[RFC PATCH 9/9] ethernet: sun8i-emac: add pm_runtime support

[Corentin Labbe]

This patch add pm_runtime support to sun8i-emac.
For the moment, only basic support is added, (the device is marked as
used when net/open)

Signed-off-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
---
 drivers/net/ethernet/allwinner/sun8i-emac.c | 62 ++++++++++++++++++++++++++++-
 1 file changed, 60 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/allwinner/sun8i-emac.c b/drivers/net/ethernet/allwinner/sun8i-emac.c
index 1c4bc80..cce886e 100644
--- a/drivers/net/ethernet/allwinner/sun8i-emac.c
+++ b/drivers/net/ethernet/allwinner/sun8i-emac.c
@@ -9,7 +9,6 @@
  * - MAC filtering
  * - Jumbo frame
  * - features rx-all (NETIF_F_RXALL_BIT)
- * - PM runtime
  */
 #include <linux/bitops.h>
 #include <linux/clk.h>
@@ -27,6 +26,7 @@
 #include <linux/pinctrl/consumer.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/scatterlist.h>
 #include <linux/skbuff.h>
@@ -1301,11 +1301,18 @@ static int sun8i_emac_open(struct net_device *ndev)
 	int err;
 	u32 v;
 
+	err = pm_runtime_get_sync(priv->dev);
+	if (err) {
+		pm_runtime_put_noidle(priv->dev);
+		dev_err(priv->dev, "pm_runtime error: %d\n", err);
+		return err;
+	}
+
 	err = request_irq(priv->irq, sun8i_emac_dma_interrupt, 0,
 			  dev_name(priv->dev), ndev);
 	if (err) {
 		dev_err(priv->dev, "Cannot request IRQ: %d\n", err);
-		return err;
+		goto err_runtime;
 	}
 
 	/* Set interface mode (and configure internal PHY on H3) */
@@ -1395,6 +1402,8 @@ err_syscon:
 	sun8i_emac_unset_syscon(ndev);
 err_irq:
 	free_irq(priv->irq, ndev);
+err_runtime:
+	pm_runtime_put(priv->dev);
 	return err;
 }
 
@@ -1483,6 +1492,8 @@ static int sun8i_emac_stop(struct net_device *ndev)
 	dma_free_coherent(priv->dev, priv->nbdesc_tx * sizeof(struct dma_desc),
 			  priv->dd_tx, priv->dd_tx_phy);
 
+	pm_runtime_put(priv->dev);
+
 	return 0;
 }
 
@@ -2210,6 +2221,8 @@ static int sun8i_emac_probe(struct platform_device *pdev)
 		goto probe_err;
 	}
 
+	pm_runtime_enable(priv->dev);
+
 	return 0;
 
 probe_err:
@@ -2221,6 +2234,8 @@ static int sun8i_emac_remove(struct platform_device *pdev)
 {
 	struct net_device *ndev = platform_get_drvdata(pdev);
 
+	pm_runtime_disable(&pdev->dev);
+
 	unregister_netdev(ndev);
 	platform_set_drvdata(pdev, NULL);
 	free_netdev(ndev);
@@ -2228,6 +2243,47 @@ static int sun8i_emac_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static int __maybe_unused sun8i_emac_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	napi_disable(&priv->napi);
+
+	if (netif_running(ndev))
+		netif_device_detach(ndev);
+
+	sun8i_emac_stop_tx(ndev);
+	sun8i_emac_stop_rx(ndev);
+
+	sun8i_emac_rx_clean(ndev);
+	sun8i_emac_tx_clean(ndev);
+
+	phy_stop(ndev->phydev);
+
+	return 0;
+}
+
+static int __maybe_unused sun8i_emac_resume(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	phy_start(ndev->phydev);
+
+	sun8i_emac_start_tx(ndev);
+	sun8i_emac_start_rx(ndev);
+
+	if (netif_running(ndev))
+		netif_device_attach(ndev);
+
+	netif_start_queue(ndev);
+
+	napi_enable(&priv->napi);
+
+	return 0;
+}
+
 static const struct of_device_id sun8i_emac_of_match_table[] = {
 	{ .compatible = "allwinner,sun8i-a83t-emac",
 	  .data = &emac_variant_a83t },
@@ -2246,6 +2302,8 @@ static struct platform_driver sun8i_emac_driver = {
 		.name           = "sun8i-emac",
 		.of_match_table	= sun8i_emac_of_match_table,
 	},
+	.suspend	= sun8i_emac_suspend,
+	.resume		= sun8i_emac_resume,
 };
 
 module_platform_driver(sun8i_emac_driver);
-- 
2.7.3