net: phy: qcom: at803x: fix kernel panic with at8031_probe

On reworking and splitting the at803x driver, in splitting function of
at803x PHYs it was added a NULL dereference bug where priv is referenced
before it's actually allocated and then is tried to write to for the
is_1000basex and is_fiber variables in the case of at8031, writing on
the wrong address.

Fix this by correctly setting priv local variable only after
at803x_probe is called and actually allocates priv in the phydev struct.

Reported-by: William Wortel <wwortel@dorpstraat.com>
Cc: <stable@vger.kernel.org>
Fixes: 25d2ba94005f ("net: phy: at803x: move specific at8031 probe mode check to dedicated probe")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240325190621.2665-1-ansuelsmth@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: phy: provide whether link has changed in c37_read_status

Some PHY driver might require additional regs call after
genphy_c37_read_status() is called.

Expand genphy_c37_read_status to provide a bool wheather the link has
changed or not to permit PHY driver to skip additional regs call if
nothing has changed.

Every user of genphy_c37_read_status() is updated with the new
additional bool.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: qcom: move more function to shared library

Move more function to shared library in preparation for introduction of
new PHY Family qca807x that will make use of both functions from at803x
and qca808x as it's a transition PHY with some implementation of at803x
and some from the new qca808x.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: qcom: detach qca808x PHY driver from at803x

Almost all the QCA8081 PHY driver OPs are specific and only some of them
use the generic at803x.

To make the at803x code slimmer, move all the specific qca808x regs and
functions to a dedicated PHY driver.

Probe function and priv struct is reworked to allocate and use only the
qca808x specific data. Unused data from at803x PHY driver are dropped
from at803x priv struct.

Also a new Kconfig is introduced QCA808X_PHY, to compile the newly
introduced PHY driver for QCA8081 PHY.

As the Kconfig name starts with Qualcomm the same order is kept.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240129141600.2592-6-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: phy: qcom: move additional functions to shared library

Move additional functions to shared library in preparation for qca808x
PHY Family to be detached from at803x driver.

Only the shared defines are moved to the shared qcom.h header.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240129141600.2592-5-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: phy: qcom: deatch qca83xx PHY driver from at803x

Deatch qca83xx PHY driver from at803x.

The QCA83xx PHYs implement specific function and doesn't use generic
at803x so it can be detached from the driver and moved to a dedicated
one.

Probe function and priv struct is reimplemented to allocate and use
only the qca83xx specific data. Unused data from at803x PHY driver
are dropped from at803x priv struct.

This is to make slimmer PHY drivers instead of including lots of bloat
that would never be used in specific SoC.

A new Kconfig flag QCA83XX_PHY is introduced to compile the new
introduced PHY driver.

As the Kconfig name starts with Qualcomm the same order is kept.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240129141600.2592-4-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: phy: qcom: create and move functions to shared library

Create and move functions to shared library in preparation for qca83xx
PHY Family to be detached from at803x driver.

Only the shared defines are moved to the shared qcom.h header.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240129141600.2592-3-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: phy: move at803x PHY driver to dedicated directory

In preparation for addition of other Qcom PHY and to tidy things up,
move the at803x PHY driver to dedicated directory.

The same order in the Kconfig selection is saved.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240129141600.2592-2-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>