* Re: [PATCH 1/4] watchdog: at91sam9_wdt: better watchdog support
@ 2013-10-03 17:31 ` Guenter Roeck
0 siblings, 0 replies; 19+ messages in thread
From: Guenter Roeck @ 2013-10-03 17:31 UTC (permalink / raw)
To: Boris BREZILLON
Cc: Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
Ian Campbell, Rob Landley, Russell King, Wim Van Sebroeck,
Fabio Porcedda, Nicolas Ferre, Guenter Roeck, Yang Wenyou,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-doc-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-watchdog-u79uwXL29TY76Z2rM5mHXA
On Thu, Oct 03, 2013 at 02:19:18PM +0200, Boris BREZILLON wrote:
> The at91sam9 watchdog timer can only be configured once, and the current
> implementation tries to configure it in a static way:
> - 2 seconds timeout
> - wdt restart every 500ms
>
> If the timer has already been configured with different values, it returns an
> error and do not create any watchdog device.
>
> This is not critical if the watchdog is disabled, but if it has been enabled with
> different timeout values it will lead to a SoC reset.
>
> This patch series tries to address this issue by adapting the heartbeat value
> according the WDT timer config:
> - it first tries to configure the timer as requested.
> - if it fails it fallbacks to the current config, adapting its heartbeat timer
> to the needs
>
> This patch series also move to a dynamically allocated at91wdt device instead
> of the static instance.
>
> It adds a new at91 wdt type: software. This new type make use of the at91 wdt
> interrupt to trigger a software reboot.
>
> Finally it adds several properties to the device tree bindings.
>
> Signed-off-by: Boris BREZILLON <b.brezillon-ZNYIgs0QAGpBDgjK7y7TUQ@public.gmane.org>
Hi Boris,
deeper dive this time ...
> ---
> drivers/watchdog/at91sam9_wdt.c | 300 ++++++++++++++++++++++++++++-----------
> 1 file changed, 217 insertions(+), 83 deletions(-)
>
> diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
> index be37dde..8f44528 100644
> --- a/drivers/watchdog/at91sam9_wdt.c
> +++ b/drivers/watchdog/at91sam9_wdt.c
> @@ -19,11 +19,13 @@
>
> #include <linux/errno.h>
> #include <linux/init.h>
> +#include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> #include <linux/platform_device.h>
> +#include <linux/reboot.h>
> #include <linux/types.h>
> #include <linux/watchdog.h>
> #include <linux/jiffies.h>
> @@ -31,22 +33,33 @@
> #include <linux/bitops.h>
> #include <linux/uaccess.h>
> #include <linux/of.h>
> +#include <linux/of_irq.h>
>
> #include "at91sam9_wdt.h"
>
> #define DRV_NAME "AT91SAM9 Watchdog"
>
> -#define wdt_read(field) \
> - __raw_readl(at91wdt_private.base + field)
> -#define wdt_write(field, val) \
> - __raw_writel((val), at91wdt_private.base + field)
> +#define wdt_read(wdt, field) \
> + __raw_readl((wdt)->base + (field))
> +#define wdt_write(wtd, field, val) \
> + __raw_writel((val), (wdt)->base + (field))
>
> /* AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
> * use this to convert a watchdog
> * value from/to milliseconds.
> */
> -#define ms_to_ticks(t) (((t << 8) / 1000) - 1)
> -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
> +#define ticks_to_hz_rounddown(t) ((((t) + 1) * HZ) >> 8)
> +#define ticks_to_hz_roundup(t) (((((t) + 1) * HZ) + 255) >> 8)
> +#define ticks_to_secs(t) (((t) + 1) >> 8)
> +#define secs_to_ticks(s) (((s) << 8) - 1)
> +
> +#define WDT_MR_RESET 0x3FFF2FFF
> +
> +/* Watchdog max counter value in ticks */
> +#define WDT_COUNTER_MAX_TICKS 0xFFF
> +
> +/* Watchdog max delta/value in secs */
> +#define WDT_COUNTER_MAX_SECS ticks_to_secs(WDT_COUNTER_MAX_TICKS)
>
> /* Hardware timeout in seconds */
> #define WDT_HW_TIMEOUT 2
> @@ -66,23 +79,40 @@ module_param(nowayout, bool, 0);
> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
> "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>
> -static struct watchdog_device at91_wdt_dev;
> -static void at91_ping(unsigned long data);
> -
> -static struct {
> +#define to_wdt(wdd) container_of(wdd, struct at91wdt, wdd)
> +struct at91wdt {
> + struct watchdog_device wdd;
> void __iomem *base;
> unsigned long next_heartbeat; /* the next_heartbeat for the timer */
> struct timer_list timer; /* The timer that pings the watchdog */
> -} at91wdt_private;
> + u32 mr;
> + u32 mr_mask;
> + unsigned long heartbeat; /* WDT heartbeat in jiffies */
> + bool nowayout;
> + unsigned int irq;
> +};
>
> /* ......................................................................... */
>
> +static irqreturn_t wdt_interrupt(int irq, void *dev_id)
> +{
> + struct at91wdt *wdt = (struct at91wdt *)dev_id;
> +
> + if (wdt_read(wdt, AT91_WDT_SR)) {
> + pr_crit("at91sam9 WDT software reset\n");
> + emergency_restart();
> + pr_crit("Reboot didn't ?????\n");
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> /*
> * Reload the watchdog timer. (ie, pat the watchdog)
> */
> -static inline void at91_wdt_reset(void)
> +static inline void at91_wdt_reset(struct at91wdt *wdt)
> {
> - wdt_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
> + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
> }
>
> /*
> @@ -90,26 +120,20 @@ static inline void at91_wdt_reset(void)
> */
> static void at91_ping(unsigned long data)
> {
> - if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
> - (!watchdog_active(&at91_wdt_dev))) {
> - at91_wdt_reset();
> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
> + struct at91wdt *wdt = (struct at91wdt *)data;
> + if (time_before(jiffies, wdt->next_heartbeat) ||
> + !watchdog_active(&wdt->wdd)) {
> + at91_wdt_reset(wdt);
> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
> } else
> pr_crit("I will reset your machine !\n");
> }
>
> static int at91_wdt_ping(struct watchdog_device *wdd)
> {
> + struct at91wdt *wdt = to_wdt(wdd);
> /* calculate when the next userspace timeout will be */
> - at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
> - return 0;
> -}
> -
> -static int at91_wdt_start(struct watchdog_device *wdd)
> -{
> - /* calculate the next userspace timeout and modify the timer */
> - at91_wdt_ping(wdd);
> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
> + wdt->next_heartbeat = jiffies + wdd->timeout * HZ;
> return 0;
> }
>
> @@ -125,36 +149,84 @@ static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int new_ti
at91_wdt_set_timeout only sets the new timeout but does not update
next_heartbeat. That is ok if the timeout decreases, but if it is
increased (say, from 1 second to 1 minute) it might result in a missed
ping as userspace will subsequently believe that the new (larger)
timeout was accepted by the driver. So I think you should also call
at91_wdt_ping here or set wdt->next_heartbeat directly.
> return 0;
> }
>
> -/*
> - * Set the watchdog time interval in 1/256Hz (write-once)
> - * Counter is 12 bit.
> - */
> -static int at91_wdt_settimeout(unsigned int timeout)
> +static int at91_wdt_init(struct platform_device *pdev, struct at91wdt *wdt)
> {
> - unsigned int reg;
> - unsigned int mr;
> -
> - /* Check if disabled */
> - mr = wdt_read(AT91_WDT_MR);
> - if (mr & AT91_WDT_WDDIS) {
> - pr_err("sorry, watchdog is disabled\n");
> - return -EIO;
> + u32 tmp;
> + u32 delta;
> + u32 value;
> + int err;
> + u32 mask = wdt->mr_mask;
> + unsigned long min_heartbeat = 1;
> +
> + tmp = wdt_read(wdt, AT91_WDT_MR);
> + if ((tmp & mask) != (wdt->mr & mask)) {
> + if (tmp == WDT_MR_RESET) {
> + wdt_write(wdt, AT91_WDT_MR, wdt->mr);
> + tmp = wdt_read(wdt, AT91_WDT_MR);
> + }
> }
>
> - /*
> - * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
> - *
> - * Since WDV is a 12-bit counter, the maximum period is
> - * 4096 / 256 = 16 seconds.
> - */
> - reg = AT91_WDT_WDRSTEN /* causes watchdog reset */
> - /* | AT91_WDT_WDRPROC causes processor reset only */
> - | AT91_WDT_WDDBGHLT /* disabled in debug mode */
> - | AT91_WDT_WDD /* restart at any time */
> - | (timeout & AT91_WDT_WDV); /* timer value */
> - wdt_write(AT91_WDT_MR, reg);
> + if (tmp & AT91_WDT_WDDIS) {
> + if (wdt->mr & AT91_WDT_WDDIS)
> + return 0;
> + dev_err(wdt->wdd.parent, "watchdog is disabled\n");
Took me a while to get why you use "wdt->wdd.parent" :).
I would just have passed the 'dev' argument. Your call, though.
> + return -EINVAL;
> + }
> +
> + value = tmp & AT91_WDT_WDV;
> + delta = (tmp & AT91_WDT_WDD) >> 16;
> +
> + if (delta < value)
> + min_heartbeat = ticks_to_hz_roundup(value - delta);
> +
> + wdt->heartbeat = ticks_to_hz_rounddown(value);
> + if (!wdt->heartbeat) {
> + dev_err(wdt->wdd.parent,
> + "heartbeat is too small for the system to handle it correctly\n");
> + return -EINVAL;
> + }
> +
> + if (wdt->heartbeat < min_heartbeat + 3) {
> + wdt->heartbeat = min_heartbeat;
> + dev_warn(wdt->wdd.parent,
> + "min heartbeat and max heartbeat might be too close for the system to handle it correctly\n");
> + if (wdt->heartbeat < 4)
> + dev_warn(wdt->wdd.parent,
> + "heartbeat might be too small for the system to handle it correctly\n");
> + } else
> + wdt->heartbeat -= 4;
That means heartbeat can be 0, correct (if min_heartbeat == 1) ?
Will that work ?
> +
> + if ((tmp & AT91_WDT_WDFIEN) && wdt->irq) {
> + err = request_irq(wdt->irq, wdt_interrupt,
> + IRQF_SHARED | IRQF_IRQPOLL,
> + pdev->name, wdt);
> + if (err)
> + return err;
> + }
> +
> + if ((tmp & wdt->mr_mask) != (wdt->mr & wdt->mr_mask))
> + dev_warn(wdt->wdd.parent,
> + "watchdog already configured differently (mr = %x expecting %x)\n",
> + tmp & wdt->mr_mask, wdt->mr & wdt->mr_mask);
> +
> + setup_timer(&wdt->timer, at91_ping, (unsigned long)wdt);
> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
> +
> + /* Try to set timeout from device tree first */
> + if (watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev))
> + watchdog_init_timeout(&wdt->wdd, heartbeat, &pdev->dev);
> + watchdog_set_nowayout(&wdt->wdd, wdt->nowayout);
> + err = watchdog_register_device(&wdt->wdd);
> + if (err)
> + goto out_stop_timer;
> +
> + wdt->next_heartbeat = jiffies + wdt->wdd.timeout * HZ;
>
> return 0;
> +
> +out_stop_timer:
> + del_timer(&wdt->timer);
> + return err;
> }
>
> /* ......................................................................... */
> @@ -167,63 +239,125 @@ static const struct watchdog_info at91_wdt_info = {
>
> static const struct watchdog_ops at91_wdt_ops = {
> .owner = THIS_MODULE,
> - .start = at91_wdt_start,
> + .start = at91_wdt_ping,
> .stop = at91_wdt_stop,
> .ping = at91_wdt_ping,
Notpick, but you don't need both start and ping. If both are the same, providing
start is sufficient. Given this, it might be cleaner to name the function
at91_wdt_start and not provide ping.
