drivers: net: phy: xgene: Add MDIO driver

Currently, SGMII based 1G rely on the hardware registers for link state
and sometimes it's not reliable.  To get most accurate link state, this
interface has to use the MDIO bus to poll the PHY.

In X-Gene SoC, MDIO bus is shared across RGMII and SGMII based 1G
interfaces, so adding this driver to manage MDIO bus.  This driver
registers the mdio bus and registers the PHYs connected to it.

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Tested-by: Fushen Chen <fchen@apm.com>
Tested-by: Toan Le <toanle@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 477 insertions, 0 deletions

diff --git a/drivers/net/phy/mdio-xgene.c b/drivers/net/phy/mdio-xgene.c
new file mode 100644
index 0000000..d94a978
--- /dev/null
+++ b/drivers/net/phy/mdio-xgene.c
@@ -0,0 +1,477 @@
+/* Applied Micro X-Gene SoC MDIO Driver
+ *
+ * Copyright (c) 2016, Applied Micro Circuits Corporation
+ * Author: Iyappan Subramanian <isubramanian@apm.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/acpi.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/efi.h>
+#include <linux/if_vlan.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/of_net.h>
+#include <linux/of_mdio.h>
+#include <linux/prefetch.h>
+#include <linux/phy.h>
+#include <net/ip.h>
+#include "mdio-xgene.h"
+
+static bool xgene_mdio_status;
+
+static u32 xgene_enet_rd_mac(void __iomem *base_addr, u32 rd_addr)
+{
+	void __iomem *addr, *rd, *cmd, *cmd_done;
+	u32 done, rd_data = BUSY_MASK;
+	u8 wait = 10;
+
+	addr = base_addr + MAC_ADDR_REG_OFFSET;
+	rd = base_addr + MAC_READ_REG_OFFSET;
+	cmd = base_addr + MAC_COMMAND_REG_OFFSET;
+	cmd_done = base_addr + MAC_COMMAND_DONE_REG_OFFSET;
+
+	iowrite32(rd_addr, addr);
+	iowrite32(XGENE_ENET_RD_CMD, cmd);
+
+	while (wait--) {
+		done = ioread32(cmd_done);
+		if (done)
+			break;
+		udelay(1);
+	}
+
+	if (!done)
+		return rd_data;
+
+	rd_data = ioread32(rd);
+	iowrite32(0, cmd);
+
+	return rd_data;
+}
+
+static void xgene_enet_wr_mac(void __iomem *base_addr, u32 wr_addr, u32 wr_data)
+{
+	void __iomem *addr, *wr, *cmd, *cmd_done;
+	u8 wait = 10;
+	u32 done;
+
+	addr = base_addr + MAC_ADDR_REG_OFFSET;
+	wr = base_addr + MAC_WRITE_REG_OFFSET;
+	cmd = base_addr + MAC_COMMAND_REG_OFFSET;
+	cmd_done = base_addr + MAC_COMMAND_DONE_REG_OFFSET;
+
+	iowrite32(wr_addr, addr);
+	iowrite32(wr_data, wr);
+	iowrite32(XGENE_ENET_WR_CMD, cmd);
+
+	while (wait--) {
+		done = ioread32(cmd_done);
+		if (done)
+			break;
+		udelay(1);
+	}
+
+	if (!done)
+		pr_err("MCX mac write failed, addr: 0x%04x\n", wr_addr);
+
+	iowrite32(0, cmd);
+}
+
+int xgene_mdio_rgmii_read(struct mii_bus *bus, int phy_id, int reg)
+{
+	void __iomem *addr = (void __iomem *)bus->priv;
+	u32 data, done;
+	u8 wait = 10;
+
+	data = SET_VAL(PHY_ADDR, phy_id) | SET_VAL(REG_ADDR, reg);
+	xgene_enet_wr_mac(addr, MII_MGMT_ADDRESS_ADDR, data);
+	xgene_enet_wr_mac(addr, MII_MGMT_COMMAND_ADDR, READ_CYCLE_MASK);
+	do {
+		usleep_range(5, 10);
+		done = xgene_enet_rd_mac(addr, MII_MGMT_INDICATORS_ADDR);
