[PATCH net 2/5] net: phy: add rxc_always_on flag to phylink_pcs

[Romain Gantois]

Some MAC drivers (e.g. stmmac) require a continuous receive clock signal to
be generated by a PCS that is handled by a standalone PCS driver.

Such a PCS driver does not have access to a PHY device, thus cannot check
the PHY_F_RXC_ALWAYS_ON flag. They cannot check max_requires_rxc in the
phylink config either, since it is a private member. Therefore, a new flag
is needed to signal to the PCS that it should keep the RX clock signal up
at all times.

Signed-off-by: Romain Gantois <romain.gantois at bootlin.com>
---
 drivers/net/phy/phylink.c | 3 +++
 include/linux/phylink.h   | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index f26b13d916d4..a5a5fe91d213 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -663,6 +663,9 @@ static int phylink_validate_mac_and_pcs(struct phylink *pl,
 			return -EINVAL;
 		}
 
+		if (pl->config->mac_requires_rxc)
+			pcs->rxc_always_on = true;
+
 		/* Validate the link parameters with the PCS */
 		if (pcs->ops->pcs_validate) {
 			ret = pcs->ops->pcs_validate(pcs, supported, state);
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 8430ac7ead11..e1527e35f997 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -462,6 +462,10 @@ struct phylink_pcs_ops;
  * @phylink: pointer to &struct phylink_config
  * @neg_mode: provide PCS neg mode via "mode" argument
  * @poll: poll the PCS for link changes
+ * @rxc_always_on: The MAC driver requires the reference clock
+ *                 to always be on. Standalone PCS drivers who
+ *                 do not have access to a PHY device can check
+ *                 this instead of PHY_F_RXC_ALWAYS_ON.
  *
  * This structure is designed to be embedded within the PCS private data,
  * and will be passed between phylink and the PCS.
@@ -474,6 +478,7 @@ struct phylink_pcs {
 	struct phylink *phylink;
 	bool neg_mode;
 	bool poll;
+	bool rxc_always_on;
 };
 
 /**
-- 
2.43.0