[PATCH 3/4] net: macb: Add pm runtime support

[Harini Katakam]

From: Harini Katakam <harinik@xxxxxxxxxx>

Add runtime pm functions and move clock handling there.
If device is suspended and not a wake device, then return from
mdio read/write functions without performing any action because
the clocks are not active.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
Signed-off-by: Harini Katakam <harinik@xxxxxxxxxx>
---
Changes from RFC:
Updated pm get sync/put sync calls.
Removed unecessary clk up in mdio helpers.

 drivers/net/ethernet/cadence/macb_main.c | 103 +++++++++++++++++++++++++------
 1 file changed, 85 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 7ae8d731..09cb4bb 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -36,6 +36,7 @@
 #include <linux/ip.h>
 #include <linux/udp.h>
 #include <linux/tcp.h>
+#include <linux/pm_runtime.h>
 #include "macb.h"
 
 #define MACB_RX_BUFFER_SIZE	128
@@ -78,6 +79,7 @@
  * 1 frame time (10 Mbits/s, full-duplex, ignoring collisions)
  */
 #define MACB_HALT_TIMEOUT	1230
+#define MACB_PM_TIMEOUT  100 /* ms */
 
 /* DMA buffer descriptor might be different size
  * depends on hardware configuration:
@@ -345,6 +347,10 @@ static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
 	int value;
 	int err;
 
+	if (pm_runtime_status_suspended(&bp->pdev->dev) &&
+	    !device_may_wakeup(&bp->dev->dev))
+		return -EAGAIN;
+
 	err = macb_mdio_wait_for_idle(bp);
 	if (err < 0)
 		return err;
@@ -370,6 +376,9 @@ static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
 	struct macb *bp = bus->priv;
 	int err;
 
+	if (pm_runtime_status_suspended(&bp->pdev->dev) &&
+	    !device_may_wakeup(&bp->dev->dev))
+		return -EAGAIN;
 
 	err = macb_mdio_wait_for_idle(bp);
 	if (err < 0)
@@ -2397,12 +2406,18 @@ static int macb_open(struct net_device *dev)
 
 	netdev_dbg(bp->dev, "open\n");
 
+	err = pm_runtime_get_sync(&bp->pdev->dev);
+	if (err < 0)
+		goto pm_exit;
+
 	/* carrier starts down */
 	netif_carrier_off(dev);
 
 	/* if the phy is not yet register, retry later*/
-	if (!dev->phydev)
-		return -EAGAIN;
+	if (!dev->phydev) {
+		err = -EAGAIN;
+		goto pm_exit;
+	}
 
 	/* RX buffers initialization */
 	macb_init_rx_buffer_size(bp, bufsz);
@@ -2411,7 +2426,7 @@ static int macb_open(struct net_device *dev)
 	if (err) {
 		netdev_err(dev, "Unable to allocate DMA memory (error %d)\n",
 			   err);
-		return err;
+		goto pm_exit;
 	}
 
 	bp->macbgem_ops.mog_init_rings(bp);
@@ -2428,6 +2443,11 @@ static int macb_open(struct net_device *dev)
 	if (bp->ptp_info)
 		bp->ptp_info->ptp_init(dev);
 
+pm_exit:
+	if (err) {
+		pm_runtime_put_sync(&bp->pdev->dev);
+		return err;
+	}
 	return 0;
 }
 
@@ -2456,6 +2476,8 @@ static int macb_close(struct net_device *dev)
 	if (bp->ptp_info)
 		bp->ptp_info->ptp_remove(dev);
 
+	pm_runtime_put(&bp->pdev->dev);
+
 	return 0;
 }
 
@@ -4019,6 +4041,11 @@ static int macb_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	pm_runtime_set_autosuspend_delay(&pdev->dev, MACB_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
 	native_io = hw_is_native_io(mem);
 
 	macb_probe_queues(mem, native_io, &queue_mask, &num_queues);
@@ -4150,6 +4177,9 @@ static int macb_probe(struct platform_device *pdev)
 		    macb_is_gem(bp) ? "GEM" : "MACB", macb_readl(bp, MID),
 		    dev->base_addr, dev->irq, dev->dev_addr);
 
