Merge tag 'rtc-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "The bulk of the patches are about replacing the uie_unsupported struct
  rtc_device member by a feature bit.

  Subsystem:

   - remove uie_unsupported, all users have been converted to clear
     RTC_FEATURE_UPDATE_INTERRUPT and provide a reason

   - RTCs with an alarm with a resolution of a minute are now letting
     the core handle rounding down the alarm time

   - fix use-after-free on device removal

  New driver:

   - OP-TEE RTC PTA

  Drivers:

   - sun6i: Add H616 support

   - cmos: Fix the AltCentury for AMD platforms

   - spear: set range"

* tag 'rtc-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (56 commits)
  rtc: check if __rtc_read_time was successful
  rtc: gamecube: Fix refcount leak in gamecube_rtc_read_offset_from_sram
  rtc: mc146818-lib: Fix the AltCentury for AMD platforms
  rtc: optee: add RTC driver for OP-TEE RTC PTA
  rtc: pm8xxx: Return -ENODEV if set_time disallowed
  rtc: pm8xxx: Attach wake irq to device
  clk: sunxi-ng: sun6i-rtc: include clk/sunxi-ng.h
  rtc: remove uie_unsupported
  rtc: xgene: stop using uie_unsupported
  rtc: hym8563: switch to RTC_FEATURE_UPDATE_INTERRUPT
  rtc: hym8563: let the core handle the alarm resolution
  rtc: hym8563: switch to devm_rtc_allocate_device
  rtc: efi: switch to RTC_FEATURE_UPDATE_INTERRUPT
  rtc: efi: switch to devm_rtc_allocate_device
  rtc: add new RTC_FEATURE_ALARM_WAKEUP_ONLY feature
  rtc: spear: fix spear_rtc_read_time
  rtc: spear: drop uie_unsupported
  rtc: spear: set range
  rtc: spear: switch to devm_rtc_allocate_device
  rtc: pcf8563: switch to RTC_FEATURE_UPDATE_INTERRUPT
  ...

25 files changed, 617 insertions, 202 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index f6d6d4c26361..41c65b4d2baf 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1293,6 +1293,16 @@ config RTC_DRV_OPAL
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-opal.
 
+config RTC_DRV_OPTEE
+	tristate "OP-TEE based RTC driver"
+	depends on OPTEE
+	help
+	  Select this to get support for OP-TEE based RTC control on SoCs where
+	  RTC are not accessible to the normal world (Linux).
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-optee.
+
 config RTC_DRV_ZYNQMP
 	tristate "Xilinx Zynq Ultrascale+ MPSoC RTC"
 	depends on OF && HAS_IOMEM
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index e92f3e943245..2d827d8261d5 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -115,6 +115,7 @@ obj-$(CONFIG_RTC_DRV_GAMECUBE)	+= rtc-gamecube.o
 obj-$(CONFIG_RTC_DRV_NTXEC)	+= rtc-ntxec.o
 obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o
 obj-$(CONFIG_RTC_DRV_OPAL)	+= rtc-opal.o
+obj-$(CONFIG_RTC_DRV_OPTEE)	+= rtc-optee.o
 obj-$(CONFIG_RTC_DRV_PALMAS)	+= rtc-palmas.o
 obj-$(CONFIG_RTC_DRV_PCAP)	+= rtc-pcap.o
 obj-$(CONFIG_RTC_DRV_PCF2123)	+= rtc-pcf2123.o
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 4b460c61f1d8..3c8eec2218df 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -26,6 +26,15 @@ struct class *rtc_class;
 static void rtc_device_release(struct device *dev)
 {
 	struct rtc_device *rtc = to_rtc_device(dev);
+	struct timerqueue_head *head = &rtc->timerqueue;
+	struct timerqueue_node *node;
+
+	mutex_lock(&rtc->ops_lock);
+	while ((node = timerqueue_getnext(head)))
+		timerqueue_del(head, node);
+	mutex_unlock(&rtc->ops_lock);
+
+	cancel_work_sync(&rtc->irqwork);
 
 	ida_simple_remove(&rtc_ida, rtc->id);
 	mutex_destroy(&rtc->ops_lock);
@@ -390,9 +399,6 @@ int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc)
 	if (!rtc->ops->set_alarm)
 		clear_bit(RTC_FEATURE_ALARM, rtc->features);
 
-	if (rtc->uie_unsupported)
-		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
-
 	if (rtc->ops->set_offset)
 		set_bit(RTC_FEATURE_CORRECTION, rtc->features);
 
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index d8e835798153..9edd662c69ac 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -804,9 +804,13 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
 	struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
 	struct rtc_time tm;
 	ktime_t now;
+	int err;
+
+	err = __rtc_read_time(rtc, &tm);
+	if (err)
+		return err;
 
 	timer->enabled = 1;
-	__rtc_read_time(rtc, &tm);
 	now = rtc_tm_to_ktime(tm);
 
 	/* Skip over expired timers */
@@ -820,7 +824,6 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
 	trace_rtc_timer_enqueue(timer);
 	if (!next || ktime_before(timer->node.expires, next->expires)) {
 		struct rtc_wkalrm alarm;
-		int err;
 
 		alarm.time = rtc_ktime_to_tm(timer->node.expires);
 		alarm.enabled = 1;
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 336cb9aa5e33..d51565bcc189 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -1955,7 +1955,7 @@ static int ds1307_probe(struct i2c_client *client,
 		dev_info(ds1307->dev,
 			 "'wakeup-source' is set, request for an IRQ is disabled!\n");
 		/* We cannot support UIE mode if we do not have an IRQ line */
-		ds1307->rtc->uie_unsupported = 1;
+		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, ds1307->rtc->features);
 	}
 
 	if (want_irq) {
diff --git a/drivers/rtc/rtc-ds1685.c b/drivers/rtc/rtc-ds1685.c
index 75db7ab654a5..a24331ba8a5f 100644
--- a/drivers/rtc/rtc-ds1685.c
+++ b/drivers/rtc/rtc-ds1685.c
@@ -1273,7 +1273,7 @@ ds1685_rtc_probe(struct platform_device *pdev)
 
