[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.montj...@gmail.com>
---
 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