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>

Author: Joakim Zhang

drivers/net/ethernet/stmicro/stmmac/stmmac.h

@@ -272,6 +272,7 @@ void stmmac_disable_eee_mode(struct stmmac_priv *priv);
 bool stmmac_eee_init(struct stmmac_priv *priv);
 int stmmac_reinit_queues(struct net_device *dev, u32 rx_cnt, u32 tx_cnt);
 int stmmac_reinit_ringparam(struct net_device *dev, u32 rx_size, u32 tx_size);
+int stmmac_bus_clks_config(struct stmmac_priv *priv, bool enabled);
 
 #if IS_ENABLED(CONFIG_STMMAC_SELFTESTS)
 void stmmac_selftest_run(struct net_device *dev,

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -28,6 +28,7 @@
 #include <linux/if_vlan.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
+#include <linux/pm_runtime.h>
 #include <linux/prefetch.h>
 #include <linux/pinctrl/consumer.h>
 #ifdef CONFIG_DEBUG_FS
@@ -113,6 +114,28 @@ static void stmmac_exit_fs(struct net_device *dev);
 
 #define STMMAC_COAL_TIMER(x) (ns_to_ktime((x) * NSEC_PER_USEC))
 
+int stmmac_bus_clks_config(struct stmmac_priv *priv, bool enabled)
+{
+int ret = 0;
+
+if (enabled) {
+ret = clk_prepare_enable(priv->plat->stmmac_clk);
+if (ret)
+return ret;
+ret = clk_prepare_enable(priv->plat->pclk);
+if (ret) {
+clk_disable_unprepare(priv->plat->stmmac_clk);
+return ret;
+}
+} else {
+clk_disable_unprepare(priv->plat->stmmac_clk);
+clk_disable_unprepare(priv->plat->pclk);
+}
+
+return ret;
+}
+EXPORT_SYMBOL_GPL(stmmac_bus_clks_config);
+
 /**
  * stmmac_verify_args - verify the driver parameters.
  * Description: it checks the driver parameters and set a default in case of
@@ -2896,6 +2919,12 @@ static int stmmac_open(struct net_device *dev)
 u32 chan;
 int ret;
 
+ret = pm_runtime_get_sync(priv->device);
+if (ret < 0) {
+pm_runtime_put_noidle(priv->device);
+return ret;
+}
+
 if (priv->hw->pcs != STMMAC_PCS_TBI &&
  priv->hw->pcs != STMMAC_PCS_RTBI &&
  priv->hw->xpcs_args.an_mode != DW_AN_C73) {
@@ -2904,7 +2933,7 @@ static int stmmac_open(struct net_device *dev)
 netdev_err(priv->dev,
  "%s: Cannot attach to PHY (error: %d)\n",
  __func__, ret);
-return ret;
+goto init_phy_error;
 }
 }
 
@@ -3020,6 +3049,8 @@ static int stmmac_open(struct net_device *dev)
 free_dma_desc_resources(priv);
 dma_desc_error:
 phylink_disconnect_phy(priv->phylink);
+init_phy_error:
+pm_runtime_put(priv->device);
 return ret;
 }
 
@@ -3070,6 +3101,8 @@ static int stmmac_release(struct net_device *dev)
 
 stmmac_release_ptp(priv);
 
+pm_runtime_put(priv->device);
+
 return 0;
 }
 
@@ -4706,6 +4739,12 @@ static int stmmac_vlan_rx_add_vid(struct net_device *ndev, __be16 proto, u16 vid
 bool is_double = false;
 int ret;
 
+ret = pm_runtime_get_sync(priv->device);
+if (ret < 0) {
+pm_runtime_put_noidle(priv->device);
+return ret;
+}
+
 if (be16_to_cpu(proto) == ETH_P_8021AD)
 is_double = true;
 
@@ -4739,10 +4778,15 @@ static int stmmac_vlan_rx_kill_vid(struct net_device *ndev, __be16 proto, u16 vi
 if (priv->hw->num_vlan) {
 ret = stmmac_del_hw_vlan_rx_fltr(priv, ndev, priv->hw, proto, vid);
 if (ret)
-return ret;
+goto del_vlan_error;
 }
 
-return stmmac_vlan_update(priv, is_double);
+ret = stmmac_vlan_update(priv, is_double);
+
+del_vlan_error:
+pm_runtime_put(priv->device);
+
+return ret;
 }
 
 static const struct net_device_ops stmmac_netdev_ops = {
@@ -5181,6 +5225,10 @@ int stmmac_dvr_probe(struct device *device,
 
 stmmac_check_pcs_mode(priv);
 
+pm_runtime_get_noresume(device);
+pm_runtime_set_active(device);
+pm_runtime_enable(device);
+
 if (priv->hw->pcs != STMMAC_PCS_TBI &&
  priv->hw->pcs != STMMAC_PCS_RTBI) {
 /* MDIO bus Registration */
@@ -5218,6 +5266,11 @@ int stmmac_dvr_probe(struct device *device,
 stmmac_init_fs(ndev);
 #endif
 
+/* Let pm_runtime_put() disable the clocks.
+ * If CONFIG_PM is not enabled, the clocks will stay powered.
+ */
+pm_runtime_put(device);
+
 return ret;
 
 error_serdes_powerup:
@@ -5232,6 +5285,7 @@ int stmmac_dvr_probe(struct device *device,
 stmmac_napi_del(ndev);
 error_hw_init:
 destroy_workqueue(priv->wq);
+stmmac_bus_clks_config(priv, false);
 
 return ret;
 }
@@ -5267,8 +5321,8 @@ int stmmac_dvr_remove(struct device *dev)
 phylink_destroy(priv->phylink);
 if (priv->plat->stmmac_rst)
 reset_control_assert(priv->plat->stmmac_rst);
-clk_disable_unprepare(priv->plat->pclk);
-clk_disable_unprepare(priv->plat->stmmac_clk);
+pm_runtime_put(dev);
+pm_runtime_disable(dev);
 if (priv->hw->pcs != STMMAC_PCS_TBI &&
  priv->hw->pcs != STMMAC_PCS_RTBI)
 stmmac_mdio_unregister(ndev);
@@ -5291,6 +5345,7 @@ int stmmac_suspend(struct device *dev)
 struct net_device *ndev = dev_get_drvdata(dev);
 struct stmmac_priv *priv = netdev_priv(ndev);
 u32 chan;
+int ret;
 
 if (!ndev || !netif_running(ndev))
 return 0;
@@ -5334,8 +5389,9 @@ int stmmac_suspend(struct device *dev)
 pinctrl_pm_select_sleep_state(priv->device);
 /* Disable clock in case of PWM is off */
 clk_disable_unprepare(priv->plat->clk_ptp_ref);
-clk_disable_unprepare(priv->plat->pclk);
-clk_disable_unprepare(priv->plat->stmmac_clk);
+ret = pm_runtime_force_suspend(dev);
+if (ret)
+return ret;
 }
 mutex_unlock(&priv->lock);
 
@@ -5401,8 +5457,9 @@ int stmmac_resume(struct device *dev)
 } else {
 pinctrl_pm_select_default_state(priv->device);
 /* enable the clk previously disabled */
-clk_prepare_enable(priv->plat->stmmac_clk);
-clk_prepare_enable(priv->plat->pclk);
+ret = pm_runtime_force_resume(dev);
+if (ret)
+return ret;
 if (priv->plat->clk_ptp_ref)
 clk_prepare_enable(priv->plat->clk_ptp_ref);
 /* reset the phy so that it's ready */