+	} while ((done & BUSY_MASK) && wait--);
+
+	if (done & BUSY_MASK) {
+		dev_err(&bus->dev, "MII_MGMT read failed\n");
+		return -EBUSY;
+	}
+
+	data = xgene_enet_rd_mac(addr, MII_MGMT_STATUS_ADDR);
+	xgene_enet_wr_mac(addr, MII_MGMT_COMMAND_ADDR, 0);
+
+	return data;
+}
+EXPORT_SYMBOL(xgene_mdio_rgmii_read);
+
+int xgene_mdio_rgmii_write(struct mii_bus *bus, int phy_id, int reg, u16 data)
+{
+	void __iomem *addr = (void __iomem *)bus->priv;
+	u32 val, done;
+	u8 wait = 10;
+
+	val = SET_VAL(PHY_ADDR, phy_id) | SET_VAL(REG_ADDR, reg);
+	xgene_enet_wr_mac(addr, MII_MGMT_ADDRESS_ADDR, val);
+
+	xgene_enet_wr_mac(addr, MII_MGMT_CONTROL_ADDR, data);
+	do {
+		usleep_range(5, 10);
+		done = xgene_enet_rd_mac(addr, MII_MGMT_INDICATORS_ADDR);
+	} while ((done & BUSY_MASK) && wait--);
+
+	if (done & BUSY_MASK) {
+		dev_err(&bus->dev, "MII_MGMT write failed\n");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(xgene_mdio_rgmii_write);
+
+static u32 xgene_menet_rd_diag_csr(struct xgene_mdio_pdata *pdata, u32 offset)
+{
+	return ioread32(pdata->diag_csr_addr + offset);
+}
+
+static void xgene_menet_wr_diag_csr(struct xgene_mdio_pdata *pdata,
+				    u32 offset, u32 val)
+{
+	iowrite32(val, pdata->diag_csr_addr + offset);
+}
+
+static int xgene_enet_ecc_init(struct xgene_mdio_pdata *pdata)
+{
+	u32 data;
+	u8 wait = 10;
+
+	xgene_menet_wr_diag_csr(pdata, MENET_CFG_MEM_RAM_SHUTDOWN_ADDR, 0x0);
+	do {
+		usleep_range(100, 110);
+		data = xgene_menet_rd_diag_csr(pdata, MENET_BLOCK_MEM_RDY_ADDR);
+	} while ((data != 0xffffffff) && wait--);
+
+	if (data != 0xffffffff) {
+		dev_err(pdata->dev, "Failed to release memory from shutdown\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void xgene_gmac_reset(struct xgene_mdio_pdata *pdata)
+{
+	xgene_enet_wr_mac(pdata->mac_csr_addr, MAC_CONFIG_1_ADDR, SOFT_RESET);
+	xgene_enet_wr_mac(pdata->mac_csr_addr, MAC_CONFIG_1_ADDR, 0);
+}
+
+static int xgene_mdio_reset(struct xgene_mdio_pdata *pdata)
+{
+	int ret;
+
+	if (pdata->dev->of_node) {
+		clk_prepare_enable(pdata->clk);
+		udelay(5);
+		clk_disable_unprepare(pdata->clk);
+		udelay(5);
+		clk_prepare_enable(pdata->clk);
+		udelay(5);
+	} else {
+#ifdef CONFIG_ACPI
+		acpi_evaluate_object(ACPI_HANDLE(pdata->dev),
+				     "_RST", NULL, NULL);
+#endif
+	}
+
+	ret = xgene_enet_ecc_init(pdata);
+	if (ret)
+		return ret;
+	xgene_gmac_reset(pdata);
+
+	return 0;
+}
+
+static void xgene_enet_rd_mdio_csr(void __iomem *base_addr,
+				   u32 offset, u32 *val)
+{
+	void __iomem *addr = base_addr  + offset;
+
+	*val = ioread32(addr);
+}
+
+static void xgene_enet_wr_mdio_csr(void __iomem *base_addr,
+				   u32 offset, u32 val)
+{
+	void __iomem *addr = base_addr  + offset;
+
+	iowrite32(val, addr);
+}
+
+static int xgene_xfi_mdio_write(struct mii_bus *bus, int phy_id,
+				int reg, u16 data)
+{
+	void __iomem *addr = (void __iomem *)bus->priv;
+	int timeout = 100;
+	u32 status, val;
+
+	val = SET_VAL(HSTPHYADX, phy_id) | SET_VAL(HSTREGADX, reg) |
+	      SET_VAL(HSTMIIMWRDAT, data);
+	xgene_enet_wr_mdio_csr(addr, MIIM_FIELD_ADDR, data);
