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/