Re: [PATCH v2 1/2] watchdog: bcm281xx: Debugfs support

From: Wim Van Sebroeck
Date: Mon Jan 13 2014 - 14:22:37 EST


Hi Markus,

> On 6 January 2014 13:56, Markus Mayer <markus.mayer@xxxxxxxxxx> wrote:
> > This change introduces debugfs support for the BCM281xx watchdog driver.
> >
> > Signed-off-by: Markus Mayer <markus.mayer@xxxxxxxxxx>
> > ---
> > drivers/watchdog/Kconfig | 10 ++++
> > drivers/watchdog/bcm_kona_wdt.c | 108 +++++++++++++++++++++++++++++++++++++--
> > 2 files changed, 114 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> > index 10d188a..af8f7c7 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -1152,6 +1152,16 @@ config BCM_KONA_WDT
> > Say 'Y' or 'M' here to enable the driver. The module will be called
> > bcm_kona_wdt.
> >
> > +config BCM_KONA_WDT_DEBUG
> > + bool "DEBUGFS support for BCM Kona Watchdog"
> > + depends on BCM_KONA_WDT
> > + help
> > + If enabled, adds /sys/kernel/debug/bcm_kona_wdt/info which provides
> > + access to the driver's internal data structures as well as watchdog
> > + timer hardware registres.
> > +
> > + If in doubt, say 'N'.
> > +
> > config LANTIQ_WDT
> > tristate "Lantiq SoC watchdog"
> > depends on LANTIQ
> > diff --git a/drivers/watchdog/bcm_kona_wdt.c b/drivers/watchdog/bcm_kona_wdt.c
> > index 7e41a83..9c24809 100644
> > --- a/drivers/watchdog/bcm_kona_wdt.c
> > +++ b/drivers/watchdog/bcm_kona_wdt.c
> > @@ -11,6 +11,7 @@
> > * GNU General Public License for more details.
> > */
> >
> > +#include <linux/debugfs.h>
> > #include <linux/delay.h>
> > #include <linux/err.h>
> > #include <linux/io.h>
> > @@ -55,9 +56,13 @@ struct bcm_kona_wdt {
> > */
> > int resolution;
> > spinlock_t lock;
> > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG
> > + unsigned long busy_count;
> > + struct dentry *debugfs;
> > +#endif
> > };
> >
> > -static int secure_register_read(void __iomem *addr)
> > +static int secure_register_read(struct bcm_kona_wdt *wdt, uint32_t offset)
> > {
> > uint32_t val;
> > unsigned count = 0;
> > @@ -70,10 +75,16 @@ static int secure_register_read(void __iomem *addr)
> > do {
> > if (unlikely(count > 1))
> > udelay(5);
> > - val = readl_relaxed(addr);
> > + val = readl_relaxed(wdt->base + offset);
> > count++;
> > } while ((val & SECWDOG_WD_LOAD_FLAG) && count < SECWDOG_MAX_TRY);
> >
> > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG
> > + /* Remember the maximum number iterations due to WD_LOAD_FLAG */
> > + if (count > wdt->busy_count)
> > + wdt->busy_count = count;
> > +#endif
> > +
> > /* This is the only place we return a negative value. */
> > if (val & SECWDOG_WD_LOAD_FLAG)
> > return -ETIMEDOUT;
> > @@ -84,6 +95,93 @@ static int secure_register_read(void __iomem *addr)
> > return val;
> > }
> >
> > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG
> > +
> > +static int bcm_kona_wdt_dbg_show(struct seq_file *s, void *data)
> > +{
> > + int ctl_val, cur_val, ret;
> > + unsigned long flags;
> > + struct bcm_kona_wdt *wdt = s->private;
> > +
> > + if (!wdt)
> > + return seq_puts(s, "No device pointer\n");
> > +
> > + spin_lock_irqsave(&wdt->lock, flags);
> > + ctl_val = secure_register_read(wdt, SECWDOG_CTRL_REG);
> > + cur_val = secure_register_read(wdt, SECWDOG_COUNT_REG);
> > + spin_unlock_irqrestore(&wdt->lock, flags);
> > +
> > + if (ctl_val < 0 || cur_val < 0) {
> > + ret = seq_puts(s, "Error accessing hardware\n");
> > + } else {
> > + int ctl, cur, ctl_sec, cur_sec, res;
> > +
