treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

1 files changed, 912 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
new file mode 100644
index 000000000..45459a4ca
--- /dev/null
+++ b/drivers/acpi/acpi_tad.c
@@ -0,0 +1,912 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACPI Time and Alarm (TAD) Device Driver
+ *
+ * Copyright (C) 2018 - 2026 Intel Corporation
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * This driver is based on ACPI 6.6, Section 9.17.
+ *
+ * Provided are sysfs attributes, available under the TAD platform device,
+ * allowing user space to manage the AC and DC wakeup timers of the TAD:
+ * set and read their values, set and check their expire timer wake policies,
+ * check and clear their status and check the capabilities of the TAD reported
+ * by AML.  The DC timer attributes are only present if the TAD supports a
+ * separate DC alarm timer.
+ *
+ * The wakeup events handling and power management of the TAD is expected to
+ * be taken care of by the ACPI PM domain attached to its platform device.
+ *
+ * If the TAD supports the get/set real time features, as indicated by the
+ * capability mask returned by _GCP under the TAD object, additional sysfs
+ * attributes are created allowing the real time to be set and read and an RTC
+ * class device is registered under the TAD platform device.
+ */
+
+#include <linux/acpi.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/rtc.h>
+#include <linux/suspend.h>
+
+MODULE_DESCRIPTION("ACPI Time and Alarm (TAD) Device Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Rafael J. Wysocki");
+
+/* ACPI TAD capability flags (ACPI 6.6, Section 9.17.2) */
+#define ACPI_TAD_AC_WAKE	BIT(0)
+#define ACPI_TAD_DC_WAKE	BIT(1)
+#define ACPI_TAD_RT		BIT(2)
+#define ACPI_TAD_RT_IN_MS	BIT(3)
+#define ACPI_TAD_S4_S5__GWS	BIT(4)
+#define ACPI_TAD_AC_S4_WAKE	BIT(5)
+#define ACPI_TAD_AC_S5_WAKE	BIT(6)
+#define ACPI_TAD_DC_S4_WAKE	BIT(7)
+#define ACPI_TAD_DC_S5_WAKE	BIT(8)
+
+/* ACPI TAD alarm timer selection */
+#define ACPI_TAD_AC_TIMER	(u32)0
+#define ACPI_TAD_DC_TIMER	(u32)1
+
+/* Special value for disabled timer or expired timer wake policy. */
+#define ACPI_TAD_WAKE_DISABLED	(~(u32)0)
+
+/* ACPI TAD RTC */
+#define ACPI_TAD_TZ_UNSPEC	2047
+#define ACPI_TAD_TIME_ISDST	3
+
+struct acpi_tad_driver_data {
+	u32 capabilities;
+};
+
+struct acpi_tad_rt {
+	u16 year;  /* 1900 - 9999 */
+	u8 month;  /* 1 - 12 */
+	u8 day;    /* 1 - 31 */
+	u8 hour;   /* 0 - 23 */
+	u8 minute; /* 0 - 59 */
+	u8 second; /* 0 - 59 */
+	u8 valid;  /* 0 (failed) or 1 (success) for reads, 0 for writes */
+	u16 msec;  /* 1 - 1000 */
+	s16 tz;    /* -1440 to 1440 or 2047 (unspecified) */
+	u8 daylight;
+	u8 padding[3]; /* must be 0 */
+} __packed;
+
+static bool acpi_tad_rt_is_invalid(struct acpi_tad_rt *rt)
+{
+	return rt->year < 1900 || rt->year > 9999 ||
+	    rt->month < 1 || rt->month > 12 ||
+	    rt->hour > 23 || rt->minute > 59 || rt->second > 59 ||
+	    rt->tz < -1440 ||
+	    (rt->tz > 1440 && rt->tz != ACPI_TAD_TZ_UNSPEC) ||
+	    rt->daylight > 3;
+}
+
+static DEFINE_MUTEX(acpi_tad_aml_lock);
+
+static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object args[] = {
+		{ .type = ACPI_TYPE_BUFFER, },
+	};
+	struct acpi_object_list arg_list = {
+		.pointer = args,
+		.count = ARRAY_SIZE(args),
+	};
+	unsigned long long retval;
+	acpi_status status;
+
+	if (acpi_tad_rt_is_invalid(rt))
+		return -EINVAL;
+
+	rt->valid = 0;
+	rt->msec = 0;
+	memset(rt->padding, 0, 3);
+
+	args[0].buffer.pointer = (u8 *)rt;
+	args[0].buffer.length = sizeof(*rt);
+
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	guard(mutex)(&acpi_tad_aml_lock);
+
+	status = acpi_evaluate_integer(handle, "_SRT", &arg_list, &retval);
+	if (ACPI_FAILURE(status) || retval)
+		return -EIO;
+
+	return 0;
+}
+
+static int acpi_tad_evaluate_grt(struct device *dev, struct acpi_tad_rt *rt)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER };
