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Commit 6e2ac20e authored by Markus Mayer's avatar Markus Mayer Committed by Wim Van Sebroeck
Browse files

watchdog: bcm281xx: Debugfs support 



This change introduces debugfs support for the BCM281xx watchdog driver.

Signed-off-by: default avatarMarkus Mayer <markus.mayer@linaro.org>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 6adb730d

arch/arm/configs/bcm_defconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/watchdog/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -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

drivers/watchdog/bcm_kona_wdt.c

+104 −4
Original line number Diff line number Diff line
@@ -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");