+
+	val = HSTLDCMD | SET_VAL(HSTMIIMCMD, MIIM_CMD_LEGACY_WRITE);
+	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, val);
+
+	do {
+		usleep_range(5, 10);
+		xgene_enet_rd_mdio_csr(addr, MIIM_INDICATOR_ADDR, &status);
+	} while ((status & BUSY_MASK) && timeout--);
+
+	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, 0);
+
+	return 0;
+}
+
+static int xgene_xfi_mdio_read(struct mii_bus *bus, int phy_id, int reg)
+{
+	void __iomem *addr = (void __iomem *)bus->priv;
+	u32 data, status, val;
+	int timeout = 100;
+
+	val = SET_VAL(HSTPHYADX, phy_id) | SET_VAL(HSTREGADX, reg);
+	xgene_enet_wr_mdio_csr(addr, MIIM_FIELD_ADDR, val);
+
+	val = HSTLDCMD | SET_VAL(HSTMIIMCMD, MIIM_CMD_LEGACY_READ);
+	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, val);
+
+	do {
+		usleep_range(5, 10);
+		xgene_enet_rd_mdio_csr(addr, MIIM_INDICATOR_ADDR, &status);
+	} while ((status & BUSY_MASK) && timeout--);
+
+	if (status & BUSY_MASK) {
+		pr_err("XGENET_MII_MGMT write failed\n");
+		return -EBUSY;
+	}
+
+	xgene_enet_rd_mdio_csr(addr, MIIMRD_FIELD_ADDR, &data);
+	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, 0);
+
+	return data;
+}
+
+struct phy_device *xgene_enet_phy_register(struct mii_bus *bus, int phy_addr)
+{
+	struct phy_device *phy_dev;
+
+	phy_dev = get_phy_device(bus, phy_addr, false);
+	if (!phy_dev || IS_ERR(phy_dev))
+		return NULL;
+
+	if (phy_device_register(phy_dev))
+		phy_device_free(phy_dev);
+
+	return phy_dev;
+}
+EXPORT_SYMBOL(xgene_enet_phy_register);
+
+#ifdef CONFIG_ACPI
+static acpi_status acpi_register_phy(acpi_handle handle, u32 lvl,
+				     void *context, void **ret)
+{
+	struct mii_bus *mdio = context;
+	struct acpi_device *adev;
+	struct phy_device *phy_dev;
+	const union acpi_object *obj;
+	u32 phy_addr;
+
+	if (acpi_bus_get_device(handle, &adev))
+		return AE_OK;
+
+	if (acpi_dev_get_property(adev, "phy-channel", ACPI_TYPE_INTEGER, &obj))
+		return AE_OK;
+	phy_addr = obj->integer.value;
+
+	phy_dev = xgene_enet_phy_register(mdio, phy_addr);
+	adev->driver_data = phy_dev;
+
+	return AE_OK;
+}
+#endif
+
+static int xgene_mdio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mii_bus *mdio_bus;
+	const struct of_device_id *of_id;
+	struct resource *res;
+	struct xgene_mdio_pdata *pdata;
+	void __iomem *csr_base;
+	int mdio_id = 0, ret = 0;
+
+	of_id = of_match_device(xgene_mdio_of_match, &pdev->dev);
+	if (of_id) {
+		mdio_id = (enum xgene_mdio_id)of_id->data;
+	} else {
+#ifdef CONFIG_ACPI
+		const struct acpi_device_id *acpi_id;
+
+		acpi_id = acpi_match_device(xgene_mdio_acpi_match, &pdev->dev);
+		if (acpi_id)
+			mdio_id = (enum xgene_mdio_id)acpi_id->driver_data;
+#endif
+	}
+
+	if (!mdio_id)
+		return -ENODEV;
+
+	pdata = devm_kzalloc(dev, sizeof(struct xgene_mdio_pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+	pdata->mdio_id = mdio_id;
+	pdata->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	csr_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(csr_base)) {
+		dev_err(dev, "Unable to retrieve mac CSR region\n");