+	acpi_status status;
+	int ret = -EIO;
+
+	guard(mutex)(&acpi_tad_aml_lock);
+
+	status = acpi_evaluate_object(handle, "_GRT", NULL, &output);
+	if (ACPI_SUCCESS(status)) {
+		union acpi_object *out_obj;
+
+		out_obj = output.pointer;
+		if (out_obj->type == ACPI_TYPE_BUFFER &&
+		    out_obj->buffer.length == sizeof(*rt)) {
+			struct acpi_tad_rt *data;
+
+			data = (struct acpi_tad_rt *)(out_obj->buffer.pointer);
+			if (data->valid) {
+				memcpy(rt, data, sizeof(*rt));
+				ret = 0;
+			}
+		}
+	}
+	ACPI_FREE(output.pointer);
+	return ret;
+}
+
+static int __acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
+{
+	int ret;
+
+	ret = acpi_tad_evaluate_grt(dev, rt);
+	if (ret)
+		return ret;
+
+	if (acpi_tad_rt_is_invalid(rt))
+		return -ENODATA;
+
+	return 0;
+}
+
+static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
+{
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	return __acpi_tad_get_real_time(dev, rt);
+}
+
+static int __acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
+			       u32 value)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object args[] = {
+		{ .type = ACPI_TYPE_INTEGER, },
+		{ .type = ACPI_TYPE_INTEGER, },
+	};
+	struct acpi_object_list arg_list = {
+		.pointer = args,
+		.count = ARRAY_SIZE(args),
+	};
+	unsigned long long retval;
+	acpi_status status;
+
+	args[0].integer.value = timer_id;
+	args[1].integer.value = value;
+
+	guard(mutex)(&acpi_tad_aml_lock);
+
+	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
+	if (ACPI_FAILURE(status) || retval)
+		return -EIO;
+
+	return 0;
+}
+
+static int __acpi_tad_wake_read(struct device *dev, char *method, u32 timer_id,
+				unsigned long long *retval)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object args[] = {
+		{ .type = ACPI_TYPE_INTEGER, },
+	};
+	struct acpi_object_list arg_list = {
+		.pointer = args,
+		.count = ARRAY_SIZE(args),
+	};
+	acpi_status status;
+
+	args[0].integer.value = timer_id;
+
+	guard(mutex)(&acpi_tad_aml_lock);
+
+	status = acpi_evaluate_integer(handle, method, &arg_list, retval);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return 0;
+}
+
+/* sysfs interface */
+
+static char *acpi_tad_rt_next_field(char *s, int *val)
+{
+	char *p;
+
+	p = strchr(s, ':');
+	if (!p)
+		return NULL;
+
+	*p = '\0';
+	if (kstrtoint(s, 10, val))
+		return NULL;
+
+	return p + 1;
+}
+
+static ssize_t time_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct acpi_tad_rt rt;
+	int val, ret;
+	char *s;
+
+	char *str __free(kfree) = kmemdup_nul(buf, count, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	s = acpi_tad_rt_next_field(str, &val);
+	if (!s)
+		return -ENODATA;
+
+	rt.year = val;
+
+	s = acpi_tad_rt_next_field(s, &val);
+	if (!s)
+		return -ENODATA;
+
+	rt.month = val;
+
+	s = acpi_tad_rt_next_field(s, &val);
+	if (!s)
+		return -ENODATA;
+
+	rt.day = val;
+
+	s = acpi_tad_rt_next_field(s, &val);
+	if (!s)
+		return -ENODATA;
+
+	rt.hour = val;
+
+	s = acpi_tad_rt_next_field(s, &val);
+	if (!s)
+		return -ENODATA;
+
+	rt.minute = val;
+
+	s = acpi_tad_rt_next_field(s, &val);
+	if (!s)
+		return -ENODATA;
+
+	rt.second = val;
+
+	s = acpi_tad_rt_next_field(s, &val);
+	if (!s)
+		return -ENODATA;
+
+	rt.tz = val;
+
+	if (kstrtoint(s, 10, &val))
+		return -ENODATA;
+
+	rt.daylight = val;
+
+	ret = acpi_tad_set_real_time(dev, &rt);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t time_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct acpi_tad_rt rt;
+	int ret;
+
+	ret = acpi_tad_get_real_time(dev, &rt);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%u:%u:%u:%u:%u:%u:%d:%u\n",
+		       rt.year, rt.month, rt.day, rt.hour, rt.minute, rt.second,
+		       rt.tz, rt.daylight);
+}
+
+static DEVICE_ATTR_RW(time);
+
+static int acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
+			     u32 value)
+{
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	return __acpi_tad_wake_set(dev, method, timer_id, value);
