On Tue, Feb 11, 2025 at 05:01:12PM +0000, Sudeep Holla wrote:

On Mon, Jan 20, 2025 at 10:25:36AM +0800, Peng Fan (OSS) wrote:

quoted

From: Peng Fan <peng.fan@nxp.com>

i.MX95 EVK has two RTCs exported by SCMI BBM protocol. Current driver
only enables the 1st RTC inside BBNSM module, leaving the board RTC
not used by Linux.

To use the 2nd RTC, use 'bbm_info' to get the number of RTCs, register
them all, and set 'bbnsm' as private info for rtc device to know which
RTC it is when using rtc_class_ops to access rtc device.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/rtc/rtc-imx-sm-bbm.c | 69 +++++++++++++++++++++++++++-----------------
 1 file changed, 43 insertions(+), 26 deletions(-)

diff --git a/drivers/rtc/rtc-imx-sm-bbm.c b/drivers/rtc/rtc-imx-sm-bbm.c
index daa472be7c80697aa3cd3432eccef0c877e4c378..a29b30555d0c0581ecaa8b79760209dc780d2f0e 100644
--- a/drivers/rtc/rtc-imx-sm-bbm.c
+++ b/drivers/rtc/rtc-imx-sm-bbm.c

@@ -15,16 +15,18 @@ struct scmi_imx_bbm {
 	struct rtc_device *rtc_dev;
 	struct scmi_protocol_handle *ph;
 	struct notifier_block nb;
+	u32 bbm_rtc_id;

Is it not same as rtc_dev->id ? Why do you need a copy in this wrapper/
container structure ?

In theroy yes. The current system I use that all RTCs are managed by BBM
protocol. So only two RTCs are registered.

In case there is other RTCs that not managed BBM, the rtc_dev->id
will not be equal to bbm_rtc_id.

For example RTC1 is directly managed by Linux, RTC0 is managed by BBM.

The RTC1 is probed first, so its rtc_dev->id is 0. But from BBM protocol,
the RTC0 use id 0 for BBM SCMI server to handle the RTC0.

I maybe overthinking here. But to avoid potential issues, I would like to
keep bbm_rtc_id.

Regards,
Peng

-- 
Regards,
Sudeep