> .set_timeout = at91_wdt_set_timeout,
> };
>
> -static struct watchdog_device at91_wdt_dev = {
> - .info = &at91_wdt_info,
> - .ops = &at91_wdt_ops,
> - .timeout = WDT_HEARTBEAT,
> - .min_timeout = 1,
> - .max_timeout = 0xFFFF,
> -};
> +#if defined(CONFIG_OF)
> +static int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
> +{
> + u32 min = 0;
> + u32 max = WDT_COUNTER_MAX_SECS;
> + const char *tmp;
> +
> + /* Get the interrupts property */
> + wdt->irq = irq_of_parse_and_map(np, 0);
> + if (!wdt->irq)
> + dev_warn(wdt->wdd.parent, "failed to get IRQ from DT\n");
> +
> + if (!of_property_read_u32_index(np, "atmel,max-heartbeat-sec", 0,
> + &max)) {
> + if (!max || max > WDT_COUNTER_MAX_SECS)
> + max = WDT_COUNTER_MAX_SECS;
> +
> + if (!of_property_read_u32_index(np, "atmel,min-heartbeat-sec",
> + 0, &min)) {
> + if (min >= max)
> + min = max - 1;
> + }
> + }
> +
> + min = secs_to_ticks(min);
> + max = secs_to_ticks(max);
> +
> + wdt->mr_mask = 0x3FFFFFFF;
> + wdt->mr = 0;
> + if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
> + !strcmp(tmp, "software")) {
> + wdt->mr |= AT91_WDT_WDFIEN;
> + wdt->mr_mask &= ~AT91_WDT_WDRPROC;
> + } else
> + wdt->mr |= AT91_WDT_WDRSTEN;
> +
> + if (!of_property_read_string(np, "atmel,reset-type", &tmp) &&
> + !strcmp(tmp, "proc"))
> + wdt->mr |= AT91_WDT_WDRPROC;
> +
> + if (of_property_read_bool(np, "atmel,disable")) {
> + wdt->mr |= AT91_WDT_WDDIS;
> + wdt->mr_mask &= AT91_WDT_WDDIS;
> + }
> +
> + 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;
> +
> + wdt->mr |= max | ((max - min) << 16);
> +
> + return 0;
> +}
> +#else
> +static inline int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
> +{
> + return 0;
> +}
> +#endif
>
> static int __init at91wdt_probe(struct platform_device *pdev)
> {
> struct resource *r;
> - int res;
> + int err;
> + struct at91wdt *wdt;
>
> - r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - if (!r)
> - return -ENODEV;
> - at91wdt_private.base = ioremap(r->start, resource_size(r));
> - if (!at91wdt_private.base) {
> - dev_err(&pdev->dev, "failed to map registers, aborting.\n");
> + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
> + if (!wdt)
> return -ENOMEM;
> - }
>
> - at91_wdt_dev.parent = &pdev->dev;
> - watchdog_init_timeout(&at91_wdt_dev, heartbeat, &pdev->dev);
> - watchdog_set_nowayout(&at91_wdt_dev, nowayout);
> + wdt->mr = (WDT_HW_TIMEOUT * 256) | AT91_WDT_WDRSTEN | AT91_WDT_WDD |
> + AT91_WDT_WDDBGHLT | AT91_WDT_WDIDLEHLT;
> + wdt->mr_mask = 0x3FFFFFFF;
> + wdt->nowayout = nowayout;
> + wdt->wdd.parent = &pdev->dev;
> + wdt->wdd.info = &at91_wdt_info;
> + wdt->wdd.ops = &at91_wdt_ops;
> + wdt->wdd.timeout = WDT_HEARTBEAT;
> + wdt->wdd.min_timeout = 1;
> + wdt->wdd.max_timeout = 0xFFFF;
>
> - /* Set watchdog */
> - res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
> - if (res)
> - return res;
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + wdt->base = devm_ioremap_resource(&pdev->dev, r);
> + if (IS_ERR(wdt->base))
> + return PTR_ERR(wdt->base);
> +
> + if (pdev->dev.of_node) {
> + err = of_at91wdt_init(pdev->dev.of_node, wdt);
> + if (err)
> + return err;
> + }
>
> - res = watchdog_register_device(&at91_wdt_dev);
> - if (res)
> - return res;
> + err = at91_wdt_init(pdev, wdt);
> + if (err)
> + return err;
>
> - at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout * HZ;
> - setup_timer(&at91wdt_private.timer, at91_ping, 0);
> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
> + platform_set_drvdata(pdev, wdt);
>
> pr_info("enabled (heartbeat=%d sec, nowayout=%d)\n",
> - at91_wdt_dev.timeout, nowayout);
> + wdt->wdd.timeout, wdt->nowayout);
>
> return 0;
> }
>
> static int __exit at91wdt_remove(struct platform_device *pdev)
> {
> - watchdog_unregister_device(&at91_wdt_dev);
> + struct at91wdt *wdt = platform_get_drvdata(pdev);
> + watchdog_unregister_device(&wdt->wdd);
>
> pr_warn("I quit now, hardware will probably reboot!\n");
> - del_timer(&at91wdt_private.timer);
> + del_timer(&wdt->timer);
>
> return 0;
> }
> --
> 1.7.9.5
>
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^ permalink raw reply [flat|nested] 19+ messages in thread* [PATCH 1/4] watchdog: at91sam9_wdt: better watchdog support
@ 2013-10-03 17:31 ` Guenter Roeck
0 siblings, 0 replies; 19+ messages in thread
From: Guenter Roeck @ 2013-10-03 17:31 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Oct 03, 2013 at 02:19:18PM +0200, Boris BREZILLON wrote:
> The at91sam9 watchdog timer can only be configured once, and the current
> implementation tries to configure it in a static way:
> - 2 seconds timeout
> - wdt restart every 500ms
>
> If the timer has already been configured with different values, it returns an
> error and do not create any watchdog device.
>
> This is not critical if the watchdog is disabled, but if it has been enabled with
> different timeout values it will lead to a SoC reset.
>
> This patch series tries to address this issue by adapting the heartbeat value
> according the WDT timer config:
> - it first tries to configure the timer as requested.
> - if it fails it fallbacks to the current config, adapting its heartbeat timer
> to the needs
>
> This patch series also move to a dynamically allocated at91wdt device instead
> of the static instance.
>
> It adds a new at91 wdt type: software. This new type make use of the at91 wdt
> interrupt to trigger a software reboot.
>
> Finally it adds several properties to the device tree bindings.
>
> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Hi Boris,
deeper dive this time ...
> ---
> drivers/watchdog/at91sam9_wdt.c | 300 ++++++++++++++++++++++++++++-----------
> 1 file changed, 217 insertions(+), 83 deletions(-)
>
> diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
> index be37dde..8f44528 100644
> --- a/drivers/watchdog/at91sam9_wdt.c
> +++ b/drivers/watchdog/at91sam9_wdt.c
> @@ -19,11 +19,13 @@
>
> #include <linux/errno.h>
> #include <linux/init.h>
> +#include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> #include <linux/platform_device.h>
> +#include <linux/reboot.h>
> #include <linux/types.h>
> #include <linux/watchdog.h>
> #include <linux/jiffies.h>
> @@ -31,22 +33,33 @@
> #include <linux/bitops.h>
> #include <linux/uaccess.h>
> #include <linux/of.h>
> +#include <linux/of_irq.h>
>
> #include "at91sam9_wdt.h"
>
> #define DRV_NAME "AT91SAM9 Watchdog"
>
> -#define wdt_read(field) \
> - __raw_readl(at91wdt_private.base + field)
> -#define wdt_write(field, val) \
> - __raw_writel((val), at91wdt_private.base + field)
> +#define wdt_read(wdt, field) \
> + __raw_readl((wdt)->base + (field))
> +#define wdt_write(wtd, field, val) \
> + __raw_writel((val), (wdt)->base + (field))
>
> /* AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
> * use this to convert a watchdog
> * value from/to milliseconds.
> */
> -#define ms_to_ticks(t) (((t << 8) / 1000) - 1)
> -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
> +#define ticks_to_hz_rounddown(t) ((((t) + 1) * HZ) >> 8)
> +#define ticks_to_hz_roundup(t) (((((t) + 1) * HZ) + 255) >> 8)
> +#define ticks_to_secs(t) (((t) + 1) >> 8)
> +#define secs_to_ticks(s) (((s) << 8) - 1)
> +
> +#define WDT_MR_RESET 0x3FFF2FFF
> +
> +/* Watchdog max counter value in ticks */
> +#define WDT_COUNTER_MAX_TICKS 0xFFF
> +
> +/* Watchdog max delta/value in secs */
> +#define WDT_COUNTER_MAX_SECS ticks_to_secs(WDT_COUNTER_MAX_TICKS)
>
> /* Hardware timeout in seconds */
> #define WDT_HW_TIMEOUT 2
> @@ -66,23 +79,40 @@ module_param(nowayout, bool, 0);
> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
> "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>
> -static struct watchdog_device at91_wdt_dev;
> -static void at91_ping(unsigned long data);
> -
> -static struct {
> +#define to_wdt(wdd) container_of(wdd, struct at91wdt, wdd)
> +struct at91wdt {
> + struct watchdog_device wdd;
> void __iomem *base;
> unsigned long next_heartbeat; /* the next_heartbeat for the timer */
> struct timer_list timer; /* The timer that pings the watchdog */
> -} at91wdt_private;
> + u32 mr;
> + u32 mr_mask;
> + unsigned long heartbeat; /* WDT heartbeat in jiffies */
> + bool nowayout;
> + unsigned int irq;
> +};
>
> /* ......................................................................... */
>
> +static irqreturn_t wdt_interrupt(int irq, void *dev_id)
> +{
> + struct at91wdt *wdt = (struct at91wdt *)dev_id;
> +
> + if (wdt_read(wdt, AT91_WDT_SR)) {
> + pr_crit("at91sam9 WDT software reset\n");
> + emergency_restart();
> + pr_crit("Reboot didn't ?????\n");
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> /*
> * Reload the watchdog timer. (ie, pat the watchdog)
> */
> -static inline void at91_wdt_reset(void)
> +static inline void at91_wdt_reset(struct at91wdt *wdt)
> {
> - wdt_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
> + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
> }
>
> /*
> @@ -90,26 +120,20 @@ static inline void at91_wdt_reset(void)
> */
> static void at91_ping(unsigned long data)
> {
> - if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
> - (!watchdog_active(&at91_wdt_dev))) {
> - at91_wdt_reset();
> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
> + struct at91wdt *wdt = (struct at91wdt *)data;
> + if (time_before(jiffies, wdt->next_heartbeat) ||
> + !watchdog_active(&wdt->wdd)) {
> + at91_wdt_reset(wdt);
> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
> } else
> pr_crit("I will reset your machine !\n");
> }
>
> static int at91_wdt_ping(struct watchdog_device *wdd)
> {
> + struct at91wdt *wdt = to_wdt(wdd);
> /* calculate when the next userspace timeout will be */
> - at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
> - return 0;
> -}
> -
> -static int at91_wdt_start(struct watchdog_device *wdd)
> -{
> - /* calculate the next userspace timeout and modify the timer */
> - at91_wdt_ping(wdd);
> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
> + wdt->next_heartbeat = jiffies + wdd->timeout * HZ;
> return 0;
> }
>
> @@ -125,36 +149,84 @@ static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int new_ti
at91_wdt_set_timeout only sets the new timeout but does not update
next_heartbeat. That is ok if the timeout decreases, but if it is
increased (say, from 1 second to 1 minute) it might result in a missed
ping as userspace will subsequently believe that the new (larger)
timeout was accepted by the driver. So I think you should also call
at91_wdt_ping here or set wdt->next_heartbeat directly.
> return 0;
> }
>
> -/*
> - * Set the watchdog time interval in 1/256Hz (write-once)
> - * Counter is 12 bit.
> - */
> -static int at91_wdt_settimeout(unsigned int timeout)
> +static int at91_wdt_init(struct platform_device *pdev, struct at91wdt *wdt)
> {
> - unsigned int reg;
> - unsigned int mr;
> -
> - /* Check if disabled */
> - mr = wdt_read(AT91_WDT_MR);
> - if (mr & AT91_WDT_WDDIS) {
> - pr_err("sorry, watchdog is disabled\n");
> - return -EIO;
> + u32 tmp;
> + u32 delta;
> + u32 value;
> + int err;
> + u32 mask = wdt->mr_mask;
> + unsigned long min_heartbeat = 1;
> +
> + tmp = wdt_read(wdt, AT91_WDT_MR);
> + if ((tmp & mask) != (wdt->mr & mask)) {
> + if (tmp == WDT_MR_RESET) {
> + wdt_write(wdt, AT91_WDT_MR, wdt->mr);
> + tmp = wdt_read(wdt, AT91_WDT_MR);
> + }
> }
>
> - /*
> - * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
> - *
> - * Since WDV is a 12-bit counter, the maximum period is
> - * 4096 / 256 = 16 seconds.
> - */
> - reg = AT91_WDT_WDRSTEN /* causes watchdog reset */
> - /* | AT91_WDT_WDRPROC causes processor reset only */
> - | AT91_WDT_WDDBGHLT /* disabled in debug mode */
> - | AT91_WDT_WDD /* restart at any time */
> - | (timeout & AT91_WDT_WDV); /* timer value */
> - wdt_write(AT91_WDT_MR, reg);
> + if (tmp & AT91_WDT_WDDIS) {
> + if (wdt->mr & AT91_WDT_WDDIS)
> + return 0;
> + dev_err(wdt->wdd.parent, "watchdog is disabled\n");
Took me a while to get why you use "wdt->wdd.parent" :).
I would just have passed the 'dev' argument. Your call, though.
> + return -EINVAL;
> + }
> +
> + value = tmp & AT91_WDT_WDV;
> + delta = (tmp & AT91_WDT_WDD) >> 16;
> +
> + if (delta < value)
> + min_heartbeat = ticks_to_hz_roundup(value - delta);
> +
> + wdt->heartbeat = ticks_to_hz_rounddown(value);
> + if (!wdt->heartbeat) {
> + dev_err(wdt->wdd.parent,
> + "heartbeat is too small for the system to handle it correctly\n");
> + return -EINVAL;
> + }
> +
> + if (wdt->heartbeat < min_heartbeat + 3) {
> + wdt->heartbeat = min_heartbeat;
> + dev_warn(wdt->wdd.parent,
> + "min heartbeat and max heartbeat might be too close for the system to handle it correctly\n");
> + if (wdt->heartbeat < 4)
> + dev_warn(wdt->wdd.parent,
> + "heartbeat might be too small for the system to handle it correctly\n");
> + } else
> + wdt->heartbeat -= 4;
That means heartbeat can be 0, correct (if min_heartbeat == 1) ?
Will that work ?
> +
> + if ((tmp & AT91_WDT_WDFIEN) && wdt->irq) {
> + err = request_irq(wdt->irq, wdt_interrupt,
> + IRQF_SHARED | IRQF_IRQPOLL,
> + pdev->name, wdt);
> + if (err)
> + return err;
> + }
> +
> + if ((tmp & wdt->mr_mask) != (wdt->mr & wdt->mr_mask))
> + dev_warn(wdt->wdd.parent,
> + "watchdog already configured differently (mr = %x expecting %x)\n",
> + tmp & wdt->mr_mask, wdt->mr & wdt->mr_mask);
> +
> + setup_timer(&wdt->timer, at91_ping, (unsigned long)wdt);
> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
> +
> + /* Try to set timeout from device tree first */
> + if (watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev))
> + watchdog_init_timeout(&wdt->wdd, heartbeat, &pdev->dev);
> + watchdog_set_nowayout(&wdt->wdd, wdt->nowayout);
> + err = watchdog_register_device(&wdt->wdd);
> + if (err)
> + goto out_stop_timer;
> +
> + wdt->next_heartbeat = jiffies + wdt->wdd.timeout * HZ;
>
> return 0;
> +
> +out_stop_timer:
> + del_timer(&wdt->timer);
> + return err;
> }
>
> /* ......................................................................... */
> @@ -167,63 +239,125 @@ static const struct watchdog_info at91_wdt_info = {
>
> static const struct watchdog_ops at91_wdt_ops = {
> .owner = THIS_MODULE,
> - .start = at91_wdt_start,
> + .start = at91_wdt_ping,
> .stop = at91_wdt_stop,
> .ping = at91_wdt_ping,
Notpick, but you don't need both start and ping. If both are the same, providing
start is sufficient. Given this, it might be cleaner to name the function
at91_wdt_start and not provide ping.