+}
+
+static int acpi_tad_wake_write(struct device *dev, const char *buf, char *method,
+			       u32 timer_id, const char *specval)
+{
+	u32 value;
+
+	if (sysfs_streq(buf, specval)) {
+		value = ACPI_TAD_WAKE_DISABLED;
+	} else {
+		int ret = kstrtou32(buf, 0, &value);
+
+		if (ret)
+			return ret;
+
+		if (value == ACPI_TAD_WAKE_DISABLED)
+			return -EINVAL;
+	}
+
+	return acpi_tad_wake_set(dev, method, timer_id, value);
+}
+
+static ssize_t acpi_tad_wake_read(struct device *dev, char *buf, char *method,
+				  u32 timer_id, const char *specval)
+{
+	unsigned long long retval;
+	int ret;
+
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	ret = __acpi_tad_wake_read(dev, method, timer_id, &retval);
+	if (ret)
+		return ret;
+
+	if ((u32)retval == ACPI_TAD_WAKE_DISABLED)
+		return sprintf(buf, "%s\n", specval);
+
+	return sprintf(buf, "%u\n", (u32)retval);
+}
+
+static const char *alarm_specval = "disabled";
+
+static int acpi_tad_alarm_write(struct device *dev, const char *buf,
+				u32 timer_id)
+{
+	return acpi_tad_wake_write(dev, buf, "_STV", timer_id, alarm_specval);
+}
+
+static ssize_t acpi_tad_alarm_read(struct device *dev, char *buf, u32 timer_id)
+{
+	return acpi_tad_wake_read(dev, buf, "_TIV", timer_id, alarm_specval);
+}
+
+static const char *policy_specval = "never";
+
+static int acpi_tad_policy_write(struct device *dev, const char *buf,
+				 u32 timer_id)
+{
+	return acpi_tad_wake_write(dev, buf, "_STP", timer_id, policy_specval);
+}
+
+static ssize_t acpi_tad_policy_read(struct device *dev, char *buf, u32 timer_id)
+{
+	return acpi_tad_wake_read(dev, buf, "_TIP", timer_id, policy_specval);
+}
+
+static int acpi_tad_clear_status(struct device *dev, u32 timer_id)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object args[] = {
+		{ .type = ACPI_TYPE_INTEGER, },
+	};
+	struct acpi_object_list arg_list = {
+		.pointer = args,
+		.count = ARRAY_SIZE(args),
+	};
+	unsigned long long retval;
+	acpi_status status;
+
+	args[0].integer.value = timer_id;
+
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	guard(mutex)(&acpi_tad_aml_lock);
+
+	status = acpi_evaluate_integer(handle, "_CWS", &arg_list, &retval);
+	if (ACPI_FAILURE(status) || retval)
+		return -EIO;
+
+	return 0;
+}
+
+static int acpi_tad_status_write(struct device *dev, const char *buf, u32 timer_id)
+{
+	int ret, value;
+
+	ret = kstrtoint(buf, 0, &value);
+	if (ret)
+		return ret;
+
+	if (value)
+		return -EINVAL;
+
+	return acpi_tad_clear_status(dev, timer_id);
+}
+
+static ssize_t acpi_tad_status_read(struct device *dev, char *buf, u32 timer_id)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object args[] = {
+		{ .type = ACPI_TYPE_INTEGER, },
+	};
+	struct acpi_object_list arg_list = {
+		.pointer = args,
+		.count = ARRAY_SIZE(args),
+	};
+	unsigned long long retval;
+	acpi_status status;
+
+	args[0].integer.value = timer_id;
+
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	guard(mutex)(&acpi_tad_aml_lock);
+
+	status = acpi_evaluate_integer(handle, "_GWS", &arg_list, &retval);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return sprintf(buf, "0x%02X\n", (u32)retval);
+}
+
+static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "0x%02X\n", dd->capabilities);
+}
+
+static DEVICE_ATTR_RO(caps);
+
+static ssize_t ac_alarm_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_AC_TIMER);
+
+	return ret ? ret : count;
+}
+
+static ssize_t ac_alarm_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	return acpi_tad_alarm_read(dev, buf, ACPI_TAD_AC_TIMER);
+}
+
+static DEVICE_ATTR_RW(ac_alarm);
+
+static ssize_t ac_policy_store(struct device *dev, struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_AC_TIMER);
+
+	return ret ? ret : count;
+}
+
+static ssize_t ac_policy_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	return acpi_tad_policy_read(dev, buf, ACPI_TAD_AC_TIMER);
+}
+
+static DEVICE_ATTR_RW(ac_policy);
+
