[RFC PATCH 1/2] net: macb: Add MDIO driver for accessing multiple PHY devices

[RFC PATCH 1/2] net: macb: Add MDIO driver for accessing multiple PHY devices

[Harini Katakam]

This patch is to add support for the hardware with multiple ethernet
MAC controllers and a single MDIO bus connected to multiple PHY devices.
MDIO lines are connected to any one of the ethernet MAC controllers and
all the PHY devices will be accessed using the PHY maintenance interface
in that MAC controller. This handling along with PHY functionality is
moved to macb_mdio.c

Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: Harini Katakam <harinik@xilinx.com>
---
 drivers/net/ethernet/cadence/Makefile    |   2 +-
 drivers/net/ethernet/cadence/macb.c      | 169 +++-----------------
 drivers/net/ethernet/cadence/macb.h      |   2 +
 drivers/net/ethernet/cadence/macb_mdio.c | 266 +++++++++++++++++++++++++++++++
 4 files changed, 294 insertions(+), 145 deletions(-)
 create mode 100644 drivers/net/ethernet/cadence/macb_mdio.c

diff --git a/drivers/net/ethernet/cadence/Makefile b/drivers/net/ethernet/cadence/Makefile
index 91f79b1..75c3d84 100644
--- a/drivers/net/ethernet/cadence/Makefile
+++ b/drivers/net/ethernet/cadence/Makefile
@@ -2,4 +2,4 @@
 # Makefile for the Atmel network device drivers.
 #
 
-obj-$(CONFIG_MACB) += macb.o
+obj-$(CONFIG_MACB) += macb.o macb_mdio.o
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 80ccfc4..ae2a797 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -232,45 +232,6 @@ static void macb_get_hwaddr(struct macb *bp)
 	eth_hw_addr_random(bp->dev);
 }
 
-static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
-{
-	struct macb *bp = bus->priv;
-	int value;
-
-	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
-			      | MACB_BF(RW, MACB_MAN_READ)
-			      | MACB_BF(PHYA, mii_id)
-			      | MACB_BF(REGA, regnum)
-			      | MACB_BF(CODE, MACB_MAN_CODE)));
-
-	/* wait for end of transfer */
-	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
-		cpu_relax();
-
-	value = MACB_BFEXT(DATA, macb_readl(bp, MAN));
-
-	return value;
-}
-
-static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
-			   u16 value)
-{
-	struct macb *bp = bus->priv;
-
-	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
-			      | MACB_BF(RW, MACB_MAN_WRITE)
-			      | MACB_BF(PHYA, mii_id)
-			      | MACB_BF(REGA, regnum)
-			      | MACB_BF(CODE, MACB_MAN_CODE)
-			      | MACB_BF(DATA, value)));
-
-	/* wait for end of transfer */
-	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
-		cpu_relax();
-
-	return 0;
-}
-
 /**
  * macb_set_tx_clk() - Set a clock to a new frequency
  * @clk		Pointer to the clock to change
@@ -385,27 +346,19 @@ static void macb_handle_link_change(struct net_device *dev)
 static int macb_mii_probe(struct net_device *dev)
 {
 	struct macb *bp = netdev_priv(dev);
-	struct macb_platform_data *pdata;
 	struct phy_device *phydev;
-	int phy_irq;
 	int ret;
 
-	phydev = phy_find_first(bp->mii_bus);
+	if (dev->phydev)
+		return 0;
+
+	phydev = of_phy_find_device(bp->phy_node);
 	if (!phydev) {
 		netdev_err(dev, "no PHY found\n");
 		return -ENXIO;
 	}
-
-	pdata = dev_get_platdata(&bp->pdev->dev);
-	if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
-		ret = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin,
-					"phy int");
-		if (!ret) {
-			phy_irq = gpio_to_irq(pdata->phy_irq_pin);
-			phydev->irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
-		}
-	}
-
+	if (bp->phy_irq)
+		phydev->irq = bp->phy_irq;
 	/* attach the mac to the phy */
 	ret = phy_connect_direct(dev, phydev, &macb_handle_link_change,
 				 bp->phy_interface);
@@ -429,80 +382,9 @@ static int macb_mii_probe(struct net_device *dev)
 	bp->speed = 0;
 	bp->duplex = -1;
 
-	return 0;
-}
-
-static int macb_mii_init(struct macb *bp)
-{
-	struct macb_platform_data *pdata;
-	struct device_node *np;
-	int err = -ENXIO, i;
-
-	/* Enable management port */
-	macb_writel(bp, NCR, MACB_BIT(MPE));
-
-	bp->mii_bus = mdiobus_alloc();
-	if (!bp->mii_bus) {
-		err = -ENOMEM;
-		goto err_out;
-	}
-
-	bp->mii_bus->name = "MACB_mii_bus";
-	bp->mii_bus->read = &macb_mdio_read;
-	bp->mii_bus->write = &macb_mdio_write;
-	snprintf(bp->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
-		 bp->pdev->name, bp->pdev->id);
-	bp->mii_bus->priv = bp;
-	bp->mii_bus->parent = &bp->pdev->dev;
-	pdata = dev_get_platdata(&bp->pdev->dev);
-
-	dev_set_drvdata(&bp->dev->dev, bp->mii_bus);
-
-	np = bp->pdev->dev.of_node;
-	if (np) {
-		/* try dt phy registration */
-		err = of_mdiobus_register(bp->mii_bus, np);
-
-		/* fallback to standard phy registration if no phy were
-		 * found during dt phy registration
-		 */
-		if (!err && !phy_find_first(bp->mii_bus)) {
-			for (i = 0; i < PHY_MAX_ADDR; i++) {
-				struct phy_device *phydev;
-
-				phydev = mdiobus_scan(bp->mii_bus, i);
-				if (IS_ERR(phydev) &&
-				    PTR_ERR(phydev) != -ENODEV) {
-					err = PTR_ERR(phydev);
-					break;
-				}
-			}
-
-			if (err)
-				goto err_out_unregister_bus;
-		}
-	} else {
-		if (pdata)
-			bp->mii_bus->phy_mask = pdata->phy_mask;
-
-		err = mdiobus_register(bp->mii_bus);
-	}
-
-	if (err)
-		goto err_out_free_mdiobus;
-
-	err = macb_mii_probe(bp->dev);
-	if (err)
-		goto err_out_unregister_bus;
+	phy_attached_info(phydev);
 
 	return 0;
-
-err_out_unregister_bus:
-	mdiobus_unregister(bp->mii_bus);
-err_out_free_mdiobus:
-	mdiobus_free(bp->mii_bus);
-err_out:
-	return err;
 }
 
 static void macb_update_stats(struct macb *bp)
@@ -2060,7 +1942,8 @@ static int macb_open(struct net_device *dev)
 	netif_carrier_off(dev);
 