> .set_timeout = at91_wdt_set_timeout,
> };
>
> -static struct watchdog_device at91_wdt_dev = {
> - .info = &at91_wdt_info,
> - .ops = &at91_wdt_ops,
> - .timeout = WDT_HEARTBEAT,
> - .min_timeout = 1,
> - .max_timeout = 0xFFFF,
> -};
> +#if defined(CONFIG_OF)
> +static int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
> +{
> + u32 min = 0;
> + u32 max = WDT_COUNTER_MAX_SECS;
> + const char *tmp;
> +
> + /* Get the interrupts property */
> + wdt->irq = irq_of_parse_and_map(np, 0);
> + if (!wdt->irq)
> + dev_warn(wdt->wdd.parent, "failed to get IRQ from DT\n");
> +
> + if (!of_property_read_u32_index(np, "atmel,max-heartbeat-sec", 0,
> + &max)) {
> + if (!max || max > WDT_COUNTER_MAX_SECS)
> + max = WDT_COUNTER_MAX_SECS;
> +
> + if (!of_property_read_u32_index(np, "atmel,min-heartbeat-sec",
> + 0, &min)) {
> + if (min >= max)
> + min = max - 1;
> + }
> + }
> +
> + min = secs_to_ticks(min);
> + max = secs_to_ticks(max);
> +
> + wdt->mr_mask = 0x3FFFFFFF;
> + wdt->mr = 0;
> + if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
> + !strcmp(tmp, "software")) {
> + wdt->mr |= AT91_WDT_WDFIEN;
> + wdt->mr_mask &= ~AT91_WDT_WDRPROC;
> + } else
> + wdt->mr |= AT91_WDT_WDRSTEN;
> +
> + if (!of_property_read_string(np, "atmel,reset-type", &tmp) &&
> + !strcmp(tmp, "proc"))
> + wdt->mr |= AT91_WDT_WDRPROC;
> +
> + if (of_property_read_bool(np, "atmel,disable")) {
> + wdt->mr |= AT91_WDT_WDDIS;
> + wdt->mr_mask &= AT91_WDT_WDDIS;
> + }
> +
> + 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;
> +
> + wdt->mr |= max | ((max - min) << 16);
> +
> + return 0;
> +}
> +#else
> +static inline int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
> +{
> + return 0;
> +}
> +#endif
>
> static int __init at91wdt_probe(struct platform_device *pdev)
> {
> struct resource *r;
> - int res;
> + int err;
> + struct at91wdt *wdt;
>
> - r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - if (!r)
> - return -ENODEV;
> - at91wdt_private.base = ioremap(r->start, resource_size(r));
> - if (!at91wdt_private.base) {
> - dev_err(&pdev->dev, "failed to map registers, aborting.\n");
> + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
> + if (!wdt)
> return -ENOMEM;
> - }
>
> - at91_wdt_dev.parent = &pdev->dev;
> - watchdog_init_timeout(&at91_wdt_dev, heartbeat, &pdev->dev);
> - watchdog_set_nowayout(&at91_wdt_dev, nowayout);
> + wdt->mr = (WDT_HW_TIMEOUT * 256) | AT91_WDT_WDRSTEN | AT91_WDT_WDD |
> + AT91_WDT_WDDBGHLT | AT91_WDT_WDIDLEHLT;
> + wdt->mr_mask = 0x3FFFFFFF;
> + wdt->nowayout = nowayout;
> + wdt->wdd.parent = &pdev->dev;
> + wdt->wdd.info = &at91_wdt_info;
> + wdt->wdd.ops = &at91_wdt_ops;
> + wdt->wdd.timeout = WDT_HEARTBEAT;
> + wdt->wdd.min_timeout = 1;
> + wdt->wdd.max_timeout = 0xFFFF;
>
> - /* Set watchdog */
> - res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
> - if (res)
> - return res;
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + wdt->base = devm_ioremap_resource(&pdev->dev, r);
> + if (IS_ERR(wdt->base))
> + return PTR_ERR(wdt->base);
> +
> + if (pdev->dev.of_node) {
> + err = of_at91wdt_init(pdev->dev.of_node, wdt);
> + if (err)
> + return err;
> + }
>
> - res = watchdog_register_device(&at91_wdt_dev);
> - if (res)
> - return res;
> + err = at91_wdt_init(pdev, wdt);
> + if (err)
> + return err;
>
> - at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout * HZ;
> - setup_timer(&at91wdt_private.timer, at91_ping, 0);
> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
> + platform_set_drvdata(pdev, wdt);
>
> pr_info("enabled (heartbeat=%d sec, nowayout=%d)\n",
> - at91_wdt_dev.timeout, nowayout);
> + wdt->wdd.timeout, wdt->nowayout);
>
> return 0;
> }
>
> static int __exit at91wdt_remove(struct platform_device *pdev)
> {
> - watchdog_unregister_device(&at91_wdt_dev);
> + struct at91wdt *wdt = platform_get_drvdata(pdev);
> + watchdog_unregister_device(&wdt->wdd);
>
> pr_warn("I quit now, hardware will probably reboot!\n");
> - del_timer(&at91wdt_private.timer);
> + del_timer(&wdt->timer);
>
> return 0;
> }
> --
> 1.7.9.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 1/4] watchdog: at91sam9_wdt: better watchdog support
2013-10-03 17:31 ` Guenter Roeck
@ 2013-10-03 17:55 ` boris brezillon
-1 siblings, 0 replies; 19+ messages in thread
From: boris brezillon @ 2013-10-03 17:55 UTC (permalink / raw)
To: Guenter Roeck
Cc: Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
Ian Campbell, Rob Landley, Russell King, Wim Van Sebroeck,
Fabio Porcedda, Nicolas Ferre, Guenter Roeck, Yang Wenyou,
devicetree, linux-doc, linux-kernel, linux-arm-kernel,
linux-watchdog
Hi Guenter,
On 03/10/2013 19:31, Guenter Roeck wrote:
> On Thu, Oct 03, 2013 at 02:19:18PM +0200, Boris BREZILLON wrote:
>> The at91sam9 watchdog timer can only be configured once, and the current
>> implementation tries to configure it in a static way:
>> - 2 seconds timeout
>> - wdt restart every 500ms
>>
>> If the timer has already been configured with different values, it returns an
>> error and do not create any watchdog device.
>>
>> This is not critical if the watchdog is disabled, but if it has been enabled with
>> different timeout values it will lead to a SoC reset.
>>
>> This patch series tries to address this issue by adapting the heartbeat value
>> according the WDT timer config:
>> - it first tries to configure the timer as requested.
>> - if it fails it fallbacks to the current config, adapting its heartbeat timer
>> to the needs
>>
>> This patch series also move to a dynamically allocated at91wdt device instead
>> of the static instance.
>>
>> It adds a new at91 wdt type: software. This new type make use of the at91 wdt
>> interrupt to trigger a software reboot.
>>
>> Finally it adds several properties to the device tree bindings.
>>
>> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
> Hi Boris,
>
> deeper dive this time ...
>
>> ---
>> drivers/watchdog/at91sam9_wdt.c | 300 ++++++++++++++++++++++++++++-----------
>> 1 file changed, 217 insertions(+), 83 deletions(-)
>>
>> diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
>> index be37dde..8f44528 100644
>> --- a/drivers/watchdog/at91sam9_wdt.c
>> +++ b/drivers/watchdog/at91sam9_wdt.c
>> @@ -19,11 +19,13 @@
>>
>> #include <linux/errno.h>
>> #include <linux/init.h>
>> +#include <linux/interrupt.h>
>> #include <linux/io.h>
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> #include <linux/moduleparam.h>
>> #include <linux/platform_device.h>
>> +#include <linux/reboot.h>
>> #include <linux/types.h>
>> #include <linux/watchdog.h>
>> #include <linux/jiffies.h>
>> @@ -31,22 +33,33 @@
>> #include <linux/bitops.h>
>> #include <linux/uaccess.h>
>> #include <linux/of.h>
>> +#include <linux/of_irq.h>
>>
>> #include "at91sam9_wdt.h"
>>
>> #define DRV_NAME "AT91SAM9 Watchdog"
>>
>> -#define wdt_read(field) \
>> - __raw_readl(at91wdt_private.base + field)
>> -#define wdt_write(field, val) \
>> - __raw_writel((val), at91wdt_private.base + field)
>> +#define wdt_read(wdt, field) \
>> + __raw_readl((wdt)->base + (field))
>> +#define wdt_write(wtd, field, val) \
>> + __raw_writel((val), (wdt)->base + (field))
>>
>> /* AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
>> * use this to convert a watchdog
>> * value from/to milliseconds.
>> */
>> -#define ms_to_ticks(t) (((t << 8) / 1000) - 1)
>> -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
>> +#define ticks_to_hz_rounddown(t) ((((t) + 1) * HZ) >> 8)
>> +#define ticks_to_hz_roundup(t) (((((t) + 1) * HZ) + 255) >> 8)
>> +#define ticks_to_secs(t) (((t) + 1) >> 8)
>> +#define secs_to_ticks(s) (((s) << 8) - 1)
>> +
>> +#define WDT_MR_RESET 0x3FFF2FFF
>> +
>> +/* Watchdog max counter value in ticks */
>> +#define WDT_COUNTER_MAX_TICKS 0xFFF
>> +
>> +/* Watchdog max delta/value in secs */
>> +#define WDT_COUNTER_MAX_SECS ticks_to_secs(WDT_COUNTER_MAX_TICKS)
>>
>> /* Hardware timeout in seconds */
>> #define WDT_HW_TIMEOUT 2
>> @@ -66,23 +79,40 @@ module_param(nowayout, bool, 0);
>> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
>> "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>>
>> -static struct watchdog_device at91_wdt_dev;
>> -static void at91_ping(unsigned long data);
>> -
>> -static struct {
>> +#define to_wdt(wdd) container_of(wdd, struct at91wdt, wdd)
>> +struct at91wdt {
>> + struct watchdog_device wdd;
>> void __iomem *base;
>> unsigned long next_heartbeat; /* the next_heartbeat for the timer */
>> struct timer_list timer; /* The timer that pings the watchdog */
>> -} at91wdt_private;
>> + u32 mr;
>> + u32 mr_mask;
>> + unsigned long heartbeat; /* WDT heartbeat in jiffies */
>> + bool nowayout;
>> + unsigned int irq;
>> +};
>>
>> /* ......................................................................... */
>>
>> +static irqreturn_t wdt_interrupt(int irq, void *dev_id)
>> +{
>> + struct at91wdt *wdt = (struct at91wdt *)dev_id;
>> +
>> + if (wdt_read(wdt, AT91_WDT_SR)) {
>> + pr_crit("at91sam9 WDT software reset\n");
>> + emergency_restart();
>> + pr_crit("Reboot didn't ?????\n");
>> + }
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> /*
>> * Reload the watchdog timer. (ie, pat the watchdog)
>> */
>> -static inline void at91_wdt_reset(void)
>> +static inline void at91_wdt_reset(struct at91wdt *wdt)
>> {
>> - wdt_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>> + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>> }
>>
>> /*
>> @@ -90,26 +120,20 @@ static inline void at91_wdt_reset(void)
>> */
>> static void at91_ping(unsigned long data)
>> {
>> - if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
>> - (!watchdog_active(&at91_wdt_dev))) {
>> - at91_wdt_reset();
>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>> + struct at91wdt *wdt = (struct at91wdt *)data;
>> + if (time_before(jiffies, wdt->next_heartbeat) ||
>> + !watchdog_active(&wdt->wdd)) {
>> + at91_wdt_reset(wdt);
>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>> } else
>> pr_crit("I will reset your machine !\n");
>> }
>>
>> static int at91_wdt_ping(struct watchdog_device *wdd)
>> {
>> + struct at91wdt *wdt = to_wdt(wdd);
>> /* calculate when the next userspace timeout will be */
>> - at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
>> - return 0;
>> -}
>> -
>> -static int at91_wdt_start(struct watchdog_device *wdd)
>> -{
>> - /* calculate the next userspace timeout and modify the timer */
>> - at91_wdt_ping(wdd);
>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>> + wdt->next_heartbeat = jiffies + wdd->timeout * HZ;
>> return 0;
>> }
>>
>> @@ -125,36 +149,84 @@ static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int new_ti
> at91_wdt_set_timeout only sets the new timeout but does not update
> next_heartbeat. That is ok if the timeout decreases, but if it is
> increased (say, from 1 second to 1 minute) it might result in a missed
> ping as userspace will subsequently believe that the new (larger)
> timeout was accepted by the driver. So I think you should also call
> at91_wdt_ping here or set wdt->next_heartbeat directly.
Absolutely, I'll call at91_wdt_ping (or start as it will be renamed).
>> return 0;
>> }
>>
>> -/*
>> - * Set the watchdog time interval in 1/256Hz (write-once)
>> - * Counter is 12 bit.