+static ssize_t ac_status_store(struct device *dev, struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_AC_TIMER);
+
+	return ret ? ret : count;
+}
+
+static ssize_t ac_status_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	return acpi_tad_status_read(dev, buf, ACPI_TAD_AC_TIMER);
+}
+
+static DEVICE_ATTR_RW(ac_status);
+
+static ssize_t dc_alarm_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_DC_TIMER);
+
+	return ret ? ret : count;
+}
+
+static ssize_t dc_alarm_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	return acpi_tad_alarm_read(dev, buf, ACPI_TAD_DC_TIMER);
+}
+
+static DEVICE_ATTR_RW(dc_alarm);
+
+static ssize_t dc_policy_store(struct device *dev, struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_DC_TIMER);
+
+	return ret ? ret : count;
+}
+
+static ssize_t dc_policy_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	return acpi_tad_policy_read(dev, buf, ACPI_TAD_DC_TIMER);
+}
+
+static DEVICE_ATTR_RW(dc_policy);
+
+static ssize_t dc_status_store(struct device *dev, struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_DC_TIMER);
+
+	return ret ? ret : count;
+}
+
+static ssize_t dc_status_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	return acpi_tad_status_read(dev, buf, ACPI_TAD_DC_TIMER);
+}
+
+static DEVICE_ATTR_RW(dc_status);
+
+static struct attribute *acpi_tad_attrs[] = {
+	&dev_attr_caps.attr,
+	&dev_attr_ac_alarm.attr,
+	&dev_attr_ac_policy.attr,
+	&dev_attr_ac_status.attr,
+	&dev_attr_dc_alarm.attr,
+	&dev_attr_dc_policy.attr,
+	&dev_attr_dc_status.attr,
+	&dev_attr_time.attr,
+	NULL,
+};
+
+static umode_t acpi_tad_attr_is_visible(struct kobject *kobj,
+					struct attribute *a, int n)
+{
+	struct acpi_tad_driver_data *dd = dev_get_drvdata(kobj_to_dev(kobj));
+
+	if (a == &dev_attr_caps.attr)
+		return a->mode;
+
+	if ((dd->capabilities & ACPI_TAD_AC_WAKE) &&
+	    (a == &dev_attr_ac_alarm.attr || a == &dev_attr_ac_policy.attr ||
+	     a == &dev_attr_ac_status.attr))
+		return a->mode;
+
+	if ((dd->capabilities & ACPI_TAD_DC_WAKE) &&
+	    (a == &dev_attr_dc_alarm.attr || a == &dev_attr_dc_policy.attr ||
+	     a == &dev_attr_dc_status.attr))
+		return a->mode;
+
+	if ((dd->capabilities & ACPI_TAD_RT) && a == &dev_attr_time.attr)
+		return a->mode;
+
+	return 0;
+}
+
+static const struct attribute_group acpi_tad_group = {
+	.attrs	= acpi_tad_attrs,
+	.is_visible = acpi_tad_attr_is_visible,
+};
+
+__ATTRIBUTE_GROUPS(acpi_tad);
+
+#ifdef CONFIG_RTC_CLASS
+/* RTC class device interface */
+
+static void acpi_tad_rt_to_tm(struct acpi_tad_rt *rt, struct rtc_time *tm)
+{
+	tm->tm_year = rt->year - 1900;
+	tm->tm_mon = rt->month - 1;
+	tm->tm_mday = rt->day;
+	tm->tm_hour = rt->hour;
+	tm->tm_min = rt->minute;
+	tm->tm_sec = rt->second;
+	tm->tm_isdst = rt->daylight == ACPI_TAD_TIME_ISDST;
+}
+
+static int acpi_tad_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct acpi_tad_rt rt;
+
+	rt.year = tm->tm_year + 1900;
+	rt.month = tm->tm_mon + 1;
+	rt.day = tm->tm_mday;
+	rt.hour = tm->tm_hour;
+	rt.minute = tm->tm_min;
+	rt.second = tm->tm_sec;
+	rt.tz = ACPI_TAD_TZ_UNSPEC;
+	rt.daylight = ACPI_TAD_TIME_ISDST * !!tm->tm_isdst;
+
+	return acpi_tad_set_real_time(dev, &rt);
+}
+
+static int acpi_tad_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct acpi_tad_rt rt;
+	int ret;
+
+	ret = acpi_tad_get_real_time(dev, &rt);
+	if (ret)
+		return ret;
+
+	acpi_tad_rt_to_tm(&rt, tm);
+
+	return 0;
+}
+
+static int acpi_tad_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+	struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);
+	s64 value = ACPI_TAD_WAKE_DISABLED;
+	struct rtc_time tm_now;
+	struct acpi_tad_rt rt;
+	int ret;
+
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	if (t->enabled) {
+		/*
+		 * The value to pass to _STV is expected to be the number of
+		 * seconds between the time when the timer is programmed and the
+		 * time when it expires represented as a 32-bit integer.
