[PATCH] drivers: power: reset: at91-reset: Provide reset reason via sysfs.
DORMANTno replies
From: David Mosberger-Tang <hidden>
Date: 2016-01-21 16:35:20
Subsystem:
system reset/shutdown drivers, the rest · Maintainers:
Sebastian Reichel, Linus Torvalds
Rather than just printing the reset-reason at boot-time, make it available via sysfs as attribute "reset_reason" of the reset controller. For example, on SAMA5D2 Xplained, this sysfs attribute is available at: /sys/devices/platform/ahb/ahb:apb/f8048000.rstc/reset_reason --- drivers/power/reset/at91-reset.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 264b9b8..184516b 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c@@ -45,6 +45,11 @@ enum reset_type { RESET_TYPE_USER = 4, }; +static ssize_t reset_reason_show(struct device *, + struct device_attribute *attr, + char *); +static DEVICE_ATTR(reset_reason, S_IRUSR, reset_reason_show, NULL); + static void __iomem *at91_ramc_base[2], *at91_rstc_base; /*
@@ -132,7 +137,7 @@ static int sama5d3_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) { u32 reg = readl(at91_rstc_base + AT91_RSTC_SR); char *reason;
@@ -157,8 +162,15 @@ static void __init at91_reset_status(struct platform_device *pdev) reason = "unknown reset"; break; } + return reason; +} - pr_info("AT91: Starting after %s\n", reason); +static ssize_t reset_reason_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + return strcpy(buf, at91_reset_reason(pdev)); } static const struct of_device_id at91_ramc_of_match[] = {
@@ -250,7 +262,13 @@ static int at91_reset_probe(struct platform_device *pdev) if (ret) return ret; - at91_reset_status(pdev); + ret = device_create_file(&pdev->dev, &dev_attr_reset_reason); + if (ret) { + dev_err(&pdev->dev, "Could not create sysfs entry\n"); + return ret; + } + + pr_info("AT91: Starting after %s\n", at91_reset_reason(pdev)); return 0; }
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1.9.1