 	/* if the phy is not yet register, retry later*/
-	if (!dev->phydev)
+	err = macb_mii_probe(dev);
+	if (err)
 		return -EAGAIN;
 
 	/* RX buffers initialization */
@@ -3122,16 +3005,16 @@ static int macb_probe(struct platform_device *pdev)
 	unsigned int queue_mask, num_queues;
 	struct macb_platform_data *pdata;
 	bool native_io;
-	struct phy_device *phydev;
 	struct net_device *dev;
 	struct resource *regs;
 	void __iomem *mem;
 	const char *mac;
 	struct macb *bp;
+	int phy_irq;
 	int err;
 
 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mem = devm_ioremap_resource(&pdev->dev, regs);
+	mem = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
 	if (IS_ERR(mem))
 		return PTR_ERR(mem);
 
@@ -3250,21 +3133,26 @@ static int macb_probe(struct platform_device *pdev)
 	if (err)
 		goto err_out_free_netdev;
 
-	err = macb_mii_init(bp);
-	if (err)
-		goto err_out_free_netdev;
-
-	phydev = dev->phydev;
-
-	netif_carrier_off(dev);
-
 	err = register_netdev(dev);
 	if (err) {
 		dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
 		goto err_out_unregister_mdio;
 	}
 
-	phy_attached_info(phydev);
+	bp->phy_node = of_parse_phandle(bp->pdev->dev.of_node,
+					"phy-handle", 0);
+
+	pdata = dev_get_platdata(&bp->pdev->dev);
+	if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
+		err = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin,
+					"phy int");
+		if (!err) {
+			phy_irq = gpio_to_irq(pdata->phy_irq_pin);
+			bp->phy_irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
+		}
+	}
+
+	netif_carrier_off(dev);
 
 	netdev_info(dev, "Cadence %s rev 0x%08x at 0x%08lx irq %d (%pM)\n",
 		    macb_is_gem(bp) ? "GEM" : "MACB", macb_readl(bp, MID),
@@ -3273,10 +3161,6 @@ static int macb_probe(struct platform_device *pdev)
 	return 0;
 
 err_out_unregister_mdio:
-	phy_disconnect(dev->phydev);
-	mdiobus_unregister(bp->mii_bus);
-	mdiobus_free(bp->mii_bus);
-
 	/* Shutdown the PHY if there is a GPIO reset */
 	if (bp->reset_gpio)
 		gpiod_set_value(bp->reset_gpio, 0);
@@ -3304,9 +3188,6 @@ static int macb_remove(struct platform_device *pdev)
 		bp = netdev_priv(dev);
 		if (dev->phydev)
 			phy_disconnect(dev->phydev);
-		mdiobus_unregister(bp->mii_bus);
-		dev->phydev = NULL;
-		mdiobus_free(bp->mii_bus);
 
 		/* Shutdown the PHY if there is a GPIO reset */
 		if (bp->reset_gpio)
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index d67adad..15e5c0f 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -874,6 +874,8 @@ struct macb {
 	unsigned int		jumbo_max_len;
 
 	u32			wol;
+	struct device_node *phy_node;
+	int phy_irq;
 };
 