+		return PTR_ERR(csr_base);
+	}
+	pdata->mac_csr_addr = csr_base;
+	pdata->mdio_csr_addr = csr_base + BLOCK_XG_MDIO_CSR_OFFSET;
+	pdata->diag_csr_addr = csr_base + BLOCK_DIAG_CSR_OFFSET;
+
+	if (dev->of_node) {
+		pdata->clk = devm_clk_get(dev, NULL);
+		if (IS_ERR(pdata->clk)) {
+			dev_err(dev, "Unable to retrieve clk\n");
+			return PTR_ERR(pdata->clk);
+		}
+	}
+
+	ret = xgene_mdio_reset(pdata);
+	if (ret)
+		return ret;
+
+	mdio_bus = mdiobus_alloc();
+	if (!mdio_bus)
+		return -ENOMEM;
+
+	mdio_bus->name = "APM X-Gene MDIO bus";
+
+	if (mdio_id == XGENE_MDIO_RGMII) {
+		mdio_bus->read = xgene_mdio_rgmii_read;
+		mdio_bus->write = xgene_mdio_rgmii_write;
+		mdio_bus->priv = (void __force *)pdata->mac_csr_addr;
+		snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "%s",
+			 "xgene-mii-rgmii");
+	} else {
+		mdio_bus->read = xgene_xfi_mdio_read;
+		mdio_bus->write = xgene_xfi_mdio_write;
+		mdio_bus->priv = (void __force *)pdata->mdio_csr_addr;
+		snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "%s",
+			 "xgene-mii-xfi");
+	}
+
+	mdio_bus->parent = dev;
+	platform_set_drvdata(pdev, pdata);
+
+	if (dev->of_node) {
+		ret = of_mdiobus_register(mdio_bus, dev->of_node);
+	} else {
+#ifdef CONFIG_ACPI
+		/* Mask out all PHYs from auto probing. */
+		mdio_bus->phy_mask = ~0;
+		ret = mdiobus_register(mdio_bus);
+		if (ret)
+			goto out;
+
+		acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_HANDLE(dev), 1,
+				    acpi_register_phy, NULL, mdio_bus, NULL);
+#endif
+	}
+
+	if (ret)
+		goto out;
+
+	pdata->mdio_bus = mdio_bus;
+	xgene_mdio_status = true;
+
+	return 0;
+
+out:
+	mdiobus_free(mdio_bus);
+
+	return ret;
+}
+
+static int xgene_mdio_remove(struct platform_device *pdev)
+{
+	struct xgene_mdio_pdata *pdata = platform_get_drvdata(pdev);
+	struct mii_bus *mdio_bus = pdata->mdio_bus;
+	struct device *dev = &pdev->dev;
+
+	mdiobus_unregister(mdio_bus);
+	mdiobus_free(mdio_bus);
+
+	if (dev->of_node) {
+		if (IS_ERR(pdata->clk))
+			clk_disable_unprepare(pdata->clk);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id xgene_mdio_of_match[] = {
+	{
+		.compatible = "apm,xgene-mdio-rgmii",
+		.data = (void *)XGENE_MDIO_RGMII
+	},
+	{
+		.compatible = "apm,xgene-mdio-xfi",
+		.data = (void *)XGENE_MDIO_XFI
+	},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, xgene_mdio_of_match);
+#endif
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id xgene_mdio_acpi_match[] = {
+	{ "APMC0D65", XGENE_MDIO_RGMII },
+	{ "APMC0D66", XGENE_MDIO_XFI },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(acpi, xgene_mdio_acpi_match);
+#endif
+
+static struct platform_driver xgene_mdio_driver = {
+	.driver = {
+		.name = "xgene-mdio",
+		.of_match_table = of_match_ptr(xgene_mdio_of_match),
+		.acpi_match_table = ACPI_PTR(xgene_mdio_acpi_match),
+	},
+	.probe = xgene_mdio_probe,
+	.remove = xgene_mdio_remove,
+};
+
+module_platform_driver(xgene_mdio_driver);
+
+MODULE_DESCRIPTION("APM X-Gene SoC MDIO driver");
+MODULE_AUTHOR("Iyappan Subramanian <isubramanian@apm.com>");
+MODULE_LICENSE("GPL");