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

[Wim Van Sebroeck <wim@iguana.be>]

Hi Markus,

> On 6 January 2014 13:56, Markus Mayer <markus.mayer@linaro.org> wrote:
> > This change introduces debugfs support for the BCM281xx watchdog driver.
> >
> > Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
> > ---
> >  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.