[PATCH v3 00/12] Add RTC support for Renesas RZ/T2H and RZ/N2H SoCs

From: Prabhakar

Date: Mon Jul 06 2026 - 13:51:59 EST


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

Hi all,

This series adds support for the RTC IP found on the Renesas RZ/T2H and
RZ/N2H SoCs.

The RTC block is closely related to the RZ/N1 implementation and can
reuse the existing driver infrastructure when operating in SCMP mode,
which is required on these SoCs due to their 195.3 kHz RTC input clock.

While the RZ/T2H and RZ/N2H variants do not implement the RTCA0SUBU
register present on RZ/N1, this register is not accessed by the driver
in SCMP mode, allowing support to be added with minimal changes.

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.

Patches have been rebased on top of next-20260706.

v2->v3:
- Added new patch to fix weekday underflow when alarm crosses month
boundary.
- Make use of devm_add_action_or_reset() to simplify driver teardown
and remove the .remove() callback.

v1->v2:
- Dropped wakeup capability support patch.
- Dropped header sort patch as it was already fixed upstream.
- Updated commit message to drop reference about RTCA0TCR register.
- Added Acked-by and Reviewed-by tags.
- Updated Kconfig help text to keep it generic and not specific to
RZ/N1 SoCs.
- Initialized rate variable to 32768 to avoid timeout_us of 0.
- Made use of RZN1_RTC_SUBU_RTCA0FX mask for SUBU register access
instead of 0x3F.

v1: https://lore.kernel.org/all/20260615154805.1619693-1-prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx/

Cheers,
Prabhakar

Lad Prabhakar (12):
dt-bindings: rtc: renesas,rzn1-rtc: Add RZ/T2H and RZ/N2H support
rtc: rzn1: Handle EPROBE_DEFER for optional pps interrupt
rtc: rzn1: fix weekday underflow when alarm crosses month boundary
rtc: rzn1: Fix malformed MODULE_AUTHOR string
rtc: Kconfig: Broaden RTC_DRV_RZN1 dependency to ARCH_RENESAS
rtc: rzn1: Fix alarm range check truncation on 32-bit systems
rtc: rzn1: Replace remove callback with devm_add_action_or_reset()
rtc: rzn1: Dynamically calculate synchronization delay based on clock
rate
rtc: rzn1: Use temporary variable for struct device
rtc: rzn1: Consistently use dev_err_probe()
rtc: rzn1: use FIELD_PREP/FIELD_GET and GENMASK for register access
rtc: rzn1: Add support for Renesas RZ/T2H and RZ/N2H SoCs

.../bindings/rtc/renesas,rzn1-rtc.yaml | 35 +++-
drivers/rtc/Kconfig | 5 +-
drivers/rtc/rtc-rzn1.c | 159 ++++++++++--------
3 files changed, 116 insertions(+), 83 deletions(-)

--
2.54.0