 static inline bool macb_is_gem(struct macb *bp)
diff --git a/drivers/net/ethernet/cadence/macb_mdio.c b/drivers/net/ethernet/cadence/macb_mdio.c
new file mode 100644
index 0000000..1277ca3
--- /dev/null
+++ b/drivers/net/ethernet/cadence/macb_mdio.c
@@ -0,0 +1,266 @@
+/*
+ * Cadence Macb mdio controller driver
+ *
+ * Copyright (C) 2014 - 2016 Xilinx, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/io.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/ptp_clock_kernel.h>
+#include "macb.h"
+
+struct macb_mdio_data {
+	void __iomem *regs;
+
+	struct clk *pclk;
+	struct clk *hclk;
+};
+
+#define macb_mdio_reg_writel(bp, offset, value)	\
+	writel_relaxed(value, bp->regs + offset)
+#define macb_mdio_writel(bp, reg, value)	\
+	macb_mdio_reg_writel(bp, MACB_##reg, value)
+
+#define macb_mdio_reg_readl(bp, offset)	readl_relaxed(bp->regs + offset)
+#define macb_mdio_readl(bp, reg)	macb_mdio_reg_readl(bp, MACB_##reg)
+
+#define MACB_MDIO_TIMEOUT	1000
+
+static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+	struct macb_mdio_data *bp = bus->priv;
+	unsigned int timeout = MACB_MDIO_TIMEOUT;
+	int value;
+
+	macb_mdio_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF) |
+				   MACB_BF(RW, MACB_MAN_READ) |
+				   MACB_BF(PHYA, mii_id) |
+				   MACB_BF(REGA, regnum) |
+				   MACB_BF(CODE, MACB_MAN_CODE)));
+
+	/* wait for end of transfer */
+	while (!MACB_BFEXT(IDLE, macb_mdio_readl(bp, NSR)) && timeout) {
+		cpu_relax();
+		timeout--;
+	}
+
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	value = MACB_BFEXT(DATA, macb_mdio_readl(bp, MAN));
+
+	return value;
+}
+
+static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+			   u16 value)
+{
+	struct macb_mdio_data *bp = bus->priv;
+	unsigned int timeout = MACB_MDIO_TIMEOUT;
+
+	macb_mdio_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF) |
+				   MACB_BF(RW, MACB_MAN_WRITE) |
+				   MACB_BF(PHYA, mii_id) |
+				   MACB_BF(REGA, regnum) |
+				   MACB_BF(CODE, MACB_MAN_CODE) |
+				   MACB_BF(DATA, value)));
+
+	/* wait for end of transfer */
+	while (!MACB_BFEXT(IDLE, macb_mdio_readl(bp, NSR)) && timeout) {
+		cpu_relax();
+		timeout--;
+	}
+
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static u32 gem_mdc_clk_div(struct macb_mdio_data *bp)
+{
+	u32 config;
+	unsigned long pclk_hz = clk_get_rate(bp->pclk);
+
+	if (pclk_hz <= 20000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV8);
+	else if (pclk_hz <= 40000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV16);
+	else if (pclk_hz <= 80000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV32);
+	else if (pclk_hz <= 120000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV48);
+	else if (pclk_hz <= 160000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV64);
+	else
+		config = GEM_BF(CLK, GEM_CLK_DIV96);
+
+	return config;
+}
+
+static int macb_mdio_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mii_bus *bus;
+	struct macb_mdio_data *bp;
+	struct resource *res;
+	int ret;
+	u32 config, i;
+
+	bus = mdiobus_alloc_size(sizeof(*bp));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "macb_mii_bus";
+	bus->read = &macb_mdio_read;
+	bus->write = &macb_mdio_write;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
+	bus->parent = &pdev->dev;
+	bus->irq = devm_kzalloc(&pdev->dev, sizeof(int) * PHY_MAX_ADDR,
+				GFP_KERNEL);
+	if (!bus->irq) {
+		ret = -ENOMEM;
+		goto err_out_free_mdiobus;
+	}
+
+	bp = bus->priv;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	bp->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (IS_ERR(bp->regs)) {
+		ret = PTR_ERR(bp->regs);
+		goto err_out_free_mdiobus;
+	}
+
+	bp->pclk = devm_clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(bp->pclk)) {
+		ret = PTR_ERR(bp->pclk);
+		dev_err(&pdev->dev, "failed to get macb_clk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	bp->hclk = devm_clk_get(&pdev->dev, "hclk");
+	if (IS_ERR(bp->hclk)) {
+		ret = PTR_ERR(bp->hclk);
+		dev_err(&pdev->dev, "failed to get hclk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	ret = clk_prepare_enable(bp->pclk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable pclk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	ret = clk_prepare_enable(bp->hclk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable hclk (%u)\n", ret);
+		goto err_disable_pclk;
+	}
+
+	platform_set_drvdata(pdev, bus);
+
+	/* Enable management port */
+	config = macb_mdio_readl(bp, NCR);
+	config |= MACB_BIT(MPE);
+	macb_mdio_writel(bp, NCR, config);
+	config = gem_mdc_clk_div(bp);
+	macb_mdio_writel(bp, NCFGR, config);
+
+	np = pdev->dev.of_node;
+	if (np) {
+		/* try dt phy registration */
+		ret = of_mdiobus_register(bus, np);
+
+		/* Fallback to standard phy registration if no phy were
+		 * found during dt phy registration
+		 */
+		if (!ret && !phy_find_first(bus)) {
+			for (i = 0; i < PHY_MAX_ADDR; i++) {
+				struct phy_device *phydev;
+
+				phydev = mdiobus_scan(bus, i);
+				if (IS_ERR(phydev) &&
+				    PTR_ERR(phydev) != -ENODEV) {
+					ret = PTR_ERR(phydev);
+					break;
+				}
+			}
+
+			if (ret)
+				goto err_out_unregister_bus;
+		}
+	} else {
+		for (i = 0; i < PHY_MAX_ADDR; i++)
+			bus->irq[i] = PHY_POLL;
+
+		ret = of_mdiobus_register(bus, np);
+	}
+
+	if (ret)
+		goto err_out_free_mdio_irq;
+
+	return 0;
+
+err_out_unregister_bus:
+	mdiobus_unregister(bus);
+err_out_free_mdio_irq:
+	kfree(bus->irq);
+err_disable_pclk:
+	clk_disable_unprepare(bp->pclk);
+	clk_disable_unprepare(bp->hclk);
+err_out_free_mdiobus:
+	mdiobus_free(bus);
+	return ret;
+}
+
+static int macb_mdio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = platform_get_drvdata(pdev);
+	struct macb_mdio_data *bp = bus->priv;
+	u32 config;
+
+	/* Disable management port */
+	config = macb_mdio_readl(bp, NCR);
+	config &= ~MACB_BIT(MPE);
+	macb_mdio_writel(bp, NCR, config);
+	mdiobus_unregister(bus);
+	clk_disable_unprepare(bp->hclk);
+	clk_disable_unprepare(bp->pclk);
+	mdiobus_free(bus);
+
+	return 0;
+}
+
+static const struct of_device_id macb_mdio_dt_ids[] = {
+	{ .compatible = "cdns,macb-mdio" },
+
+};
+MODULE_DEVICE_TABLE(of, macb_mdio_dt_ids);
+
+static struct platform_driver macb_mdio_driver = {
+	.probe = macb_mdio_probe,
+	.remove = macb_mdio_remove,
+	.driver = {
+		.name = "macb-mdio",
+		.of_match_table = macb_mdio_dt_ids,
+	},
+};
+
+module_platform_driver(macb_mdio_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cadence MACB MDIO driver");
+MODULE_AUTHOR("Xilinx");
-- 
2.7.4

Re: [RFC PATCH 1/2] net: macb: Add MDIO driver for accessing multiple PHY devices

[Andrew Lunn]