 	/* See if the platform doesn't support UIE. */
 	if (pdata->uie_unsupported)
-		rtc_dev->uie_unsupported = 1;
+		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc_dev->features);
 
 	rtc->dev = rtc_dev;
 
@@ -1285,13 +1285,10 @@ ds1685_rtc_probe(struct platform_device *pdev)
 	 * there won't be an automatic way of notifying the kernel about it,
 	 * unless ctrlc is explicitly polled.
 	 */
-	if (!pdata->no_irq) {
-		ret = platform_get_irq(pdev, 0);
-		if (ret <= 0)
-			return ret;
-
-		rtc->irq_num = ret;
-
+	rtc->irq_num = platform_get_irq(pdev, 0);
+	if (rtc->irq_num <= 0) {
+		clear_bit(RTC_FEATURE_ALARM, rtc_dev->features);
+	} else {
 		/* Request an IRQ. */
 		ret = devm_request_threaded_irq(&pdev->dev, rtc->irq_num,
 				       NULL, ds1685_rtc_irq_handler,
@@ -1305,7 +1302,6 @@ ds1685_rtc_probe(struct platform_device *pdev)
 			rtc->irq_num = 0;
 		}
 	}
-	rtc->no_irq = pdata->no_irq;
 
 	/* Setup complete. */
 	ds1685_rtc_switch_to_bank0(rtc);
@@ -1394,7 +1390,7 @@ ds1685_rtc_poweroff(struct platform_device *pdev)
 		 * have been taken care of by the shutdown scripts and this
 		 * is the final function call.
 		 */
-		if (!rtc->no_irq)
+		if (rtc->irq_num)
 			disable_irq_nosync(rtc->irq_num);
 
 		/* Oscillator must be on and the countdown chain enabled. */
diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
index 138c5e0046c8..11850c2880ad 100644
--- a/drivers/rtc/rtc-efi.c
+++ b/drivers/rtc/rtc-efi.c
@@ -261,15 +261,17 @@ static int __init efi_rtc_probe(struct platform_device *dev)
 	if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
 		return -ENODEV;
 
-	rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops,
-					THIS_MODULE);
+	rtc = devm_rtc_allocate_device(&dev->dev);
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);
 
-	rtc->uie_unsupported = 1;
 	platform_set_drvdata(dev, rtc);
 
-	return 0;
+	rtc->ops = &efi_rtc_ops;
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
+	set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
+
+	return devm_rtc_register_device(rtc);
 }
 
 static struct platform_driver efi_rtc_driver = {
diff --git a/drivers/rtc/rtc-gamecube.c b/drivers/rtc/rtc-gamecube.c
index f717b36f4738..18ca3b38b2d0 100644
--- a/drivers/rtc/rtc-gamecube.c
+++ b/drivers/rtc/rtc-gamecube.c
@@ -235,6 +235,7 @@ static int gamecube_rtc_read_offset_from_sram(struct priv *d)
 	}
 
 	ret = of_address_to_resource(np, 0, &res);
+	of_node_put(np);
 	if (ret) {
 		pr_err("no io memory range found\n");
 		return -1;
diff --git a/drivers/rtc/rtc-hym8563.c b/drivers/rtc/rtc-hym8563.c
index 0751cae27285..90e602e99d03 100644
--- a/drivers/rtc/rtc-hym8563.c
+++ b/drivers/rtc/rtc-hym8563.c
@@ -220,24 +220,6 @@ static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 	u8 buf[4];
 	int ret;
 
-	/*
-	 * The alarm has no seconds so deal with it
-	 */
-	if (alm_tm->tm_sec) {
-		alm_tm->tm_sec = 0;
-		alm_tm->tm_min++;
-		if (alm_tm->tm_min >= 60) {
-			alm_tm->tm_min = 0;
-			alm_tm->tm_hour++;
-			if (alm_tm->tm_hour >= 24) {
-				alm_tm->tm_hour = 0;
-				alm_tm->tm_mday++;
-				if (alm_tm->tm_mday > 31)
-					alm_tm->tm_mday = 0;
-			}
-		}
-	}
-
 	ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 	if (ret < 0)
 		return ret;
@@ -523,6 +505,10 @@ static int hym8563_probe(struct i2c_client *client,
 	if (!hym8563)
 		return -ENOMEM;
 
+	hym8563->rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(hym8563->rtc))
+		return PTR_ERR(hym8563->rtc);
+
 	hym8563->client = client;
 	i2c_set_clientdata(client, hym8563);
 
@@ -557,19 +543,15 @@ static int hym8563_probe(struct i2c_client *client,
 	dev_dbg(&client->dev, "rtc information is %s\n",
 		(ret & HYM8563_SEC_VL) ? "invalid" : "valid");
 
-	hym8563->rtc = devm_rtc_device_register(&client->dev, client->name,
-						&hym8563_rtc_ops, THIS_MODULE);
-	if (IS_ERR(hym8563->rtc))
-		return PTR_ERR(hym8563->rtc);
-
-	/* the hym8563 alarm only supports a minute accuracy */
-	hym8563->rtc->uie_unsupported = 1;
+	hym8563->rtc->ops = &hym8563_rtc_ops;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, hym8563->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, hym8563->rtc->features);
 
 #ifdef CONFIG_COMMON_CLK
 	hym8563_clkout_register_clk(hym8563);
 #endif
 
-	return 0;
+	return devm_rtc_register_device(hym8563->rtc);
 }
 
 static const struct i2c_device_id hym8563_id[] = {
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 6d383b629d20..d868458cd40e 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -932,10 +932,8 @@ static int m41t80_probe(struct i2c_client *client,
 	m41t80_data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	m41t80_data->rtc->range_max = RTC_TIMESTAMP_END_2099;
 
