[PATCH v2 10/10] rtc: rzn1: Add support for Renesas RZ/T2H and RZ/N2H SoCs

From: Prabhakar

Date: Wed Jul 01 2026 - 10:50:01 EST


From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Add support for the RTC block found on the Renesas RZ/T2H (R9A09G077)
and RZ/N2H (R9A09G087) SoCs by matching the new
"renesas,r9a09g077-rtc" compatible string.

These SoCs integrate a closely related variant of the RZ/N1 RTC IP.
Unlike the RZ/N1 implementation, the RZ/T2H and RZ/N2H variants lack
the RTCA0SUBU register. However, this register is not accessed when
operating in SCMP mode using the existing rzn1_rtc_ops_scmp
configuration, allowing the current driver infrastructure to be reused
without modification.

The RZ/T2H RTC variant also supports a 1 Hz output signal on the
RTCAT1HZ pin, controlled by the RTCA0CTL1[RTCA01HZE] bit. This bit is
marked as reserved in the RZ/N1 hardware manual, making RZ/T2H a
distinct RTC variant despite its overall compatibility with the RZ/N1
implementation.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
v1->v2:
- Updated commit message to drop reference about RTCA0TCR register.
- Added Reviewed-by tag.
---
drivers/rtc/rtc-rzn1.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
index 2afd8251c868..9469160129df 100644
--- a/drivers/rtc/rtc-rzn1.c
+++ b/drivers/rtc/rtc-rzn1.c
@@ -517,6 +517,7 @@ static void rzn1_rtc_remove(struct platform_device *pdev)
}

static const struct of_device_id rzn1_rtc_of_match[] = {
+ { .compatible = "renesas,r9a09g077-rtc" },
{ .compatible = "renesas,rzn1-rtc" },
{},
};
--
2.54.0