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Message-Id: <20170601213521.58141-1-cbostic@linux.vnet.ibm.com>
Date: Thu, 1 Jun 2017 16:35:21 -0500
From: Christopher Bostic <cbostic@...ux.vnet.ibm.com>
To: wim@...ana.be, linux@...ck-us.net
Cc: Christopher Bostic <cbostic@...ux.vnet.ibm.com>, joel@....id.au,
linux-kernel@...r.kernel.org, linux-watchdog@...r.kernel.org,
andrew@...id.au
Subject: [PATCH] drivers/watchdog: Add sys files to modify watchdog behavior
Add files to enable/disable Aspeed watchdog:
* External signal after timeout
* Reset system after timeout
Signed-off-by: Christopher Bostic <cbostic@...ux.vnet.ibm.com>
---
.../ABI/testing/sysfs-platform-aspeed-wdt | 40 +++++++++++
drivers/watchdog/aspeed_wdt.c | 79 +++++++++++++++++++++-
2 files changed, 118 insertions(+), 1 deletion(-)
create mode 100644 Documentation/ABI/testing/sysfs-platform-aspeed-wdt
diff --git a/Documentation/ABI/testing/sysfs-platform-aspeed-wdt b/Documentation/ABI/testing/sysfs-platform-aspeed-wdt
new file mode 100644
index 0000000..a582176
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-aspeed-wdt
@@ -0,0 +1,40 @@
+What: /sys/bus/platform/devices/1e785000.wdt/watchdog/watchdog0/
+ reset_system
+Date: May 2017
+KernelVersion: 4.12
+Contact: Christopher Bostic <cbostic@...ux.vnet.ibm.com>
+Description:
+ Value indicates if a watchdog time out results in a reset of
+ system. 'off': no system reset on timeout. 'on' there will
+ be a system reset on timeout.
+
+ Default: off
+
+ - Enable 'reset system' on watchdog timeout:
+ echo on > /sys/bus/platform/devices/1e785000.wdt/watchdog/
+ watchdog0/reset_system;
+
+ - Disable 'reset system' on watchdog timeout:
+ echo off > /sys/bus/platform/devices/1e785000.wdt/watchdog/
+ watchdog0/reset_system;
+
+What: /sys/bus/platform/devices/1e785000.wdt/watchdog/watchdog0/
+ ext_signal
+Date: May 2017
+KernelVersion: 4.12
+Contact: Christopher Bostic <cbostic@...ux.vnet.ibm.com>
+Description:
+ Value indicates if a watchdog time out results in an active
+ high pulse sent out an output pin. 'off': No output pulse
+ generated on watchdog time out. 'on': output pulse
+ generated on watchdog time out.
+
+ Default: off
+
+ - Enable 'external signal' on watchdog timeout:
+ echo on > /sys/bus/platform/devices/1e785000.wdt/watchdog/
+ watchdog0/ext_signal;
+
+ - Disable 'external signal' on watchdog timeout:
+ echo off > /sys/bus/platform/devices/1e785000.wdt/watchdog/
+ watchdog0/ext_signal;
diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index 1c65258..66b27e8 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -136,6 +136,83 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd,
.identity = KBUILD_MODNAME,
};
+static ssize_t aspeed_wdt_cntl_get_state(struct device *dev, char *buf,
+ uint32_t mask)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct aspeed_wdt *wdt = platform_get_drvdata(pdev);
+ int ret;
+
+ if (readl(wdt->base + WDT_CTRL) & mask)
+ ret = sprintf(buf, "on\n");
+ else
+ ret = sprintf(buf, "off\n");
+
+ return ret;
+}
+
+static ssize_t aspeed_wdt_cntl_set_state(struct device *dev, const char *buf,
+ size_t count, uint32_t mask)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct aspeed_wdt *wdt = platform_get_drvdata(pdev);
+
+ if (!strncmp(buf, "on", strlen("on"))) {
+ wdt->ctrl |= mask;
+ writel(wdt->ctrl, wdt->base + WDT_CTRL);
+ } else if (!strncmp(buf, "off", strlen("off"))) {
+ wdt->ctrl &= ~mask;
+ writel(wdt->ctrl, wdt->base + WDT_CTRL);
+ } else {
+ dev_warn(dev, "Unknown reset system mode command: [%s]\n", buf);
+ return -EINVAL;
+ }
+
+ return count;
+}
+
+static ssize_t aspeed_wdt_reset_system_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return aspeed_wdt_cntl_set_state(dev, buf, count,
+ WDT_CTRL_RESET_SYSTEM);
+}
+
+static ssize_t aspeed_wdt_reset_system_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return aspeed_wdt_cntl_get_state(dev, buf, WDT_CTRL_RESET_SYSTEM);
+}
+
+static DEVICE_ATTR(reset_system, 0644,
+ aspeed_wdt_reset_system_show, aspeed_wdt_reset_system_store);
+
+static ssize_t aspeed_wdt_ext_signal_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return aspeed_wdt_cntl_set_state(dev, buf, count, WDT_CTRL_WDT_EXT);
+}
+
+static ssize_t aspeed_wdt_ext_signal_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return aspeed_wdt_cntl_get_state(dev, buf, WDT_CTRL_WDT_EXT);
+}
+
+static DEVICE_ATTR(ext_signal, 0644,
+ aspeed_wdt_ext_signal_show, aspeed_wdt_ext_signal_store);
+
+static struct attribute *aspeed_wdt_attrs[] = {
+ &dev_attr_reset_system.attr,
+ &dev_attr_ext_signal.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(aspeed_wdt);
+
static int aspeed_wdt_probe(struct platform_device *pdev)
{
struct aspeed_wdt *wdt;
@@ -160,7 +237,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
wdt->wdd.ops = &aspeed_wdt_ops;
wdt->wdd.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT_MS;
wdt->wdd.parent = &pdev->dev;
-
+ wdt->wdd.groups = aspeed_wdt_groups;
wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT;
watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev);
--
1.8.2.2
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