On Mon, Nov 28, 2016 at 03:19:14PM +0530, Harini Katakam wrote:
> This patch is to add support for the hardware with multiple ethernet
> MAC controllers and a single MDIO bus connected to multiple PHY devices.
> MDIO lines are connected to any one of the ethernet MAC controllers and
> all the PHY devices will be accessed using the PHY maintenance interface
> in that MAC controller. This handling along with PHY functionality is
> moved to macb_mdio.c
> 
> Signed-off-by: Punnaiah Choudary Kalluri <punnaia-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Harini Katakam <harinik-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/net/ethernet/cadence/Makefile    |   2 +-
>  drivers/net/ethernet/cadence/macb.c      | 169 +++-----------------
>  drivers/net/ethernet/cadence/macb.h      |   2 +
>  drivers/net/ethernet/cadence/macb_mdio.c | 266 +++++++++++++++++++++++++++++++
>  4 files changed, 294 insertions(+), 145 deletions(-)
>  create mode 100644 drivers/net/ethernet/cadence/macb_mdio.c
> 
> diff --git a/drivers/net/ethernet/cadence/Makefile b/drivers/net/ethernet/cadence/Makefile
> index 91f79b1..75c3d84 100644
> --- a/drivers/net/ethernet/cadence/Makefile
> +++ b/drivers/net/ethernet/cadence/Makefile
> @@ -2,4 +2,4 @@
>  # Makefile for the Atmel network device drivers.
>  #
>  
> -obj-$(CONFIG_MACB) += macb.o
> +obj-$(CONFIG_MACB) += macb.o macb_mdio.o
> diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
> index 80ccfc4..ae2a797 100644
> --- a/drivers/net/ethernet/cadence/macb.c
> +++ b/drivers/net/ethernet/cadence/macb.c
> @@ -232,45 +232,6 @@ static void macb_get_hwaddr(struct macb *bp)
>  	eth_hw_addr_random(bp->dev);
>  }
>  
> -static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
> -{
> -	struct macb *bp = bus->priv;
> -	int value;
> -
> -	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
> -			      | MACB_BF(RW, MACB_MAN_READ)
> -			      | MACB_BF(PHYA, mii_id)
> -			      | MACB_BF(REGA, regnum)
> -			      | MACB_BF(CODE, MACB_MAN_CODE)));
> -
> -	/* wait for end of transfer */
> -	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> -		cpu_relax();
> -
> -	value = MACB_BFEXT(DATA, macb_readl(bp, MAN));
> -
> -	return value;
> -}
> -
> -static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
> -			   u16 value)
> -{
> -	struct macb *bp = bus->priv;
> -
> -	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
> -			      | MACB_BF(RW, MACB_MAN_WRITE)
> -			      | MACB_BF(PHYA, mii_id)
> -			      | MACB_BF(REGA, regnum)
> -			      | MACB_BF(CODE, MACB_MAN_CODE)
> -			      | MACB_BF(DATA, value)));
> -
> -	/* wait for end of transfer */
> -	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> -		cpu_relax();
> -
> -	return 0;
> -}
> -
>  /**
>   * macb_set_tx_clk() - Set a clock to a new frequency
>   * @clk		Pointer to the clock to change
> @@ -385,27 +346,19 @@ static void macb_handle_link_change(struct net_device *dev)
>  static int macb_mii_probe(struct net_device *dev)
>  {
>  	struct macb *bp = netdev_priv(dev);
> -	struct macb_platform_data *pdata;
>  	struct phy_device *phydev;
> -	int phy_irq;
>  	int ret;
>  
> -	phydev = phy_find_first(bp->mii_bus);
> +	if (dev->phydev)
> +		return 0;
> +
> +	phydev = of_phy_find_device(bp->phy_node);
>  	if (!phydev) {
>  		netdev_err(dev, "no PHY found\n");
>  		return -ENXIO;
>  	}
> -
> -	pdata = dev_get_platdata(&bp->pdev->dev);
> -	if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
> -		ret = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin,
> -					"phy int");
> -		if (!ret) {
> -			phy_irq = gpio_to_irq(pdata->phy_irq_pin);
> -			phydev->irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
> -		}
> -	}
> -
> +	if (bp->phy_irq)
> +		phydev->irq = bp->phy_irq;
>  	/* attach the mac to the phy */
>  	ret = phy_connect_direct(dev, phydev, &macb_handle_link_change,
>  				 bp->phy_interface);
> @@ -429,80 +382,9 @@ static int macb_mii_probe(struct net_device *dev)
>  	bp->speed = 0;
>  	bp->duplex = -1;
>  
> -	return 0;
> -}
> -
> -static int macb_mii_init(struct macb *bp)
> -{
> -	struct macb_platform_data *pdata;
> -	struct device_node *np;
> -	int err = -ENXIO, i;
> -
> -	/* Enable management port */
> -	macb_writel(bp, NCR, MACB_BIT(MPE));
> -
> -	bp->mii_bus = mdiobus_alloc();
> -	if (!bp->mii_bus) {
> -		err = -ENOMEM;
> -		goto err_out;
> -	}
> -
> -	bp->mii_bus->name = "MACB_mii_bus";
> -	bp->mii_bus->read = &macb_mdio_read;
> -	bp->mii_bus->write = &macb_mdio_write;
> -	snprintf(bp->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
> -		 bp->pdev->name, bp->pdev->id);
> -	bp->mii_bus->priv = bp;
> -	bp->mii_bus->parent = &bp->pdev->dev;
> -	pdata = dev_get_platdata(&bp->pdev->dev);
> -
> -	dev_set_drvdata(&bp->dev->dev, bp->mii_bus);
> -
> -	np = bp->pdev->dev.of_node;
> -	if (np) {
> -		/* try dt phy registration */
> -		err = of_mdiobus_register(bp->mii_bus, np);
> -
> -		/* fallback to standard phy registration if no phy were
> -		 * found during dt phy registration
> -		 */
> -		if (!err && !phy_find_first(bp->mii_bus)) {
> -			for (i = 0; i < PHY_MAX_ADDR; i++) {
> -				struct phy_device *phydev;
> -
> -				phydev = mdiobus_scan(bp->mii_bus, i);
> -				if (IS_ERR(phydev) &&
> -				    PTR_ERR(phydev) != -ENODEV) {
> -					err = PTR_ERR(phydev);
> -					break;
> -				}
> -			}
> -
> -			if (err)
> -				goto err_out_unregister_bus;
> -		}
> -	} else {
> -		if (pdata)
> -			bp->mii_bus->phy_mask = pdata->phy_mask;
> -
> -		err = mdiobus_register(bp->mii_bus);
> -	}
> -
> -	if (err)
> -		goto err_out_free_mdiobus;
> -
> -	err = macb_mii_probe(bp->dev);
> -	if (err)
> -		goto err_out_unregister_bus;
> +	phy_attached_info(phydev);
>  
>  	return 0;
> -
> -err_out_unregister_bus:
> -	mdiobus_unregister(bp->mii_bus);
> -err_out_free_mdiobus:
> -	mdiobus_free(bp->mii_bus);
> -err_out:
> -	return err;
>  }
>  
>  static void macb_update_stats(struct macb *bp)
> @@ -2060,7 +1942,8 @@ static int macb_open(struct net_device *dev)
>  	netif_carrier_off(dev);
>  
>  	/* if the phy is not yet register, retry later*/
> -	if (!dev->phydev)
> +	err = macb_mii_probe(dev);
> +	if (err)
>  		return -EAGAIN;
>  
>  	/* RX buffers initialization */
> @@ -3122,16 +3005,16 @@ static int macb_probe(struct platform_device *pdev)
>  	unsigned int queue_mask, num_queues;
>  	struct macb_platform_data *pdata;
