[PATCH net-next v3 3/6] net: hisilicon: add support for hisi_femac core on Hi3798MV200

[Yang Xiwen via B4 Relay <devnull+forbidden405.outlook.com@kernel.org>]

From: Yang Xiwen <forbidden405@outlook.com>

Register the sub MDIO bus if it is found. Also implement the internal
PHY reset procedure as needed.

Note it's unable to put the MDIO bus node outside of MAC controller
(i.e. at the same level in the parent bus node). Because we need to
control all clocks and resets in FEMAC driver due to the phy reset
procedure. So the clocks can't be assigned to MDIO bus device, which is
an essential resource for the MDIO bus to work.

No backward compatibility is maintained since the only existing
user(Hi3516DV300) has not received any updates from HiSilicon for about
8 years already. And till today, no mainline dts for this SoC is found.
It seems unlikely that there are still existing mainline Hi3516DV300
users. The effort to maintain the old binding seems gain a little.

Signed-off-by: Yang Xiwen <forbidden405@outlook.com>
---
 drivers/net/ethernet/hisilicon/hisi_femac.c | 77 +++++++++++++++++++++++------
 1 file changed, 61 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hisi_femac.c b/drivers/net/ethernet/hisilicon/hisi_femac.c
index 2406263c9dd3..fedfc7219fad 100644
--- a/drivers/net/ethernet/hisilicon/hisi_femac.c
+++ b/drivers/net/ethernet/hisilicon/hisi_femac.c
@@ -10,8 +10,10 @@
 #include <linux/etherdevice.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/of_mdio.h>
 #include <linux/of_net.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
 
@@ -97,6 +99,13 @@ enum phy_reset_delays {
 	DELAYS_NUM,
 };
 
+enum clk_type {
+	CLK_MAC,
+	CLK_MACIF,
+	CLK_PHY,
+	CLK_NUM,
+};
+
 struct hisi_femac_queue {
 	struct sk_buff **skb;
 	dma_addr_t *dma_phys;
@@ -108,7 +117,7 @@ struct hisi_femac_queue {
 struct hisi_femac_priv {
 	void __iomem *port_base;
 	void __iomem *glb_base;
-	struct clk *clk;
+	struct clk_bulk_data *clks;
 	struct reset_control *mac_rst;
 	struct reset_control *phy_rst;
 	u32 phy_reset_delays[DELAYS_NUM];
@@ -116,6 +125,7 @@ struct hisi_femac_priv {
 
 	struct device *dev;
 	struct net_device *ndev;
+	struct platform_device *mdio_pdev;
 
 	struct hisi_femac_queue txq;
 	struct hisi_femac_queue rxq;
@@ -693,6 +703,7 @@ static const struct net_device_ops hisi_femac_netdev_ops = {
 static void hisi_femac_core_reset(struct hisi_femac_priv *priv)
 {
 	reset_control_assert(priv->mac_rst);
+	usleep_range(200, 300);
 	reset_control_deassert(priv->mac_rst);
 }
 
@@ -712,6 +723,10 @@ static void hisi_femac_sleep_us(u32 time_us)
 
 static void hisi_femac_phy_reset(struct hisi_femac_priv *priv)
 {
+	/* MAC clock must be disabled before PHY reset
+	 */
+	clk_disable(priv->clks[CLK_MAC].clk);
+	clk_disable(priv->clks[CLK_MACIF].clk);
 	/* To make sure PHY hardware reset success,
 	 * we must keep PHY in deassert state first and
 	 * then complete the hardware reset operation
@@ -727,6 +742,9 @@ static void hisi_femac_phy_reset(struct hisi_femac_priv *priv)
 	reset_control_deassert(priv->phy_rst);
 	/* delay some time to ensure later MDIO access */
 	hisi_femac_sleep_us(priv->phy_reset_delays[POST_DELAY]);
+
+	clk_enable(priv->clks[CLK_MAC].clk);
+	clk_enable(priv->clks[CLK_MACIF].clk);
 }
 
 static void hisi_femac_port_init(struct hisi_femac_priv *priv)
@@ -768,11 +786,12 @@ static void hisi_femac_port_init(struct hisi_femac_priv *priv)
 static int hisi_femac_drv_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct device_node *node = dev->of_node;
+	struct device_node *node = dev->of_node, *mdio_np;
 	struct net_device *ndev;
 	struct hisi_femac_priv *priv;
 	struct phy_device *phy;
 	int ret;
+	bool mdio_registered = false;
 
 	ndev = alloc_etherdev(sizeof(*priv));
 	if (!ndev)
@@ -797,23 +816,22 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
 		goto out_free_netdev;
 	}
 
