diff options
Diffstat (limited to 'drivers/watchdog/bcm_kona_wdt.c')
| -rw-r--r-- | drivers/watchdog/bcm_kona_wdt.c | 108 |
1 files changed, 104 insertions, 4 deletions
diff --git a/drivers/watchdog/bcm_kona_wdt.c b/drivers/watchdog/bcm_kona_wdt.c index 7e41a83eb45e..9c248099f4a2 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"); |