-	if (client->irq <= 0) {
-		/* We cannot support UIE mode if we do not have an IRQ line */
-		m41t80_data->rtc->uie_unsupported = 1;
-	}
+	if (client->irq <= 0)
+		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, m41t80_data->rtc->features);
 
 	/* Make sure HT (Halt Update) bit is cleared */
 	rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c
index ae9f131b43c0..522449b25921 100644
--- a/drivers/rtc/rtc-mc146818-lib.c
+++ b/drivers/rtc/rtc-mc146818-lib.c
@@ -176,6 +176,17 @@ int mc146818_get_time(struct rtc_time *time)
 }
 EXPORT_SYMBOL_GPL(mc146818_get_time);
 
+/* AMD systems don't allow access to AltCentury with DV1 */
+static bool apply_amd_register_a_behavior(void)
+{
+#ifdef CONFIG_X86
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+	    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
+		return true;
+#endif
+	return false;
+}
+
 /* Set the current date and time in the real time clock. */
 int mc146818_set_time(struct rtc_time *time)
 {
@@ -232,8 +243,10 @@ int mc146818_set_time(struct rtc_time *time)
 	if (yrs >= 100)
 		yrs -= 100;
 
-	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
-	    || RTC_ALWAYS_BCD) {
+	spin_lock_irqsave(&rtc_lock, flags);
+	save_control = CMOS_READ(RTC_CONTROL);
+	spin_unlock_irqrestore(&rtc_lock, flags);
+	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 		sec = bin2bcd(sec);
 		min = bin2bcd(min);
 		hrs = bin2bcd(hrs);
@@ -247,7 +260,10 @@ int mc146818_set_time(struct rtc_time *time)
 	save_control = CMOS_READ(RTC_CONTROL);
 	CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
 	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
-	CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
+	if (apply_amd_register_a_behavior())
+		CMOS_WRITE((save_freq_select & ~RTC_AMD_BANK_SELECT), RTC_FREQ_SELECT);
+	else
+		CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
 
 #ifdef CONFIG_MACH_DECSTATION
 	CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
diff --git a/drivers/rtc/rtc-mpc5121.c b/drivers/rtc/rtc-mpc5121.c
index bb2ea9bc56f2..6d7656a75cae 100644
--- a/drivers/rtc/rtc-mpc5121.c
+++ b/drivers/rtc/rtc-mpc5121.c
@@ -210,20 +210,6 @@ static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 	struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 	struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 
-	/*
-	 * the alarm has no seconds so deal with it
-	 */
-	if (alarm->time.tm_sec) {
-		alarm->time.tm_sec = 0;
-		alarm->time.tm_min++;
-		if (alarm->time.tm_min >= 60) {
-			alarm->time.tm_min = 0;
-			alarm->time.tm_hour++;
-			if (alarm->time.tm_hour >= 24)
-				alarm->time.tm_hour = 0;
-		}
-	}
-
 	alarm->time.tm_mday = -1;
 	alarm->time.tm_mon = -1;
 	alarm->time.tm_year = -1;
@@ -349,7 +335,8 @@ static int mpc5121_rtc_probe(struct platform_device *op)
 	}
 
 	rtc->rtc->ops = &mpc5200_rtc_ops;
-	rtc->rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc->features);
 	rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
 	rtc->rtc->range_max = 65733206399ULL; /* 4052-12-31 23:59:59 */
 
diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c
index f8f49a969c23..ad41aaf8a17f 100644
--- a/drivers/rtc/rtc-opal.c
+++ b/drivers/rtc/rtc-opal.c
@@ -250,7 +250,7 @@ static int opal_rtc_probe(struct platform_device *pdev)
 	rtc->ops = &opal_rtc_ops;
 	rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
 	rtc->range_max = RTC_TIMESTAMP_END_9999;
-	rtc->uie_unsupported = 1;
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
 
