[net-next 3/9] net: ethernet: ravb: Simplify gPTP start and stop

[Niklas Söderlund]

For devices that do not support the gPTP clock in config mode the
somewhat oddly named flag gptp is set, compared to devices that do
support the gPTP clock in config and operation mode where the flag
ccc_gac is set instead. The two flags are mutually exclusive.

For the gptp-flag devices (Gen2) the clock is tied to the AVB-DMAC, when
it is stopped so is the gPTP clock. For ccc_gac-flag devices (Gen3) the
gPTP clock is available whenever the ndev is open.

Prepare to add Gen4 support which will add a third way by cleaning the
Gen2 and Gen3 cases up a bit.

Fold the gptp-flag start and stop calls into ravb_dmac_init() and
ravb_stop_dma(), which start and stops the AVB-DMAC. There are no
functional change as all call sites to the construct,

    if (info->gptp)
        ravb_ptp_init(ndev, priv->pdev);

Are always just after a call to into ravb_dmac_init() and all call sites
to the to the construct,

    if (info->gptp)
        ravb_ptp_stop(ndev);

Are always directly followed by a call to ravb_stop_dma().

There are two special cases where the calling construct covers both the
gptp-flag and info->ccc_gac devices, one for start and one for stop. The
condition that it is preceded by a call to ravb_dmac_init(), or followed
by a call to ravb_stop_dma() are however true for them too. Reworked the
two special cases to drop the check of info->gptp.

The end result is that the gPTP clock will be started or stopped for the
gptp-flag devices in tandem with the AVB-DMAC, while the info->ccc_gac
devices will be controlled, as before, when the ndev is opened or
closed.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
---
 drivers/net/ethernet/renesas/ravb_main.c | 37 ++++++++++--------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index dc2fbbeff895..dff66a347baf 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -707,7 +707,15 @@ static int ravb_dmac_init(struct net_device *ndev)
 		return error;
 
 	/* Setting the control will start the AVB-DMAC process. */
-	return ravb_set_opmode(ndev, CCC_OPC_OPERATION);
+	error = ravb_set_opmode(ndev, CCC_OPC_OPERATION);
+	if (error)
+		return error;
+
+	/* Initialise PTP Clock driver */
+	if (info->gptp)
+		ravb_ptp_init(ndev, priv->pdev);
+
+	return 0;
 }
 
 static void ravb_get_tx_tstamp(struct net_device *ndev)
@@ -1115,6 +1123,10 @@ static int ravb_stop_dma(struct net_device *ndev)
 			netdev_err(ndev, "failed to stop AXI BUS\n");
 	}
 
+	/* Stop PTP Clock driver */
+	if (info->gptp)
+		ravb_ptp_stop(ndev);
+
 	/* Stop AVB-DMAC process */
 	return ravb_set_opmode(ndev, CCC_OPC_CONFIG);
 }
@@ -1719,9 +1731,7 @@ static int ravb_set_ringparam(struct net_device *ndev,
 
 	if (netif_running(ndev)) {
 		netif_device_detach(ndev);
-		/* Stop PTP Clock driver */
-		if (info->gptp)
-			ravb_ptp_stop(ndev);
+
 		/* Wait for DMA stopping */
 		error = ravb_stop_dma(ndev);
 		if (error) {
@@ -1752,10 +1762,6 @@ static int ravb_set_ringparam(struct net_device *ndev,
 
 		ravb_emac_init(ndev);
 
-		/* Initialise PTP Clock driver */
-		if (info->gptp)
-			ravb_ptp_init(ndev, priv->pdev);
-
 		netif_device_attach(ndev);
 	}
 
@@ -1961,7 +1967,7 @@ static int ravb_open(struct net_device *ndev)
 	ravb_emac_init(ndev);
 
 	/* Initialise PTP Clock driver */
-	if (info->gptp || info->ccc_gac)
+	if (info->ccc_gac)
 		ravb_ptp_init(ndev, priv->pdev);
 
 	/* PHY control start */
@@ -1974,9 +1980,6 @@ static int ravb_open(struct net_device *ndev)
 	return 0;
 
 out_ptp_stop:
-	/* Stop PTP Clock driver */
-	if (info->gptp || info->ccc_gac)
-		ravb_ptp_stop(ndev);
 	ravb_stop_dma(ndev);
 out_set_reset:
 	ravb_set_opmode(ndev, CCC_OPC_RESET);
@@ -2020,10 +2023,6 @@ static void ravb_tx_timeout_work(struct work_struct *work)
 
 	netif_tx_stop_all_queues(ndev);
 
-	/* Stop PTP Clock driver */
-	if (info->gptp)
-		ravb_ptp_stop(ndev);
-
 	/* Wait for DMA stopping */
 	if (ravb_stop_dma(ndev)) {
 		/* If ravb_stop_dma() fails, the hardware is still operating
@@ -2056,10 +2055,6 @@ static void ravb_tx_timeout_work(struct work_struct *work)
 	ravb_emac_init(ndev);
 
 out:
-	/* Initialise PTP Clock driver */
-	if (info->gptp)
-		ravb_ptp_init(ndev, priv->pdev);
-
 	netif_tx_start_all_queues(ndev);
 
 out_unlock:
@@ -2374,7 +2369,7 @@ static int ravb_close(struct net_device *ndev)
 	}
 
 	/* Stop PTP Clock driver */
-	if (info->gptp || info->ccc_gac)
+	if (info->ccc_gac)
 		ravb_ptp_stop(ndev);
 
 	/* Set the config mode to stop the AVB-DMAC's processes */
-- 
2.54.0