watchdog: bcm281xx: Debugfs support

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>

watchdog: bcm281xx: Debugfs support
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>
Markus Mayer · Wim Van Sebroeck
1 parent 6adb730dc2
Showing 3 changed files with 115 additions and 4 deletions Side-by-side Diff
arch/arm/configs/bcm_defconfig
drivers/watchdog/Kconfig
drivers/watchdog/bcm_kona_wdt.c
@@ -128,4 +128,5 @@
 CONFIG_PINCTRL_CAPRI=y
 CONFIG_WATCHDOG=y
 CONFIG_BCM_KONA_WDT=y
+CONFIG_BCM_KONA_WDT_DEBUG=y
@@ -1151,6 +1151,16 @@
 	  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
@@ -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 @@
 	 */
 	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 @@
 	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 @@
 	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 @@
  
 	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 @@
 	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 @@
 		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_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");
...	...	@@ -128,4 +128,5 @@
128	128	CONFIG_PINCTRL_CAPRI=y
129	129	CONFIG_WATCHDOG=y
130	130	CONFIG_BCM_KONA_WDT=y
	131	+CONFIG_BCM_KONA_WDT_DEBUG=y
...	...	@@ -1151,6 +1151,16 @@
1151	1151	Say 'Y' or 'M' here to enable the driver. The module will be called
1152	1152	bcm_kona_wdt.
1153	1153
	1154	+config BCM_KONA_WDT_DEBUG
	1155	+ bool "DEBUGFS support for BCM Kona Watchdog"
	1156	+ depends on BCM_KONA_WDT
	1157	+ help
	1158	+ If enabled, adds /sys/kernel/debug/bcm_kona_wdt/info which provides
	1159	+ access to the driver's internal data structures as well as watchdog
	1160	+ timer hardware registres.
	1161	+
	1162	+ If in doubt, say 'N'.
	1163	+
1154	1164	config LANTIQ_WDT
1155	1165	tristate "Lantiq SoC watchdog"
1156	1166	depends on LANTIQ
...	...	@@ -11,6 +11,7 @@
11	11	* GNU General Public License for more details.
12	12	*/
13	13
	14	+#include <linux/debugfs.h>
14	15	#include <linux/delay.h>
15	16	#include <linux/err.h>
16	17	#include <linux/io.h>
17	18
...	...	@@ -55,9 +56,13 @@
55	56	*/
56	57	int resolution;
57	58	spinlock_t lock;
	59	+#ifdef CONFIG_BCM_KONA_WDT_DEBUG
	60	+ unsigned long busy_count;
	61	+ struct dentry *debugfs;
	62	+#endif
58	63	};
59	64
60		-static int secure_register_read(void __iomem *addr)
	65	+static int secure_register_read(struct bcm_kona_wdt *wdt, uint32_t offset)
61	66	{
62	67	uint32_t val;
63	68	unsigned count = 0;
64	69
...	...	@@ -70,10 +75,16 @@
70	75	do {
71	76	if (unlikely(count > 1))
72	77	udelay(5);
73		- val = readl_relaxed(addr);
	78	+ val = readl_relaxed(wdt->base + offset);
74	79	count++;
75	80	} while ((val & SECWDOG_WD_LOAD_FLAG) && count < SECWDOG_MAX_TRY);
76	81
	82	+#ifdef CONFIG_BCM_KONA_WDT_DEBUG
	83	+ /* Remember the maximum number iterations due to WD_LOAD_FLAG */
	84	+ if (count > wdt->busy_count)
	85	+ wdt->busy_count = count;
	86	+#endif
	87	+
77	88	/* This is the only place we return a negative value. */
78	89	if (val & SECWDOG_WD_LOAD_FLAG)
79	90	return -ETIMEDOUT;
...	...	@@ -84,6 +95,93 @@
84	95	return val;
85	96	}
86	97
	98	+#ifdef CONFIG_BCM_KONA_WDT_DEBUG
	99	+
	100	+static int bcm_kona_wdt_dbg_show(struct seq_file s, void data)
	101	+{
	102	+ int ctl_val, cur_val, ret;
	103	+ unsigned long flags;
	104	+ struct bcm_kona_wdt *wdt = s->private;
	105	+
	106	+ if (!wdt)
	107	+ return seq_puts(s, "No device pointer\n");
	108	+
	109	+ spin_lock_irqsave(&wdt->lock, flags);
	110	+ ctl_val = secure_register_read(wdt, SECWDOG_CTRL_REG);
