Add support for the watchdog integrated into the (Fujitsu Theseus version of)
the sch5636 superio hwmon part. Using the new watchdog timer core.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/hwmon/sch5636.c | 233 ++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 231 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/sch5636.c b/drivers/hwmon/sch5636.c
index 244407a..8cf3630 100644
--- a/drivers/hwmon/sch5636.c
+++ b/drivers/hwmon/sch5636.c
@@ -28,14 +28,23 @@
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
+#include <linux/watchdog.h>
+#include <linux/kref.h>
#include "sch56xx-common.h"
+/* Insmod parameters */
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
#define DRVNAME "sch5636"
#define DEVNAME "theseus" /* We only support one model for now */
#define SCH5636_REG_FUJITSU_ID 0x780
#define SCH5636_REG_FUJITSU_REV 0x783
+/* hwmon registers */
#define SCH5636_NO_INS 5
#define SCH5636_NO_TEMPS 16
#define SCH5636_NO_FANS 8
@@ -63,11 +72,18 @@ static const u16 SCH5636_REG_FAN_VAL[SCH5636_NO_FANS] = {
#define SCH5636_FAN_NOT_PRESENT 0x08
#define SCH5636_FAN_DEACTIVATED 0x80
+/* Watchdog registers */
+#define SCH5636_REG_WDOG_PRESET 0x58B
+#define SCH5636_REG_WDOG_CONTROL 0x58C
+#define SCH5636_WDOG_TIME_BASE_SEC 0x01
+#define SCH5636_REG_WDOG_OUTPUT_ENABLE 0x58E
+#define SCH5636_WDOG_OUTPUT_ENABLE 0x02
struct sch5636_data {
unsigned short addr;
- struct device *hwmon_dev;
+ /* hwmon related variables */
+ struct device *hwmon_dev;
struct mutex update_lock;
char valid; /* !=0 if following fields are valid */
unsigned long last_updated; /* In jiffies */
@@ -76,8 +92,25 @@ struct sch5636_data {
u8 temp_ctrl[SCH5636_NO_TEMPS];
u16 fan_val[SCH5636_NO_FANS];
u8 fan_ctrl[SCH5636_NO_FANS];
+
+ /* watchdog related variables */
+ struct watchdog_device wddev;
+ struct watchdog_info wdinfo;
+ struct kref kref;
+ bool watchdog_registered;
+ u8 watchdog_preset;
+ u8 watchdog_control;
+ u8 watchdog_output_enable;
};
+/* Release our data struct when the platform device has been released *and*
+ all references to our watchdog device are released */
+static void sch5636_release_resources(struct kref *r)
+{
+ struct sch5636_data *data = container_of(r, struct sch5636_data, kref);
+ kfree(data);
+}
+
static struct sch5636_data *sch5636_update_device(struct device *dev)
{
struct sch5636_data *data = dev_get_drvdata(dev);
@@ -379,11 +412,154 @@ static struct sensor_device_attribute sch5636_fan_attr[] = {
SENSOR_ATTR(fan8_alarm, 0444, show_fan_alarm, NULL, 7),
};
+/*
+ * Watchdog routines
+ */
+
+static int watchdog_set_timeout(struct watchdog_device *wddev,
+ unsigned int timeout)
+{
+ struct sch5636_data *data = watchdog_get_drvdata(wddev);
+ int err, resolution;
+ u8 control;
+
+ /* 1 second or 60 second resolution? */
+ if (timeout <= 255)
+ resolution = 1;
+ else
+ resolution = 60;
+
+ if (resolution == 1)
+ control = data->watchdog_control | SCH5636_WDOG_TIME_BASE_SEC;
+ else
+ control = data->watchdog_control & ~SCH5636_WDOG_TIME_BASE_SEC;
+
+ if (data->watchdog_control != control) {
+ err = sch56xx_write_virtual_reg(data->addr,
+ SCH5636_REG_WDOG_CONTROL,
+ control);
+ if (err)
+ return err;
+
+ data->watchdog_control = control;
+ }
+
+ /* Remember new timeout value, but do not write as that (re)starts
+ the watchdog countdown */
+ data->watchdog_preset = DIV_ROUND_UP(timeout, resolution);
+ wddev->timeout = data->watchdog_preset * resolution;
+
+ return 0;
+}
+
+static int watchdog_start(struct watchdog_device *wddev)
+{
+ struct sch5636_data *data = watchdog_get_drvdata(wddev);
+ int err;
+ u8 val;
+
+ /*
+ * The sch5636's watchdog cannot really be started / stopped
+ * it is always running, but we can avoid the timer expiring
+ * from causing a system reset by clearing the output enable bit.
+ *
+ * The sch5636's watchdog will set the watchdog event bit, bit 0
+ * of the second interrupt source register (at base-address + 9),
+ * when the timer expires.
+ *
+ * This will only cause a system reset if the 0-1 flank happens when
+ * output enable is true. Setting output enable after the flank will
+ * not cause a reset, nor will the timer expiring a second time.
+ * This means we must clear the watchdog event bit in case it is set.
+ *
+ * The timer may still be running (after a recent watchdog_stop) and
+ * mere milliseconds away from expiring, so the timer must be reset
+ * first!
