From d40befed9a581740f6ceb0e5998ec2f59bfbc559 Mon Sep 17 00:00:00 2001 From: Kamel Bouhara Date: Tue, 20 Jun 2023 08:26:57 +0200 Subject: [PATCH] power: reset: at91-reset: add sysfs interface to the power on reason Introduce a list of generic reset sources and use them to export the power on reason through sysfs. Update the ABI documentation to describe this new interface. Signed-off-by: Kamel Bouhara Acked-by: Nicolas Ferre [Miquel Raynal: Follow-up on Kamel's work, 4 years later] Signed-off-by: Miquel Raynal Signed-off-by: Sebastian Reichel --- .../ABI/testing/sysfs-platform-power-on-reason | 12 +++++++ drivers/power/reset/at91-reset.c | 37 ++++++++++++++++------ include/linux/power/power_on_reason.h | 19 +++++++++++ 3 files changed, 58 insertions(+), 10 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-platform-power-on-reason create mode 100644 include/linux/power/power_on_reason.h diff --git a/Documentation/ABI/testing/sysfs-platform-power-on-reason b/Documentation/ABI/testing/sysfs-platform-power-on-reason new file mode 100644 index 0000000..c3b29db --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform-power-on-reason @@ -0,0 +1,12 @@ +What: /sys/devices/platform/.../power_on_reason +Date: June 2023 +KernelVersion: 6.5 +Contact: Kamel Bouhara +Description: Shows system power on reason. The following strings/reasons can + be read (the list can be extended): + "regular power-up", "RTC wakeup", "watchdog timeout", + "software reset", "reset button action", "CPU clock failure", + "crystal oscillator failure", "brown-out reset", + "unknown reason". + + The file is read only. diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c index d688484..aa9b012 100644 --- a/drivers/power/reset/at91-reset.c +++ b/drivers/power/reset/at91-reset.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -149,44 +150,54 @@ static int at91_reset(struct notifier_block *this, unsigned long mode, return NOTIFY_DONE; } -static const char * __init at91_reset_reason(struct at91_reset *reset) +static const char *at91_reset_reason(struct at91_reset *reset) { u32 reg = readl(reset->rstc_base + AT91_RSTC_SR); const char *reason; switch ((reg & AT91_RSTC_RSTTYP) >> 8) { case RESET_TYPE_GENERAL: - reason = "general reset"; + reason = POWER_ON_REASON_REGULAR; 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_RST_BTN; break; case RESET_TYPE_CPU_FAIL: - reason = "CPU clock failure detection"; + reason = POWER_ON_REASON_CPU_CLK_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_BROWN_OUT; break; default: - reason = "unknown reset"; + reason = POWER_ON_REASON_UNKNOWN; break; } return reason; } +static ssize_t power_on_reason_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + struct at91_reset *reset = platform_get_drvdata(pdev); + + return sprintf(buf, "%s\n", at91_reset_reason(reset)); +} +static DEVICE_ATTR_RO(power_on_reason); + static const struct of_device_id at91_ramc_of_match[] = { { .compatible = "atmel,at91sam9260-sdramc", @@ -391,6 +402,12 @@ static int __init at91_reset_probe(struct platform_device *pdev) if (ret) goto disable_clk; + 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\n", at91_reset_reason(reset)); 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 0000000..95a1ec0 --- /dev/null +++ b/include/linux/power/power_on_reason.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Author: Kamel Bouhra + */ + +#ifndef POWER_ON_REASON_H +#define POWER_ON_REASON_H + +#define POWER_ON_REASON_REGULAR "regular power-up" +#define POWER_ON_REASON_RTC "RTC wakeup" +#define POWER_ON_REASON_WATCHDOG "watchdog timeout" +#define POWER_ON_REASON_SOFTWARE "software reset" +#define POWER_ON_REASON_RST_BTN "reset button action" +#define POWER_ON_REASON_CPU_CLK_FAIL "CPU clock failure" +#define POWER_ON_REASON_XTAL_FAIL "crystal oscillator failure" +#define POWER_ON_REASON_BROWN_OUT "brown-out reset" +#define POWER_ON_REASON_UNKNOWN "unknown reason" + +#endif /* POWER_ON_REASON_H */ -- 2.7.4