Merge branch 'Add-Ethernet-support-for-Intel-Keem-Bay-SoC'

Vineetha G. Jaya Kumaran says:

====================
Add Ethernet support for Intel Keem Bay SoC

This patch set enables support for Ethernet on the Intel Keem Bay SoC.
The first patch contains the required Device Tree bindings documentation,
while the second patch adds the Intel platform glue layer for the stmmac
device driver.

This driver was tested on the Keem Bay evaluation module board.
Changes since v2:
-Add a select in DT documentation to avoid matching with all nodes containing 'snps,dwmac'
-Rebased to 5.9-rc1

Changes since v1:
-Removed clocks maxItems property from DT bindings documentation
-Removed phy compatible strings from DT bindings documentation
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 202 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 9a47c5aec91a..7572cea9d59e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -209,6 +209,16 @@ config DWMAC_IMX8
 	  device driver. This driver is used for i.MX8 series like
 	  iMX8MP/iMX8DXL GMAC ethernet controller.
 
+config DWMAC_INTEL_PLAT
+	tristate "Intel dwmac support"
+	depends on OF && COMMON_CLK
+	depends on STMMAC_ETH
+	help
+	  Support for ethernet controllers on Intel SoCs
+
+	  This selects the Intel platform specific glue layer support for
+	  the stmmac device driver. This driver is used for the Intel Keem Bay
+	  SoC.
 endif
 
