net: partial revert of the "Make timestamping selectable: series

Revert following commits:

commit acec05fb78ab ("net_tstamp: Add TIMESTAMPING SOFTWARE and HARDWARE mask")
commit 11d55be06df0 ("net: ethtool: Add a command to expose current time stamping layer")
commit bb8645b00ced ("netlink: specs: Introduce new netlink command to get current timestamp")
commit d905f9c75329 ("net: ethtool: Add a command to list available time stamping layers")
commit aed5004ee7a0 ("netlink: specs: Introduce new netlink command to list available time stamping layers")
commit 51bdf3165f01 ("net: Replace hwtstamp_source by timestamping layer")
commit 0f7f463d4821 ("net: Change the API of PHY default timestamp to MAC")
commit 091fab122869 ("net: ethtool: ts: Update GET_TS to reply the current selected timestamp")
commit 152c75e1d002 ("net: ethtool: ts: Let the active time stamping layer be selectable")
commit ee60ea6be0d3 ("netlink: specs: Introduce time stamping set command")

They need more time for reviews.

Link: https://lore.kernel.org/all/20231118183529.6e67100c@kernel.org/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: Change the API of PHY default timestamp to MAC

Change the API to select MAC default time stamping instead of the PHY.
Indeed the PHY is closer to the wire therefore theoretically it has less
delay than the MAC timestamping but the reality is different. Due to lower
time stamping clock frequency, latency in the MDIO bus and no PHC hardware
synchronization between different PHY, the PHY PTP is often less precise
than the MAC. The exception is for PHY designed specially for PTP case but
these devices are not very widespread. For not breaking the compatibility I
introduce a default_timestamp flag in phy_device that is set by the phy
driver to know we are using the old API behavior.

The phy_set_timestamp function is called at each call of phy_attach_direct.
In case of MAC driver using phylink this function is called when the
interface is turned up. Then if the interface goes down and up again the
last choice of timestamp will be overwritten by the default choice.
A solution could be to cache the timestamp status but it can bring other
issues. In case of SFP, if we change the module, it doesn't make sense to
blindly re-set the timestamp back to PHY, if the new module has a PHY with
mediocre timestamping capabilities.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Convert PHYs hwtstamp callback to use kernel_hwtstamp_config

The PHYs hwtstamp callback are still getting the timestamp config from
ifreq and using copy_from/to_user.
Get rid of these functions by using timestamp configuration in parameter.
This also allow to move on to kernel_hwtstamp_config and be similar to
net devices using the new ndo_hwstamp_get/set.

This adds the possibility to manipulate the timestamp configuration
from the kernel which was not possible with the copy_from/to_user.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: fill in missing MODULE_DESCRIPTION()s

W=1 builds now warn if a module is built without a
MODULE_DESCRIPTION(). Fill them in based on the Kconfig text, or
similar.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20231028184458.99448-2-andrew@lunn.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: phy: Add support for 1PPS out and external timestamps

The perout function is used to generate a 1PPS signal, synchronized
to the PHC. This is accomplished by a using the hardware oneshot
functionality, which is reset by a timer.

The external timestamp function is set up for a 1PPS input pulse,
and uses a timer to poll for temestamps.

Both functions use the SYNC_OUT/SYNC_IN1 pin, so cannot run
simultaneously.

Co-developed-by: Lasse Johnsen <l@ssejohnsen.me>
Signed-off-by: Lasse Johnsen <l@ssejohnsen.me>
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: phy: broadcom: Add PTP support for some Broadcom PHYs.

This adds PTP support for BCM54210E Broadcom PHYs, in particular,
the BCM54213PE, as used in the Rasperry PI CM4. It has only been
tested on that hardware.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>