[PATCH V6 2/2] net: stmmac: tegra: Add MGBE support

Jon Hunter
2022-12-01T15:59:07Z

From: Bhadram Varka <vbhadram@nvidia.com>

Add support for the Multi-Gigabit Ethernet (MGBE/XPCS) IP found on
NVIDIA Tegra234 SoCs.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bhadram Varka <vbhadram@nvidia.com>
Co-developed-by: Revanth Kumar Uppala <ruppala@nvidia.com>
Signed-off-by: Revanth Kumar Uppala <ruppala@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
Changes since V5:
- Fixed clang warning
- Updated Kconfig help information
Changes since V4:
- Reduce time spent polling for the RX link to be ready
- Propagate the errors when bringing up the link fails.
- Added suspend/resume support
- Ensure clocks are disabled again on probe/resume failure
Changes since V3:
- None
Changes since V2:
- None
Changes since V1:
- None

drivers/net/ethernet/stmicro/stmmac/Kconfig | 9 +
drivers/net/ethernet/stmicro/stmmac/Makefile | 1 +
.../net/ethernet/stmicro/stmmac/dwmac-tegra.c | 388 ++++++++++++++++++
3 files changed, 398 insertions(+)
create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 31ff35174034..f77511fe4e87 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -235,6 +235,15 @@ config DWMAC_INTEL_PLAT
the stmmac device driver. This driver is used for the Intel Keem Bay
SoC.

+config DWMAC_TEGRA
+ tristate "NVIDIA Tegra MGBE support"
+ depends on ARCH_TEGRA || COMPILE_TEST
+ help
+ This selects the Multi-GigaBit Ethernet (MGBE) Controller that is
+ found on the NVIDIA Tegra SoC devices. This driver provides the glue
+ layer on top of the stmmac driver required for these NVIDIA Tegra SoC
+ devices.
+
config DWMAC_VISCONTI
tristate "Toshiba Visconti DWMAC support"
default ARCH_VISCONTI
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index d4e12e9ace4f..057e4bab5c08 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -31,6 +31,7 @@ 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
+obj-$(CONFIG_DWMAC_TEGRA) += dwmac-tegra.o
obj-$(CONFIG_DWMAC_VISCONTI) += dwmac-visconti.o
stmmac-platform-objs:= stmmac_platform.o
dwmac-altr-socfpga-objs := altr_tse_pcs.o dwmac-socfpga.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c
new file mode 100644
index 000000000000..bdf990cf2f31
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/module.h>
+#include <linux/stmmac.h>
+#include <linux/clk.h>
+
+#include "stmmac_platform.h"
+
+static const char *const mgbe_clks[] = {
+ "rx-pcs", "tx", "tx-pcs", "mac-divider", "mac", "mgbe", "ptp-ref", "mac"
+};
+
+struct tegra_mgbe {
+ struct device *dev;
+
+ struct clk_bulk_data *clks;
+
+ struct reset_control *rst_mac;
+ struct reset_control *rst_pcs;
+
+ void __iomem *hv;
+ void __iomem *regs;
+ void __iomem *xpcs;
+
+ struct mii_bus *mii;
+};
+
+#define XPCS_WRAP_UPHY_RX_CONTROL 0x801c
+#define XPCS_WRAP_UPHY_RX_CONTROL_RX_SW_OVRD BIT(31)
+#define XPCS_WRAP_UPHY_RX_CONTROL_RX_PCS_PHY_RDY BIT(10)
+#define XPCS_WRAP_UPHY_RX_CONTROL_RX_CDR_RESET BIT(9)
+#define XPCS_WRAP_UPHY_RX_CONTROL_RX_CAL_EN BIT(8)
+#define XPCS_WRAP_UPHY_RX_CONTROL_RX_SLEEP (BIT(7) | BIT(6))