>> - */
>> -static int at91_wdt_settimeout(unsigned int timeout)
>> +static int at91_wdt_init(struct platform_device *pdev, struct at91wdt *wdt)
>> {
>> - unsigned int reg;
>> - unsigned int mr;
>> -
>> - /* Check if disabled */
>> - mr = wdt_read(AT91_WDT_MR);
>> - if (mr & AT91_WDT_WDDIS) {
>> - pr_err("sorry, watchdog is disabled\n");
>> - return -EIO;
>> + u32 tmp;
>> + u32 delta;
>> + u32 value;
>> + int err;
>> + u32 mask = wdt->mr_mask;
>> + unsigned long min_heartbeat = 1;
>> +
>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>> + if ((tmp & mask) != (wdt->mr & mask)) {
>> + if (tmp == WDT_MR_RESET) {
>> + wdt_write(wdt, AT91_WDT_MR, wdt->mr);
>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>> + }
>> }
>>
>> - /*
>> - * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
>> - *
>> - * Since WDV is a 12-bit counter, the maximum period is
>> - * 4096 / 256 = 16 seconds.
>> - */
>> - reg = AT91_WDT_WDRSTEN /* causes watchdog reset */
>> - /* | AT91_WDT_WDRPROC causes processor reset only */
>> - | AT91_WDT_WDDBGHLT /* disabled in debug mode */
>> - | AT91_WDT_WDD /* restart at any time */
>> - | (timeout & AT91_WDT_WDV); /* timer value */
>> - wdt_write(AT91_WDT_MR, reg);
>> + if (tmp & AT91_WDT_WDDIS) {
>> + if (wdt->mr & AT91_WDT_WDDIS)
>> + return 0;
>> + dev_err(wdt->wdd.parent, "watchdog is disabled\n");
> Took me a while to get why you use "wdt->wdd.parent" :).
> I would just have passed the 'dev' argument. Your call, though.
I can't use wdt->wdd.dev, because the watchdog device is not registered yet,
but I can use &pdev->dev instead.
What do you prefer ?
>> + return -EINVAL;
>> + }
>> +
>> + value = tmp & AT91_WDT_WDV;
>> + delta = (tmp & AT91_WDT_WDD) >> 16;
>> +
>> + if (delta < value)
>> + min_heartbeat = ticks_to_hz_roundup(value - delta);
>> +
>> + wdt->heartbeat = ticks_to_hz_rounddown(value);
>> + if (!wdt->heartbeat) {
>> + dev_err(wdt->wdd.parent,
>> + "heartbeat is too small for the system to handle it correctly\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (wdt->heartbeat < min_heartbeat + 3) {
>> + wdt->heartbeat = min_heartbeat;
>> + dev_warn(wdt->wdd.parent,
>> + "min heartbeat and max heartbeat might be too close for the system to handle it correctly\n");
>> + if (wdt->heartbeat < 4)
>> + dev_warn(wdt->wdd.parent,
>> + "heartbeat might be too small for the system to handle it correctly\n");
>> + } else
>> + wdt->heartbeat -= 4;
> That means heartbeat can be 0, correct (if min_heartbeat == 1) ?
Yes, this is a mistake. It should be
if (wdt->heartbeat < min_heartbeat + 4) {
...
}
> Will that work ?
Absolutely not :)
I'll fix it.
>
>> +
>> + if ((tmp & AT91_WDT_WDFIEN) && wdt->irq) {
>> + err = request_irq(wdt->irq, wdt_interrupt,
>> + IRQF_SHARED | IRQF_IRQPOLL,
>> + pdev->name, wdt);
>> + if (err)
>> + return err;
>> + }
>> +
>> + if ((tmp & wdt->mr_mask) != (wdt->mr & wdt->mr_mask))
>> + dev_warn(wdt->wdd.parent,
>> + "watchdog already configured differently (mr = %x expecting %x)\n",
>> + tmp & wdt->mr_mask, wdt->mr & wdt->mr_mask);
>> +
>> + setup_timer(&wdt->timer, at91_ping, (unsigned long)wdt);
>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>> +
>> + /* Try to set timeout from device tree first */
>> + if (watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev))
>> + watchdog_init_timeout(&wdt->wdd, heartbeat, &pdev->dev);
>> + watchdog_set_nowayout(&wdt->wdd, wdt->nowayout);
>> + err = watchdog_register_device(&wdt->wdd);
>> + if (err)
>> + goto out_stop_timer;
>> +
>> + wdt->next_heartbeat = jiffies + wdt->wdd.timeout * HZ;
>>
>> return 0;
>> +
>> +out_stop_timer:
>> + del_timer(&wdt->timer);
>> + return err;
>> }
>>
>> /* ......................................................................... */
>> @@ -167,63 +239,125 @@ static const struct watchdog_info at91_wdt_info = {
>>
>> static const struct watchdog_ops at91_wdt_ops = {
>> .owner = THIS_MODULE,
>> - .start = at91_wdt_start,
>> + .start = at91_wdt_ping,
>> .stop = at91_wdt_stop,
>> .ping = at91_wdt_ping,
> Notpick, but you don't need both start and ping. If both are the same, providing
> start is sufficient. Given this, it might be cleaner to name the function
> at91_wdt_start and not provide ping.
I'll change this too.
Thanks, for catching these bugs.
Regards,
Boris
>> .set_timeout = at91_wdt_set_timeout,
>> };
>>
>> -static struct watchdog_device at91_wdt_dev = {
>> - .info = &at91_wdt_info,
>> - .ops = &at91_wdt_ops,
>> - .timeout = WDT_HEARTBEAT,
>> - .min_timeout = 1,
>> - .max_timeout = 0xFFFF,
>> -};
>> +#if defined(CONFIG_OF)
>> +static int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
>> +{
>> + u32 min = 0;
>> + u32 max = WDT_COUNTER_MAX_SECS;
>> + const char *tmp;
>> +
>> + /* Get the interrupts property */
>> + wdt->irq = irq_of_parse_and_map(np, 0);
>> + if (!wdt->irq)
>> + dev_warn(wdt->wdd.parent, "failed to get IRQ from DT\n");
>> +
>> + if (!of_property_read_u32_index(np, "atmel,max-heartbeat-sec", 0,
>> + &max)) {
>> + if (!max || max > WDT_COUNTER_MAX_SECS)
>> + max = WDT_COUNTER_MAX_SECS;
>> +
>> + if (!of_property_read_u32_index(np, "atmel,min-heartbeat-sec",
>> + 0, &min)) {
>> + if (min >= max)
>> + min = max - 1;
>> + }
>> + }
>> +
>> + min = secs_to_ticks(min);
>> + max = secs_to_ticks(max);
>> +
>> + wdt->mr_mask = 0x3FFFFFFF;
>> + wdt->mr = 0;
>> + if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
>> + !strcmp(tmp, "software")) {
>> + wdt->mr |= AT91_WDT_WDFIEN;
>> + wdt->mr_mask &= ~AT91_WDT_WDRPROC;
>> + } else
>> + wdt->mr |= AT91_WDT_WDRSTEN;
>> +
>> + if (!of_property_read_string(np, "atmel,reset-type", &tmp) &&
>> + !strcmp(tmp, "proc"))
>> + wdt->mr |= AT91_WDT_WDRPROC;
>> +
>> + if (of_property_read_bool(np, "atmel,disable")) {
>> + wdt->mr |= AT91_WDT_WDDIS;
>> + wdt->mr_mask &= AT91_WDT_WDDIS;
>> + }
>> +
>> + 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;
>> +
>> + wdt->mr |= max | ((max - min) << 16);
>> +
>> + return 0;
>> +}
>> +#else
>> +static inline int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
>> +{
>> + return 0;
>> +}
>> +#endif
>>
>> static int __init at91wdt_probe(struct platform_device *pdev)
>> {
>> struct resource *r;
>> - int res;
>> + int err;
>> + struct at91wdt *wdt;
>>
>> - r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> - if (!r)
>> - return -ENODEV;
>> - at91wdt_private.base = ioremap(r->start, resource_size(r));
>> - if (!at91wdt_private.base) {
>> - dev_err(&pdev->dev, "failed to map registers, aborting.\n");
>> + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
>> + if (!wdt)
>> return -ENOMEM;
>> - }
>>
>> - at91_wdt_dev.parent = &pdev->dev;
>> - watchdog_init_timeout(&at91_wdt_dev, heartbeat, &pdev->dev);
>> - watchdog_set_nowayout(&at91_wdt_dev, nowayout);
>> + wdt->mr = (WDT_HW_TIMEOUT * 256) | AT91_WDT_WDRSTEN | AT91_WDT_WDD |
>> + AT91_WDT_WDDBGHLT | AT91_WDT_WDIDLEHLT;
>> + wdt->mr_mask = 0x3FFFFFFF;
>> + wdt->nowayout = nowayout;
>> + wdt->wdd.parent = &pdev->dev;
>> + wdt->wdd.info = &at91_wdt_info;
>> + wdt->wdd.ops = &at91_wdt_ops;
>> + wdt->wdd.timeout = WDT_HEARTBEAT;
>> + wdt->wdd.min_timeout = 1;
>> + wdt->wdd.max_timeout = 0xFFFF;
>>
>> - /* Set watchdog */
>> - res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
>> - if (res)
>> - return res;
>> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + wdt->base = devm_ioremap_resource(&pdev->dev, r);
>> + if (IS_ERR(wdt->base))
>> + return PTR_ERR(wdt->base);
>> +
>> + if (pdev->dev.of_node) {
>> + err = of_at91wdt_init(pdev->dev.of_node, wdt);
>> + if (err)
>> + return err;
>> + }
>>
>> - res = watchdog_register_device(&at91_wdt_dev);
>> - if (res)
>> - return res;
>> + err = at91_wdt_init(pdev, wdt);
>> + if (err)
>> + return err;
>>
>> - at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout * HZ;
>> - setup_timer(&at91wdt_private.timer, at91_ping, 0);
>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>> + platform_set_drvdata(pdev, wdt);
>>
>> pr_info("enabled (heartbeat=%d sec, nowayout=%d)\n",
>> - at91_wdt_dev.timeout, nowayout);
>> + wdt->wdd.timeout, wdt->nowayout);
>>
>> return 0;
>> }
>>
>> static int __exit at91wdt_remove(struct platform_device *pdev)
>> {
>> - watchdog_unregister_device(&at91_wdt_dev);
>> + struct at91wdt *wdt = platform_get_drvdata(pdev);
>> + watchdog_unregister_device(&wdt->wdd);
>>
>> pr_warn("I quit now, hardware will probably reboot!\n");
>> - del_timer(&at91wdt_private.timer);
>> + del_timer(&wdt->timer);
>>
>> return 0;
>> }
>> --
>> 1.7.9.5
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
^ permalink raw reply [flat|nested] 19+ messages in thread* [PATCH 1/4] watchdog: at91sam9_wdt: better watchdog support
@ 2013-10-03 17:55 ` boris brezillon
0 siblings, 0 replies; 19+ messages in thread
From: boris brezillon @ 2013-10-03 17:55 UTC (permalink / raw)
To: linux-arm-kernel
Hi Guenter,
On 03/10/2013 19:31, Guenter Roeck wrote:
> On Thu, Oct 03, 2013 at 02:19:18PM +0200, Boris BREZILLON wrote:
>> The at91sam9 watchdog timer can only be configured once, and the current
>> implementation tries to configure it in a static way:
>> - 2 seconds timeout
>> - wdt restart every 500ms
>>
>> If the timer has already been configured with different values, it returns an
>> error and do not create any watchdog device.
>>
>> This is not critical if the watchdog is disabled, but if it has been enabled with
>> different timeout values it will lead to a SoC reset.
>>
>> This patch series tries to address this issue by adapting the heartbeat value
>> according the WDT timer config:
>> - it first tries to configure the timer as requested.
>> - if it fails it fallbacks to the current config, adapting its heartbeat timer
>> to the needs
>>
>> This patch series also move to a dynamically allocated at91wdt device instead
>> of the static instance.
>>
>> It adds a new at91 wdt type: software. This new type make use of the at91 wdt
>> interrupt to trigger a software reboot.
>>
>> Finally it adds several properties to the device tree bindings.
>>
>> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
> Hi Boris,
>
> deeper dive this time ...
>
>> ---
>> drivers/watchdog/at91sam9_wdt.c | 300 ++++++++++++++++++++++++++++-----------
>> 1 file changed, 217 insertions(+), 83 deletions(-)
>>
>> diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
>> index be37dde..8f44528 100644
>> --- a/drivers/watchdog/at91sam9_wdt.c
>> +++ b/drivers/watchdog/at91sam9_wdt.c
>> @@ -19,11 +19,13 @@
>>
>> #include <linux/errno.h>
>> #include <linux/init.h>
>> +#include <linux/interrupt.h>
>> #include <linux/io.h>
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> #include <linux/moduleparam.h>
>> #include <linux/platform_device.h>
>> +#include <linux/reboot.h>
>> #include <linux/types.h>
>> #include <linux/watchdog.h>
>> #include <linux/jiffies.h>
>> @@ -31,22 +33,33 @@
>> #include <linux/bitops.h>
>> #include <linux/uaccess.h>
>> #include <linux/of.h>
>> +#include <linux/of_irq.h>
>>
>> #include "at91sam9_wdt.h"
>>
>> #define DRV_NAME "AT91SAM9 Watchdog"
>>
>> -#define wdt_read(field) \
>> - __raw_readl(at91wdt_private.base + field)
>> -#define wdt_write(field, val) \
>> - __raw_writel((val), at91wdt_private.base + field)
>> +#define wdt_read(wdt, field) \
>> + __raw_readl((wdt)->base + (field))
>> +#define wdt_write(wtd, field, val) \
>> + __raw_writel((val), (wdt)->base + (field))
>>
>> /* AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
>> * use this to convert a watchdog
>> * value from/to milliseconds.