+		 */
+		ret = __acpi_tad_get_real_time(dev, &rt);
+		if (ret)
+			return ret;
+
+		acpi_tad_rt_to_tm(&rt, &tm_now);
+
+		value = rtc_tm_to_time64(&t->time) - rtc_tm_to_time64(&tm_now);
+		if (value <= 0 || value >= U32_MAX)
+			return -EINVAL;
+	}
+
+	ret = __acpi_tad_wake_set(dev, "_STV", ACPI_TAD_AC_TIMER, value);
+	if (ret && t->enabled)
+		return ret;
+
+	/*
+	 * If a separate DC alarm timer is supported, set it to the same value
+	 * as the AC alarm timer.
+	 */
+	if (dd->capabilities & ACPI_TAD_DC_WAKE) {
+		ret = __acpi_tad_wake_set(dev, "_STV", ACPI_TAD_DC_TIMER, value);
+		if (ret && t->enabled) {
+			__acpi_tad_wake_set(dev, "_STV", ACPI_TAD_AC_TIMER,
+					    ACPI_TAD_WAKE_DISABLED);
+			return ret;
+		}
+	}
+
+	/* Assume success if the alarm is being disabled. */
+	return 0;
+}
+
+static int acpi_tad_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+	unsigned long long retval;
+	struct rtc_time tm_now;
+	struct acpi_tad_rt rt;
+	int ret;
+
+	PM_RUNTIME_ACQUIRE(dev, pm);
+	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+		return -ENXIO;
+
+	ret = __acpi_tad_get_real_time(dev, &rt);
+	if (ret)
+		return ret;
+
+	acpi_tad_rt_to_tm(&rt, &tm_now);
+
+	/*
+	 * Assume that the alarm was set by acpi_tad_rtc_set_alarm(), so the AC
+	 * and DC alarm timer settings are the same and it is sufficient to read
+	 * the former.
+	 *
+	 * The value returned by _TIV should be the number of seconds till the
+	 * expiration of the timer, represented as a 32-bit integer, or the
+	 * special ACPI_TAD_WAKE_DISABLED value meaning that the timer has
+	 * been disabled.