+#define XPCS_WRAP_UPHY_RX_CONTROL_AUX_RX_IDDQ BIT(5)
+#define XPCS_WRAP_UPHY_RX_CONTROL_RX_IDDQ BIT(4)
+#define XPCS_WRAP_UPHY_RX_CONTROL_RX_DATA_EN BIT(0)
+#define XPCS_WRAP_UPHY_HW_INIT_CTRL 0x8020
+#define XPCS_WRAP_UPHY_HW_INIT_CTRL_TX_EN BIT(0)
+#define XPCS_WRAP_UPHY_HW_INIT_CTRL_RX_EN BIT(2)
+#define XPCS_WRAP_UPHY_STATUS 0x8044
+#define XPCS_WRAP_UPHY_STATUS_TX_P_UP BIT(0)
+#define XPCS_WRAP_IRQ_STATUS 0x8050
+#define XPCS_WRAP_IRQ_STATUS_PCS_LINK_STS BIT(6)
+
+#define XPCS_REG_ADDR_SHIFT 10
+#define XPCS_REG_ADDR_MASK 0x1fff
+#define XPCS_ADDR 0x3fc
+
+#define MGBE_WRAP_COMMON_INTR_ENABLE 0x8704
+#define MAC_SBD_INTR BIT(2)
+#define MGBE_WRAP_AXI_ASID0_CTRL 0x8400
+#define MGBE_SID 0x6
+
+static int __maybe_unused tegra_mgbe_suspend(struct device *dev)
+{
+ struct tegra_mgbe *mgbe = get_stmmac_bsp_priv(dev);
+ int err;
+
+ err = stmmac_suspend(dev);
+ if (err)
+ return err;
+
+ clk_bulk_disable_unprepare(ARRAY_SIZE(mgbe_clks), mgbe->clks);
+
+ return reset_control_assert(mgbe->rst_mac);
+}
+
+static int __maybe_unused tegra_mgbe_resume(struct device *dev)
+{
+ struct tegra_mgbe *mgbe = get_stmmac_bsp_priv(dev);
+ u32 value;
+ int err;
+
+ err = clk_bulk_prepare_enable(ARRAY_SIZE(mgbe_clks), mgbe->clks);
+ if (err < 0)
+ return err;
+
+ err = reset_control_deassert(mgbe->rst_mac);
+ if (err < 0)
+ return err;
+
+ /* Enable common interrupt at wrapper level */
+ writel(MAC_SBD_INTR, mgbe->regs + MGBE_WRAP_COMMON_INTR_ENABLE);
+
+ /* Program SID */
+ writel(MGBE_SID, mgbe->hv + MGBE_WRAP_AXI_ASID0_CTRL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_STATUS);
+ if ((value & XPCS_WRAP_UPHY_STATUS_TX_P_UP) == 0) {
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_HW_INIT_CTRL);
+ value |= XPCS_WRAP_UPHY_HW_INIT_CTRL_TX_EN;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_HW_INIT_CTRL);
+ }
+
+ err = readl_poll_timeout(mgbe->xpcs + XPCS_WRAP_UPHY_HW_INIT_CTRL, value,
+ (value & XPCS_WRAP_UPHY_HW_INIT_CTRL_TX_EN) == 0,
+ 500, 500 * 2000);
+ if (err < 0) {
+ dev_err(mgbe->dev, "timeout waiting for TX lane to become enabled\n");
+ clk_bulk_disable_unprepare(ARRAY_SIZE(mgbe_clks), mgbe->clks);
+ return err;
+ }
+
+ err = stmmac_resume(dev);
+ if (err < 0)
+ clk_bulk_disable_unprepare(ARRAY_SIZE(mgbe_clks), mgbe->clks);
+
+ return err;
+}
+
+static int mgbe_uphy_lane_bringup_serdes_up(struct net_device *ndev, void *mgbe_data)
+{
+ struct tegra_mgbe *mgbe = (struct tegra_mgbe *)mgbe_data;
+ u32 value;
+ int err;
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_SW_OVRD;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_IDDQ;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value &= ~XPCS_WRAP_UPHY_RX_CONTROL_AUX_RX_IDDQ;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_SLEEP;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_CAL_EN;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ err = readl_poll_timeout(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL, value,
+ (value & XPCS_WRAP_UPHY_RX_CONTROL_RX_CAL_EN) == 0,
