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watchdog: bcm281xx: Debugfs support

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This change introduces debugfs support for the BCM281xx watchdog driver.

Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Markus Mayer 2014-01-06 13:56:10 -08:00 committed by Wim Van Sebroeck
parent 6adb730dc2
commit 6e2ac20e9c
3 changed files with 115 additions and 4 deletions
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1
arch/arm/configs/bcm_defconfig
View file

@ -128,3 +128,4 @@ CONFIG_AVERAGE=y
CONFIG_PINCTRL_CAPRI=y
CONFIG_WATCHDOG=y
CONFIG_BCM_KONA_WDT=y
CONFIG_BCM_KONA_WDT_DEBUG=y

10
drivers/watchdog/Kconfig
View file

@ -1151,6 +1151,16 @@ 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

108
drivers/watchdog/bcm_kona_wdt.c
View file

@ -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");