Messages in this thread | | | From | <> | Subject | Re: [PATCH] power: reset: at91-reset: add sysfs interface to the power on reason | Date | Fri, 29 Nov 2019 11:15:18 +0000 |
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On 29.11.2019 13:02, Alexandre Belloni wrote:
> On 29/11/2019 10:57:45+0000, Claudiu.Beznea@microchip.com wrote: >> Hi Kamel, >> >> On 17.10.2019 15:40, Kamel Bouhara wrote: >>> 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"
Hi,
Looks rather odd to have a hardcoded crystal value inside a generic header. Also how is REASON_CPU_FAIL related to CPU Clock ?
Eugen
>>> +#define POWER_ON_REASON_LOW_POWER "Low power exit" >>> +#define POWER_ON_REASON_UNKNOWN "Unknown" >>> + >>> +#endif /* POWER_ON_REASON_H */ >> >> Is this new header necessary? >> > > Yes because we want other drivers to be able to reuse them as-is so the > ABI is stable. > > -- > Alexandre Belloni, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
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