+	pm_runtime_mark_last_busy(&bp->pdev->dev);
+	pm_runtime_put_autosuspend(&bp->pdev->dev);
+
 	return 0;
 
 err_out_unregister_mdio:
@@ -4169,6 +4199,9 @@ static int macb_probe(struct platform_device *pdev)
 	clk_disable_unprepare(pclk);
 	clk_disable_unprepare(rx_clk);
 	clk_disable_unprepare(tsu_clk);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 
 	return err;
 }
@@ -4192,11 +4225,16 @@ static int macb_remove(struct platform_device *pdev)
 		mdiobus_free(bp->mii_bus);
 
 		unregister_netdev(dev);
-		clk_disable_unprepare(bp->tx_clk);
-		clk_disable_unprepare(bp->hclk);
-		clk_disable_unprepare(bp->pclk);
-		clk_disable_unprepare(bp->rx_clk);
-		clk_disable_unprepare(bp->tsu_clk);
+		pm_runtime_disable(&pdev->dev);
+		pm_runtime_dont_use_autosuspend(&pdev->dev);
+		if (!pm_runtime_suspended(&pdev->dev)) {
+			clk_disable_unprepare(bp->tx_clk);
+			clk_disable_unprepare(bp->hclk);
+			clk_disable_unprepare(bp->pclk);
+			clk_disable_unprepare(bp->rx_clk);
+			clk_disable_unprepare(bp->tsu_clk);
+			pm_runtime_set_suspended(&pdev->dev);
+		}
 		of_node_put(bp->phy_node);
 		free_netdev(dev);
 	}
@@ -4217,13 +4255,9 @@ static int __maybe_unused macb_suspend(struct device *dev)
 		macb_writel(bp, IER, MACB_BIT(WOL));
 		macb_writel(bp, WOL, MACB_BIT(MAG));
 		enable_irq_wake(bp->queues[0].irq);
-	} else {
-		clk_disable_unprepare(bp->tx_clk);
-		clk_disable_unprepare(bp->hclk);
-		clk_disable_unprepare(bp->pclk);
-		clk_disable_unprepare(bp->rx_clk);
 	}
-	clk_disable_unprepare(bp->tsu_clk);
+
+	pm_runtime_force_suspend(dev);
 
 	return 0;
 }
@@ -4234,11 +4268,43 @@ static int __maybe_unused macb_resume(struct device *dev)
 	struct net_device *netdev = platform_get_drvdata(pdev);
 	struct macb *bp = netdev_priv(netdev);
 
+	pm_runtime_force_resume(dev);
+
 	if (bp->wol & MACB_WOL_ENABLED) {
 		macb_writel(bp, IDR, MACB_BIT(WOL));
 		macb_writel(bp, WOL, 0);
 		disable_irq_wake(bp->queues[0].irq);
-	} else {
+	}
+
+	netif_device_attach(netdev);
+
+	return 0;
+}
+
+static int __maybe_unused macb_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct net_device *netdev = platform_get_drvdata(pdev);
+	struct macb *bp = netdev_priv(netdev);
+
+	if (!(device_may_wakeup(&bp->dev->dev))) {
+		clk_disable_unprepare(bp->tx_clk);
+		clk_disable_unprepare(bp->hclk);
+		clk_disable_unprepare(bp->pclk);
+		clk_disable_unprepare(bp->rx_clk);
+	}
+	clk_disable_unprepare(bp->tsu_clk);
+
+	return 0;
+}
+
+static int __maybe_unused macb_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct net_device *netdev = platform_get_drvdata(pdev);
+	struct macb *bp = netdev_priv(netdev);
+
+	if (!(device_may_wakeup(&bp->dev->dev))) {
 		clk_prepare_enable(bp->pclk);
 		clk_prepare_enable(bp->hclk);
 		clk_prepare_enable(bp->tx_clk);
@@ -4246,12 +4312,13 @@ static int __maybe_unused macb_resume(struct device *dev)
 	}
 	clk_prepare_enable(bp->tsu_clk);
 
-	netif_device_attach(netdev);
-
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(macb_pm_ops, macb_suspend, macb_resume);
+static const struct dev_pm_ops macb_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(macb_suspend, macb_resume)
+	SET_RUNTIME_PM_OPS(macb_runtime_suspend, macb_runtime_resume, NULL)
+};
 
 static struct platform_driver macb_driver = {
 	.probe		= macb_probe,
-- 
2.7.4