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authorKamel Bouhara <kamel.bouhara@bootlin.com>2023-06-20 08:26:57 +0200
committerSebastian Reichel <sebastian.reichel@collabora.com>2023-07-19 23:15:21 +0200
commitd40befed9a581740f6ceb0e5998ec2f59bfbc559 (patch)
treef3e86211c054264c3cdb4c78318d3ec7dc04c2af /drivers
parent7b9fc309c0b57c5b1230bf3e0a8bb9e937eb6529 (diff)
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 <kamel.bouhara@bootlin.com> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> [Miquel Raynal: Follow-up on Kamel's work, 4 years later] Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/power/reset/at91-reset.c37
1 files changed, 27 insertions, 10 deletions
diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index d6884841a6dc..aa9b012d3d00 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -18,6 +18,7 @@
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/reset-controller.h>
+#include <linux/power/power_on_reason.h>
#include <soc/at91/at91sam9_ddrsdr.h>
#include <soc/at91/at91sam9_sdramc.h>
@@ -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;