> > + ctl = ctl_val & SECWDOG_COUNT_MASK;
> > + res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT;
> > + cur = cur_val & SECWDOG_COUNT_MASK;
> > + ctl_sec = TICKS_TO_SECS(ctl, wdt);
> > + cur_sec = TICKS_TO_SECS(cur, wdt);
> > + ret = seq_printf(s, "Resolution: %d / %d\n"
> > + "Control: %d s / %d (%#x) ticks\n"
> > + "Current: %d s / %d (%#x) ticks\n"
> > + "Busy count: %lu\n", res,
> > + wdt->resolution, ctl_sec, ctl, ctl, cur_sec,
> > + cur, cur, wdt->busy_count);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int bcm_kona_dbg_open(struct inode *inode, struct file *file)
> > +{
> > + return single_open(file, bcm_kona_wdt_dbg_show, inode->i_private);
> > +}
> > +
> > +static const struct file_operations bcm_kona_dbg_operations = {
> > + .open = bcm_kona_dbg_open,
> > + .read = seq_read,
> > + .llseek = seq_lseek,
> > + .release = single_release,
> > +};
> > +
> > +static void bcm_kona_wdt_debug_init(struct platform_device *pdev)
> > +{
> > + struct dentry *dir;
> > + struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev);
> > +
> > + if (!wdt)
> > + return;
> > +
> > + wdt->debugfs = NULL;
> > +
> > + dir = debugfs_create_dir(BCM_KONA_WDT_NAME, NULL);
> > + if (IS_ERR_OR_NULL(dir))
> > + return;
> > +
> > + if (debugfs_create_file("info", S_IFREG | S_IRUGO, dir, wdt,
> > + &bcm_kona_dbg_operations))
> > + wdt->debugfs = dir;
> > + else
> > + debugfs_remove_recursive(dir);
> > +}
> > +
> > +static void bcm_kona_wdt_debug_exit(struct platform_device *pdev)
> > +{
> > + struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev);
> > +
> > + if (wdt && wdt->debugfs) {
> > + debugfs_remove_recursive(wdt->debugfs);
> > + wdt->debugfs = NULL;
> > + }
> > +}
> > +
> > +#else
> > +
> > +static void bcm_kona_wdt_debug_init(struct platform_device *pdev) {}
> > +static void bcm_kona_wdt_debug_exit(struct platform_device *pdev) {}
> > +
> > +#endif /* CONFIG_BCM_KONA_WDT_DEBUG */
> > +
> > static int bcm_kona_wdt_ctrl_reg_modify(struct bcm_kona_wdt *wdt,
> > unsigned mask, unsigned newval)
> > {
> > @@ -93,7 +191,7 @@ static int bcm_kona_wdt_ctrl_reg_modify(struct bcm_kona_wdt *wdt,
> >
> > spin_lock_irqsave(&wdt->lock, flags);
> >
> > - val = secure_register_read(wdt->base + SECWDOG_CTRL_REG);
> > + val = secure_register_read(wdt, SECWDOG_CTRL_REG);
> > if (val < 0) {
> > ret = val;
> > } else {
> > @@ -140,7 +238,7 @@ static unsigned int bcm_kona_wdt_get_timeleft(struct watchdog_device *wdog)
> > unsigned long flags;
> >
> > spin_lock_irqsave(&wdt->lock, flags);
> > - val = secure_register_read(wdt->base + SECWDOG_COUNT_REG);
> > + val = secure_register_read(wdt, SECWDOG_COUNT_REG);
> > spin_unlock_irqrestore(&wdt->lock, flags);
> >
> > if (val < 0)
> > @@ -229,6 +327,7 @@ static int bcm_kona_wdt_probe(struct platform_device *pdev)
> > return ret;
> > }
> >
> > + bcm_kona_wdt_debug_init(pdev);
> > dev_dbg(dev, "Broadcom Kona Watchdog Timer");
> >
> > return 0;
> > @@ -236,6 +335,7 @@ static int bcm_kona_wdt_probe(struct platform_device *pdev)
> >
> > static int bcm_kona_wdt_remove(struct platform_device *pdev)
> > {
> > + bcm_kona_wdt_debug_exit(pdev);
> > bcm_kona_wdt_shutdown(pdev);
> > watchdog_unregister_device(&bcm_kona_wdt_wdd);
> > dev_dbg(&pdev->dev, "Watchdog driver disabled");
> > --
> > 1.7.9.5
> >
>
> Hi Wim,
>
>
> I was wondering if this series be queued for 3.14?
>

That's indeed the goal.

Kind regards,
Wim.

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