-	priv->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(priv->clk)) {
-		dev_err(dev, "failed to get clk\n");
-		ret = -ENODEV;
+	ret = devm_clk_bulk_get_all(&pdev->dev, &priv->clks);
+	if (ret < 0 || ret != CLK_NUM) {
+		dev_err(dev, "failed to get clk bulk: %d\n", ret);
 		goto out_free_netdev;
 	}
 
-	ret = clk_prepare_enable(priv->clk);
+	ret = clk_bulk_prepare_enable(CLK_NUM, priv->clks);
 	if (ret) {
-		dev_err(dev, "failed to enable clk %d\n", ret);
+		dev_err(dev, "failed to enable clk bulk: %d\n", ret);
 		goto out_free_netdev;
 	}
 
 	priv->mac_rst = devm_reset_control_get(dev, "mac");
 	if (IS_ERR(priv->mac_rst)) {
 		ret = PTR_ERR(priv->mac_rst);
-		goto out_disable_clk;
+		goto out_free_netdev;
 	}
 	hisi_femac_core_reset(priv);
 
@@ -826,15 +844,34 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
 						 priv->phy_reset_delays,
 						 DELAYS_NUM);
 		if (ret)
-			goto out_disable_clk;
+			goto out_free_netdev;
 		hisi_femac_phy_reset(priv);
 	}
 
+	// Register the optional MDIO bus
+	for_each_available_child_of_node(node, mdio_np) {
+		if (of_node_name_prefix(mdio_np, "mdio")) {
+			priv->mdio_pdev = of_platform_device_create(mdio_np, NULL, dev);
+			of_node_put(mdio_np);
+			if (!priv->mdio_pdev) {
+				dev_err(dev, "failed to register MDIO bus device\n");
+				ret = -ENODEV;
+				goto out_free_netdev;
+			}
+			mdio_registered = true;
+			break;
+		}
+		of_node_put(mdio_np);
+	}
+
+	if (!mdio_registered)
+		dev_warn(dev, "MDIO subnode not found. This is usually a bug.\n");
+
 	phy = of_phy_get_and_connect(ndev, node, hisi_femac_adjust_link);
 	if (!phy) {
 		dev_err(dev, "connect to PHY failed!\n");
 		ret = -ENODEV;
-		goto out_disable_clk;
+		goto out_unregister_mdio_bus;
 	}
 
 	phy_attached_print(phy, "phy_id=0x%.8lx, phy_mode=%s\n",
@@ -885,8 +922,8 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
 out_disconnect_phy:
 	netif_napi_del(&priv->napi);
 	phy_disconnect(phy);
-out_disable_clk:
-	clk_disable_unprepare(priv->clk);
+out_unregister_mdio_bus:
+	platform_device_unregister(priv->mdio_pdev);
 out_free_netdev:
 	free_netdev(ndev);
 
@@ -902,7 +939,8 @@ static void hisi_femac_drv_remove(struct platform_device *pdev)
 	unregister_netdev(ndev);
 
 	phy_disconnect(ndev->phydev);
-	clk_disable_unprepare(priv->clk);
+	platform_device_unregister(priv->mdio_pdev);
+	clk_bulk_disable_unprepare(CLK_NUM, priv->clks);
 	free_netdev(ndev);
 }
 
@@ -919,7 +957,7 @@ static int hisi_femac_drv_suspend(struct platform_device *pdev,
 		netif_device_detach(ndev);
 	}
 
-	clk_disable_unprepare(priv->clk);
+	clk_bulk_disable_unprepare(CLK_NUM, priv->clks);
 
 	return 0;
 }
@@ -928,8 +966,14 @@ static int hisi_femac_drv_resume(struct platform_device *pdev)
 {
 	struct net_device *ndev = platform_get_drvdata(pdev);
 	struct hisi_femac_priv *priv = netdev_priv(ndev);
+	int ret;
+
+	ret = clk_bulk_prepare_enable(CLK_NUM, priv->clks);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable clk bulk: %d\n", ret);
+		return ret;
+	}
 
-	clk_prepare_enable(priv->clk);
 	if (priv->phy_rst)
 		hisi_femac_phy_reset(priv);
 
@@ -948,6 +992,7 @@ static const struct of_device_id hisi_femac_match[] = {
 	{.compatible = "hisilicon,hisi-femac-v1",},
 	{.compatible = "hisilicon,hisi-femac-v2",},
 	{.compatible = "hisilicon,hi3516cv300-femac",},
+	{.compatible = "hisilicon,hi3798mv200-femac",},
 	{},
 };
 

-- 
2.43.0