>> */
>> -#define ms_to_ticks(t) (((t << 8) / 1000) - 1)
>> -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
>> +#define ticks_to_hz_rounddown(t) ((((t) + 1) * HZ) >> 8)
>> +#define ticks_to_hz_roundup(t) (((((t) + 1) * HZ) + 255) >> 8)
>> +#define ticks_to_secs(t) (((t) + 1) >> 8)
>> +#define secs_to_ticks(s) (((s) << 8) - 1)
>> +
>> +#define WDT_MR_RESET 0x3FFF2FFF
>> +
>> +/* Watchdog max counter value in ticks */
>> +#define WDT_COUNTER_MAX_TICKS 0xFFF
>> +
>> +/* Watchdog max delta/value in secs */
>> +#define WDT_COUNTER_MAX_SECS ticks_to_secs(WDT_COUNTER_MAX_TICKS)
>>
>> /* Hardware timeout in seconds */
>> #define WDT_HW_TIMEOUT 2
>> @@ -66,23 +79,40 @@ module_param(nowayout, bool, 0);
>> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
>> "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>>
>> -static struct watchdog_device at91_wdt_dev;
>> -static void at91_ping(unsigned long data);
>> -
>> -static struct {
>> +#define to_wdt(wdd) container_of(wdd, struct at91wdt, wdd)
>> +struct at91wdt {
>> + struct watchdog_device wdd;
>> void __iomem *base;
>> unsigned long next_heartbeat; /* the next_heartbeat for the timer */
>> struct timer_list timer; /* The timer that pings the watchdog */
>> -} at91wdt_private;
>> + u32 mr;
>> + u32 mr_mask;
>> + unsigned long heartbeat; /* WDT heartbeat in jiffies */
>> + bool nowayout;
>> + unsigned int irq;
>> +};
>>
>> /* ......................................................................... */
>>
>> +static irqreturn_t wdt_interrupt(int irq, void *dev_id)
>> +{
>> + struct at91wdt *wdt = (struct at91wdt *)dev_id;
>> +
>> + if (wdt_read(wdt, AT91_WDT_SR)) {
>> + pr_crit("at91sam9 WDT software reset\n");
>> + emergency_restart();
>> + pr_crit("Reboot didn't ?????\n");
>> + }
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> /*
>> * Reload the watchdog timer. (ie, pat the watchdog)
>> */
>> -static inline void at91_wdt_reset(void)
>> +static inline void at91_wdt_reset(struct at91wdt *wdt)
>> {
>> - wdt_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>> + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>> }
>>
>> /*
>> @@ -90,26 +120,20 @@ static inline void at91_wdt_reset(void)
>> */
>> static void at91_ping(unsigned long data)
>> {
>> - if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
>> - (!watchdog_active(&at91_wdt_dev))) {
>> - at91_wdt_reset();
>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>> + struct at91wdt *wdt = (struct at91wdt *)data;
>> + if (time_before(jiffies, wdt->next_heartbeat) ||
>> + !watchdog_active(&wdt->wdd)) {
>> + at91_wdt_reset(wdt);
>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>> } else
>> pr_crit("I will reset your machine !\n");
>> }
>>
>> static int at91_wdt_ping(struct watchdog_device *wdd)
>> {
>> + struct at91wdt *wdt = to_wdt(wdd);
>> /* calculate when the next userspace timeout will be */
>> - at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
>> - return 0;
>> -}
>> -
>> -static int at91_wdt_start(struct watchdog_device *wdd)
>> -{
>> - /* calculate the next userspace timeout and modify the timer */
>> - at91_wdt_ping(wdd);
>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>> + wdt->next_heartbeat = jiffies + wdd->timeout * HZ;
>> return 0;
>> }
>>
>> @@ -125,36 +149,84 @@ static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int new_ti
> at91_wdt_set_timeout only sets the new timeout but does not update
> next_heartbeat. That is ok if the timeout decreases, but if it is
> increased (say, from 1 second to 1 minute) it might result in a missed
> ping as userspace will subsequently believe that the new (larger)
> timeout was accepted by the driver. So I think you should also call
> at91_wdt_ping here or set wdt->next_heartbeat directly.
Absolutely, I'll call at91_wdt_ping (or start as it will be renamed).
>> return 0;
>> }
>>
>> -/*
>> - * Set the watchdog time interval in 1/256Hz (write-once)
>> - * Counter is 12 bit.
>> - */
>> -static int at91_wdt_settimeout(unsigned int timeout)
>> +static int at91_wdt_init(struct platform_device *pdev, struct at91wdt *wdt)
>> {
>> - unsigned int reg;
>> - unsigned int mr;
>> -
>> - /* Check if disabled */
>> - mr = wdt_read(AT91_WDT_MR);
>> - if (mr & AT91_WDT_WDDIS) {
>> - pr_err("sorry, watchdog is disabled\n");
>> - return -EIO;
>> + u32 tmp;
>> + u32 delta;
>> + u32 value;
>> + int err;
>> + u32 mask = wdt->mr_mask;
>> + unsigned long min_heartbeat = 1;
>> +
>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>> + if ((tmp & mask) != (wdt->mr & mask)) {
>> + if (tmp == WDT_MR_RESET) {
>> + wdt_write(wdt, AT91_WDT_MR, wdt->mr);
>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>> + }
>> }
>>
>> - /*
>> - * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
>> - *
>> - * Since WDV is a 12-bit counter, the maximum period is
>> - * 4096 / 256 = 16 seconds.
>> - */
>> - reg = AT91_WDT_WDRSTEN /* causes watchdog reset */
>> - /* | AT91_WDT_WDRPROC causes processor reset only */
>> - | AT91_WDT_WDDBGHLT /* disabled in debug mode */
>> - | AT91_WDT_WDD /* restart at any time */
>> - | (timeout & AT91_WDT_WDV); /* timer value */
>> - wdt_write(AT91_WDT_MR, reg);
>> + if (tmp & AT91_WDT_WDDIS) {
>> + if (wdt->mr & AT91_WDT_WDDIS)
>> + return 0;
>> + dev_err(wdt->wdd.parent, "watchdog is disabled\n");
> Took me a while to get why you use "wdt->wdd.parent" :).
> I would just have passed the 'dev' argument. Your call, though.
I can't use wdt->wdd.dev, because the watchdog device is not registered yet,
but I can use &pdev->dev instead.
What do you prefer ?
>> + return -EINVAL;
>> + }
>> +
>> + value = tmp & AT91_WDT_WDV;
>> + delta = (tmp & AT91_WDT_WDD) >> 16;
>> +
>> + if (delta < value)
>> + min_heartbeat = ticks_to_hz_roundup(value - delta);
>> +
>> + wdt->heartbeat = ticks_to_hz_rounddown(value);
>> + if (!wdt->heartbeat) {
>> + dev_err(wdt->wdd.parent,
>> + "heartbeat is too small for the system to handle it correctly\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (wdt->heartbeat < min_heartbeat + 3) {
>> + wdt->heartbeat = min_heartbeat;
>> + dev_warn(wdt->wdd.parent,
>> + "min heartbeat and max heartbeat might be too close for the system to handle it correctly\n");
>> + if (wdt->heartbeat < 4)
>> + dev_warn(wdt->wdd.parent,
>> + "heartbeat might be too small for the system to handle it correctly\n");
>> + } else
>> + wdt->heartbeat -= 4;
> That means heartbeat can be 0, correct (if min_heartbeat == 1) ?
Yes, this is a mistake. It should be
if (wdt->heartbeat < min_heartbeat + 4) {
...
}
> Will that work ?
Absolutely not :)
I'll fix it.
>
>> +
>> + if ((tmp & AT91_WDT_WDFIEN) && wdt->irq) {
>> + err = request_irq(wdt->irq, wdt_interrupt,
>> + IRQF_SHARED | IRQF_IRQPOLL,
>> + pdev->name, wdt);
>> + if (err)
>> + return err;
>> + }
>> +
>> + if ((tmp & wdt->mr_mask) != (wdt->mr & wdt->mr_mask))
>> + dev_warn(wdt->wdd.parent,
>> + "watchdog already configured differently (mr = %x expecting %x)\n",
>> + tmp & wdt->mr_mask, wdt->mr & wdt->mr_mask);
>> +
>> + setup_timer(&wdt->timer, at91_ping, (unsigned long)wdt);
>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>> +
>> + /* Try to set timeout from device tree first */
>> + if (watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev))
>> + watchdog_init_timeout(&wdt->wdd, heartbeat, &pdev->dev);
>> + watchdog_set_nowayout(&wdt->wdd, wdt->nowayout);
>> + err = watchdog_register_device(&wdt->wdd);
>> + if (err)
>> + goto out_stop_timer;
>> +
>> + wdt->next_heartbeat = jiffies + wdt->wdd.timeout * HZ;
>>
>> return 0;
>> +
>> +out_stop_timer:
>> + del_timer(&wdt->timer);
>> + return err;
>> }
>>
>> /* ......................................................................... */
>> @@ -167,63 +239,125 @@ static const struct watchdog_info at91_wdt_info = {
>>
>> static const struct watchdog_ops at91_wdt_ops = {
>> .owner = THIS_MODULE,
>> - .start = at91_wdt_start,
>> + .start = at91_wdt_ping,
>> .stop = at91_wdt_stop,
>> .ping = at91_wdt_ping,
> Notpick, but you don't need both start and ping. If both are the same, providing
> start is sufficient. Given this, it might be cleaner to name the function
> at91_wdt_start and not provide ping.
I'll change this too.
Thanks, for catching these bugs.
Regards,
Boris
>> .set_timeout = at91_wdt_set_timeout,
>> };
>>
>> -static struct watchdog_device at91_wdt_dev = {
>> - .info = &at91_wdt_info,
>> - .ops = &at91_wdt_ops,
>> - .timeout = WDT_HEARTBEAT,
>> - .min_timeout = 1,
>> - .max_timeout = 0xFFFF,
>> -};
>> +#if defined(CONFIG_OF)
>> +static int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
>> +{
>> + u32 min = 0;
>> + u32 max = WDT_COUNTER_MAX_SECS;
>> + const char *tmp;
>> +
>> + /* Get the interrupts property */
>> + wdt->irq = irq_of_parse_and_map(np, 0);
>> + if (!wdt->irq)
>> + dev_warn(wdt->wdd.parent, "failed to get IRQ from DT\n");
>> +
>> + if (!of_property_read_u32_index(np, "atmel,max-heartbeat-sec", 0,
>> + &max)) {
>> + if (!max || max > WDT_COUNTER_MAX_SECS)
>> + max = WDT_COUNTER_MAX_SECS;
>> +
>> + if (!of_property_read_u32_index(np, "atmel,min-heartbeat-sec",
>> + 0, &min)) {
>> + if (min >= max)
>> + min = max - 1;
>> + }
>> + }
>> +
>> + min = secs_to_ticks(min);
>> + max = secs_to_ticks(max);
>> +
>> + wdt->mr_mask = 0x3FFFFFFF;
>> + wdt->mr = 0;
>> + if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
>> + !strcmp(tmp, "software")) {
>> + wdt->mr |= AT91_WDT_WDFIEN;
>> + wdt->mr_mask &= ~AT91_WDT_WDRPROC;
>> + } else
>> + wdt->mr |= AT91_WDT_WDRSTEN;
>> +
>> + if (!of_property_read_string(np, "atmel,reset-type", &tmp) &&
>> + !strcmp(tmp, "proc"))
>> + wdt->mr |= AT91_WDT_WDRPROC;
>> +
>> + if (of_property_read_bool(np, "atmel,disable")) {
>> + wdt->mr |= AT91_WDT_WDDIS;
>> + wdt->mr_mask &= AT91_WDT_WDDIS;
>> + }
>> +
>> + 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;
>> +
>> + wdt->mr |= max | ((max - min) << 16);
>> +
>> + return 0;
>> +}
>> +#else
>> +static inline int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
>> +{
>> + return 0;
>> +}
>> +#endif
>>
>> static int __init at91wdt_probe(struct platform_device *pdev)
>> {
>> struct resource *r;
>> - int res;
>> + int err;
>> + struct at91wdt *wdt;
>>
>> - r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> - if (!r)
>> - return -ENODEV;
>> - at91wdt_private.base = ioremap(r->start, resource_size(r));
>> - if (!at91wdt_private.base) {
>> - dev_err(&pdev->dev, "failed to map registers, aborting.\n");
>> + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
>> + if (!wdt)
>> return -ENOMEM;
>> - }
>>
>> - at91_wdt_dev.parent = &pdev->dev;
>> - watchdog_init_timeout(&at91_wdt_dev, heartbeat, &pdev->dev);
>> - watchdog_set_nowayout(&at91_wdt_dev, nowayout);
>> + wdt->mr = (WDT_HW_TIMEOUT * 256) | AT91_WDT_WDRSTEN | AT91_WDT_WDD |
>> + AT91_WDT_WDDBGHLT | AT91_WDT_WDIDLEHLT;
>> + wdt->mr_mask = 0x3FFFFFFF;
>> + wdt->nowayout = nowayout;
>> + wdt->wdd.parent = &pdev->dev;
>> + wdt->wdd.info = &at91_wdt_info;
>> + wdt->wdd.ops = &at91_wdt_ops;
>> + wdt->wdd.timeout = WDT_HEARTBEAT;
>> + wdt->wdd.min_timeout = 1;
>> + wdt->wdd.max_timeout = 0xFFFF;
>>
>> - /* Set watchdog */
>> - res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
>> - if (res)
>> - return res;
>> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + wdt->base = devm_ioremap_resource(&pdev->dev, r);
>> + if (IS_ERR(wdt->base))
>> + return PTR_ERR(wdt->base);
>> +
>> + if (pdev->dev.of_node) {
>> + err = of_at91wdt_init(pdev->dev.of_node, wdt);
>> + if (err)
>> + return err;
>> + }
>>
>> - res = watchdog_register_device(&at91_wdt_dev);
>> - if (res)
>> - return res;
>> + err = at91_wdt_init(pdev, wdt);
>> + if (err)
>> + return err;
>>
>> - at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout * HZ;
>> - setup_timer(&at91wdt_private.timer, at91_ping, 0);
>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>> + platform_set_drvdata(pdev, wdt);
>>
>> pr_info("enabled (heartbeat=%d sec, nowayout=%d)\n",
>> - at91_wdt_dev.timeout, nowayout);
>> + wdt->wdd.timeout, wdt->nowayout);
>>
>> return 0;
>> }
>>
>> static int __exit at91wdt_remove(struct platform_device *pdev)
>> {
>> - watchdog_unregister_device(&at91_wdt_dev);
>> + struct at91wdt *wdt = platform_get_drvdata(pdev);
>> + watchdog_unregister_device(&wdt->wdd);
>>
>> pr_warn("I quit now, hardware will probably reboot!\n");
>> - del_timer(&at91wdt_private.timer);
>> + del_timer(&wdt->timer);
>>
>> return 0;
>> }
>> --
>> 1.7.9.5
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
>> the body of a message to majordomo at vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 1/4] watchdog: at91sam9_wdt: better watchdog support
2013-10-03 17:55 ` boris brezillon
@ 2013-10-03 18:33 ` boris brezillon
-1 siblings, 0 replies; 19+ messages in thread
From: boris brezillon @ 2013-10-03 18:33 UTC (permalink / raw)
To: boris brezillon, Guenter Roeck
Cc: Mark Rutland, devicetree, Russell King, linux-doc, Pawel Moll,
Ian Campbell, Stephen Warren, Nicolas Ferre, linux-kernel,
Rob Herring, Yang Wenyou, Wim Van Sebroeck, Fabio Porcedda,
linux-arm-kernel, Rob Landley, Guenter Roeck, linux-watchdog
On 03/10/2013 19:55, boris brezillon wrote:
> Hi Guenter,
>
> On 03/10/2013 19:31, Guenter Roeck wrote:
>> On Thu, Oct 03, 2013 at 02:19:18PM +0200, Boris BREZILLON wrote:
>>> The at91sam9 watchdog timer can only be configured once, and the current
>>> implementation tries to configure it in a static way:
>>> - 2 seconds timeout
>>> - wdt restart every 500ms
>>>
>>> If the timer has already been configured with different values, it
>>> returns an
>>> error and do not create any watchdog device.
