This patch export the power on reason through the sysfs interface and
introduce some generic reset sources.
Update the ABI documentation to list current power on sources.
Signed-off-by: Kamel Bouhara <kamel.bouh...@bootlin.com>
---
.../sysfs-devices-platform-power-on-reason | 14 ++++++
drivers/power/reset/at91-reset.c | 44 +++++++++++++------
include/linux/power/power_on_reason.h | 19 ++++++++
3 files changed, 64 insertions(+), 13 deletions(-)
create mode 100644
Documentation/ABI/testing/sysfs-devices-platform-power-on-reason
create mode 100644 include/linux/power/power_on_reason.h
diff --git a/Documentation/ABI/testing/sysfs-devices-platform-power-on-reason
b/Documentation/ABI/testing/sysfs-devices-platform-power-on-reason
new file mode 100644
index 000000000000..83daeb9b1aa2
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-platform-power-on-reason
@@ -0,0 +1,14 @@
+What: /sys/devices/platform/.../power_on_reason
+
+Date: October 2019
+KernelVersion: 5.4
+Contact: Kamel Bouhara <kamel.bouh...@bootlin.com>
+Description: This file shows system power on reason.
+ The possible sources are:
+ General System Power-ON, RTC wakeup, Watchdog timeout,
+ Software Reset, User pressed reset button,
+ CPU Clock failure, 32.768kHz Oscillator Failure,
+ Low power mode exit, Unknown.
+
+ The file is read only.
+
diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 44ca983a49a1..3cb2df40af37 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -17,7 +17,7 @@
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
-
+#include <linux/power/power_on_reason.h>
#include <soc/at91/at91sam9_ddrsdr.h>
#include <soc/at91/at91sam9_sdramc.h>
@@ -146,42 +146,42 @@ static int samx7_restart(struct notifier_block *this,
unsigned long mode,
return NOTIFY_DONE;
}
-static void __init at91_reset_status(struct platform_device *pdev)
+static const char *at91_reset_reason(struct platform_device *pdev)
{
const char *reason;
u32 reg = readl(at91_rstc_base + AT91_RSTC_SR);
switch ((reg & AT91_RSTC_RSTTYP) >> 8) {
case RESET_TYPE_GENERAL:
- reason = "general reset";
+ reason = POWER_ON_REASON_GENERAL;
break;
case RESET_TYPE_WAKEUP:
- reason = "wakeup";
+ reason = POWER_ON_REASON_RTC;
break;
case RESET_TYPE_WATCHDOG:
- reason = "watchdog reset";
+ reason = POWER_ON_REASON_WATCHDOG;
break;
case RESET_TYPE_SOFTWARE:
- reason = "software reset";
+ reason = POWER_ON_REASON_SOFTWARE;
break;
case RESET_TYPE_USER:
- reason = "user reset";
+ reason = POWER_ON_REASON_USER;
break;
case RESET_TYPE_CPU_FAIL:
- reason = "CPU clock failure detection";
+ reason = POWER_ON_REASON_CPU_FAIL;
break;
case RESET_TYPE_XTAL_FAIL:
- reason = "32.768 kHz crystal failure detection";
+ reason = POWER_ON_REASON_XTAL_FAIL;
break;
case RESET_TYPE_ULP2:
- reason = "ULP2 reset";
+ reason = POWER_ON_REASON_LOW_POWER;
break;
default:
- reason = "unknown reset";
+ reason = POWER_ON_REASON_UNKNOWN;
break;
}
- dev_info(&pdev->dev, "Starting after %s\n", reason);
+ return reason;
}
static const struct of_device_id at91_ramc_of_match[] = {
@@ -204,6 +204,17 @@ static struct notifier_block at91_restart_nb = {
.priority = 192,
};
+static ssize_t power_on_reason_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+
+ return sprintf(buf, "%s\n", at91_reset_reason(pdev));
+}
+
+static DEVICE_ATTR_RO(power_on_reason);
+
static int __init at91_reset_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
@@ -248,7 +259,14 @@ static int __init at91_reset_probe(struct platform_device
*pdev)
return ret;
}
- at91_reset_status(pdev);
+ ret = device_create_file(&pdev->dev, &dev_attr_power_on_reason);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not create sysfs entry\n");
+ return ret;
+ }
+
+ dev_info(&pdev->dev, "Starting after %s reset\n",
+ at91_reset_reason(pdev));
return 0;
}
diff --git a/include/linux/power/power_on_reason.h
b/include/linux/power/power_on_reason.h
new file mode 100644
index 000000000000..9978cc757427
--- /dev/null
+++ b/include/linux/power/power_on_reason.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Author: Kamel Bouhra <kamel.bouh...@bootlin.com>
+ */
+
+#ifndef POWER_ON_REASON_H
+#define POWER_ON_REASON_H
+
+#define POWER_ON_REASON_GENERAL "General"
+#define POWER_ON_REASON_RTC "RTC wakeup"
+#define POWER_ON_REASON_WATCHDOG "Watchdog timeout"
+#define POWER_ON_REASON_SOFTWARE "Software"
+#define POWER_ON_REASON_USER "User"
+#define POWER_ON_REASON_CPU_FAIL "CPU Clock Failure"
+#define POWER_ON_REASON_XTAL_FAIL "32.768k Crystal oscillator Failure"
+#define POWER_ON_REASON_LOW_POWER "Low power exit"
+#define POWER_ON_REASON_UNKNOWN "Unknown"
+
+#endif /* POWER_ON_REASON_H */
--
2.23.0
