Re: [PATCH v5 15/17] rtc: rzn1: Add OF match data to gate SUBU register access
From: Alexandre Belloni <alexandre.belloni@bootlin.com>
Date: 2026-08-21 20:40:24
Also in:
linux-renesas-soc, linux-rtc, lkml
On 21/08/2026 21:37:43+0100, Lad, Prabhakar wrote:
Hi Alexandre, On Fri, Aug 21, 2026 at 5:40 PM Alexandre Belloni [off-list ref] wrote:quoted
Hello, On 21/08/2026 14:56:06+0100, Prabhakar wrote:quoted
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> The RZ/N1 RTC driver selects SCMP mode only when an optional xtal clock is provided at a valid rate other than 32768 Hz. Without an xtal clock, or when it runs at 32768 Hz, the driver uses SUBU mode. However, the RTCA0SUBU register used by SUBU mode is not present on all SoCs that integrate a similar variant of the RTC block. Allowing SUBU mode on those variants would expose RTC offset operations that access a non-existent register. Add OF match data to describe whether the RTC supports the SUBU register. Reject probe with -EOPNOTSUPP when SUBU mode would be selected on a variant without SUBU support. Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Suggested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- v4->v5: - Renamed rzn1_data to rzn1_rtc_rzn1_data - Added a print message to indicate that SUBU mode is not supported on the variant. - Added a comment to indicate that the xtal clock is NULL when SUBU mode is not supported. - Added Suggested-by tag from Wolfram. v3->v4: - New patch --- drivers/rtc/rtc-rzn1.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)This doesn't apply cleanly, can you rebase on rtc-next? If you do so today, I'll include the series this merge window.Oouch, I'll do that right away. Hopefully Im not late.
Not late, don't forget the other comment about the sentinel from Wolfram. -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com