>>>
>>> This is not critical if the watchdog is disabled, but if it has been
>>> enabled with
>>> different timeout values it will lead to a SoC reset.
>>>
>>> This patch series tries to address this issue by adapting the
>>> heartbeat value
>>> according the WDT timer config:
>>> - it first tries to configure the timer as requested.
>>> - if it fails it fallbacks to the current config, adapting its
>>> heartbeat timer
>>> to the needs
>>>
>>> This patch series also move to a dynamically allocated at91wdt device
>>> instead
>>> of the static instance.
>>>
>>> It adds a new at91 wdt type: software. This new type make use of the
>>> at91 wdt
>>> interrupt to trigger a software reboot.
>>>
>>> Finally it adds several properties to the device tree bindings.
>>>
>>> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
>> Hi Boris,
>>
>> deeper dive this time ...
>>
>>> ---
>>> drivers/watchdog/at91sam9_wdt.c | 300
>>> ++++++++++++++++++++++++++++-----------
>>> 1 file changed, 217 insertions(+), 83 deletions(-)
>>>
>>> diff --git a/drivers/watchdog/at91sam9_wdt.c
>>> b/drivers/watchdog/at91sam9_wdt.c
>>> index be37dde..8f44528 100644
>>> --- a/drivers/watchdog/at91sam9_wdt.c
>>> +++ b/drivers/watchdog/at91sam9_wdt.c
>>> @@ -19,11 +19,13 @@
>>> #include <linux/errno.h>
>>> #include <linux/init.h>
>>> +#include <linux/interrupt.h>
>>> #include <linux/io.h>
>>> #include <linux/kernel.h>
>>> #include <linux/module.h>
>>> #include <linux/moduleparam.h>
>>> #include <linux/platform_device.h>
>>> +#include <linux/reboot.h>
>>> #include <linux/types.h>
>>> #include <linux/watchdog.h>
>>> #include <linux/jiffies.h>
>>> @@ -31,22 +33,33 @@
>>> #include <linux/bitops.h>
>>> #include <linux/uaccess.h>
>>> #include <linux/of.h>
>>> +#include <linux/of_irq.h>
>>> #include "at91sam9_wdt.h"
>>> #define DRV_NAME "AT91SAM9 Watchdog"
>>> -#define wdt_read(field) \
>>> - __raw_readl(at91wdt_private.base + field)
>>> -#define wdt_write(field, val) \
>>> - __raw_writel((val), at91wdt_private.base + field)
>>> +#define wdt_read(wdt, field) \
>>> + __raw_readl((wdt)->base + (field))
>>> +#define wdt_write(wtd, field, val) \
>>> + __raw_writel((val), (wdt)->base + (field))
>>> /* AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
>>> * use this to convert a watchdog
>>> * value from/to milliseconds.
>>> */
>>> -#define ms_to_ticks(t) (((t << 8) / 1000) - 1)
>>> -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
>>> +#define ticks_to_hz_rounddown(t) ((((t) + 1) * HZ) >> 8)
>>> +#define ticks_to_hz_roundup(t) (((((t) + 1) * HZ) + 255) >> 8)
>>> +#define ticks_to_secs(t) (((t) + 1) >> 8)
>>> +#define secs_to_ticks(s) (((s) << 8) - 1)
>>> +
>>> +#define WDT_MR_RESET 0x3FFF2FFF
>>> +
>>> +/* Watchdog max counter value in ticks */
>>> +#define WDT_COUNTER_MAX_TICKS 0xFFF
>>> +
>>> +/* Watchdog max delta/value in secs */
>>> +#define WDT_COUNTER_MAX_SECS ticks_to_secs(WDT_COUNTER_MAX_TICKS)
>>> /* Hardware timeout in seconds */
>>> #define WDT_HW_TIMEOUT 2
>>> @@ -66,23 +79,40 @@ module_param(nowayout, bool, 0);
>>> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
>>> "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>>> -static struct watchdog_device at91_wdt_dev;
>>> -static void at91_ping(unsigned long data);
>>> -
>>> -static struct {
>>> +#define to_wdt(wdd) container_of(wdd, struct at91wdt, wdd)
>>> +struct at91wdt {
>>> + struct watchdog_device wdd;
>>> void __iomem *base;
>>> unsigned long next_heartbeat; /* the next_heartbeat for the
>>> timer */
>>> struct timer_list timer; /* The timer that pings the
>>> watchdog */
>>> -} at91wdt_private;
>>> + u32 mr;
>>> + u32 mr_mask;
>>> + unsigned long heartbeat; /* WDT heartbeat in jiffies */
>>> + bool nowayout;
>>> + unsigned int irq;
>>> +};
>>> /*
>>> .........................................................................
>>> */
>>> +static irqreturn_t wdt_interrupt(int irq, void *dev_id)
>>> +{
>>> + struct at91wdt *wdt = (struct at91wdt *)dev_id;
>>> +
>>> + if (wdt_read(wdt, AT91_WDT_SR)) {
>>> + pr_crit("at91sam9 WDT software reset\n");
>>> + emergency_restart();
>>> + pr_crit("Reboot didn't ?????\n");
>>> + }
>>> +
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> /*
>>> * Reload the watchdog timer. (ie, pat the watchdog)
>>> */
>>> -static inline void at91_wdt_reset(void)
>>> +static inline void at91_wdt_reset(struct at91wdt *wdt)
>>> {
>>> - wdt_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>>> + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>>> }
>>> /*
>>> @@ -90,26 +120,20 @@ static inline void at91_wdt_reset(void)
>>> */
>>> static void at91_ping(unsigned long data)
>>> {
>>> - if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
>>> - (!watchdog_active(&at91_wdt_dev))) {
>>> - at91_wdt_reset();
>>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>>> + struct at91wdt *wdt = (struct at91wdt *)data;
>>> + if (time_before(jiffies, wdt->next_heartbeat) ||
>>> + !watchdog_active(&wdt->wdd)) {
>>> + at91_wdt_reset(wdt);
>>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>>> } else
>>> pr_crit("I will reset your machine !\n");
>>> }
>>> static int at91_wdt_ping(struct watchdog_device *wdd)
>>> {
>>> + struct at91wdt *wdt = to_wdt(wdd);
>>> /* calculate when the next userspace timeout will be */
>>> - at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
>>> - return 0;
>>> -}
>>> -
>>> -static int at91_wdt_start(struct watchdog_device *wdd)
>>> -{
>>> - /* calculate the next userspace timeout and modify the timer */
>>> - at91_wdt_ping(wdd);
>>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>>> + wdt->next_heartbeat = jiffies + wdd->timeout * HZ;
>>> return 0;
>>> }
>>> @@ -125,36 +149,84 @@ static int at91_wdt_set_timeout(struct
>>> watchdog_device *wdd, unsigned int new_ti
>> at91_wdt_set_timeout only sets the new timeout but does not update
>> next_heartbeat. That is ok if the timeout decreases, but if it is
>> increased (say, from 1 second to 1 minute) it might result in a missed
>> ping as userspace will subsequently believe that the new (larger)
>> timeout was accepted by the driver. So I think you should also call
>> at91_wdt_ping here or set wdt->next_heartbeat directly.
> Absolutely, I'll call at91_wdt_ping (or start as it will be renamed).
>
>>> return 0;
>>> }
>>> -/*
>>> - * Set the watchdog time interval in 1/256Hz (write-once)
>>> - * Counter is 12 bit.
>>> - */
>>> -static int at91_wdt_settimeout(unsigned int timeout)
>>> +static int at91_wdt_init(struct platform_device *pdev, struct
>>> at91wdt *wdt)
>>> {
>>> - unsigned int reg;
>>> - unsigned int mr;
>>> -
>>> - /* Check if disabled */
>>> - mr = wdt_read(AT91_WDT_MR);
>>> - if (mr & AT91_WDT_WDDIS) {
>>> - pr_err("sorry, watchdog is disabled\n");
>>> - return -EIO;
>>> + u32 tmp;
>>> + u32 delta;
>>> + u32 value;
>>> + int err;
>>> + u32 mask = wdt->mr_mask;
>>> + unsigned long min_heartbeat = 1;
>>> +
>>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>>> + if ((tmp & mask) != (wdt->mr & mask)) {
>>> + if (tmp == WDT_MR_RESET) {
>>> + wdt_write(wdt, AT91_WDT_MR, wdt->mr);
>>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>>> + }
>>> }
>>> - /*
>>> - * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
>>> - *
>>> - * Since WDV is a 12-bit counter, the maximum period is
>>> - * 4096 / 256 = 16 seconds.
>>> - */
>>> - reg = AT91_WDT_WDRSTEN /* causes watchdog reset */
>>> - /* | AT91_WDT_WDRPROC causes processor reset only */
>>> - | AT91_WDT_WDDBGHLT /* disabled in debug mode */
>>> - | AT91_WDT_WDD /* restart at any time */
>>> - | (timeout & AT91_WDT_WDV); /* timer value */
>>> - wdt_write(AT91_WDT_MR, reg);
>>> + if (tmp & AT91_WDT_WDDIS) {
>>> + if (wdt->mr & AT91_WDT_WDDIS)
>>> + return 0;
>>> + dev_err(wdt->wdd.parent, "watchdog is disabled\n");
>> Took me a while to get why you use "wdt->wdd.parent" :).
>> I would just have passed the 'dev' argument. Your call, though.
>
> I can't use wdt->wdd.dev, because the watchdog device is not registered
> yet,
> but I can use &pdev->dev instead.
> What do you prefer ?
Oops. I should have read your mail more carefully, I though you were
talking about using the dev field of the wdd struct.
I still prefer using wdt->wdd.parent or &pdev->dev rather (or declare a
struct device *dev = &pdev->dev) rather than passing an additional
'struct device *' argument.
>
>>> + return -EINVAL;
>>> + }
>>> +
>>> + value = tmp & AT91_WDT_WDV;
>>> + delta = (tmp & AT91_WDT_WDD) >> 16;
>>> +
>>> + if (delta < value)
>>> + min_heartbeat = ticks_to_hz_roundup(value - delta);
>>> +
>>> + wdt->heartbeat = ticks_to_hz_rounddown(value);
>>> + if (!wdt->heartbeat) {
>>> + dev_err(wdt->wdd.parent,
>>> + "heartbeat is too small for the system to handle it
>>> correctly\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (wdt->heartbeat < min_heartbeat + 3) {
>>> + wdt->heartbeat = min_heartbeat;
>>> + dev_warn(wdt->wdd.parent,
>>> + "min heartbeat and max heartbeat might be too close for
>>> the system to handle it correctly\n");
>>> + if (wdt->heartbeat < 4)
>>> + dev_warn(wdt->wdd.parent,
>>> + "heartbeat might be too small for the system to
>>> handle it correctly\n");
>>> + } else
>>> + wdt->heartbeat -= 4;
>> That means heartbeat can be 0, correct (if min_heartbeat == 1) ?
> Yes, this is a mistake. It should be
>
> if (wdt->heartbeat < min_heartbeat + 4) {
> ...
> }
>
>> Will that work ?
> Absolutely not :)
> I'll fix it.
