Merge branch 'for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git

7 files changed, 161 insertions, 15 deletions

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 124afb99febe..bce996bbef28 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -128,6 +128,18 @@ config POWER_RESET_LINKSTATION
 
 	  Say Y here if you have a Buffalo LinkStation LS421D/E.
 
+config POWER_RESET_MCF_RCM
+	tristate "Freescale ColdFire RCM power-on reason driver"
+	depends on M5441x || COMPILE_TEST
+	depends on HAS_IOMEM
+	help
+	  This driver exposes the cause of the last reset on Freescale
+	  ColdFire 5441x SoCs through the standard power_on_reason sysfs
+	  ABI. It reads the Reset Status Register (RSR) of the Reset
+	  Controller Module once at probe time and reports a normalised
+	  string (regular power-up, reset button action, software reset
+	  or unknown reason).
+
 config POWER_RESET_MACSMC
 	tristate "Apple SMC reset/power-off driver"
 	depends on MFD_MACSMC
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index d7ae97241a83..e31cab4ba78e 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
 obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
 obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
 obj-$(CONFIG_POWER_RESET_LINKSTATION) += linkstation-poweroff.o
+obj-$(CONFIG_POWER_RESET_MCF_RCM) += mcf-rcm-reset.o
 obj-$(CONFIG_POWER_RESET_MACSMC) += macsmc-reboot.o
 obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
 obj-$(CONFIG_POWER_RESET_MT6323) += mt6323-poweroff.o
diff --git a/drivers/power/reset/mcf-rcm-reset.c b/drivers/power/reset/mcf-rcm-reset.c
new file mode 100644
index 000000000000..18f11c05a868
--- /dev/null
+++ b/drivers/power/reset/mcf-rcm-reset.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Freescale ColdFire MCF5441x RCM power-on reason driver
+ *
+ * Copyright (C) 2026 Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
+ */
+
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power/power_on_reason.h>
+
+/*
+ * Reset Status Register (RSR) layout, MCF54418 Reference Manual chapter
+ * 12.3.2. The register is 8-bit read-only and latches the cause (or
+ * causes) of the most recent reset until the next one occurs.
+ */
+#define MCF_RSR_SOFT		0x20	/* Last reset caused by software */
+#define MCF_RSR_LOC		0x10	/* Last reset caused by PLL loss of clock */
+#define MCF_RSR_POR		0x08	/* Last reset caused by power-on */
+#define MCF_RSR_EXT		0x04	/* Last reset caused by external pin */
+#define MCF_RSR_WDRCORE		0x02	/* Last reset caused by core watchdog */
+#define MCF_RSR_LOL		0x01	/* Last reset caused by PLL loss of lock */
+
+#define MCF_RSR_KNOWN_CAUSES	(MCF_RSR_POR | MCF_RSR_EXT | MCF_RSR_WDRCORE | \
+				 MCF_RSR_LOC | MCF_RSR_LOL | MCF_RSR_SOFT)
+
+struct mcf_rcm {
+	const char *reason;
+};
+
+/*
+ * Decode RSR into a power_on_reason string.
+ *
+ * The MCF5441x Reset Status Register can latch several cause bits at the
+ * same time (Reference Manual chapter 12.3.2: "one or more status bits
+ * may be set at the same time"). A power-on, for example, also resets
+ * the PLL and may co-flag LOC and LOL during the boot sequence. The
+ * power_on_reason ABI carries a single string, so this routine picks
+ * one cause; the chosen priority surfaces the most explanatory one for
+ * diagnostics:
+ *
+ *   POR              cold boot dominates any spurious co-flagged cause
+ *   EXT              operator action via the RESET pin
+ *   WDRCORE          core watchdog timeout, a fault to investigate
+ *   LOC, LOL         PLL clock or lock failure, hardware fault
+ *   SOFT             explicit software-requested reset
+ */
+static const char *mcf_rcm_decode(u8 rsr)
+{
+	if (rsr & MCF_RSR_POR)
+		return POWER_ON_REASON_REGULAR;
+	if (rsr & MCF_RSR_EXT)
+		return POWER_ON_REASON_RST_BTN;
+	if (rsr & MCF_RSR_WDRCORE)
+		return POWER_ON_REASON_WATCHDOG;
+	if (rsr & (MCF_RSR_LOC | MCF_RSR_LOL))
+		return POWER_ON_REASON_CPU_CLK_FAIL;
+	if (rsr & MCF_RSR_SOFT)
+		return POWER_ON_REASON_SOFTWARE;
+	return POWER_ON_REASON_UNKNOWN;
+}
+
+static ssize_t power_on_reason_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct mcf_rcm *rcm = platform_get_drvdata(to_platform_device(dev));
+
+	return sysfs_emit(buf, "%s\n", rcm->reason);
+}
+static DEVICE_ATTR_RO(power_on_reason);
+
+static struct attribute *mcf_rcm_attrs[] = {
+	&dev_attr_power_on_reason.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(mcf_rcm);
+
+static int mcf_rcm_probe(struct platform_device *pdev)
+{
+	struct mcf_rcm *rcm;
+	void __iomem *base;
+	u8 rsr;
+
+	rcm = devm_kzalloc(&pdev->dev, sizeof(*rcm), GFP_KERNEL);
+	if (!rcm)
+		return -ENOMEM;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	rsr = readb_relaxed(base);
+	rcm->reason = mcf_rcm_decode(rsr);
+
+	platform_set_drvdata(pdev, rcm);
+
+	if (!(rsr & MCF_RSR_KNOWN_CAUSES))
+		dev_warn(&pdev->dev, "Unknown reset cause (RSR=0x%02x)\n", rsr);
+	else
+		dev_info(&pdev->dev, "Starting after %s (RSR=0x%02x)\n",
+			 rcm->reason, rsr);
+
+	return 0;
+}
+
+static const struct platform_device_id mcf_rcm_id[] = {
+	{ "mcf-rcm-reset" },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, mcf_rcm_id);
+
+static struct platform_driver mcf_rcm_driver = {
+	.probe = mcf_rcm_probe,
+	.id_table = mcf_rcm_id,
+	.driver = {
+		.name = "mcf-rcm-reset",
+		.dev_groups = mcf_rcm_groups,
+	},
+};
+module_platform_driver(mcf_rcm_driver);
+
+MODULE_AUTHOR("Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>");
+MODULE_DESCRIPTION("Freescale ColdFire RCM power-on reason driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/power/reset/piix4-poweroff.c b/drivers/power/reset/piix4-poweroff.c
index e6822c021000..1a6f3d22d297 100644
--- a/drivers/power/reset/piix4-poweroff.c
+++ b/drivers/power/reset/piix4-poweroff.c
@@ -96,6 +96,7 @@ static const struct pci_device_id piix4_poweroff_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
 	{ 0 },
 };
+MODULE_DEVICE_TABLE(pci, piix4_poweroff_ids);
 
