On 12/9/18 12:08 PM, Andrew Lunn wrote:
Some TQ-Systems ComExpress modules have an IO controller with a
watchdog time.
watchdog timer ?
Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
---
v2:
Fix various typos
Sort header files
Use watchdog_init_timeout(() to handle module parameter
Get core to validate timeout
Remove redundant ping function
Remove redundant stop function
Use devm_watchdog_register_device allowing release to be removed
Use WATCHDOG_NOWAYOUT
---
drivers/watchdog/Kconfig | 12 ++++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/tqmx86_wdt.c | 126 ++++++++++++++++++++++++++++++++++
3 files changed, 139 insertions(+)
create mode 100644 drivers/watchdog/tqmx86_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 2d64333f4782..7c7528e8644b 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1308,6 +1308,18 @@ config SMSC37B787_WDT
Most people will say N.
+config TQMX86_WDT
+ tristate "TQ-Systems TQMX86 Watchdog Timer"
+ depends on X86
+ help
+ This is the driver for the hardware watchdog timer in the TQMN86 IO
TQMN86 or TQMX86 ?
+ controller found on some of their ComExpress Modules.
+
+ To compile this driver as a module, choose M here; the module
+ will be called tqmx86_wdt.
+
+ Most people will say N.
+
config VIA_WDT
tristate "VIA Watchdog Timer"
depends on X86 && PCI
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index f69cdff5ad7f..b077e35414e2 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -129,6 +129,7 @@ obj-$(CONFIG_SBC7240_WDT) += sbc7240_wdt.o
obj-$(CONFIG_CPU5_WDT) += cpu5wdt.o
obj-$(CONFIG_SMSC_SCH311X_WDT) += sch311x_wdt.o
obj-$(CONFIG_SMSC37B787_WDT) += smsc37b787_wdt.o
+obj-$(CONFIG_TQMX86_WDT) += tqmx86_wdt.o
obj-$(CONFIG_VIA_WDT) += via_wdt.o
obj-$(CONFIG_W83627HF_WDT) += w83627hf_wdt.o
obj-$(CONFIG_W83877F_WDT) += w83877f_wdt.o
diff --git a/drivers/watchdog/tqmx86_wdt.c b/drivers/watchdog/tqmx86_wdt.c
new file mode 100644
index 000000000000..9d2ff7bcb061
--- /dev/null
+++ b/drivers/watchdog/tqmx86_wdt.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Watchdog driver for TQMx86 PLD.
+ *
+ * The watchdog supports power of 2 timeouts from 1 to 4096sec.
+ * Once started, it cannot be stopped.
+ */
+
+#include <linux/io.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/timer.h>
+#include <linux/watchdog.h>
+
+/* default timeout (secs) */
+#define WDT_TIMEOUT 32
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. (1<=timeout<=4096, default="
+ __MODULE_STRING(WDT_TIMEOUT) ")");
+struct tqmx86_wdt {
+ struct watchdog_device wdd;
+ void __iomem *io_base;
+};
+
+#define TQMX86_WDCFG 0x00 /* Watchdog Configuration Register */
+#define TQMX86_WDCS 0x01 /* Watchdog Config/Status Register */
+
+static int tqmx86_wdt_start(struct watchdog_device *wdd)
+{
+ struct tqmx86_wdt *priv = watchdog_get_drvdata(wdd);
+
+ iowrite8(0x81, priv->io_base + TQMX86_WDCS);
+
+ return 0;
+}
+
+static int tqmx86_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int new_timeout)
+{
+ struct tqmx86_wdt *priv = watchdog_get_drvdata(wdd);
+ u8 val;
+
+ timeout = roundup_pow_of_two(new_timeout);
This won't work as (I think it is) intended. 'timeout' is the global
variable. This function is called from the probe function with
WDT_TIMEOUT as parameter. The overwritten variable is then later
used in the call to watchdog_init_timeout(). This means that any
value passed as module parameter will be ignored.
You could just reassign the value to new_timeout; there is no need
for a second variable here. I would also suggest to just use 't'
as variable name, but that is really optional.
+ val = ilog2(timeout) | 0x90;
+ val += 3; /* values 0,1,2 correspond to 0.125,0.25,0.5s timeouts */
+ iowrite8(val, priv->io_base + TQMX86_WDCFG);
+
+ wdd->timeout = timeout;
+
+ return 0;
+}
+
+static const struct watchdog_info tqmx86_wdt_info = {
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING,
+ .identity = "TQMx86 Watchdog",
+};
+
+static struct watchdog_ops tqmx86_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = tqmx86_wdt_start,
+ .set_timeout = tqmx86_wdt_set_timeout,
+};
+
+static int tqmx86_wdt_probe(struct platform_device *pdev)
+{
+ struct tqmx86_wdt *priv;
+ struct resource *res;
+ int err;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+
+ priv->io_base = devm_ioport_map(&pdev->dev, res->start,
+ resource_size(res));
+ if (IS_ERR(priv->io_base))
+ return PTR_ERR(priv->io_base);
+
+ platform_set_drvdata(pdev, priv);
Unless I am missing something, this is no longer needed
(no remove function).
+ watchdog_set_drvdata(&priv->wdd, priv);
+
+ tqmx86_wdt_set_timeout(&priv->wdd, WDT_TIMEOUT);
+
It might be better to call this with wdd->timeout as parameter
after the call to watchdog_init_timeout(). This would set it
to the value you actually want (and update wdd->timeout to a
supported value if it was set with a module parameter).
+ priv->wdd.parent = &pdev->dev;
+ priv->wdd.info = &tqmx86_wdt_info;
+ priv->wdd.ops = &tqmx86_wdt_ops;
+ priv->wdd.min_timeout = 1;
+ priv->wdd.max_timeout = 4096;
+ priv->wdd.max_hw_heartbeat_ms = 4096*1000;
+ priv->wdd.timeout = WDT_TIMEOUT;
+
+ watchdog_init_timeout(&priv->wdd, timeout, &pdev->dev);
+
+ watchdog_set_nowayout(&priv->wdd, WATCHDOG_NOWAYOUT);
+
+ err = devm_watchdog_register_device(&pdev->dev, &priv->wdd);
+ if (err)
+ return err;
+
+ dev_info(&pdev->dev, "TQMx86 watchdog\n");
+
+ return 0;
+}
+
+static struct platform_driver tqmx86_wdt_driver = {
+ .driver = {
+ .name = "tqmx86-wdt",
+ },
+ .probe = tqmx86_wdt_probe,
+};
+
+module_platform_driver(tqmx86_wdt_driver);
+
+MODULE_AUTHOR("Vadim V.Vlasov <vvlasov@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("TQMx86 Watchdog");
+MODULE_ALIAS("platform:tqmx86-wdt");
+MODULE_LICENSE("GPL");