>
>>
>>> +
>>> + if ((tmp & AT91_WDT_WDFIEN) && wdt->irq) {
>>> + err = request_irq(wdt->irq, wdt_interrupt,
>>> + IRQF_SHARED | IRQF_IRQPOLL,
>>> + pdev->name, wdt);
>>> + if (err)
>>> + return err;
>>> + }
>>> +
>>> + if ((tmp & wdt->mr_mask) != (wdt->mr & wdt->mr_mask))
>>> + dev_warn(wdt->wdd.parent,
>>> + "watchdog already configured differently (mr = %x
>>> expecting %x)\n",
>>> + tmp & wdt->mr_mask, wdt->mr & wdt->mr_mask);
>>> +
>>> + setup_timer(&wdt->timer, at91_ping, (unsigned long)wdt);
>>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>>> +
>>> + /* Try to set timeout from device tree first */
>>> + if (watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev))
>>> + watchdog_init_timeout(&wdt->wdd, heartbeat, &pdev->dev);
>>> + watchdog_set_nowayout(&wdt->wdd, wdt->nowayout);
>>> + err = watchdog_register_device(&wdt->wdd);
>>> + if (err)
>>> + goto out_stop_timer;
>>> +
>>> + wdt->next_heartbeat = jiffies + wdt->wdd.timeout * HZ;
>>> return 0;
>>> +
>>> +out_stop_timer:
>>> + del_timer(&wdt->timer);
>>> + return err;
>>> }
>>> /*
>>> .........................................................................
>>> */
>>> @@ -167,63 +239,125 @@ static const struct watchdog_info
>>> at91_wdt_info = {
>>> static const struct watchdog_ops at91_wdt_ops = {
>>> .owner = THIS_MODULE,
>>> - .start = at91_wdt_start,
>>> + .start = at91_wdt_ping,
>>> .stop = at91_wdt_stop,
>>> .ping = at91_wdt_ping,
>> Notpick, but you don't need both start and ping. If both are the same,
>> providing
>> start is sufficient. Given this, it might be cleaner to name the function
>> at91_wdt_start and not provide ping.
> I'll change this too.
>
> Thanks, for catching these bugs.
>
> Regards,
>
> Boris
>
>>> .set_timeout = at91_wdt_set_timeout,
>>> };
>>> -static struct watchdog_device at91_wdt_dev = {
>>> - .info = &at91_wdt_info,
>>> - .ops = &at91_wdt_ops,
>>> - .timeout = WDT_HEARTBEAT,
>>> - .min_timeout = 1,
>>> - .max_timeout = 0xFFFF,
>>> -};
>>> +#if defined(CONFIG_OF)
>>> +static int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
>>> +{
>>> + u32 min = 0;
>>> + u32 max = WDT_COUNTER_MAX_SECS;
>>> + const char *tmp;
>>> +
>>> + /* Get the interrupts property */
>>> + wdt->irq = irq_of_parse_and_map(np, 0);
>>> + if (!wdt->irq)
>>> + dev_warn(wdt->wdd.parent, "failed to get IRQ from DT\n");
>>> +
>>> + if (!of_property_read_u32_index(np, "atmel,max-heartbeat-sec", 0,
>>> + &max)) {
>>> + if (!max || max > WDT_COUNTER_MAX_SECS)
>>> + max = WDT_COUNTER_MAX_SECS;
>>> +
>>> + if (!of_property_read_u32_index(np, "atmel,min-heartbeat-sec",
>>> + 0, &min)) {
>>> + if (min >= max)
>>> + min = max - 1;
>>> + }
>>> + }
>>> +
>>> + min = secs_to_ticks(min);
>>> + max = secs_to_ticks(max);
>>> +
>>> + wdt->mr_mask = 0x3FFFFFFF;
>>> + wdt->mr = 0;
>>> + if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
>>> + !strcmp(tmp, "software")) {
>>> + wdt->mr |= AT91_WDT_WDFIEN;
>>> + wdt->mr_mask &= ~AT91_WDT_WDRPROC;
>>> + } else
>>> + wdt->mr |= AT91_WDT_WDRSTEN;
>>> +
>>> + if (!of_property_read_string(np, "atmel,reset-type", &tmp) &&
>>> + !strcmp(tmp, "proc"))
>>> + wdt->mr |= AT91_WDT_WDRPROC;
>>> +
>>> + if (of_property_read_bool(np, "atmel,disable")) {
>>> + wdt->mr |= AT91_WDT_WDDIS;
>>> + wdt->mr_mask &= AT91_WDT_WDDIS;
>>> + }
>>> +
>>> + 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;
>>> +
>>> + wdt->mr |= max | ((max - min) << 16);
>>> +
>>> + return 0;
>>> +}
>>> +#else
>>> +static inline int of_at91wdt_init(struct device_node *np, struct
>>> at91wdt *wdt)
>>> +{
>>> + return 0;
>>> +}
>>> +#endif
>>> static int __init at91wdt_probe(struct platform_device *pdev)
>>> {
>>> struct resource *r;
>>> - int res;
>>> + int err;
>>> + struct at91wdt *wdt;
>>> - r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> - if (!r)
>>> - return -ENODEV;
>>> - at91wdt_private.base = ioremap(r->start, resource_size(r));
>>> - if (!at91wdt_private.base) {
>>> - dev_err(&pdev->dev, "failed to map registers, aborting.\n");
>>> + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
>>> + if (!wdt)
>>> return -ENOMEM;
>>> - }
>>> - at91_wdt_dev.parent = &pdev->dev;
>>> - watchdog_init_timeout(&at91_wdt_dev, heartbeat, &pdev->dev);
>>> - watchdog_set_nowayout(&at91_wdt_dev, nowayout);
>>> + wdt->mr = (WDT_HW_TIMEOUT * 256) | AT91_WDT_WDRSTEN |
>>> AT91_WDT_WDD |
>>> + AT91_WDT_WDDBGHLT | AT91_WDT_WDIDLEHLT;
>>> + wdt->mr_mask = 0x3FFFFFFF;
>>> + wdt->nowayout = nowayout;
>>> + wdt->wdd.parent = &pdev->dev;
>>> + wdt->wdd.info = &at91_wdt_info;
>>> + wdt->wdd.ops = &at91_wdt_ops;
>>> + wdt->wdd.timeout = WDT_HEARTBEAT;
>>> + wdt->wdd.min_timeout = 1;
>>> + wdt->wdd.max_timeout = 0xFFFF;
>>> - /* Set watchdog */
>>> - res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
>>> - if (res)
>>> - return res;
>>> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + wdt->base = devm_ioremap_resource(&pdev->dev, r);
>>> + if (IS_ERR(wdt->base))
>>> + return PTR_ERR(wdt->base);
>>> +
>>> + if (pdev->dev.of_node) {
>>> + err = of_at91wdt_init(pdev->dev.of_node, wdt);
>>> + if (err)
>>> + return err;
>>> + }
>>> - res = watchdog_register_device(&at91_wdt_dev);
>>> - if (res)
>>> - return res;
>>> + err = at91_wdt_init(pdev, wdt);
>>> + if (err)
>>> + return err;
>>> - at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout
>>> * HZ;
>>> - setup_timer(&at91wdt_private.timer, at91_ping, 0);
>>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>>> + platform_set_drvdata(pdev, wdt);
>>> pr_info("enabled (heartbeat=%d sec, nowayout=%d)\n",
>>> - at91_wdt_dev.timeout, nowayout);
>>> + wdt->wdd.timeout, wdt->nowayout);
>>> return 0;
>>> }
>>> static int __exit at91wdt_remove(struct platform_device *pdev)
>>> {
>>> - watchdog_unregister_device(&at91_wdt_dev);
>>> + struct at91wdt *wdt = platform_get_drvdata(pdev);
>>> + watchdog_unregister_device(&wdt->wdd);
>>> pr_warn("I quit now, hardware will probably reboot!\n");
>>> - del_timer(&at91wdt_private.timer);
>>> + del_timer(&wdt->timer);
>>> return 0;
>>> }
>>> --
>>> 1.7.9.5
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe
>>> linux-watchdog" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 19+ messages in thread* [PATCH 1/4] watchdog: at91sam9_wdt: better watchdog support
@ 2013-10-03 18:33 ` boris brezillon
0 siblings, 0 replies; 19+ messages in thread
From: boris brezillon @ 2013-10-03 18:33 UTC (permalink / raw)
To: linux-arm-kernel
On 03/10/2013 19:55, boris brezillon wrote:
> Hi Guenter,
>
> On 03/10/2013 19:31, Guenter Roeck wrote:
>> On Thu, Oct 03, 2013 at 02:19:18PM +0200, Boris BREZILLON wrote:
>>> The at91sam9 watchdog timer can only be configured once, and the current
>>> implementation tries to configure it in a static way:
>>> - 2 seconds timeout
>>> - wdt restart every 500ms
>>>
>>> If the timer has already been configured with different values, it
>>> returns an
>>> error and do not create any watchdog device.
>>>
>>> This is not critical if the watchdog is disabled, but if it has been
>>> enabled with
>>> different timeout values it will lead to a SoC reset.
>>>
>>> This patch series tries to address this issue by adapting the
>>> heartbeat value
>>> according the WDT timer config:
>>> - it first tries to configure the timer as requested.
>>> - if it fails it fallbacks to the current config, adapting its
>>> heartbeat timer
>>> to the needs
>>>
>>> This patch series also move to a dynamically allocated at91wdt device
>>> instead
>>> of the static instance.
>>>
>>> It adds a new at91 wdt type: software. This new type make use of the
>>> at91 wdt
>>> interrupt to trigger a software reboot.
>>>
>>> Finally it adds several properties to the device tree bindings.
>>>
>>> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
>> Hi Boris,
>>
>> deeper dive this time ...
>>
>>> ---
>>> drivers/watchdog/at91sam9_wdt.c | 300
>>> ++++++++++++++++++++++++++++-----------
>>> 1 file changed, 217 insertions(+), 83 deletions(-)
>>>
>>> diff --git a/drivers/watchdog/at91sam9_wdt.c
>>> b/drivers/watchdog/at91sam9_wdt.c
>>> index be37dde..8f44528 100644
>>> --- a/drivers/watchdog/at91sam9_wdt.c
>>> +++ b/drivers/watchdog/at91sam9_wdt.c
>>> @@ -19,11 +19,13 @@
>>> #include <linux/errno.h>
>>> #include <linux/init.h>
>>> +#include <linux/interrupt.h>
>>> #include <linux/io.h>
>>> #include <linux/kernel.h>
>>> #include <linux/module.h>
>>> #include <linux/moduleparam.h>
>>> #include <linux/platform_device.h>
>>> +#include <linux/reboot.h>
>>> #include <linux/types.h>
>>> #include <linux/watchdog.h>
>>> #include <linux/jiffies.h>
>>> @@ -31,22 +33,33 @@
>>> #include <linux/bitops.h>
>>> #include <linux/uaccess.h>
>>> #include <linux/of.h>
>>> +#include <linux/of_irq.h>
>>> #include "at91sam9_wdt.h"
>>> #define DRV_NAME "AT91SAM9 Watchdog"
>>> -#define wdt_read(field) \
>>> - __raw_readl(at91wdt_private.base + field)
>>> -#define wdt_write(field, val) \
>>> - __raw_writel((val), at91wdt_private.base + field)
>>> +#define wdt_read(wdt, field) \
>>> + __raw_readl((wdt)->base + (field))
>>> +#define wdt_write(wtd, field, val) \
>>> + __raw_writel((val), (wdt)->base + (field))
>>> /* AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
>>> * use this to convert a watchdog
>>> * value from/to milliseconds.
>>> */
>>> -#define ms_to_ticks(t) (((t << 8) / 1000) - 1)
>>> -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
>>> +#define ticks_to_hz_rounddown(t) ((((t) + 1) * HZ) >> 8)
>>> +#define ticks_to_hz_roundup(t) (((((t) + 1) * HZ) + 255) >> 8)
>>> +#define ticks_to_secs(t) (((t) + 1) >> 8)
>>> +#define secs_to_ticks(s) (((s) << 8) - 1)
>>> +
>>> +#define WDT_MR_RESET 0x3FFF2FFF
>>> +
>>> +/* Watchdog max counter value in ticks */
>>> +#define WDT_COUNTER_MAX_TICKS 0xFFF
>>> +
>>> +/* Watchdog max delta/value in secs */
>>> +#define WDT_COUNTER_MAX_SECS ticks_to_secs(WDT_COUNTER_MAX_TICKS)
>>> /* Hardware timeout in seconds */
>>> #define WDT_HW_TIMEOUT 2
>>> @@ -66,23 +79,40 @@ module_param(nowayout, bool, 0);
>>> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
>>> "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>>> -static struct watchdog_device at91_wdt_dev;
>>> -static void at91_ping(unsigned long data);
>>> -
>>> -static struct {
>>> +#define to_wdt(wdd) container_of(wdd, struct at91wdt, wdd)
>>> +struct at91wdt {
>>> + struct watchdog_device wdd;
>>> void __iomem *base;
>>> unsigned long next_heartbeat; /* the next_heartbeat for the
>>> timer */
>>> struct timer_list timer; /* The timer that pings the
>>> watchdog */
>>> -} at91wdt_private;
>>> + u32 mr;
>>> + u32 mr_mask;
>>> + unsigned long heartbeat; /* WDT heartbeat in jiffies */
>>> + bool nowayout;
>>> + unsigned int irq;
>>> +};
>>> /*
>>> .........................................................................
