net: stmmac: add clocks management for gmac driver

This patch intends to add clocks management for stmmac driver:

If CONFIG_PM enabled:
1. Keep clocks disabled after driver probed.
2. Enable clocks when up the net device, and disable clocks when down
the net device.

If CONFIG_PM disabled:
Keep clocks always enabled after driver probed.

Note:
1. It is fine for ethtool, since the way of implementing ethtool_ops::begin
in stmmac is only can be accessed when interface is enabled, so the clocks
are ticked.
2. The MDIO bus has a different life cycle to the MAC, need ensure
clocks are enabled when _mdio_read/write() need clocks, because these
functions can be called while the interface it not opened.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 2 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 6dc9f10414e4..a70b0bc84b2a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -744,10 +744,30 @@ static int stmmac_pltfr_resume(struct device *dev)
 
 	return stmmac_resume(dev);
 }
+
+static int stmmac_runtime_suspend(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+
+	stmmac_bus_clks_config(priv, false);
+
+	return 0;
+}
+
+static int stmmac_runtime_resume(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+
+	return stmmac_bus_clks_config(priv, true);
+}
 #endif /* CONFIG_PM_SLEEP */
 
-SIMPLE_DEV_PM_OPS(stmmac_pltfr_pm_ops, stmmac_pltfr_suspend,
-				       stmmac_pltfr_resume);
+const struct dev_pm_ops stmmac_pltfr_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(stmmac_pltfr_suspend, stmmac_pltfr_resume)
+	SET_RUNTIME_PM_OPS(stmmac_runtime_suspend, stmmac_runtime_resume, NULL)
+};
 EXPORT_SYMBOL_GPL(stmmac_pltfr_pm_ops);
 
 MODULE_DESCRIPTION("STMMAC 10/100/1000 Ethernet platform support");