+	 */
+	ret = __acpi_tad_wake_read(dev, "_TIV", ACPI_TAD_AC_TIMER, &retval);
+	if (ret)
+		return ret;
+
+	if (retval > U32_MAX)
+		return -ENODATA;
+
+	t->pending = 0;
+
+	if (retval != ACPI_TAD_WAKE_DISABLED) {
+		t->enabled = 1;
+		rtc_time64_to_tm(rtc_tm_to_time64(&tm_now) + retval, &t->time);
+	} else {
+		t->enabled = 0;
+		t->time = tm_now;
+	}
+
+	return 0;
+}
+
+static const struct rtc_class_ops acpi_tad_rtc_ops = {
+	.read_time = acpi_tad_rtc_read_time,
+	.set_time = acpi_tad_rtc_set_time,
+	.set_alarm = acpi_tad_rtc_set_alarm,
+	.read_alarm = acpi_tad_rtc_read_alarm,
+};
+
+static void acpi_tad_register_rtc(struct device *dev, unsigned long long caps)
+{
+	struct rtc_device *rtc;
+
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return;
+
+	rtc->range_min = mktime64(1900,  1,  1,  0,  0,  0);
+	rtc->range_max = mktime64(9999, 12, 31, 23, 59, 59);
+
+	rtc->ops = &acpi_tad_rtc_ops;
+
+	if (!(caps & ACPI_TAD_AC_WAKE))
+		clear_bit(RTC_FEATURE_ALARM, rtc->features);
+
+	devm_rtc_register_device(rtc);
+}
+#else /* !CONFIG_RTC_CLASS */
+static inline void acpi_tad_register_rtc(struct device *dev,
+					 unsigned long long caps) {}
+#endif /* !CONFIG_RTC_CLASS */
+
+/* Platform driver interface */
+
+static int acpi_tad_disable_timer(struct device *dev, u32 timer_id)
+{
+	return acpi_tad_wake_set(dev, "_STV", timer_id, ACPI_TAD_WAKE_DISABLED);
+}
+
+static void acpi_tad_remove(void *data)
+{
+	struct device *dev = data;
+	struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);
+
+	device_init_wakeup(dev, false);
+
+	scoped_guard(pm_runtime_noresume, dev) {
+		if (dd->capabilities & ACPI_TAD_AC_WAKE) {
+			acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER);
+			acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER);
+		}
+		if (dd->capabilities & ACPI_TAD_DC_WAKE) {
+			acpi_tad_disable_timer(dev, ACPI_TAD_DC_TIMER);
+			acpi_tad_clear_status(dev, ACPI_TAD_DC_TIMER);
+		}
+	}
+
+	pm_runtime_suspend(dev);
+	pm_runtime_disable(dev);
+}
+
+static int acpi_tad_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct acpi_tad_driver_data *dd;
+	acpi_handle handle;
+	acpi_status status;
+	unsigned long long caps;
+	int ret;
+
+	handle = ACPI_HANDLE(dev);
+	if (!handle)
+		return -ENODEV;
+
+	/*
+	 * Initialization failure messages are mostly about firmware issues, so
+	 * print them at the "info" level.
+	 */
+	status = acpi_evaluate_integer(handle, "_GCP", NULL, &caps);
+	if (ACPI_FAILURE(status)) {
+		dev_info(dev, "Unable to get capabilities\n");
+		return -ENODEV;
+	}
+
+	if (!acpi_has_method(handle, "_PRW")) {
+		dev_info(dev, "Missing _PRW\n");
+		caps &= ~(ACPI_TAD_AC_WAKE | ACPI_TAD_DC_WAKE);
+	}
+
+	if (!(caps & ACPI_TAD_AC_WAKE))
+		caps &= ~ACPI_TAD_DC_WAKE;
+
+	dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
+	if (!dd)
+		return -ENOMEM;
+
+	dd->capabilities = caps;
+	dev_set_drvdata(dev, dd);
+
+	/*
+	 * Assume that the ACPI PM domain has been attached to the device and
+	 * simply enable system wakeup and runtime PM and put the device into
+	 * runtime suspend.  Everything else should be taken care of by the ACPI
+	 * PM domain callbacks.
+	 */
+	if (caps & ACPI_TAD_AC_WAKE) {
+		device_init_wakeup(dev, true);
+		dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
+					     DPM_FLAG_MAY_SKIP_RESUME);
+	}
+
+	/*
+	 * The platform bus type probe callback tells the ACPI PM domain to
+	 * power up the device, so set the runtime PM status of it to "active".
+	 */
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+	pm_runtime_suspend(dev);
+
+	/*
+	 * acpi_tad_remove() needs to run after unregistering the RTC class
+	 * device to avoid racing with the latter's callbacks.
+	 */
+	ret = devm_add_action_or_reset(&pdev->dev, acpi_tad_remove, &pdev->dev);
+	if (ret)
+		return ret;
+
+	if (caps & ACPI_TAD_RT)
+		acpi_tad_register_rtc(dev, caps);
+
+	return 0;
+}
+
+static const struct acpi_device_id acpi_tad_ids[] = {
+	{"ACPI000E", 0},
+	{}
+};
+
+static struct platform_driver acpi_tad_driver = {
+	.driver = {
+		.name = "acpi-tad",
+		.acpi_match_table = acpi_tad_ids,
+		.dev_groups = acpi_tad_groups,
+	},
+	.probe = acpi_tad_probe,
+};
+MODULE_DEVICE_TABLE(acpi, acpi_tad_ids);
+
+module_platform_driver(acpi_tad_driver);