 	return devm_rtc_register_device(rtc);
 }
diff --git a/drivers/rtc/rtc-optee.c b/drivers/rtc/rtc-optee.c
new file mode 100644
index 000000000000..9f8b5d4a8f6b
--- /dev/null
+++ b/drivers/rtc/rtc-optee.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Microchip.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/tee_drv.h>
+
+#define RTC_INFO_VERSION	0x1
+
+#define TA_CMD_RTC_GET_INFO		0x0
+#define TA_CMD_RTC_GET_TIME		0x1
+#define TA_CMD_RTC_SET_TIME		0x2
+#define TA_CMD_RTC_GET_OFFSET		0x3
+#define TA_CMD_RTC_SET_OFFSET		0x4
+
+#define TA_RTC_FEATURE_CORRECTION	BIT(0)
+
+struct optee_rtc_time {
+	u32 tm_sec;
+	u32 tm_min;
+	u32 tm_hour;
+	u32 tm_mday;
+	u32 tm_mon;
+	u32 tm_year;
+	u32 tm_wday;
+};
+
+struct optee_rtc_info {
+	u64 version;
+	u64 features;
+	struct optee_rtc_time range_min;
+	struct optee_rtc_time range_max;
+};
+
+/**
+ * struct optee_rtc - OP-TEE RTC private data
+ * @dev:		OP-TEE based RTC device.
+ * @ctx:		OP-TEE context handler.
+ * @session_id:		RTC TA session identifier.
+ * @shm:		Memory pool shared with RTC device.
+ * @features:		Bitfield of RTC features
+ */
+struct optee_rtc {
+	struct device *dev;
+	struct tee_context *ctx;
+	u32 session_id;
+	struct tee_shm *shm;
+	u64 features;
+};
+
+static int optee_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct optee_rtc_time *optee_tm;
+	struct tee_param param[4] = {0};
+	int ret;
+
+	inv_arg.func = TA_CMD_RTC_GET_TIME;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	/* Fill invoke cmd params */
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(struct optee_rtc_time);
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	optee_tm = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(optee_tm))
+		return PTR_ERR(optee_tm);
+
+	if (param[0].u.memref.size != sizeof(*optee_tm))
+		return -EPROTO;
+
+	tm->tm_sec = optee_tm->tm_sec;
+	tm->tm_min = optee_tm->tm_min;
+	tm->tm_hour = optee_tm->tm_hour;
+	tm->tm_mday = optee_tm->tm_mday;
+	tm->tm_mon = optee_tm->tm_mon;
+	tm->tm_year = optee_tm->tm_year - 1900;
+	tm->tm_wday = optee_tm->tm_wday;
+	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+
+	return 0;
+}
+
+static int optee_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	struct optee_rtc_time optee_tm;
+	void *rtc_data;
+	int ret;
+
+	optee_tm.tm_sec = tm->tm_sec;
+	optee_tm.tm_min = tm->tm_min;
+	optee_tm.tm_hour = tm->tm_hour;
+	optee_tm.tm_mday = tm->tm_mday;
+	optee_tm.tm_mon = tm->tm_mon;
+	optee_tm.tm_year = tm->tm_year + 1900;
+	optee_tm.tm_wday = tm->tm_wday;
+
+	inv_arg.func = TA_CMD_RTC_SET_TIME;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(struct optee_rtc_time);
+
+	rtc_data = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(rtc_data))
+		return PTR_ERR(rtc_data);
+
+	memcpy(rtc_data, &optee_tm, sizeof(struct optee_rtc_time));
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static int optee_rtc_readoffset(struct device *dev, long *offset)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = TA_CMD_RTC_GET_OFFSET;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	*offset = param[0].u.value.a;
+
+	return 0;
+}
+
+static int optee_rtc_setoffset(struct device *dev, long offset)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = TA_CMD_RTC_SET_OFFSET;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+	param[0].u.value.a = offset;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static const struct rtc_class_ops optee_rtc_ops = {
+	.read_time	= optee_rtc_readtime,
+	.set_time	= optee_rtc_settime,
+	.set_offset	= optee_rtc_setoffset,
+	.read_offset	= optee_rtc_readoffset,
+};
+
+static int optee_rtc_read_info(struct device *dev, struct rtc_device *rtc,
+			       u64 *features)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	struct optee_rtc_info *info;
+	struct optee_rtc_time *tm;
+	int ret;
+
+	inv_arg.func = TA_CMD_RTC_GET_INFO;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(*info);
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	info = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(info))
+		return PTR_ERR(info);
+
+	if (param[0].u.memref.size != sizeof(*info))
+		return -EPROTO;
+
+	if (info->version != RTC_INFO_VERSION)
+		return -EPROTO;
+
+	*features = info->features;
+
+	tm = &info->range_min;
+	rtc->range_min = mktime64(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min,
+				  tm->tm_sec);
+	tm = &info->range_max;
+	rtc->range_max = mktime64(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min,
+				  tm->tm_sec);
+
+	return 0;
+}
+
+static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+	if (ver->impl_id == TEE_IMPL_ID_OPTEE)
+		return 1;
+	else
+		return 0;
+}
+
+static int optee_rtc_probe(struct device *dev)
+{
+	struct tee_client_device *rtc_device = to_tee_client_device(dev);
+	struct tee_ioctl_open_session_arg sess_arg;
+	struct optee_rtc *priv;
+	struct rtc_device *rtc;
+	struct tee_shm *shm;
+	int ret, err;
+
+	memset(&sess_arg, 0, sizeof(sess_arg));
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	/* Open context with TEE driver */
+	priv->ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
+	if (IS_ERR(priv->ctx))
+		return -ENODEV;
+
+	/* Open session with rtc Trusted App */
+	export_uuid(sess_arg.uuid, &rtc_device->id.uuid);
+	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+
+	ret = tee_client_open_session(priv->ctx, &sess_arg, NULL);
+	if (ret < 0 || sess_arg.ret != 0) {
+		dev_err(dev, "tee_client_open_session failed, err: %x\n", sess_arg.ret);
+		err = -EINVAL;
+		goto out_ctx;
+	}
+	priv->session_id = sess_arg.session;
+
+	shm = tee_shm_alloc_kernel_buf(priv->ctx, sizeof(struct optee_rtc_info));
+	if (IS_ERR(shm)) {
+		dev_err(priv->dev, "tee_shm_alloc_kernel_buf failed\n");
+		err = PTR_ERR(shm);
+		goto out_sess;
+	}
+
+	priv->shm = shm;
+	priv->dev = dev;
+	dev_set_drvdata(dev, priv);
+
+	rtc->ops = &optee_rtc_ops;
+
+	err = optee_rtc_read_info(dev, rtc, &priv->features);
+	if (err) {
+		dev_err(dev, "Failed to get RTC features from OP-TEE\n");
+		goto out_shm;
+	}
+
+	err = devm_rtc_register_device(rtc);
+	if (err)
+		goto out_shm;
+
+	/*
+	 * We must clear this bit after registering because rtc_register_device
+	 * will set it if it sees that .set_offset is provided.
+	 */
+	if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
+		clear_bit(RTC_FEATURE_CORRECTION, rtc->features);
+
+	return 0;
+
+out_shm:
+	tee_shm_free(priv->shm);
+out_sess:
+	tee_client_close_session(priv->ctx, priv->session_id);
+out_ctx:
+	tee_client_close_context(priv->ctx);
+
+	return err;
+}
+
+static int optee_rtc_remove(struct device *dev)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+
+	tee_client_close_session(priv->ctx, priv->session_id);
+	tee_client_close_context(priv->ctx);
+
+	return 0;
+}
+
+static const struct tee_client_device_id optee_rtc_id_table[] = {
+	{UUID_INIT(0xf389f8c8, 0x845f, 0x496c,
+		   0x8b, 0xbe, 0xd6, 0x4b, 0xd2, 0x4c, 0x92, 0xfd)},
+	{}
+};
+
+MODULE_DEVICE_TABLE(tee, optee_rtc_id_table);
+
+static struct tee_client_driver optee_rtc_driver = {
+	.id_table	= optee_rtc_id_table,
+	.driver		= {
+		.name		= "optee_rtc",
+		.bus		= &tee_bus_type,
+		.probe		= optee_rtc_probe,
+		.remove		= optee_rtc_remove,
+	},
+};
+
+static int __init optee_rtc_mod_init(void)
+{
+	return driver_register(&optee_rtc_driver.driver);
+}
+
+static void __exit optee_rtc_mod_exit(void)
+{
+	driver_unregister(&optee_rtc_driver.driver);
+}
+
+module_init(optee_rtc_mod_init);
+module_exit(optee_rtc_mod_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Clément Léger <clement.leger@bootlin.com>");
+MODULE_DESCRIPTION("OP-TEE based RTC driver");
diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c
index 7473e6c8a183..e13b5e695d06 100644
--- a/drivers/rtc/rtc-pcf2123.c
+++ b/drivers/rtc/rtc-pcf2123.c
@@ -427,7 +427,8 @@ static int pcf2123_probe(struct spi_device *spi)
 	 * support to this driver to generate interrupts more than once
 	 * per minute.
 	 */
-	rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
 	rtc->ops = &pcf2123_rtc_ops;
 	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	rtc->range_max = RTC_TIMESTAMP_END_2099;
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 81a5b1f2e68c..63b275b014bd 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -374,7 +374,8 @@ static int pcf2127_watchdog_init(struct device *dev, struct pcf2127 *pcf2127)
 static int pcf2127_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
-	unsigned int buf[5], ctrl2;
+	u8 buf[5];
+	unsigned int ctrl2;
 	int ret;
 
