can: m_can: Add tx coalescing ethtool support

Add TX support to get/set functions for ethtool coalescing.
tx-frames-irq and tx-usecs-irq can only be set/unset together.
tx-frames-irq needs to be less than TXE and TXB.

As rx and tx share the same timer, rx-usecs-irq and tx-usecs-irq can be
enabled/disabled individually but they need to have the same value if
enabled.

Polling is excluded from TX irq coalescing.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/all/20240207093220.2681425-8-msp@baylibre.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 6dad1f569f820338220d9166498f824d9cf55d74..b31df3e3ceeb4159d6fac7601d1bc76970497164 100644 (file)
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1986,6 +1986,8 @@ static int m_can_get_coalesce(struct net_device *dev,
 
        ec->rx_max_coalesced_frames_irq = cdev->rx_max_coalesced_frames_irq;
        ec->rx_coalesce_usecs_irq = cdev->rx_coalesce_usecs_irq;
+       ec->tx_max_coalesced_frames_irq = cdev->tx_max_coalesced_frames_irq;
+       ec->tx_coalesce_usecs_irq = cdev->tx_coalesce_usecs_irq;
 
        return 0;
 }
@@ -2012,16 +2014,50 @@ static int m_can_set_coalesce(struct net_device *dev,
                netdev_err(dev, "rx-frames-irq and rx-usecs-irq can only be set together\n");
                return -EINVAL;
        }
+       if (ec->tx_max_coalesced_frames_irq > cdev->mcfg[MRAM_TXE].num) {
+               netdev_err(dev, "tx-frames-irq %u greater than the TX event FIFO %u\n",
+                          ec->tx_max_coalesced_frames_irq,
+                          cdev->mcfg[MRAM_TXE].num);
+               return -EINVAL;
+       }
+       if (ec->tx_max_coalesced_frames_irq > cdev->mcfg[MRAM_TXB].num) {
+               netdev_err(dev, "tx-frames-irq %u greater than the TX FIFO %u\n",
+                          ec->tx_max_coalesced_frames_irq,
+                          cdev->mcfg[MRAM_TXB].num);
+               return -EINVAL;
+       }
+       if ((ec->tx_max_coalesced_frames_irq == 0) != (ec->tx_coalesce_usecs_irq == 0)) {
+               netdev_err(dev, "tx-frames-irq and tx-usecs-irq can only be set together\n");
+               return -EINVAL;
+       }
+       if (ec->rx_coalesce_usecs_irq != 0 && ec->tx_coalesce_usecs_irq != 0 &&
+           ec->rx_coalesce_usecs_irq != ec->tx_coalesce_usecs_irq) {
+               netdev_err(dev, "rx-usecs-irq %u needs to be equal to tx-usecs-irq %u if both are enabled\n",
+                          ec->rx_coalesce_usecs_irq,
+                          ec->tx_coalesce_usecs_irq);
+               return -EINVAL;
+       }
 
        cdev->rx_max_coalesced_frames_irq = ec->rx_max_coalesced_frames_irq;
        cdev->rx_coalesce_usecs_irq = ec->rx_coalesce_usecs_irq;
+       cdev->tx_max_coalesced_frames_irq = ec->tx_max_coalesced_frames_irq;
+       cdev->tx_coalesce_usecs_irq = ec->tx_coalesce_usecs_irq;
+
+       if (cdev->rx_coalesce_usecs_irq)
+               cdev->irq_timer_wait =
+                       ns_to_ktime(cdev->rx_coalesce_usecs_irq * NSEC_PER_USEC);
+       else
+               cdev->irq_timer_wait =
+                       ns_to_ktime(cdev->tx_coalesce_usecs_irq * NSEC_PER_USEC);
 
        return 0;
 }
 
 static const struct ethtool_ops m_can_ethtool_ops = {
        .supported_coalesce_params = ETHTOOL_COALESCE_RX_USECS_IRQ |
-               ETHTOOL_COALESCE_RX_MAX_FRAMES_IRQ,
+               ETHTOOL_COALESCE_RX_MAX_FRAMES_IRQ |
+               ETHTOOL_COALESCE_TX_USECS_IRQ |
+               ETHTOOL_COALESCE_TX_MAX_FRAMES_IRQ,
        .get_ts_info = ethtool_op_get_ts_info,
        .get_coalesce = m_can_get_coalesce,
        .set_coalesce = m_can_set_coalesce,