET_LATE_SYSTEM_SLEEP_PM_OPS(sama5d4_wdt_suspend_late,
sama5d4_wdt_resume_early)
};
static struct platform_driver sama5d4_wdt_driver = {
.probe = sama5d4_wdt_probe,
.driver = {
.name = "sama5d4_wdt",
.pm = &sama5d4_wdt_pm_ops,
.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");