net/fsl: introduce Freescale 10G MDIO driver

Similar to fsl_pq_mdio.c, this driver is for the 10G MDIO controller on
Freescale Frame Manager Ethernet controllers.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 274 insertions, 0 deletions

diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c
new file mode 100644
index 00000000000..1afb5ea2a98
--- /dev/null
+++ b/drivers/net/ethernet/freescale/xgmac_mdio.c
@@ -0,0 +1,274 @@
+/*
+ * QorIQ 10G MDIO Controller
+ *
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * Authors: Andy Fleming <afleming@freescale.com>
+ *          Timur Tabi <timur@freescale.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/mdio.h>
+#include <linux/of_platform.h>
+#include <linux/of_mdio.h>
+
+/* Number of microseconds to wait for a register to respond */
+#define TIMEOUT	1000
+
+struct tgec_mdio_controller {
+	__be32	reserved[12];
+	__be32	mdio_stat;	/* MDIO configuration and status */
+	__be32	mdio_ctl;	/* MDIO control */
+	__be32	mdio_data;	/* MDIO data */
+	__be32	mdio_addr;	/* MDIO address */
+} __packed;
+
+#define MDIO_STAT_CLKDIV(x)	(((x>>1) & 0xff) << 8)
+#define MDIO_STAT_BSY		(1 << 0)
+#define MDIO_STAT_RD_ER		(1 << 1)
+#define MDIO_CTL_DEV_ADDR(x) 	(x & 0x1f)
+#define MDIO_CTL_PORT_ADDR(x)	((x & 0x1f) << 5)
+#define MDIO_CTL_PRE_DIS	(1 << 10)
+#define MDIO_CTL_SCAN_EN	(1 << 11)
+#define MDIO_CTL_POST_INC	(1 << 14)
+#define MDIO_CTL_READ		(1 << 15)
+
+#define MDIO_DATA(x)		(x & 0xffff)
+#define MDIO_DATA_BSY		(1 << 31)
+
+/*
+ * Wait untill the MDIO bus is free
+ */
+static int xgmac_wait_until_free(struct device *dev,
+				 struct tgec_mdio_controller __iomem *regs)
+{
+	uint32_t status;
+
+	/* Wait till the bus is free */
+	status = spin_event_timeout(
+		!((in_be32(&regs->mdio_stat)) & MDIO_STAT_BSY), TIMEOUT, 0);
+	if (!status) {
+		dev_err(dev, "timeout waiting for bus to be free\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/*
+ * Wait till the MDIO read or write operation is complete
+ */
+static int xgmac_wait_until_done(struct device *dev,
+				 struct tgec_mdio_controller __iomem *regs)
+{
+	uint32_t status;
+
+	/* Wait till the MDIO write is complete */
+	status = spin_event_timeout(
+		!((in_be32(&regs->mdio_data)) & MDIO_DATA_BSY), TIMEOUT, 0);
+	if (!status) {
+		dev_err(dev, "timeout waiting for operation to complete\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/*
+ * Write value to the PHY for this device to the register at regnum,waiting
+ * until the write is done before it returns.  All PHY configuration has to be
+ * done through the TSEC1 MIIM regs.
+ */
+static int xgmac_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 value)
+{
+	struct tgec_mdio_controller __iomem *regs = bus->priv;
+	uint16_t dev_addr = regnum >> 16;
+	int ret;
+
+	/* Setup the MII Mgmt clock speed */
+	out_be32(&regs->mdio_stat, MDIO_STAT_CLKDIV(100));
+
+	ret = xgmac_wait_until_free(&bus->dev, regs);
+	if (ret)
+		return ret;
+
+	/* Set the port and dev addr */
+	out_be32(&regs->mdio_ctl,
+		 MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr));
+
+	/* Set the register address */
+	out_be32(&regs->mdio_addr, regnum & 0xffff);
+
+	ret = xgmac_wait_until_free(&bus->dev, regs);
+	if (ret)
+		return ret;
+
+	/* Write the value to the register */
+	out_be32(&regs->mdio_data, MDIO_DATA(value));
+
+	ret = xgmac_wait_until_done(&bus->dev, regs);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * Reads from register regnum in the PHY for device dev, returning the value.