>>> */
>>> +static irqreturn_t wdt_interrupt(int irq, void *dev_id)
>>> +{
>>> + struct at91wdt *wdt = (struct at91wdt *)dev_id;
>>> +
>>> + if (wdt_read(wdt, AT91_WDT_SR)) {
>>> + pr_crit("at91sam9 WDT software reset\n");
>>> + emergency_restart();
>>> + pr_crit("Reboot didn't ?????\n");
>>> + }
>>> +
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> /*
>>> * Reload the watchdog timer. (ie, pat the watchdog)
>>> */
>>> -static inline void at91_wdt_reset(void)
>>> +static inline void at91_wdt_reset(struct at91wdt *wdt)
>>> {
>>> - wdt_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>>> + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
>>> }
>>> /*
>>> @@ -90,26 +120,20 @@ static inline void at91_wdt_reset(void)
>>> */
>>> static void at91_ping(unsigned long data)
>>> {
>>> - if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
>>> - (!watchdog_active(&at91_wdt_dev))) {
>>> - at91_wdt_reset();
>>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>>> + struct at91wdt *wdt = (struct at91wdt *)data;
>>> + if (time_before(jiffies, wdt->next_heartbeat) ||
>>> + !watchdog_active(&wdt->wdd)) {
>>> + at91_wdt_reset(wdt);
>>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>>> } else
>>> pr_crit("I will reset your machine !\n");
>>> }
>>> static int at91_wdt_ping(struct watchdog_device *wdd)
>>> {
>>> + struct at91wdt *wdt = to_wdt(wdd);
>>> /* calculate when the next userspace timeout will be */
>>> - at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
>>> - return 0;
>>> -}
>>> -
>>> -static int at91_wdt_start(struct watchdog_device *wdd)
>>> -{
>>> - /* calculate the next userspace timeout and modify the timer */
>>> - at91_wdt_ping(wdd);
>>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>>> + wdt->next_heartbeat = jiffies + wdd->timeout * HZ;
>>> return 0;
>>> }
>>> @@ -125,36 +149,84 @@ static int at91_wdt_set_timeout(struct
>>> watchdog_device *wdd, unsigned int new_ti
>> at91_wdt_set_timeout only sets the new timeout but does not update
>> next_heartbeat. That is ok if the timeout decreases, but if it is
>> increased (say, from 1 second to 1 minute) it might result in a missed
>> ping as userspace will subsequently believe that the new (larger)
>> timeout was accepted by the driver. So I think you should also call
>> at91_wdt_ping here or set wdt->next_heartbeat directly.
> Absolutely, I'll call at91_wdt_ping (or start as it will be renamed).
>
>>> return 0;
>>> }
>>> -/*
>>> - * Set the watchdog time interval in 1/256Hz (write-once)
>>> - * Counter is 12 bit.
>>> - */
>>> -static int at91_wdt_settimeout(unsigned int timeout)
>>> +static int at91_wdt_init(struct platform_device *pdev, struct
>>> at91wdt *wdt)
>>> {
>>> - unsigned int reg;
>>> - unsigned int mr;
>>> -
>>> - /* Check if disabled */
>>> - mr = wdt_read(AT91_WDT_MR);
>>> - if (mr & AT91_WDT_WDDIS) {
>>> - pr_err("sorry, watchdog is disabled\n");
>>> - return -EIO;
>>> + u32 tmp;
>>> + u32 delta;
>>> + u32 value;
>>> + int err;
>>> + u32 mask = wdt->mr_mask;
>>> + unsigned long min_heartbeat = 1;
>>> +
>>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>>> + if ((tmp & mask) != (wdt->mr & mask)) {
>>> + if (tmp == WDT_MR_RESET) {
>>> + wdt_write(wdt, AT91_WDT_MR, wdt->mr);
>>> + tmp = wdt_read(wdt, AT91_WDT_MR);
>>> + }
>>> }
>>> - /*
>>> - * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
>>> - *
>>> - * Since WDV is a 12-bit counter, the maximum period is
>>> - * 4096 / 256 = 16 seconds.
>>> - */
>>> - reg = AT91_WDT_WDRSTEN /* causes watchdog reset */
>>> - /* | AT91_WDT_WDRPROC causes processor reset only */
>>> - | AT91_WDT_WDDBGHLT /* disabled in debug mode */
>>> - | AT91_WDT_WDD /* restart at any time */
>>> - | (timeout & AT91_WDT_WDV); /* timer value */
>>> - wdt_write(AT91_WDT_MR, reg);
>>> + if (tmp & AT91_WDT_WDDIS) {
>>> + if (wdt->mr & AT91_WDT_WDDIS)
>>> + return 0;
>>> + dev_err(wdt->wdd.parent, "watchdog is disabled\n");
>> Took me a while to get why you use "wdt->wdd.parent" :).
>> I would just have passed the 'dev' argument. Your call, though.
>
> I can't use wdt->wdd.dev, because the watchdog device is not registered
> yet,
> but I can use &pdev->dev instead.
> What do you prefer ?
Oops. I should have read your mail more carefully, I though you were
talking about using the dev field of the wdd struct.
I still prefer using wdt->wdd.parent or &pdev->dev rather (or declare a
struct device *dev = &pdev->dev) rather than passing an additional
'struct device *' argument.
>
>>> + return -EINVAL;
>>> + }
>>> +
>>> + value = tmp & AT91_WDT_WDV;
>>> + delta = (tmp & AT91_WDT_WDD) >> 16;
>>> +
>>> + if (delta < value)
>>> + min_heartbeat = ticks_to_hz_roundup(value - delta);
>>> +
>>> + wdt->heartbeat = ticks_to_hz_rounddown(value);
>>> + if (!wdt->heartbeat) {
>>> + dev_err(wdt->wdd.parent,
>>> + "heartbeat is too small for the system to handle it
>>> correctly\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (wdt->heartbeat < min_heartbeat + 3) {
>>> + wdt->heartbeat = min_heartbeat;
>>> + dev_warn(wdt->wdd.parent,
>>> + "min heartbeat and max heartbeat might be too close for
>>> the system to handle it correctly\n");
>>> + if (wdt->heartbeat < 4)
>>> + dev_warn(wdt->wdd.parent,
>>> + "heartbeat might be too small for the system to
>>> handle it correctly\n");
>>> + } else
>>> + wdt->heartbeat -= 4;
>> That means heartbeat can be 0, correct (if min_heartbeat == 1) ?
> Yes, this is a mistake. It should be
>
> if (wdt->heartbeat < min_heartbeat + 4) {
> ...
> }
>
>> Will that work ?
> Absolutely not :)
> I'll fix it.
>
>>
>>> +
>>> + if ((tmp & AT91_WDT_WDFIEN) && wdt->irq) {
>>> + err = request_irq(wdt->irq, wdt_interrupt,
>>> + IRQF_SHARED | IRQF_IRQPOLL,
>>> + pdev->name, wdt);
>>> + if (err)
>>> + return err;
>>> + }
>>> +
>>> + if ((tmp & wdt->mr_mask) != (wdt->mr & wdt->mr_mask))
>>> + dev_warn(wdt->wdd.parent,
>>> + "watchdog already configured differently (mr = %x
>>> expecting %x)\n",
>>> + tmp & wdt->mr_mask, wdt->mr & wdt->mr_mask);
>>> +
>>> + setup_timer(&wdt->timer, at91_ping, (unsigned long)wdt);
>>> + mod_timer(&wdt->timer, jiffies + wdt->heartbeat);
>>> +
>>> + /* Try to set timeout from device tree first */
>>> + if (watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev))
>>> + watchdog_init_timeout(&wdt->wdd, heartbeat, &pdev->dev);
>>> + watchdog_set_nowayout(&wdt->wdd, wdt->nowayout);
>>> + err = watchdog_register_device(&wdt->wdd);
>>> + if (err)
>>> + goto out_stop_timer;
>>> +
>>> + wdt->next_heartbeat = jiffies + wdt->wdd.timeout * HZ;
>>> return 0;
>>> +
>>> +out_stop_timer:
>>> + del_timer(&wdt->timer);
>>> + return err;
>>> }
>>> /*
>>> .........................................................................
>>> */
>>> @@ -167,63 +239,125 @@ static const struct watchdog_info
>>> at91_wdt_info = {
>>> static const struct watchdog_ops at91_wdt_ops = {
>>> .owner = THIS_MODULE,
>>> - .start = at91_wdt_start,
>>> + .start = at91_wdt_ping,
>>> .stop = at91_wdt_stop,
>>> .ping = at91_wdt_ping,
>> Notpick, but you don't need both start and ping. If both are the same,
>> providing
>> start is sufficient. Given this, it might be cleaner to name the function
>> at91_wdt_start and not provide ping.
> I'll change this too.
>
> Thanks, for catching these bugs.
>
> Regards,
>
> Boris
>
>>> .set_timeout = at91_wdt_set_timeout,
>>> };
>>> -static struct watchdog_device at91_wdt_dev = {
>>> - .info = &at91_wdt_info,
>>> - .ops = &at91_wdt_ops,
>>> - .timeout = WDT_HEARTBEAT,
>>> - .min_timeout = 1,
>>> - .max_timeout = 0xFFFF,
>>> -};
>>> +#if defined(CONFIG_OF)
>>> +static int of_at91wdt_init(struct device_node *np, struct at91wdt *wdt)
>>> +{
>>> + u32 min = 0;
>>> + u32 max = WDT_COUNTER_MAX_SECS;
>>> + const char *tmp;
>>> +
>>> + /* Get the interrupts property */
>>> + wdt->irq = irq_of_parse_and_map(np, 0);
>>> + if (!wdt->irq)
>>> + dev_warn(wdt->wdd.parent, "failed to get IRQ from DT\n");
>>> +
>>> + if (!of_property_read_u32_index(np, "atmel,max-heartbeat-sec", 0,
>>> + &max)) {
>>> + if (!max || max > WDT_COUNTER_MAX_SECS)
>>> + max = WDT_COUNTER_MAX_SECS;
>>> +
>>> + if (!of_property_read_u32_index(np, "atmel,min-heartbeat-sec",
>>> + 0, &min)) {
>>> + if (min >= max)
>>> + min = max - 1;
>>> + }
>>> + }
>>> +
>>> + min = secs_to_ticks(min);
>>> + max = secs_to_ticks(max);
>>> +
>>> + wdt->mr_mask = 0x3FFFFFFF;
>>> + wdt->mr = 0;
>>> + if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
>>> + !strcmp(tmp, "software")) {
>>> + wdt->mr |= AT91_WDT_WDFIEN;
>>> + wdt->mr_mask &= ~AT91_WDT_WDRPROC;
>>> + } else
>>> + wdt->mr |= AT91_WDT_WDRSTEN;
>>> +
>>> + if (!of_property_read_string(np, "atmel,reset-type", &tmp) &&
>>> + !strcmp(tmp, "proc"))
>>> + wdt->mr |= AT91_WDT_WDRPROC;
>>> +
>>> + if (of_property_read_bool(np, "atmel,disable")) {
>>> + wdt->mr |= AT91_WDT_WDDIS;
>>> + wdt->mr_mask &= AT91_WDT_WDDIS;
>>> + }
>>> +
>>> + 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;
>>> +
>>> + wdt->mr |= max | ((max - min) << 16);
>>> +
>>> + return 0;
>>> +}
>>> +#else
>>> +static inline int of_at91wdt_init(struct device_node *np, struct
>>> at91wdt *wdt)
>>> +{
>>> + return 0;
>>> +}
>>> +#endif
>>> static int __init at91wdt_probe(struct platform_device *pdev)
>>> {
>>> struct resource *r;
>>> - int res;
>>> + int err;
>>> + struct at91wdt *wdt;
>>> - r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> - if (!r)
>>> - return -ENODEV;
>>> - at91wdt_private.base = ioremap(r->start, resource_size(r));
>>> - if (!at91wdt_private.base) {
>>> - dev_err(&pdev->dev, "failed to map registers, aborting.\n");
>>> + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
>>> + if (!wdt)
>>> return -ENOMEM;
>>> - }
>>> - at91_wdt_dev.parent = &pdev->dev;
>>> - watchdog_init_timeout(&at91_wdt_dev, heartbeat, &pdev->dev);
>>> - watchdog_set_nowayout(&at91_wdt_dev, nowayout);
>>> + wdt->mr = (WDT_HW_TIMEOUT * 256) | AT91_WDT_WDRSTEN |
>>> AT91_WDT_WDD |
>>> + AT91_WDT_WDDBGHLT | AT91_WDT_WDIDLEHLT;
>>> + wdt->mr_mask = 0x3FFFFFFF;
>>> + wdt->nowayout = nowayout;
>>> + wdt->wdd.parent = &pdev->dev;
>>> + wdt->wdd.info = &at91_wdt_info;
>>> + wdt->wdd.ops = &at91_wdt_ops;
>>> + wdt->wdd.timeout = WDT_HEARTBEAT;
>>> + wdt->wdd.min_timeout = 1;
>>> + wdt->wdd.max_timeout = 0xFFFF;
>>> - /* Set watchdog */
>>> - res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
>>> - if (res)
>>> - return res;
>>> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + wdt->base = devm_ioremap_resource(&pdev->dev, r);
>>> + if (IS_ERR(wdt->base))
>>> + return PTR_ERR(wdt->base);
>>> +
>>> + if (pdev->dev.of_node) {
>>> + err = of_at91wdt_init(pdev->dev.of_node, wdt);
>>> + if (err)
>>> + return err;
>>> + }
>>> - res = watchdog_register_device(&at91_wdt_dev);
>>> - if (res)
>>> - return res;
>>> + err = at91_wdt_init(pdev, wdt);
>>> + if (err)
>>> + return err;
>>> - at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout
>>> * HZ;
>>> - setup_timer(&at91wdt_private.timer, at91_ping, 0);
>>> - mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
>>> + platform_set_drvdata(pdev, wdt);
>>> pr_info("enabled (heartbeat=%d sec, nowayout=%d)\n",
>>> - at91_wdt_dev.timeout, nowayout);
>>> + wdt->wdd.timeout, wdt->nowayout);
>>> return 0;
>>> }
>>> static int __exit at91wdt_remove(struct platform_device *pdev)
>>> {
>>> - watchdog_unregister_device(&at91_wdt_dev);
>>> + struct at91wdt *wdt = platform_get_drvdata(pdev);
>>> + watchdog_unregister_device(&wdt->wdd);
>>> pr_warn("I quit now, hardware will probably reboot!\n");
>>> - del_timer(&at91wdt_private.timer);
>>> + del_timer(&wdt->timer);
>>> return 0;
>>> }
>>> --
>>> 1.7.9.5
>>>
>>> --
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>>> linux-watchdog" in
>>> the body of a message to majordomo at vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>
>
> _______________________________________________
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> linux-arm-kernel at lists.infradead.org
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^ permalink raw reply [flat|nested] 19+ messages in thread