| Message ID | 20210810154436.125678-1-i.mikhaylov@yadro.com |
|---|---|
| Headers | show |
| Series | rtc: pch-rtc: add Intel Series PCH built-in read-only RTC | expand |
On Tue, Aug 10, 2021 at 06:44:34PM +0300, Ivan Mikhaylov wrote: > Add RTC driver with dt binding tree document. Also this driver adds one sysfs > attribute for host power control which I think is odd for RTC driver. > Need I cut it off and use I2C_SLAVE_FORCE? I2C_SLAVE_FORCE is not good > way too from my point of view. Is there any better approach? Reading the C620 datasheet I see this interface also allows other commands (wake up, watchdog feeding, reboot etc.) and reading statuses (e.g Intruder Detect, POWER_OK_BAD). I think if there's any plan to use anything other but RTC via this interface then the driver should be registered as an MFD.
On 15/08/2021 01:42:15+0300, Paul Fertser wrote: > On Tue, Aug 10, 2021 at 06:44:34PM +0300, Ivan Mikhaylov wrote: > > Add RTC driver with dt binding tree document. Also this driver adds one sysfs > > attribute for host power control which I think is odd for RTC driver. > > Need I cut it off and use I2C_SLAVE_FORCE? I2C_SLAVE_FORCE is not good > > way too from my point of view. Is there any better approach? > > Reading the C620 datasheet I see this interface also allows other > commands (wake up, watchdog feeding, reboot etc.) and reading statuses > (e.g Intruder Detect, POWER_OK_BAD). > > I think if there's any plan to use anything other but RTC via this > interface then the driver should be registered as an MFD. > This is not the current thinking, if everything is integrated, then there is no issue registering a watchdog from the RTC driver. I'll let you check with Lee... However, I'm not sure what is the correct interface for poweroff/reboot control.
On Aug 16, 2021, Alexandre Belloni wrote: >On 15/08/2021 01:42:15+0300, Paul Fertser wrote: >> On Tue, Aug 10, 2021 at 06:44:34PM +0300, Ivan Mikhaylov wrote: >> > Add RTC driver with dt binding tree document. Also this driver >adds one sysfs >> > attribute for host power control which I think is odd for RTC >driver. >> > Need I cut it off and use I2C_SLAVE_FORCE? I2C_SLAVE_FORCE is not >good >> > way too from my point of view. Is there any better approach? >> >> Reading the C620 datasheet I see this interface also allows other >> commands (wake up, watchdog feeding, reboot etc.) and reading >statuses >> (e.g Intruder Detect, POWER_OK_BAD). >> >> I think if there's any plan to use anything other but RTC via this >> interface then the driver should be registered as an MFD. >> > >This is not the current thinking, if everything is integrated, then >there is no issue registering a watchdog from the RTC driver. I'll >let >you check with Lee... I think the current statement is "if they are truly disjoint hardware controls" then an MFD might suffice, but if they require software cordination the new auxillary bus seems to be desired. >>However, I'm not sure what is the correct interface for >poweroff/reboot >control. While there is a gpio interface to a simple regulator switch, the project to date has been asserting direct or indirect gpios etc to control the host. If these are events to trigger a change in state and not a direct state change that some controller trys to follow, maybe a message delivery model? (this is not to reboot or cycle the bmc). milton
On 17/08/2021 18:04:09+0000, Milton Miller II wrote: > > On Aug 16, 2021, Alexandre Belloni wrote: > >On 15/08/2021 01:42:15+0300, Paul Fertser wrote: > >> On Tue, Aug 10, 2021 at 06:44:34PM +0300, Ivan Mikhaylov wrote: > >> > Add RTC driver with dt binding tree document. Also this driver > >adds one sysfs > >> > attribute for host power control which I think is odd for RTC > >driver. > >> > Need I cut it off and use I2C_SLAVE_FORCE? I2C_SLAVE_FORCE is not > >good > >> > way too from my point of view. Is there any better approach? > >> > >> Reading the C620 datasheet I see this interface also allows other > >> commands (wake up, watchdog feeding, reboot etc.) and reading > >statuses > >> (e.g Intruder Detect, POWER_OK_BAD). > >> > >> I think if there's any plan to use anything other but RTC via this > >> interface then the driver should be registered as an MFD. > >> > > > >This is not the current thinking, if everything is integrated, then > >there is no issue registering a watchdog from the RTC driver. I'll > >let > >you check with Lee... > > I think the current statement is "if they are truly disjoint > hardware controls" then an MFD might suffice, but if they require > software cordination the new auxillary bus seems to be desired. > Honestly, the auxiliary bus doesn't provide anything that you can't do by registering a device in multiple subsystem from a single driver. (Lee Jones, Mark Brown and I did complain at the time that this was yet another back channel for misuses). > >>However, I'm not sure what is the correct interface for > >poweroff/reboot > >control. > > While there is a gpio interface to a simple regulator switch, > the project to date has been asserting direct or indirect > gpios etc to control the host. If these are events to > trigger a change in state and not a direct state change > that some controller trys to follow, maybe a message delivery > model? (this is not to reboot or cycle the bmc). > > milton