>  	bool native_io;
> -	struct phy_device *phydev;
>  	struct net_device *dev;
>  	struct resource *regs;
>  	void __iomem *mem;
>  	const char *mac;
>  	struct macb *bp;
> +	int phy_irq;
>  	int err;
>  
>  	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	mem = devm_ioremap_resource(&pdev->dev, regs);
> +	mem = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
>  	if (IS_ERR(mem))
>  		return PTR_ERR(mem);
>  
> @@ -3250,21 +3133,26 @@ static int macb_probe(struct platform_device *pdev)
>  	if (err)
>  		goto err_out_free_netdev;
>  
> -	err = macb_mii_init(bp);
> -	if (err)
> -		goto err_out_free_netdev;
> -
> -	phydev = dev->phydev;
> -
> -	netif_carrier_off(dev);
> -
>  	err = register_netdev(dev);
>  	if (err) {
>  		dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
>  		goto err_out_unregister_mdio;
>  	}
>  
> -	phy_attached_info(phydev);
> +	bp->phy_node = of_parse_phandle(bp->pdev->dev.of_node,
> +					"phy-handle", 0);
> +
> +	pdata = dev_get_platdata(&bp->pdev->dev);
> +	if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
> +		err = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin,
> +					"phy int");
> +		if (!err) {
> +			phy_irq = gpio_to_irq(pdata->phy_irq_pin);
> +			bp->phy_irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
> +		}
> +	}
> +
> +	netif_carrier_off(dev);
>  
>  	netdev_info(dev, "Cadence %s rev 0x%08x at 0x%08lx irq %d (%pM)\n",
>  		    macb_is_gem(bp) ? "GEM" : "MACB", macb_readl(bp, MID),
> @@ -3273,10 +3161,6 @@ static int macb_probe(struct platform_device *pdev)
>  	return 0;
>  
>  err_out_unregister_mdio:
> -	phy_disconnect(dev->phydev);
> -	mdiobus_unregister(bp->mii_bus);
> -	mdiobus_free(bp->mii_bus);
> -
>  	/* Shutdown the PHY if there is a GPIO reset */
>  	if (bp->reset_gpio)
>  		gpiod_set_value(bp->reset_gpio, 0);
> @@ -3304,9 +3188,6 @@ static int macb_remove(struct platform_device *pdev)
>  		bp = netdev_priv(dev);
>  		if (dev->phydev)
>  			phy_disconnect(dev->phydev);
> -		mdiobus_unregister(bp->mii_bus);
> -		dev->phydev = NULL;
> -		mdiobus_free(bp->mii_bus);
>  
>  		/* Shutdown the PHY if there is a GPIO reset */
>  		if (bp->reset_gpio)
> diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> index d67adad..15e5c0f 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/drivers/net/ethernet/cadence/macb.h
> @@ -874,6 +874,8 @@ struct macb {
>  	unsigned int		jumbo_max_len;
>  
>  	u32			wol;
> +	struct device_node *phy_node;
> +	int phy_irq;
>  };
>  
>  static inline bool macb_is_gem(struct macb *bp)
> diff --git a/drivers/net/ethernet/cadence/macb_mdio.c b/drivers/net/ethernet/cadence/macb_mdio.c
> new file mode 100644
> index 0000000..1277ca3
> --- /dev/null
> +++ b/drivers/net/ethernet/cadence/macb_mdio.c
> @@ -0,0 +1,266 @@
> +/*
> + * Cadence Macb mdio controller driver
> + *
> + * Copyright (C) 2014 - 2016 Xilinx, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify it under
> + * the terms of the GNU General Public License version 2 as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + */
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/netdevice.h>
> +#include <linux/of_address.h>
> +#include <linux/of_mdio.h>
> +#include <linux/io.h>
> +#include <linux/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/ptp_clock_kernel.h>
> +#include "macb.h"
> +
> +struct macb_mdio_data {
> +	void __iomem *regs;
> +
> +	struct clk *pclk;
> +	struct clk *hclk;
> +};
> +
> +#define macb_mdio_reg_writel(bp, offset, value)	\
> +	writel_relaxed(value, bp->regs + offset)
> +#define macb_mdio_writel(bp, reg, value)	\
> +	macb_mdio_reg_writel(bp, MACB_##reg, value)
> +
> +#define macb_mdio_reg_readl(bp, offset)	readl_relaxed(bp->regs + offset)
> +#define macb_mdio_readl(bp, reg)	macb_mdio_reg_readl(bp, MACB_##reg)
> +
> +#define MACB_MDIO_TIMEOUT	1000
> +
> +static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
> +{
> +	struct macb_mdio_data *bp = bus->priv;
> +	unsigned int timeout = MACB_MDIO_TIMEOUT;
> +	int value;
> +
> +	macb_mdio_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF) |
> +				   MACB_BF(RW, MACB_MAN_READ) |
> +				   MACB_BF(PHYA, mii_id) |
> +				   MACB_BF(REGA, regnum) |
> +				   MACB_BF(CODE, MACB_MAN_CODE)));
> +
> +	/* wait for end of transfer */
> +	while (!MACB_BFEXT(IDLE, macb_mdio_readl(bp, NSR)) && timeout) {
> +		cpu_relax();
> +		timeout--;
> +	}
> +
> +	if (!timeout)
> +		return -ETIMEDOUT;
> +
> +	value = MACB_BFEXT(DATA, macb_mdio_readl(bp, MAN));
> +
> +	return value;
> +}
> +
> +static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
> +			   u16 value)
> +{
> +	struct macb_mdio_data *bp = bus->priv;
> +	unsigned int timeout = MACB_MDIO_TIMEOUT;
> +
> +	macb_mdio_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF) |
> +				   MACB_BF(RW, MACB_MAN_WRITE) |
> +				   MACB_BF(PHYA, mii_id) |
> +				   MACB_BF(REGA, regnum) |
> +				   MACB_BF(CODE, MACB_MAN_CODE) |
> +				   MACB_BF(DATA, value)));
> +
> +	/* wait for end of transfer */
> +	while (!MACB_BFEXT(IDLE, macb_mdio_readl(bp, NSR)) && timeout) {
> +		cpu_relax();
> +		timeout--;
> +	}
> +
> +	if (!timeout)
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
> +static u32 gem_mdc_clk_div(struct macb_mdio_data *bp)
> +{
> +	u32 config;
> +	unsigned long pclk_hz = clk_get_rate(bp->pclk);
> +
> +	if (pclk_hz <= 20000000)
> +		config = GEM_BF(CLK, GEM_CLK_DIV8);
> +	else if (pclk_hz <= 40000000)
> +		config = GEM_BF(CLK, GEM_CLK_DIV16);
> +	else if (pclk_hz <= 80000000)
> +		config = GEM_BF(CLK, GEM_CLK_DIV32);
> +	else if (pclk_hz <= 120000000)
> +		config = GEM_BF(CLK, GEM_CLK_DIV48);
> +	else if (pclk_hz <= 160000000)
> +		config = GEM_BF(CLK, GEM_CLK_DIV64);
> +	else
> +		config = GEM_BF(CLK, GEM_CLK_DIV96);
> +
> +	return config;
> +}
> +
> +static int macb_mdio_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct mii_bus *bus;
> +	struct macb_mdio_data *bp;
> +	struct resource *res;
> +	int ret;
> +	u32 config, i;
> +
> +	bus = mdiobus_alloc_size(sizeof(*bp));
> +	if (!bus)
> +		return -ENOMEM;
> +
> +	bus->name = "macb_mii_bus";
> +	bus->read = &macb_mdio_read;
> +	bus->write = &macb_mdio_write;
> +	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
> +	bus->parent = &pdev->dev;
> +	bus->irq = devm_kzalloc(&pdev->dev, sizeof(int) * PHY_MAX_ADDR,
> +				GFP_KERNEL);