 	ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
@@ -655,13 +656,25 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
 	pcf2127->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099;
 	pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */
-	pcf2127->rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_2S, pcf2127->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf2127->rtc->features);
 	clear_bit(RTC_FEATURE_ALARM, pcf2127->rtc->features);
 
 	if (alarm_irq > 0) {
+		unsigned long flags;
+
+		/*
+		 * If flags = 0, devm_request_threaded_irq() will use IRQ flags
+		 * obtained from device tree.
+		 */
+		if (dev_fwnode(dev))
+			flags = 0;
+		else
+			flags = IRQF_TRIGGER_LOW;
+
 		ret = devm_request_threaded_irq(dev, alarm_irq, NULL,
 						pcf2127_rtc_irq,
-						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						flags | IRQF_ONESHOT,
 						dev_name(dev), dev);
 		if (ret) {
 			dev_err(dev, "failed to request alarm irq\n");
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index df2b072c394d..9760824ec199 100644
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -616,7 +616,8 @@ static int pcf85063_probe(struct i2c_client *client)
 	pcf85063->rtc->ops = &pcf85063_rtc_ops;
 	pcf85063->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	pcf85063->rtc->range_max = RTC_TIMESTAMP_END_2099;
-	pcf85063->rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_2S, pcf85063->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf85063->rtc->features);
 	clear_bit(RTC_FEATURE_ALARM, pcf85063->rtc->features);
 
 	if (config->has_alarms && client->irq > 0) {
diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c
index c93acade7205..b1b1943de844 100644
--- a/drivers/rtc/rtc-pcf8523.c
+++ b/drivers/rtc/rtc-pcf8523.c
@@ -212,14 +212,6 @@ static int pcf8523_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 	if (err < 0)
 		return err;
 
-	/* The alarm has no seconds, round up to nearest minute */
-	if (tm->time.tm_sec) {
-		time64_t alarm_time = rtc_tm_to_time64(&tm->time);
-
-		alarm_time += 60 - tm->time.tm_sec;
-		rtc_time64_to_tm(alarm_time, &tm->time);
-	}
-
 	regs[0] = bin2bcd(tm->time.tm_min);
 	regs[1] = bin2bcd(tm->time.tm_hour);
 	regs[2] = bin2bcd(tm->time.tm_mday);
@@ -240,9 +232,9 @@ static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
 {
 	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 	int ret;
+	u32 value;
 
 	switch(param->param) {
-		u32 value;
 
 	case RTC_PARAM_BACKUP_SWITCH_MODE:
 		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
@@ -279,9 +271,9 @@ static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
 static int pcf8523_param_set(struct device *dev, struct rtc_param *param)
 {
 	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 mode;
 
 	switch(param->param) {
-		u8 mode;
 	case RTC_PARAM_BACKUP_SWITCH_MODE:
 		switch (param->uvalue) {
 		case RTC_BSM_DISABLED:
@@ -450,7 +442,8 @@ static int pcf8523_probe(struct i2c_client *client,
 	rtc->ops = &pcf8523_rtc_ops;
 	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	rtc->range_max = RTC_TIMESTAMP_END_2099;
-	rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
 
 	if (client->irq > 0) {
 		err = regmap_write(pcf8523->regmap, PCF8523_TMR_CLKOUT_CTRL, 0x38);
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index c8bddfb94129..9d06813e2e6d 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -330,19 +330,6 @@ static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 	unsigned char buf[4];
 	int err;
 
-	/* The alarm has no seconds, round up to nearest minute */
-	if (tm->time.tm_sec) {
-		time64_t alarm_time = rtc_tm_to_time64(&tm->time);
-
-		alarm_time += 60 - tm->time.tm_sec;
-		rtc_time64_to_tm(alarm_time, &tm->time);
-	}
-
-	dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
-		"enabled=%d pending=%d\n", __func__,
-		tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
-		tm->time.tm_mday, tm->enabled, tm->pending);
-
 	buf[0] = bin2bcd(tm->time.tm_min);
 	buf[1] = bin2bcd(tm->time.tm_hour);
 	buf[2] = bin2bcd(tm->time.tm_mday);
@@ -565,7 +552,8 @@ static int pcf8563_probe(struct i2c_client *client,
 
 	pcf8563->rtc->ops = &pcf8563_rtc_ops;
 	/* the pcf8563 alarm only supports a minute accuracy */
-	pcf8563->rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf8563->rtc->features);
 	pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
 	pcf8563->rtc->set_start_time = true;
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index e38ee8848385..bad6a5d9c683 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -350,9 +350,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 		}
 	}
 
