[PATCH 4/4] rtc: imx-sm-bbm: Support multiple RTCs
Peng Fan
peng.fan at oss.nxp.com
Tue Feb 11 22:41:17 PST 2025
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:
>> From: Peng Fan <peng.fan at 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 at 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
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