This looks wrong, or at least old. It used to be a pointer to an array,
but it is now an actual array.

> +static const struct of_device_id macb_mdio_dt_ids[] = {
> +	{ .compatible = "cdns,macb-mdio" },
> +
> +};


I've not looked hard enough to know, but can you keep backwards
compatibility? Won't old device tree's assume the mdio bus is always
present? Now you need an explicit node otherwise there will not be an
mdio bus?

     Andrew
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Re: [RFC PATCH 1/2] net: macb: Add MDIO driver for accessing multiple PHY devices

[Harini Katakam]

Hi Andrew,

On Mon, Nov 28, 2016 at 10:03 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> On Mon, Nov 28, 2016 at 03:19:14PM +0530, Harini Katakam wrote:
>> This patch is to add support for the hardware with multiple ethernet
>> MAC controllers and a single MDIO bus connected to multiple PHY devices.
>> MDIO lines are connected to any one of the ethernet MAC controllers and
>> all the PHY devices will be accessed using the PHY maintenance interface
>> in that MAC controller. This handling along with PHY functionality is
>> moved to macb_mdio.c
>>
>> Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
>> Signed-off-by: Harini Katakam <harinik@xilinx.com>
>> ---
>>  drivers/net/ethernet/cadence/Makefile    |   2 +-
>>  drivers/net/ethernet/cadence/macb.c      | 169 +++-----------------
>>  drivers/net/ethernet/cadence/macb.h      |   2 +
>>  drivers/net/ethernet/cadence/macb_mdio.c | 266 +++++++++++++++++++++++++++++++
>>  4 files changed, 294 insertions(+), 145 deletions(-)
>>  create mode 100644 drivers/net/ethernet/cadence/macb_mdio.c
>>
<snip>
>> +     bus->irq = devm_kzalloc(&pdev->dev, sizeof(int) * PHY_MAX_ADDR,
>> +                             GFP_KERNEL);
>
> This looks wrong, or at least old. It used to be a pointer to an array,
> but it is now an actual array.

Sorry, this was a mistake.
I changed this after rebase, will update in next version.

>
>> +static const struct of_device_id macb_mdio_dt_ids[] = {
>> +     { .compatible = "cdns,macb-mdio" },
>> +
>> +};
>
>
> I've not looked hard enough to know, but can you keep backwards
> compatibility? Won't old device tree's assume the mdio bus is always
> present? Now you need an explicit node otherwise there will not be an
> mdio bus?

Yes, an explicit MDIO bus is required. But I'm not sure
how to maintain backward compatibility (without using this separate
macb_mdio) and have different MACs use the same MDIO bus
with separate PHYs.

Regards,
Harini

[RFC PATCH 1/2] net: macb: Add MDIO driver for accessing multiple PHY devices

[Harini Katakam]

This patch is to add support for the hardware with multiple ethernet
MAC controllers and a single MDIO bus connected to multiple PHY devices.
MDIO lines are connected to any one of the ethernet MAC controllers and
all the PHY devices will be accessed using the PHY maintenance interface
in that MAC controller. This handling along with PHY functionality is
moved to macb_mdio.c

Signed-off-by: Punnaiah Choudary Kalluri <punnaia-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Harini Katakam <harinik-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
---
 drivers/net/ethernet/cadence/Makefile    |    2 +-
 drivers/net/ethernet/cadence/macb.c      |  183 ++++----------------
 drivers/net/ethernet/cadence/macb.h      |    2 +
 drivers/net/ethernet/cadence/macb_mdio.c |  266 ++++++++++++++++++++++++++++++
 4 files changed, 302 insertions(+), 151 deletions(-)
 create mode 100644 drivers/net/ethernet/cadence/macb_mdio.c

diff --git a/drivers/net/ethernet/cadence/Makefile b/drivers/net/ethernet/cadence/Makefile
index 91f79b1..75c3d84 100644
--- a/drivers/net/ethernet/cadence/Makefile
+++ b/drivers/net/ethernet/cadence/Makefile
@@ -2,4 +2,4 @@
 # Makefile for the Atmel network device drivers.
 #
 
-obj-$(CONFIG_MACB) += macb.o
+obj-$(CONFIG_MACB) += macb.o macb_mdio.o
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index cb07d95..6e8ff4e 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -218,45 +218,6 @@ static void macb_get_hwaddr(struct macb *bp)
 	eth_hw_addr_random(bp->dev);
 }
 
-static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
-{
-	struct macb *bp = bus->priv;
-	int value;
-
-	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
-			      | MACB_BF(RW, MACB_MAN_READ)
-			      | MACB_BF(PHYA, mii_id)
-			      | MACB_BF(REGA, regnum)
-			      | MACB_BF(CODE, MACB_MAN_CODE)));
-
-	/* wait for end of transfer */
-	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
-		cpu_relax();
-
-	value = MACB_BFEXT(DATA, macb_readl(bp, MAN));
-
-	return value;
-}
-
-static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
-			   u16 value)
-{
-	struct macb *bp = bus->priv;
-
-	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
-			      | MACB_BF(RW, MACB_MAN_WRITE)
-			      | MACB_BF(PHYA, mii_id)
-			      | MACB_BF(REGA, regnum)
-			      | MACB_BF(CODE, MACB_MAN_CODE)
-			      | MACB_BF(DATA, value)));
-
-	/* wait for end of transfer */
-	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
-		cpu_relax();
-
-	return 0;
-}
-
 /**
  * macb_set_tx_clk() - Set a clock to a new frequency
  * @clk		Pointer to the clock to change
@@ -371,27 +332,19 @@ static void macb_handle_link_change(struct net_device *dev)
 static int macb_mii_probe(struct net_device *dev)
 {
 	struct macb *bp = netdev_priv(dev);
-	struct macb_platform_data *pdata;
 	struct phy_device *phydev;
-	int phy_irq;
 	int ret;
 