-	if (!adev->irq[0])
-		clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
-
 	device_init_wakeup(&adev->dev, true);
 	ldata->rtc = devm_rtc_allocate_device(&adev->dev);
 	if (IS_ERR(ldata->rtc)) {
@@ -360,6 +357,9 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 		goto out;
 	}
 
+	if (!adev->irq[0])
+		clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features);
+
 	ldata->rtc->ops = ops;
 	ldata->rtc->range_min = vendor->range_min;
 	ldata->rtc->range_max = vendor->range_max;
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
index 29a1c65661e9..dc6d1476baa5 100644
--- a/drivers/rtc/rtc-pm8xxx.c
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -7,6 +7,7 @@
 #include <linux/rtc.h>
 #include <linux/platform_device.h>
 #include <linux/pm.h>
+#include <linux/pm_wakeirq.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -83,7 +84,7 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
 
 	if (!rtc_dd->allow_set_time)
-		return -EACCES;
+		return -ENODEV;
 
 	secs = rtc_tm_to_time64(tm);
 
@@ -527,40 +528,28 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev)
 		return rc;
 	}
 
-	return devm_rtc_register_device(rtc_dd->rtc);
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int pm8xxx_rtc_resume(struct device *dev)
-{
-	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+	rc = devm_rtc_register_device(rtc_dd->rtc);
+	if (rc)
+		return rc;
 
-	if (device_may_wakeup(dev))
-		disable_irq_wake(rtc_dd->rtc_alarm_irq);
+	rc = dev_pm_set_wake_irq(&pdev->dev, rtc_dd->rtc_alarm_irq);
+	if (rc)
+		return rc;
 
 	return 0;
 }
 
-static int pm8xxx_rtc_suspend(struct device *dev)
+static int pm8xxx_remove(struct platform_device *pdev)
 {
-	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
-
-	if (device_may_wakeup(dev))
-		enable_irq_wake(rtc_dd->rtc_alarm_irq);
-
+	dev_pm_clear_wake_irq(&pdev->dev);
 	return 0;
 }
-#endif
-
-static SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops,
-			 pm8xxx_rtc_suspend,
-			 pm8xxx_rtc_resume);
 
 static struct platform_driver pm8xxx_rtc_driver = {
 	.probe		= pm8xxx_rtc_probe,
+	.remove		= pm8xxx_remove,
 	.driver	= {
 		.name		= "rtc-pm8xxx",
-		.pm		= &pm8xxx_rtc_pm_ops,
 		.of_match_table	= pm8xxx_id_table,
 	},
 };
diff --git a/drivers/rtc/rtc-spear.c b/drivers/rtc/rtc-spear.c
index b4a520056b1a..d4777b01ab22 100644
--- a/drivers/rtc/rtc-spear.c
+++ b/drivers/rtc/rtc-spear.c
@@ -204,8 +204,10 @@ static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	/* we don't report wday/yday/isdst ... */
 	rtc_wait_not_busy(config);
 
-	time = readl(config->ioaddr + TIME_REG);
-	date = readl(config->ioaddr + DATE_REG);
+	do {
+		time = readl(config->ioaddr + TIME_REG);
+		date = readl(config->ioaddr + DATE_REG);
+	} while (time == readl(config->ioaddr + TIME_REG));
 	tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
 	tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
 	tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
@@ -352,6 +354,10 @@ static int spear_rtc_probe(struct platform_device *pdev)
 	if (!config)
 		return -ENOMEM;
 
+	config->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(config->rtc))
+		return PTR_ERR(config->rtc);
+
 	/* alarm irqs */
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
@@ -380,16 +386,13 @@ static int spear_rtc_probe(struct platform_device *pdev)
 	spin_lock_init(&config->lock);
 	platform_set_drvdata(pdev, config);
 
-	config->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
-					&spear_rtc_ops, THIS_MODULE);
-	if (IS_ERR(config->rtc)) {
-		dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
-				PTR_ERR(config->rtc));
-		status = PTR_ERR(config->rtc);
-		goto err_disable_clock;
-	}
+	config->rtc->ops = &spear_rtc_ops;
+	config->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
+	config->rtc->range_min = RTC_TIMESTAMP_END_9999;
 
-	config->rtc->uie_unsupported = 1;
+	status = devm_rtc_register_device(config->rtc);
+	if (status)
+		goto err_disable_clock;
 
 	if (!device_can_wakeup(&pdev->dev))
 		device_init_wakeup(&pdev->dev, 1);
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index 711832c758ae..5b3e4da63406 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -13,6 +13,7 @@
 
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/clk/sunxi-ng.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/fs.h>
@@ -48,7 +49,8 @@
 
 /* Alarm 0 (counter) */
 #define SUN6I_ALRM_COUNTER			0x0020
-#define SUN6I_ALRM_CUR_VAL			0x0024
+/* This holds the remaining alarm seconds on older SoCs (current value) */
+#define SUN6I_ALRM_COUNTER_HMS			0x0024
 #define SUN6I_ALRM_EN				0x0028
 #define SUN6I_ALRM_EN_CNT_EN			BIT(0)
 #define SUN6I_ALRM_IRQ_EN			0x002c
@@ -110,6 +112,8 @@
 #define SUN6I_YEAR_MIN				1970
 #define SUN6I_YEAR_OFF				(SUN6I_YEAR_MIN - 1900)
 