+ */
+
+ /* 1. Reset the watchdog countdown counter */
+ err = sch56xx_write_virtual_reg(data->addr, SCH5636_REG_WDOG_PRESET,
+ data->watchdog_preset);
+ if (err)
+ return err;
+
+ /* 2. Enable output (if not already enabled) */
+ val = data->watchdog_output_enable | SCH5636_WDOG_OUTPUT_ENABLE;
+ err = sch56xx_write_virtual_reg(data->addr,
+ SCH5636_REG_WDOG_OUTPUT_ENABLE, val);
+ if (err)
+ return err;
+ data->watchdog_output_enable = val;
+
+ /* 3. Clear the watchdog event bit if set */
+ val = inb(data->addr + 9);
+ if (val & 0x01)
+ outb(0x01, data->addr + 9);
+
+ return 0;
+}
+
+static int watchdog_trigger(struct watchdog_device *wddev)
+{
+ struct sch5636_data *data = watchdog_get_drvdata(wddev);
+
+ /* Reset the watchdog countdown counter */
+ return sch56xx_write_virtual_reg(data->addr, SCH5636_REG_WDOG_PRESET,
+ data->watchdog_preset);
+}
+
+static int watchdog_stop(struct watchdog_device *wddev)
+{
+ struct sch5636_data *data = watchdog_get_drvdata(wddev);
+ int err;
+ u8 val;
+
+ val = data->watchdog_output_enable & ~SCH5636_WDOG_OUTPUT_ENABLE;
+ err = sch56xx_write_virtual_reg(data->addr,
+ SCH5636_REG_WDOG_OUTPUT_ENABLE, val);
+ if (err)
+ return err;
+ data->watchdog_output_enable = val;
+
+ return 0;
+}
+
+static void watchdog_ref(struct watchdog_device *wddev)
+{
+ struct sch5636_data *data = watchdog_get_drvdata(wddev);
+
+ kref_get(&data->kref);
+}
+
+static void watchdog_unref(struct watchdog_device *wddev)
+{
+ struct sch5636_data *data = watchdog_get_drvdata(wddev);
+
+ kref_put(&data->kref, sch5636_release_resources);
+}
+
+static const struct watchdog_ops watchdog_ops = {
+ .owner = THIS_MODULE,
+ .start = watchdog_start,
+ .stop = watchdog_stop,
+ .ref = watchdog_ref,
+ .unref = watchdog_unref,
+ .ping = watchdog_trigger,
+ .set_timeout = watchdog_set_timeout,
+};
+
+/*
+ * Remove, probe, register and unregister device functions
+ */
+
static int sch5636_remove(struct platform_device *pdev)
{
struct sch5636_data *data = platform_get_drvdata(pdev);
int i;
+ if (data->watchdog_registered)
+ watchdog_unregister_device(&data->wddev);
+
if (data->hwmon_dev)
hwmon_device_unregister(data->hwmon_dev);
@@ -399,7 +575,7 @@ static int sch5636_remove(struct platform_device *pdev)
&sch5636_fan_attr[i].dev_attr);
platform_set_drvdata(pdev, NULL);
- kfree(data);
+ kref_put(&data->kref, sch5636_release_resources);
return 0;
}
@@ -416,6 +592,7 @@ static int __devinit sch5636_probe(struct platform_device *pdev)
data->addr = platform_get_resource(pdev, IORESOURCE_IO, 0)->start;
mutex_init(&data->update_lock);
+ kref_init(&data->kref);
platform_set_drvdata(pdev, data);
for (i = 0; i < 3; i++) {
@@ -450,6 +627,8 @@ static int __devinit sch5636_probe(struct platform_device *pdev)
pr_info("Found %s chip at %#hx, revison: %d.%02d\n", DEVNAME,
data->addr, revision[0], revision[1]);
+ /********* hwmon initialization *********/
+
/* Read all temp + fan ctrl registers to determine which are active */
for (i = 0; i < SCH5636_NO_TEMPS; i++) {
val = sch56xx_read_virtual_reg(data->addr,
@@ -505,6 +684,56 @@ static int __devinit sch5636_probe(struct platform_device *pdev)
goto error;
}
+ /********* watchdog initialization *********/
+
+ data->wdinfo.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT;
+ strlcpy(data->wdinfo.identity, "Fujitsu watchdog",
+ sizeof(data->wdinfo.identity));
+ data->wdinfo.firmware_version = revision[0];
+ data->wddev.info = &data->wdinfo;
+ data->wddev.ops = &watchdog_ops;
+ data->wddev.min_timeout = 1;
+ data->wddev.max_timeout = 255 * 60;
+ if (nowayout)
+ data->wddev.status |= WDOG_NO_WAY_OUT;
+ else
+ data->wdinfo.options |= WDIOF_MAGICCLOSE;
+
+ /* Since the watchdog uses a downcounter there is no register to read
+ the BIOS set timeout from (if any was set at all) -> choose a preset
+ which will give us a 1 minute timeout */
+ val = sch56xx_read_virtual_reg(data->addr, SCH5636_REG_WDOG_CONTROL);
+ if (val < 0) {
+ err = val;
+ goto error;
+ }
+ data->watchdog_control = val;
+ if (data->watchdog_control & SCH5636_WDOG_TIME_BASE_SEC)
+ data->watchdog_preset = 60; /* seconds */
+ else
+ data->watchdog_preset = 1; /* minute */
+ data->wddev.timeout = 60;
+
+ /* Check if the watchdog was already enabled by the BIOS */
+ val = sch56xx_read_virtual_reg(data->addr,
+ SCH5636_REG_WDOG_OUTPUT_ENABLE);
+ if (val < 0) {
+ err = val;
+ goto error;
+ }
+ data->watchdog_output_enable = val;
+ if (data->watchdog_output_enable & SCH5636_WDOG_OUTPUT_ENABLE)
+ data->wddev.status |= WDOG_ACTIVE;
+
+ /*
+ * Note we don't abort on failure to register the watchdog, as we
+ * still want to stick around for the hwmon stuff.
+ */
+ watchdog_set_drvdata(&data->wddev, data);
+ err = watchdog_register_device(&data->wddev);
+ if (!err)
+ data->watchdog_registered = true;
+
return 0;
error:
--
1.7.6.2
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