-	phydev = phy_find_first(bp->mii_bus);
+	if (bp->phy_dev)
+		return 0;
+
+	phydev = of_phy_find_device(bp->phy_node);
 	if (!phydev) {
 		netdev_err(dev, "no PHY found\n");
 		return -ENXIO;
 	}
-
-	pdata = dev_get_platdata(&bp->pdev->dev);
-	if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
-		ret = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin,
-					"phy int");
-		if (!ret) {
-			phy_irq = gpio_to_irq(pdata->phy_irq_pin);
-			phydev->irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
-		}
-	}
-
+	if (bp->phy_irq)
+		phydev->irq = bp->phy_irq;
 	/* attach the mac to the phy */
 	ret = phy_connect_direct(dev, phydev, &macb_handle_link_change,
 				 bp->phy_interface);
@@ -416,80 +369,9 @@ static int macb_mii_probe(struct net_device *dev)
 	bp->duplex = -1;
 	bp->phy_dev = phydev;
 
-	return 0;
-}
-
-static int macb_mii_init(struct macb *bp)
-{
-	struct macb_platform_data *pdata;
-	struct device_node *np;
-	int err = -ENXIO, i;
-
-	/* Enable management port */
-	macb_writel(bp, NCR, MACB_BIT(MPE));
-
-	bp->mii_bus = mdiobus_alloc();
-	if (!bp->mii_bus) {
-		err = -ENOMEM;
-		goto err_out;
-	}
-
-	bp->mii_bus->name = "MACB_mii_bus";
-	bp->mii_bus->read = &macb_mdio_read;
-	bp->mii_bus->write = &macb_mdio_write;
-	snprintf(bp->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
-		 bp->pdev->name, bp->pdev->id);
-	bp->mii_bus->priv = bp;
-	bp->mii_bus->parent = &bp->pdev->dev;
-	pdata = dev_get_platdata(&bp->pdev->dev);
-
-	dev_set_drvdata(&bp->dev->dev, bp->mii_bus);
-
-	np = bp->pdev->dev.of_node;
-	if (np) {
-		/* try dt phy registration */
-		err = of_mdiobus_register(bp->mii_bus, np);
-
-		/* fallback to standard phy registration if no phy were
-		 * found during dt phy registration
-		 */
-		if (!err && !phy_find_first(bp->mii_bus)) {
-			for (i = 0; i < PHY_MAX_ADDR; i++) {
-				struct phy_device *phydev;
-
-				phydev = mdiobus_scan(bp->mii_bus, i);
-				if (IS_ERR(phydev) &&
-				    PTR_ERR(phydev) != -ENODEV) {
-					err = PTR_ERR(phydev);
-					break;
-				}
-			}
-
-			if (err)
-				goto err_out_unregister_bus;
-		}
-	} else {
-		if (pdata)
-			bp->mii_bus->phy_mask = pdata->phy_mask;
-
-		err = mdiobus_register(bp->mii_bus);
-	}
-
-	if (err)
-		goto err_out_free_mdiobus;
-
-	err = macb_mii_probe(bp->dev);
-	if (err)
-		goto err_out_unregister_bus;
+	phy_attached_info(phydev);
 
 	return 0;
-
-err_out_unregister_bus:
-	mdiobus_unregister(bp->mii_bus);
-err_out_free_mdiobus:
-	mdiobus_free(bp->mii_bus);
-err_out:
-	return err;
 }
 
 static void macb_update_stats(struct macb *bp)
@@ -1582,15 +1464,18 @@ static void macb_init_rings(struct macb *bp)
 static void macb_reset_hw(struct macb *bp)
 {
 	struct macb_queue *queue;
-	unsigned int q;
+	unsigned int q, ctrl;
 
 	/* Disable RX and TX (XXX: Should we halt the transmission
 	 * more gracefully?)
 	 */
-	macb_writel(bp, NCR, 0);
+	ctrl = macb_readl(bp, NCR);
+	ctrl &= ~(MACB_BIT(RE) | MACB_BIT(TE));
+	macb_writel(bp, NCR, ctrl);
 
 	/* Clear the stats registers (XXX: Update stats first?) */
-	macb_writel(bp, NCR, MACB_BIT(CLRSTAT));
+	ctrl |= MACB_BIT(CLRSTAT);
+	macb_writel(bp, NCR, ctrl);
 
 	/* Clear all status flags */
 	macb_writel(bp, TSR, -1);
@@ -1886,7 +1771,8 @@ static int macb_open(struct net_device *dev)
 	netif_carrier_off(dev);
 
 	/* if the phy is not yet register, retry later*/
-	if (!bp->phy_dev)
+	err = macb_mii_probe(dev);
+	if (err)
 		return -EAGAIN;
 
 	/* RX buffers initialization */
@@ -2891,16 +2777,16 @@ static int macb_probe(struct platform_device *pdev)
 	unsigned int queue_mask, num_queues;
 	struct macb_platform_data *pdata;
 	bool native_io;
-	struct phy_device *phydev;
 	struct net_device *dev;
 	struct resource *regs;
 	void __iomem *mem;
 	const char *mac;
 	struct macb *bp;
+	int phy_irq;
 	int err;
 
 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mem = devm_ioremap_resource(&pdev->dev, regs);
+	mem = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
 	if (IS_ERR(mem))
 		return PTR_ERR(mem);
 
@@ -3006,21 +2892,26 @@ static int macb_probe(struct platform_device *pdev)
 	if (err)
 		goto err_out_free_netdev;
 
-	err = macb_mii_init(bp);
-	if (err)
-		goto err_out_free_netdev;
-
-	phydev = bp->phy_dev;
-
-	netif_carrier_off(dev);
-
 	err = register_netdev(dev);
 	if (err) {
 		dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
-		goto err_out_unregister_mdio;
+		goto err_out_free_netdev;
 	}
 
-	phy_attached_info(phydev);
+	bp->phy_node = of_parse_phandle(bp->pdev->dev.of_node,
+					"phy-handle", 0);
+
+	pdata = dev_get_platdata(&bp->pdev->dev);
+	if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
+		err = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin,
+					"phy int");
+		if (!err) {
+			phy_irq = gpio_to_irq(pdata->phy_irq_pin);
+			bp->phy_irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
+		}
+	}
+
+	netif_carrier_off(dev);
 
 	netdev_info(dev, "Cadence %s rev 0x%08x at 0x%08lx irq %d (%pM)\n",
 		    macb_is_gem(bp) ? "GEM" : "MACB", macb_readl(bp, MID),
@@ -3028,16 +2919,10 @@ static int macb_probe(struct platform_device *pdev)
 
 	return 0;
 