 static struct pci_driver piix4_poweroff_driver = {
 	.name		= "piix4-poweroff",
diff --git a/drivers/power/reset/pwr-mlxbf.c b/drivers/power/reset/pwr-mlxbf.c
index 15d92c9f64dd..459c2b7f3a21 100644
--- a/drivers/power/reset/pwr-mlxbf.c
+++ b/drivers/power/reset/pwr-mlxbf.c
@@ -68,8 +68,6 @@ static int pwr_mlxbf_probe(struct platform_device *pdev)
 		return err;
 
 	err = devm_request_irq(dev, irq, pwr_mlxbf_irq, 0, hid, priv);
-	if (err)
-		dev_err(dev, "Failed request of %s irq\n", priv->hid);
 
 	return err;
 }
diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index d20e44db0532..af00c00eceee 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -10,6 +10,7 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/property.h>
 #include <linux/reboot.h>
 #include <linux/reboot-mode.h>
 #include <linux/slab.h>
@@ -168,10 +169,11 @@ error:
  */
 int reboot_mode_register(struct reboot_mode_driver *reboot)
 {
-	struct mode_info *info;
+	struct mode_info *info = NULL;
 	struct property *prop;
 	struct device_node *np = reboot->dev->of_node;
 	size_t len = strlen(PREFIX);
+	u32 magic;
 	int ret;
 
 	INIT_LIST_HEAD(&reboot->head);
@@ -180,22 +182,22 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 		if (strncmp(prop->name, PREFIX, len))
 			continue;
 
-		info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
+		if (device_property_read_u32(reboot->dev, prop->name, &magic)) {
+			dev_dbg(reboot->dev, "reboot mode %s without magic number\n",
+				prop->name);
+			continue;
+		}
+
+		info = kzalloc_obj(*info, GFP_KERNEL);
 		if (!info) {
 			ret = -ENOMEM;
 			goto error;
 		}
 
-		if (of_property_read_u32(np, prop->name, &info->magic)) {
-			dev_err(reboot->dev, "reboot mode %s without magic number\n",
-				info->mode);
-			devm_kfree(reboot->dev, info);
-			continue;
-		}
-
+		info->magic = magic;
 		info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
 		if (!info->mode) {
-			ret =  -ENOMEM;
+			ret = -ENOMEM;
 			goto error;
 		} else if (info->mode[0] == '\0') {
 			kfree_const(info->mode);
@@ -206,6 +208,7 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 		}
 
 		list_add_tail(&info->list, &reboot->head);
+		info = NULL;
 	}
 
 	reboot->reboot_notifier.notifier_call = reboot_mode_notify;
@@ -218,6 +221,7 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 	return 0;
 
 error:
+	kfree(info);
 	reboot_mode_unregister(reboot);
 	return ret;
 }
@@ -261,12 +265,16 @@ static inline void reboot_mode_unregister_device(struct reboot_mode_driver *rebo
 int reboot_mode_unregister(struct reboot_mode_driver *reboot)
 {
 	struct mode_info *info;
+	struct mode_info *next;
 
 	unregister_reboot_notifier(&reboot->reboot_notifier);
 	reboot_mode_unregister_device(reboot);
 
-	list_for_each_entry(info, &reboot->head, list)
+	list_for_each_entry_safe(info, next, &reboot->head, list) {
+		list_del(&info->list);
 		kfree_const(info->mode);
+		kfree(info);
+	}
 
 	return 0;
 }
diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c
index 2e2cf5f62d73..60e855cae68e 100644
--- a/drivers/power/reset/syscon-reboot.c
+++ b/drivers/power/reset/syscon-reboot.c
@@ -67,7 +67,7 @@ static int syscon_reboot_probe(struct platform_device *pdev)
 {
 	struct syscon_reboot_context *ctx;
 	struct device *dev = &pdev->dev;
-	int priority;
+	u32 priority;
 	int err;
 
 	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
@@ -81,7 +81,7 @@ static int syscon_reboot_probe(struct platform_device *pdev)
 			return PTR_ERR(ctx->map);
 	}
 
-	if (of_property_read_s32(pdev->dev.of_node, "priority", &priority))
+	if (of_property_read_u32(pdev->dev.of_node, "priority", &priority))
 		priority = 192;
 
 	ctx->rd = of_device_get_match_data(dev);