+ 1000, 1000 * 2000);
+ if (err < 0) {
+ dev_err(mgbe->dev, "timeout waiting for RX calibration to become enabled\n");
+ return err;
+ }
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_DATA_EN;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_CDR_RESET;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_CDR_RESET;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_PCS_PHY_RDY;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ err = readl_poll_timeout(mgbe->xpcs + XPCS_WRAP_IRQ_STATUS, value,
+ value & XPCS_WRAP_IRQ_STATUS_PCS_LINK_STS,
+ 500, 500 * 2000);
+ if (err < 0) {
+ dev_err(mgbe->dev, "timeout waiting for link to become ready\n");
+ return err;
+ }
+
+ /* clear status */
+ writel(value, mgbe->xpcs + XPCS_WRAP_IRQ_STATUS);
+
+ return 0;
+}
+
+static void mgbe_uphy_lane_bringup_serdes_down(struct net_device *ndev, void *mgbe_data)
+{
+ struct tegra_mgbe *mgbe = (struct tegra_mgbe *)mgbe_data;
+ u32 value;
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_SW_OVRD;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value &= ~XPCS_WRAP_UPHY_RX_CONTROL_RX_DATA_EN;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_SLEEP;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_AUX_RX_IDDQ;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+ value |= XPCS_WRAP_UPHY_RX_CONTROL_RX_IDDQ;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_RX_CONTROL);
+}
+
+static int tegra_mgbe_probe(struct platform_device *pdev)
+{
+ struct plat_stmmacenet_data *plat;
+ struct stmmac_resources res;
+ struct tegra_mgbe *mgbe;
+ int irq, err, i;
+ u32 value;
+
+ mgbe = devm_kzalloc(&pdev->dev, sizeof(*mgbe), GFP_KERNEL);
+ if (!mgbe)
+ return -ENOMEM;
+
+ mgbe->dev = &pdev->dev;
+
+ memset(&res, 0, sizeof(res));
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ mgbe->hv = devm_platform_ioremap_resource_byname(pdev, "hypervisor");
+ if (IS_ERR(mgbe->hv))
+ return PTR_ERR(mgbe->hv);
+
+ mgbe->regs = devm_platform_ioremap_resource_byname(pdev, "mac");
+ if (IS_ERR(mgbe->regs))
+ return PTR_ERR(mgbe->regs);
+
+ mgbe->xpcs = devm_platform_ioremap_resource_byname(pdev, "xpcs");
+ if (IS_ERR(mgbe->xpcs))
+ return PTR_ERR(mgbe->xpcs);
+
+ res.addr = mgbe->regs;
+ res.irq = irq;
+
+ mgbe->clks = devm_kzalloc(&pdev->dev, sizeof(*mgbe->clks), GFP_KERNEL);
+ if (!mgbe->clks)
+ return -ENOMEM;
+
+ for (i = 0; i < ARRAY_SIZE(mgbe_clks); i++)
+ mgbe->clks[i].id = mgbe_clks[i];
+
+ err = devm_clk_bulk_get(mgbe->dev, ARRAY_SIZE(mgbe_clks), mgbe->clks);
+ if (err < 0)
+ return err;
+
+ err = clk_bulk_prepare_enable(ARRAY_SIZE(mgbe_clks), mgbe->clks);
+ if (err < 0)
+ return err;
+
+ /* Perform MAC reset */
+ mgbe->rst_mac = devm_reset_control_get(&pdev->dev, "mac");
+ if (IS_ERR(mgbe->rst_mac)) {
+ err = PTR_ERR(mgbe->rst_mac);
+ goto disable_clks;
+ }
+
+ err = reset_control_assert(mgbe->rst_mac);
+ if (err < 0)
+ goto disable_clks;
+
+ usleep_range(2000, 4000);
+
+ err = reset_control_deassert(mgbe->rst_mac);
+ if (err < 0)
+ goto disable_clks;
+
+ /* Perform PCS reset */