+#define SECS_PER_DAY				(24 * 3600ULL)
+
 /*
  * There are other differences between models, including:
  *
@@ -133,12 +137,15 @@ struct sun6i_rtc_clk_data {
 	unsigned int has_auto_swt : 1;
 };
 
+#define RTC_LINEAR_DAY	BIT(0)
+
 struct sun6i_rtc_dev {
 	struct rtc_device *rtc;
 	const struct sun6i_rtc_clk_data *data;
 	void __iomem *base;
 	int irq;
-	unsigned long alarm;
+	time64_t alarm;
+	unsigned long flags;
 
 	struct clk_hw hw;
 	struct clk_hw *int_osc;
@@ -363,23 +370,6 @@ CLK_OF_DECLARE_DRIVER(sun8i_h3_rtc_clk, "allwinner,sun8i-h3-rtc",
 CLK_OF_DECLARE_DRIVER(sun50i_h5_rtc_clk, "allwinner,sun50i-h5-rtc",
 		      sun8i_h3_rtc_clk_init);
 
-static const struct sun6i_rtc_clk_data sun50i_h6_rtc_data = {
-	.rc_osc_rate = 16000000,
-	.fixed_prescaler = 32,
-	.has_prescaler = 1,
-	.has_out_clk = 1,
-	.export_iosc = 1,
-	.has_losc_en = 1,
-	.has_auto_swt = 1,
-};
-
-static void __init sun50i_h6_rtc_clk_init(struct device_node *node)
-{
-	sun6i_rtc_clk_init(node, &sun50i_h6_rtc_data);
-}
-CLK_OF_DECLARE_DRIVER(sun50i_h6_rtc_clk, "allwinner,sun50i-h6-rtc",
-		      sun50i_h6_rtc_clk_init);
-
 /*
  * The R40 user manual is self-conflicting on whether the prescaler is
  * fixed or configurable. The clock diagram shows it as fixed, but there
@@ -467,22 +457,30 @@ static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 	} while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
 		 (time != readl(chip->base + SUN6I_RTC_HMS)));
 
+	if (chip->flags & RTC_LINEAR_DAY) {
+		/*
+		 * Newer chips store a linear day number, the manual
+		 * does not mandate any epoch base. The BSP driver uses
+		 * the UNIX epoch, let's just copy that, as it's the
+		 * easiest anyway.
+		 */
+		rtc_time64_to_tm((date & 0xffff) * SECS_PER_DAY, rtc_tm);
+	} else {
+		rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
+		rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date) - 1;
+		rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
+
+		/*
+		 * switch from (data_year->min)-relative offset to
+		 * a (1900)-relative one
+		 */
+		rtc_tm->tm_year += SUN6I_YEAR_OFF;
+	}
+
 	rtc_tm->tm_sec  = SUN6I_TIME_GET_SEC_VALUE(time);
 	rtc_tm->tm_min  = SUN6I_TIME_GET_MIN_VALUE(time);
 	rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
 
-	rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
-	rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date);
-	rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
-
-	rtc_tm->tm_mon  -= 1;
-
-	/*
-	 * switch from (data_year->min)-relative offset to
-	 * a (1900)-relative one
-	 */
-	rtc_tm->tm_year += SUN6I_YEAR_OFF;
-
 	return 0;
 }
 
@@ -510,36 +508,54 @@ static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 	struct rtc_time *alrm_tm = &wkalrm->time;
 	struct rtc_time tm_now;
-	unsigned long time_now = 0;
-	unsigned long time_set = 0;
-	unsigned long time_gap = 0;
-	int ret = 0;
-
-	ret = sun6i_rtc_gettime(dev, &tm_now);
-	if (ret < 0) {
-		dev_err(dev, "Error in getting time\n");
-		return -EINVAL;
-	}
+	time64_t time_set;
+	u32 counter_val, counter_val_hms;
+	int ret;
 
 	time_set = rtc_tm_to_time64(alrm_tm);
-	time_now = rtc_tm_to_time64(&tm_now);
-	if (time_set <= time_now) {
-		dev_err(dev, "Date to set in the past\n");
-		return -EINVAL;
-	}
-
-	time_gap = time_set - time_now;
 
-	if (time_gap > U32_MAX) {
-		dev_err(dev, "Date too far in the future\n");
-		return -EINVAL;
+	if (chip->flags & RTC_LINEAR_DAY) {
+		/*
+		 * The alarm registers hold the actual alarm time, encoded
+		 * in the same way (linear day + HMS) as the current time.
+		 */
+		counter_val_hms = SUN6I_TIME_SET_SEC_VALUE(alrm_tm->tm_sec)  |
+				  SUN6I_TIME_SET_MIN_VALUE(alrm_tm->tm_min)  |
+				  SUN6I_TIME_SET_HOUR_VALUE(alrm_tm->tm_hour);
+		/* The division will cut off the H:M:S part of alrm_tm. */
+		counter_val = div_u64(rtc_tm_to_time64(alrm_tm), SECS_PER_DAY);
+	} else {
+		/* The alarm register holds the number of seconds left. */
+		time64_t time_now;
+
+		ret = sun6i_rtc_gettime(dev, &tm_now);
+		if (ret < 0) {
+			dev_err(dev, "Error in getting time\n");
+			return -EINVAL;
+		}
+
+		time_now = rtc_tm_to_time64(&tm_now);
+		if (time_set <= time_now) {
+			dev_err(dev, "Date to set in the past\n");
+			return -EINVAL;
+		}
+		if ((time_set - time_now) > U32_MAX) {
+			dev_err(dev, "Date too far in the future\n");
+			return -EINVAL;
+		}
+
+		counter_val = time_set - time_now;
 	}
 
 	sun6i_rtc_setaie(0, chip);
 	writel(0, chip->base + SUN6I_ALRM_COUNTER);
+	if (chip->flags & RTC_LINEAR_DAY)
+		writel(0, chip->base + SUN6I_ALRM_COUNTER_HMS);
 	usleep_range(100, 300);
 
