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Violators will be prosecuted for from ; Thu, 1 Jun 2017 17:35:27 -0400 From: Christopher Bostic To: wim@iguana.be, linux@roeck-us.net Cc: Christopher Bostic , joel@jms.id.au, linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, andrew@aj.id.au Subject: [PATCH] drivers/watchdog: Add sys files to modify watchdog behavior Date: Thu, 1 Jun 2017 16:35:21 -0500 Message-Id: <20170601213521.58141-1-cbostic@linux.vnet.ibm.com> Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org Add files to enable/disable Aspeed watchdog: * External signal after timeout * Reset system after timeout Signed-off-by: Christopher Bostic --- .../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 +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 +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