On Tue, 2021-08-17 at 22:05 +0200, Alexandre Belloni wrote: > On 17/08/2021 18:04:09+0000, Milton Miller II wrote: > > > > On Aug 16, 2021, Alexandre Belloni wrote: > > > On 15/08/2021 01:42:15+0300, Paul Fertser wrote: > > > > On Tue, Aug 10, 2021 at 06:44:34PM +0300, Ivan Mikhaylov wrote: > > > > > Add RTC driver with dt binding tree document. Also this driver > > > adds one sysfs > > > > > attribute for host power control which I think is odd for RTC > > > driver. > > > > > Need I cut it off and use I2C_SLAVE_FORCE? I2C_SLAVE_FORCE is not > > > good > > > > > way too from my point of view. Is there any better approach? > > > > > > > > Reading the C620 datasheet I see this interface also allows other > > > > commands (wake up, watchdog feeding, reboot etc.) and reading > > > statuses > > > > (e.g Intruder Detect, POWER_OK_BAD). > > > > > > > > I think if there's any plan to use anything other but RTC via this > > > > interface then the driver should be registered as an MFD. > > > > > > > > > > This is not the current thinking, if everything is integrated, then > > > there is no issue registering a watchdog from the RTC driver. I'll > > > let > > > you check with Lee... > > > > I think the current statement is "if they are truly disjoint > > hardware controls" then an MFD might suffice, but if they require > > software cordination the new auxillary bus seems to be desired. > > > > Honestly, the auxiliary bus doesn't provide anything that you can't do > by registering a device in multiple subsystem from a single driver. > (Lee Jones, Mark Brown and I did complain at the time that this was yet > another back channel for misuses). > > > > > However, I'm not sure what is the correct interface for > > > poweroff/reboot > > > control. > > > > While there is a gpio interface to a simple regulator switch, > > the project to date has been asserting direct or indirect > > gpios etc to control the host. If these are events to > > trigger a change in state and not a direct state change > > that some controller trys to follow, maybe a message delivery > > model? (this is not to reboot or cycle the bmc). > > > > milton > Alexandre, gentle reminder about this one series. I can get rid off from sysfs attribute and put it like RO rtc without any additional things for now as starter. Thanks.
On Mon, 2021-08-30 at 14:56 +0300, Ivan Mikhaylov wrote: > On Tue, 2021-08-17 at 22:05 +0200, Alexandre Belloni wrote: > > On 17/08/2021 18:04:09+0000, Milton Miller II wrote: > > > > > > On Aug 16, 2021, Alexandre Belloni wrote: > > > > On 15/08/2021 01:42:15+0300, Paul Fertser wrote: > > > > > On Tue, Aug 10, 2021 at 06:44:34PM +0300, Ivan Mikhaylov wrote: > > > > > > Add RTC driver with dt binding tree document. Also this driver > > > > adds one sysfs > > > > > > attribute for host power control which I think is odd for RTC > > > > driver. > > > > > > Need I cut it off and use I2C_SLAVE_FORCE? I2C_SLAVE_FORCE is not > > > > good > > > > > > way too from my point of view. Is there any better approach? > > > > > > > > > > Reading the C620 datasheet I see this interface also allows other > > > > > commands (wake up, watchdog feeding, reboot etc.) and reading > > > > statuses > > > > > (e.g Intruder Detect, POWER_OK_BAD). > > > > > > > > > > I think if there's any plan to use anything other but RTC via this > > > > > interface then the driver should be registered as an MFD. > > > > > > > > > > > > > This is not the current thinking, if everything is integrated, then > > > > there is no issue registering a watchdog from the RTC driver. I'll > > > > let > > > > you check with Lee... > > > > > > I think the current statement is "if they are truly disjoint > > > hardware controls" then an MFD might suffice, but if they require > > > software cordination the new auxillary bus seems to be desired. > > > > > > > Honestly, the auxiliary bus doesn't provide anything that you can't do > > by registering a device in multiple subsystem from a single driver. > > (Lee Jones, Mark Brown and I did complain at the time that this was yet > > another back channel for misuses). > > > > > > > However, I'm not sure what is the correct interface for > > > > poweroff/reboot > > > > control. > > > > > > While there is a gpio interface to a simple regulator switch, > > > the project to date has been asserting direct or indirect > > > gpios etc to control the host. If these are events to > > > trigger a change in state and not a direct state change > > > that some controller trys to follow, maybe a message delivery > > > model? (this is not to reboot or cycle the bmc). > > > > > > milton > > > > Alexandre, gentle reminder about this one series. I can get rid off from sysfs > attribute and put it like RO rtc without any additional things for now as > starter. > > Thanks. > ping Thanks.