-	writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
+	writel(counter_val, chip->base + SUN6I_ALRM_COUNTER);
+	if (chip->flags & RTC_LINEAR_DAY)
+		writel(counter_val_hms, chip->base + SUN6I_ALRM_COUNTER_HMS);
 	chip->alarm = time_set;
 
 	sun6i_rtc_setaie(wkalrm->enabled, chip);
@@ -571,20 +587,25 @@ static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
 	u32 date = 0;
 	u32 time = 0;
 
-	rtc_tm->tm_year -= SUN6I_YEAR_OFF;
-	rtc_tm->tm_mon += 1;
-
-	date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
-		SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
-		SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
-
-	if (is_leap_year(rtc_tm->tm_year + SUN6I_YEAR_MIN))
-		date |= SUN6I_LEAP_SET_VALUE(1);
-
 	time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |
 		SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |
 		SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
 
+	if (chip->flags & RTC_LINEAR_DAY) {
+		/* The division will cut off the H:M:S part of rtc_tm. */
+		date = div_u64(rtc_tm_to_time64(rtc_tm), SECS_PER_DAY);
+	} else {
+		rtc_tm->tm_year -= SUN6I_YEAR_OFF;
+		rtc_tm->tm_mon += 1;
+
+		date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
+			SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
+			SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
+
+		if (is_leap_year(rtc_tm->tm_year + SUN6I_YEAR_MIN))
+			date |= SUN6I_LEAP_SET_VALUE(1);
+	}
+
 	/* Check whether registers are writable */
 	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
 			   SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
@@ -668,11 +689,35 @@ static int sun6i_rtc_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(sun6i_rtc_pm_ops,
 	sun6i_rtc_suspend, sun6i_rtc_resume);
 
+static void sun6i_rtc_bus_clk_cleanup(void *data)
+{
+	struct clk *bus_clk = data;
+
+	clk_disable_unprepare(bus_clk);
+}
+
 static int sun6i_rtc_probe(struct platform_device *pdev)
 {
 	struct sun6i_rtc_dev *chip = sun6i_rtc;
+	struct device *dev = &pdev->dev;
+	struct clk *bus_clk;
 	int ret;
 
+	bus_clk = devm_clk_get_optional(dev, "bus");
+	if (IS_ERR(bus_clk))
+		return PTR_ERR(bus_clk);
+
+	if (bus_clk) {
+		ret = clk_prepare_enable(bus_clk);
+		if (ret)
+			return ret;
+
+		ret = devm_add_action_or_reset(dev, sun6i_rtc_bus_clk_cleanup,
+					       bus_clk);
+		if (ret)
+			return ret;
+	}
+
 	if (!chip) {
 		chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
 		if (!chip)
@@ -683,10 +728,18 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
 		chip->base = devm_platform_ioremap_resource(pdev, 0);
 		if (IS_ERR(chip->base))
 			return PTR_ERR(chip->base);
+
+		if (IS_REACHABLE(CONFIG_SUN6I_RTC_CCU)) {
+			ret = sun6i_rtc_ccu_probe(dev, chip->base);
+			if (ret)
+				return ret;
+		}
 	}
 
 	platform_set_drvdata(pdev, chip);
 
+	chip->flags = (unsigned long)of_device_get_match_data(&pdev->dev);
+
 	chip->irq = platform_get_irq(pdev, 0);
 	if (chip->irq < 0)
 		return chip->irq;
@@ -733,7 +786,10 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
 		return PTR_ERR(chip->rtc);
 
 	chip->rtc->ops = &sun6i_rtc_ops;
-	chip->rtc->range_max = 2019686399LL; /* 2033-12-31 23:59:59 */
+	if (chip->flags & RTC_LINEAR_DAY)
+		chip->rtc->range_max = (65536 * SECS_PER_DAY) - 1;
+	else
+		chip->rtc->range_max = 2019686399LL; /* 2033-12-31 23:59:59 */
 
 	ret = devm_rtc_register_device(chip->rtc);
 	if (ret)
@@ -758,6 +814,8 @@ static const struct of_device_id sun6i_rtc_dt_ids[] = {
 	{ .compatible = "allwinner,sun8i-v3-rtc" },
 	{ .compatible = "allwinner,sun50i-h5-rtc" },
 	{ .compatible = "allwinner,sun50i-h6-rtc" },
+	{ .compatible = "allwinner,sun50i-h616-rtc",
+		.data = (void *)RTC_LINEAR_DAY },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
diff --git a/drivers/rtc/rtc-wm8350.c b/drivers/rtc/rtc-wm8350.c
index 2018614f258f..6eaa9321c074 100644
--- a/drivers/rtc/rtc-wm8350.c
+++ b/drivers/rtc/rtc-wm8350.c
@@ -432,14 +432,21 @@ static int wm8350_rtc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC,
+	ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC,
 			    wm8350_rtc_update_handler, 0,
 			    "RTC Seconds", wm8350);
+	if (ret)
+		return ret;
+
 	wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC);
 
-	wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM,
+	ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM,
 			    wm8350_rtc_alarm_handler, 0,
 			    "RTC Alarm", wm8350);
+	if (ret) {
+		wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);
+		return ret;
+	}
 
 	return 0;
 }
diff --git a/drivers/rtc/rtc-xgene.c b/drivers/rtc/rtc-xgene.c
index cf68a9b1c9eb..d3d0054e21fd 100644
--- a/drivers/rtc/rtc-xgene.c
+++ b/drivers/rtc/rtc-xgene.c
@@ -180,8 +180,6 @@ static int xgene_rtc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	/* HW does not support update faster than 1 seconds */
-	pdata->rtc->uie_unsupported = 1;
 	pdata->rtc->ops = &xgene_rtc_ops;
 	pdata->rtc->range_max = U32_MAX;