	111	+ cur_val = secure_register_read(wdt, SECWDOG_COUNT_REG);
	112	+ spin_unlock_irqrestore(&wdt->lock, flags);
	113	+
	114	+ if (ctl_val < 0 \|\| cur_val < 0) {
	115	+ ret = seq_puts(s, "Error accessing hardware\n");
	116	+ } else {
	117	+ int ctl, cur, ctl_sec, cur_sec, res;
	118	+
	119	+ ctl = ctl_val & SECWDOG_COUNT_MASK;
	120	+ res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT;
	121	+ cur = cur_val & SECWDOG_COUNT_MASK;
	122	+ ctl_sec = TICKS_TO_SECS(ctl, wdt);
	123	+ cur_sec = TICKS_TO_SECS(cur, wdt);
	124	+ ret = seq_printf(s, "Resolution: %d / %d\n"
	125	+ "Control: %d s / %d (%#x) ticks\n"
	126	+ "Current: %d s / %d (%#x) ticks\n"
	127	+ "Busy count: %lu\n", res,
	128	+ wdt->resolution, ctl_sec, ctl, ctl, cur_sec,
	129	+ cur, cur, wdt->busy_count);
	130	+ }
	131	+
	132	+ return ret;
	133	+}
	134	+
	135	+static int bcm_kona_dbg_open(struct inode inode, struct file file)
	136	+{
	137	+ return single_open(file, bcm_kona_wdt_dbg_show, inode->i_private);
	138	+}
	139	+
	140	+static const struct file_operations bcm_kona_dbg_operations = {
	141	+ .open = bcm_kona_dbg_open,
	142	+ .read = seq_read,
	143	+ .llseek = seq_lseek,
	144	+ .release = single_release,
	145	+};
	146	+
	147	+static void bcm_kona_wdt_debug_init(struct platform_device *pdev)
	148	+{
	149	+ struct dentry *dir;
	150	+ struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev);
	151	+
	152	+ if (!wdt)
	153	+ return;
	154	+
	155	+ wdt->debugfs = NULL;
	156	+
	157	+ dir = debugfs_create_dir(BCM_KONA_WDT_NAME, NULL);
	158	+ if (IS_ERR_OR_NULL(dir))
	159	+ return;
	160	+
	161	+ if (debugfs_create_file("info", S_IFREG \| S_IRUGO, dir, wdt,
	162	+ &bcm_kona_dbg_operations))
	163	+ wdt->debugfs = dir;
	164	+ else
	165	+ debugfs_remove_recursive(dir);
	166	+}
	167	+
	168	+static void bcm_kona_wdt_debug_exit(struct platform_device *pdev)
	169	+{
	170	+ struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev);
	171	+
	172	+ if (wdt && wdt->debugfs) {
	173	+ debugfs_remove_recursive(wdt->debugfs);
	174	+ wdt->debugfs = NULL;
	175	+ }
	176	+}
	177	+
	178	+#else
	179	+
	180	+static void bcm_kona_wdt_debug_init(struct platform_device *pdev) {}
	181	+static void bcm_kona_wdt_debug_exit(struct platform_device *pdev) {}
	182	+
	183	+#endif /* CONFIG_BCM_KONA_WDT_DEBUG */
	184	+
87	185	static int bcm_kona_wdt_ctrl_reg_modify(struct bcm_kona_wdt *wdt,
88	186	unsigned mask, unsigned newval)
89	187	{
...	...	@@ -93,7 +191,7 @@
93	191
94	192	spin_lock_irqsave(&wdt->lock, flags);
95	193
96		- val = secure_register_read(wdt->base + SECWDOG_CTRL_REG);
	194	+ val = secure_register_read(wdt, SECWDOG_CTRL_REG);
97	195	if (val < 0) {
98	196	ret = val;
99	197	} else {
...	...	@@ -140,7 +238,7 @@
140	238	unsigned long flags;
141	239
142	240	spin_lock_irqsave(&wdt->lock, flags);
143		- val = secure_register_read(wdt->base + SECWDOG_COUNT_REG);
	241	+ val = secure_register_read(wdt, SECWDOG_COUNT_REG);
144	242	spin_unlock_irqrestore(&wdt->lock, flags);
145	243
146	244	if (val < 0)
...	...	@@ -229,6 +327,7 @@
229	327	return ret;
230	328	}
231	329
	330	+ bcm_kona_wdt_debug_init(pdev);
232	331	dev_dbg(dev, "Broadcom Kona Watchdog Timer");
233	332
234	333	return 0;
...	...	@@ -236,6 +335,7 @@
236	335
237	336	static int bcm_kona_wdt_remove(struct platform_device *pdev)
238	337	{
	338	+ bcm_kona_wdt_debug_exit(pdev);
239	339	bcm_kona_wdt_shutdown(pdev);
240	340	watchdog_unregister_device(&bcm_kona_wdt_wdd);
241	341	dev_dbg(&pdev->dev, "Watchdog driver disabled");