Messages in this thread Patch in this message | | | From | Kamel Bouhara <> | Subject | [PATCH] power: reset: at91-reset: add sysfs interface to the power on reason | Date | Thu, 17 Oct 2019 14:40:58 +0200 |
| |
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.bouhara@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.bouhara@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.bouhara@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
| |