 config DWMAC_INTEL
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 295615ab36a7..24e6145d4eae 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_DWMAC_STM32)	+= dwmac-stm32.o
 obj-$(CONFIG_DWMAC_SUNXI)	+= dwmac-sunxi.o
 obj-$(CONFIG_DWMAC_SUN8I)	+= dwmac-sun8i.o
 obj-$(CONFIG_DWMAC_DWC_QOS_ETH)	+= dwmac-dwc-qos-eth.o
+obj-$(CONFIG_DWMAC_INTEL_PLAT)	+= dwmac-intel-plat.o
 obj-$(CONFIG_DWMAC_GENERIC)	+= dwmac-generic.o
 obj-$(CONFIG_DWMAC_IMX8)	+= dwmac-imx.o
 stmmac-platform-objs:= stmmac_platform.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c
new file mode 100644
index 000000000000..ccac7bf2a9d3
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Intel DWMAC platform driver
+ *
+ * Copyright(C) 2020 Intel Corporation
+ */
+
+#include <linux/ethtool.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/stmmac.h>
+
+#include "stmmac.h"
+#include "stmmac_platform.h"
+
+struct intel_dwmac {
+	struct device *dev;
+	struct clk *tx_clk;
+	const struct intel_dwmac_data *data;
+};
+
+struct intel_dwmac_data {
+	void (*fix_mac_speed)(void *priv, unsigned int speed);
+	unsigned long ptp_ref_clk_rate;
+	unsigned long tx_clk_rate;
+	bool tx_clk_en;
+};
+
+static void kmb_eth_fix_mac_speed(void *priv, unsigned int speed)
+{
+	struct intel_dwmac *dwmac = priv;
+	unsigned long rate;
+	int ret;
+
+	rate = clk_get_rate(dwmac->tx_clk);
+
+	switch (speed) {
+	case SPEED_1000:
+		rate = 125000000;
+		break;
+
+	case SPEED_100:
+		rate = 25000000;
+		break;
+
+	case SPEED_10:
+		rate = 2500000;
+		break;
+
+	default:
+		dev_err(dwmac->dev, "Invalid speed\n");
+		break;
+	}
+
+	ret = clk_set_rate(dwmac->tx_clk, rate);
+	if (ret)
+		dev_err(dwmac->dev, "Failed to configure tx clock rate\n");
+}
+
+static const struct intel_dwmac_data kmb_data = {
+	.fix_mac_speed = kmb_eth_fix_mac_speed,
+	.ptp_ref_clk_rate = 200000000,
+	.tx_clk_rate = 125000000,
+	.tx_clk_en = true,
+};
+
+static const struct of_device_id intel_eth_plat_match[] = {
+	{ .compatible = "intel,keembay-dwmac", .data = &kmb_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, intel_eth_plat_match);
+
+static int intel_eth_plat_probe(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	const struct of_device_id *match;
+	struct intel_dwmac *dwmac;
+	unsigned long rate;
+	int ret;
+
+	plat_dat = priv->plat;
+	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+	if (ret)
+		return ret;
+
+	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	if (IS_ERR(plat_dat)) {
+		dev_err(&pdev->dev, "dt configuration failed\n");
+		return PTR_ERR(plat_dat);
+	}
+
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+	if (!dwmac) {
+		ret = -ENOMEM;
+		goto err_remove_config_dt;
+	}
+
+	dwmac->dev = &pdev->dev;
+	dwmac->tx_clk = NULL;
+
+	match = of_match_device(intel_eth_plat_match, &pdev->dev);
+	if (match && match->data) {
+		dwmac->data = (const struct intel_dwmac_data *)match->data;
+
+		if (dwmac->data->fix_mac_speed)
+			plat_dat->fix_mac_speed = dwmac->data->fix_mac_speed;
+
+		/* Enable TX clock */
+		if (dwmac->data->tx_clk_en) {
+			dwmac->tx_clk = devm_clk_get(&pdev->dev, "tx_clk");
+			if (IS_ERR(dwmac->tx_clk))
+				goto err_remove_config_dt;
+
+			clk_prepare_enable(dwmac->tx_clk);
+
+			/* Check and configure TX clock rate */
+			rate = clk_get_rate(dwmac->tx_clk);
+			if (dwmac->data->tx_clk_rate &&
+			    rate != dwmac->data->tx_clk_rate) {
+				rate = dwmac->data->tx_clk_rate;
+				ret = clk_set_rate(dwmac->tx_clk, rate);
+				if (ret) {
+					dev_err(&pdev->dev,
+						"Failed to set tx_clk\n");
+					return ret;
+				}
+			}
+		}
+
+		/* Check and configure PTP ref clock rate */
+		rate = clk_get_rate(plat_dat->clk_ptp_ref);
+		if (dwmac->data->ptp_ref_clk_rate &&
+		    rate != dwmac->data->ptp_ref_clk_rate) {
+			rate = dwmac->data->ptp_ref_clk_rate;
+			ret = clk_set_rate(plat_dat->clk_ptp_ref, rate);
+			if (ret) {
+				dev_err(&pdev->dev,
+					"Failed to set clk_ptp_ref\n");
+				return ret;
+			}
+		}
+	}
+
+	plat_dat->bsp_priv = dwmac;
+
+	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
+	if (ret) {
+		if (dwmac->tx_clk)
+			clk_disable_unprepare(dwmac->tx_clk);
+
+		goto err_remove_config_dt;
+	}
+
+	return 0;
+
+err_remove_config_dt:
+	stmmac_remove_config_dt(pdev, plat_dat);
+
+	return ret;
+}
+
+static int intel_eth_plat_remove(struct platform_device *pdev)
+{
+	struct intel_dwmac *dwmac = get_stmmac_bsp_priv(&pdev->dev);
+	int ret;
+
+	ret = stmmac_pltfr_remove(pdev);
+
+	if (dwmac->tx_clk)
+		clk_disable_unprepare(dwmac->tx_clk);
+
+	return ret;
+}
+
+static struct platform_driver intel_eth_plat_driver = {
+	.probe  = intel_eth_plat_probe,
+	.remove = intel_eth_plat_remove,
+	.driver = {
+		.name		= "intel-eth-plat",
+		.pm		= &stmmac_pltfr_pm_ops,
+		.of_match_table = intel_eth_plat_match,
+	},
+};
+module_platform_driver(intel_eth_plat_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel DWMAC platform driver");