+ * Clears miimcom first.  All PHY configuration has to be done through the
+ * TSEC1 MIIM regs.
+ */
+static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
+{
+	struct tgec_mdio_controller __iomem *regs = bus->priv;
+	uint16_t dev_addr = regnum >> 16;
+	uint32_t mdio_ctl;
+	uint16_t value;
+	int ret;
+
+	/* Setup the MII Mgmt clock speed */
+	out_be32(&regs->mdio_stat, MDIO_STAT_CLKDIV(100));
+
+	ret = xgmac_wait_until_free(&bus->dev, regs);
+	if (ret)
+		return ret;
+
+	/* Set the Port and Device Addrs */
+	mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
+	out_be32(&regs->mdio_ctl, mdio_ctl);
+
+	/* Set the register address */
+	out_be32(&regs->mdio_addr, regnum & 0xffff);
+
+	ret = xgmac_wait_until_free(&bus->dev, regs);
+	if (ret)
+		return ret;
+
+	/* Initiate the read */
+	out_be32(&regs->mdio_ctl, mdio_ctl | MDIO_CTL_READ);
+
+	ret = xgmac_wait_until_done(&bus->dev, regs);
+	if (ret)
+		return ret;
+
+	/* Return all Fs if nothing was there */
+	if (in_be32(&regs->mdio_stat) & MDIO_STAT_RD_ER) {
+		dev_err(&bus->dev, "MDIO read error\n");
+		return 0xffff;
+	}
+
+	value = in_be32(&regs->mdio_data) & 0xffff;
+	dev_dbg(&bus->dev, "read %04x\n", value);
+
+	return value;
+}
+
+/* Reset the MIIM registers, and wait for the bus to free */
+static int xgmac_mdio_reset(struct mii_bus *bus)
+{
+	struct tgec_mdio_controller __iomem *regs = bus->priv;
+	int ret;
+
+	mutex_lock(&bus->mdio_lock);
+
+	/* Setup the MII Mgmt clock speed */
+	out_be32(&regs->mdio_stat, MDIO_STAT_CLKDIV(100));
+
+	ret = xgmac_wait_until_free(&bus->dev, regs);
+
+	mutex_unlock(&bus->mdio_lock);
+
+	return ret;
+}
+
+static int __devinit xgmac_mdio_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mii_bus *bus;
+	struct resource res;
+	int ret;
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		dev_err(&pdev->dev, "could not obtain address\n");
+		return ret;
+	}
+
+	bus = mdiobus_alloc_size(PHY_MAX_ADDR * sizeof(int));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "Freescale XGMAC MDIO Bus";
+	bus->read = xgmac_mdio_read;
+	bus->write = xgmac_mdio_write;
+	bus->reset = xgmac_mdio_reset;
+	bus->irq = bus->priv;
+	bus->parent = &pdev->dev;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%llx", (unsigned long long)res.start);
+
+	/* Set the PHY base address */
+	bus->priv = of_iomap(np, 0);
+	if (!bus->priv) {
+		ret = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	ret = of_mdiobus_register(bus, np);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot register MDIO bus\n");
+		goto err_registration;
+	}
+
+	dev_set_drvdata(&pdev->dev, bus);
+
+	return 0;
+
+err_registration:
+	iounmap(bus->priv);
+
+err_ioremap:
+	mdiobus_free(bus);
+
+	return ret;
+}
+
+static int __devexit xgmac_mdio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = dev_get_drvdata(&pdev->dev);
+
+	mdiobus_unregister(bus);
+	iounmap(bus->priv);
+	mdiobus_free(bus);
+
+	return 0;
+}
+
+static struct of_device_id xgmac_mdio_match[] = {
+	{
+		.compatible = "fsl,fman-xmdio",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, xgmac_mdio_match);
+
+static struct platform_driver xgmac_mdio_driver = {
+	.driver = {
+		.name = "fsl-fman_xmdio",
+		.of_match_table = xgmac_mdio_match,
+	},
+	.probe = xgmac_mdio_probe,
+	.remove = xgmac_mdio_remove,
+};
+
+module_platform_driver(xgmac_mdio_driver);
+
+MODULE_DESCRIPTION("Freescale QorIQ 10G MDIO Controller");
+MODULE_LICENSE("GPL v2");