+ mgbe->rst_pcs = devm_reset_control_get(&pdev->dev, "pcs");
+ if (IS_ERR(mgbe->rst_pcs)) {
+ err = PTR_ERR(mgbe->rst_pcs);
+ goto disable_clks;
+ }
+
+ err = reset_control_assert(mgbe->rst_pcs);
+ if (err < 0)
+ goto disable_clks;
+
+ usleep_range(2000, 4000);
+
+ err = reset_control_deassert(mgbe->rst_pcs);
+ if (err < 0)
+ goto disable_clks;
+
+ plat = stmmac_probe_config_dt(pdev, res.mac);
+ if (IS_ERR(plat)) {
+ err = PTR_ERR(plat);
+ goto disable_clks;
+ }
+
+ plat->has_xgmac = 1;
+ plat->tso_en = 1;
+ plat->pmt = 1;
+ plat->bsp_priv = mgbe;
+
+ if (!plat->mdio_node)
+ plat->mdio_node = of_get_child_by_name(pdev->dev.of_node, "mdio");
+
+ if (!plat->mdio_bus_data) {
+ plat->mdio_bus_data = devm_kzalloc(&pdev->dev, sizeof(*plat->mdio_bus_data),
+ GFP_KERNEL);
+ if (!plat->mdio_bus_data) {
+ err = -ENOMEM;
+ goto remove;
+ }
+ }
+
+ plat->mdio_bus_data->needs_reset = true;
+
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_STATUS);
+ if ((value & XPCS_WRAP_UPHY_STATUS_TX_P_UP) == 0) {
+ value = readl(mgbe->xpcs + XPCS_WRAP_UPHY_HW_INIT_CTRL);
+ value |= XPCS_WRAP_UPHY_HW_INIT_CTRL_TX_EN;
+ writel(value, mgbe->xpcs + XPCS_WRAP_UPHY_HW_INIT_CTRL);
+ }
+
+ err = readl_poll_timeout(mgbe->xpcs + XPCS_WRAP_UPHY_HW_INIT_CTRL, value,
+ (value & XPCS_WRAP_UPHY_HW_INIT_CTRL_TX_EN) == 0,
+ 500, 500 * 2000);
+ if (err < 0) {
+ dev_err(mgbe->dev, "timeout waiting for TX lane to become enabled\n");
+ goto remove;
+ }
+
+ plat->serdes_powerup = mgbe_uphy_lane_bringup_serdes_up;
+ plat->serdes_powerdown = mgbe_uphy_lane_bringup_serdes_down;
+
+ /* Tx FIFO Size - 128KB */
+ plat->tx_fifo_size = 131072;
+ /* Rx FIFO Size - 192KB */
+ plat->rx_fifo_size = 196608;
+
+ /* Enable common interrupt at wrapper level */
+ writel(MAC_SBD_INTR, mgbe->regs + MGBE_WRAP_COMMON_INTR_ENABLE);
+
+ /* Program SID */
+ writel(MGBE_SID, mgbe->hv + MGBE_WRAP_AXI_ASID0_CTRL);
+
+ plat->serdes_up_after_phy_linkup = 1;
+
+ err = stmmac_dvr_probe(&pdev->dev, plat, &res);
+ if (err < 0)
+ goto remove;
+
+ return 0;
+
+remove:
+ stmmac_remove_config_dt(pdev, plat);
+disable_clks:
+ clk_bulk_disable_unprepare(ARRAY_SIZE(mgbe_clks), mgbe->clks);
+
+ return err;
+}
+
+static int tegra_mgbe_remove(struct platform_device *pdev)
+{
+ struct tegra_mgbe *mgbe = get_stmmac_bsp_priv(&pdev->dev);
+
+ clk_bulk_disable_unprepare(ARRAY_SIZE(mgbe_clks), mgbe->clks);
+
+ stmmac_pltfr_remove(pdev);
+
+ return 0;
+}
+
+static const struct of_device_id tegra_mgbe_match[] = {
+ { .compatible = "nvidia,tegra234-mgbe", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, tegra_mgbe_match);
+
+static SIMPLE_DEV_PM_OPS(tegra_mgbe_pm_ops, tegra_mgbe_suspend, tegra_mgbe_resume);
+
+static struct platform_driver tegra_mgbe_driver = {
+ .probe = tegra_mgbe_probe,
+ .remove = tegra_mgbe_remove,
+ .driver = {
+ .name = "tegra-mgbe",
+ .pm = &tegra_mgbe_pm_ops,
+ .of_match_table = tegra_mgbe_match,
+ },
+};
+module_platform_driver(tegra_mgbe_driver);
+
+MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra MGBE driver");
+MODULE_LICENSE("GPL");
--
2.25.1