-err_out_unregister_mdio:
-	phy_disconnect(bp->phy_dev);
-	mdiobus_unregister(bp->mii_bus);
-	mdiobus_free(bp->mii_bus);
-
+err_out_free_netdev:
 	/* Shutdown the PHY if there is a GPIO reset */
 	if (bp->reset_gpio)
 		gpiod_set_value(bp->reset_gpio, 0);
-
-err_out_free_netdev:
 	free_netdev(dev);
 
 err_disable_clocks:
@@ -3059,8 +2944,6 @@ static int macb_remove(struct platform_device *pdev)
 		bp = netdev_priv(dev);
 		if (bp->phy_dev)
 			phy_disconnect(bp->phy_dev);
-		mdiobus_unregister(bp->mii_bus);
-		mdiobus_free(bp->mii_bus);
 
 		/* Shutdown the PHY if there is a GPIO reset */
 		if (bp->reset_gpio)
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 8a13824..a63b215 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -846,6 +846,8 @@ struct macb {
 	unsigned int		jumbo_max_len;
 
 	u32			wol;
+	struct device_node *phy_node;
+	int phy_irq;
 };
 
 static inline bool macb_is_gem(struct macb *bp)
diff --git a/drivers/net/ethernet/cadence/macb_mdio.c b/drivers/net/ethernet/cadence/macb_mdio.c
new file mode 100644
index 0000000..1277ca3
--- /dev/null
+++ b/drivers/net/ethernet/cadence/macb_mdio.c
@@ -0,0 +1,266 @@
+/*
+ * Cadence Macb mdio controller driver
+ *
+ * Copyright (C) 2014 - 2016 Xilinx, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/io.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/ptp_clock_kernel.h>
+#include "macb.h"
+
+struct macb_mdio_data {
+	void __iomem *regs;
+
+	struct clk *pclk;
+	struct clk *hclk;
+};
+
+#define macb_mdio_reg_writel(bp, offset, value)	\
+	writel_relaxed(value, bp->regs + offset)
+#define macb_mdio_writel(bp, reg, value)	\
+	macb_mdio_reg_writel(bp, MACB_##reg, value)
+
+#define macb_mdio_reg_readl(bp, offset)	readl_relaxed(bp->regs + offset)
+#define macb_mdio_readl(bp, reg)	macb_mdio_reg_readl(bp, MACB_##reg)
+
+#define MACB_MDIO_TIMEOUT	1000
+
+static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+	struct macb_mdio_data *bp = bus->priv;
+	unsigned int timeout = MACB_MDIO_TIMEOUT;
+	int value;
+
+	macb_mdio_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF) |
+				   MACB_BF(RW, MACB_MAN_READ) |
+				   MACB_BF(PHYA, mii_id) |
+				   MACB_BF(REGA, regnum) |
+				   MACB_BF(CODE, MACB_MAN_CODE)));
+
+	/* wait for end of transfer */
+	while (!MACB_BFEXT(IDLE, macb_mdio_readl(bp, NSR)) && timeout) {
+		cpu_relax();
+		timeout--;
+	}
+
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	value = MACB_BFEXT(DATA, macb_mdio_readl(bp, MAN));
+
+	return value;
+}
+
+static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+			   u16 value)
+{
+	struct macb_mdio_data *bp = bus->priv;
+	unsigned int timeout = MACB_MDIO_TIMEOUT;
+
+	macb_mdio_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF) |
+				   MACB_BF(RW, MACB_MAN_WRITE) |
+				   MACB_BF(PHYA, mii_id) |
+				   MACB_BF(REGA, regnum) |
+				   MACB_BF(CODE, MACB_MAN_CODE) |
+				   MACB_BF(DATA, value)));
+
+	/* wait for end of transfer */
+	while (!MACB_BFEXT(IDLE, macb_mdio_readl(bp, NSR)) && timeout) {
+		cpu_relax();
+		timeout--;
+	}
+
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static u32 gem_mdc_clk_div(struct macb_mdio_data *bp)
+{
+	u32 config;
+	unsigned long pclk_hz = clk_get_rate(bp->pclk);
+
+	if (pclk_hz <= 20000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV8);
+	else if (pclk_hz <= 40000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV16);
+	else if (pclk_hz <= 80000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV32);
+	else if (pclk_hz <= 120000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV48);
+	else if (pclk_hz <= 160000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV64);
+	else
+		config = GEM_BF(CLK, GEM_CLK_DIV96);
+
+	return config;
+}
+
+static int macb_mdio_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mii_bus *bus;
+	struct macb_mdio_data *bp;
+	struct resource *res;
+	int ret;
+	u32 config, i;
+
+	bus = mdiobus_alloc_size(sizeof(*bp));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "macb_mii_bus";
+	bus->read = &macb_mdio_read;
+	bus->write = &macb_mdio_write;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
+	bus->parent = &pdev->dev;
+	bus->irq = devm_kzalloc(&pdev->dev, sizeof(int) * PHY_MAX_ADDR,
+				GFP_KERNEL);
+	if (!bus->irq) {
+		ret = -ENOMEM;
+		goto err_out_free_mdiobus;
+	}
+
+	bp = bus->priv;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	bp->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (IS_ERR(bp->regs)) {
+		ret = PTR_ERR(bp->regs);
+		goto err_out_free_mdiobus;
+	}
+
+	bp->pclk = devm_clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(bp->pclk)) {
+		ret = PTR_ERR(bp->pclk);
+		dev_err(&pdev->dev, "failed to get macb_clk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	bp->hclk = devm_clk_get(&pdev->dev, "hclk");
+	if (IS_ERR(bp->hclk)) {
+		ret = PTR_ERR(bp->hclk);
+		dev_err(&pdev->dev, "failed to get hclk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	ret = clk_prepare_enable(bp->pclk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable pclk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	ret = clk_prepare_enable(bp->hclk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable hclk (%u)\n", ret);
+		goto err_disable_pclk;
+	}
+
+	platform_set_drvdata(pdev, bus);
+
+	/* Enable management port */
+	config = macb_mdio_readl(bp, NCR);
+	config |= MACB_BIT(MPE);
+	macb_mdio_writel(bp, NCR, config);
+	config = gem_mdc_clk_div(bp);
+	macb_mdio_writel(bp, NCFGR, config);
+
+	np = pdev->dev.of_node;
+	if (np) {
+		/* try dt phy registration */
+		ret = of_mdiobus_register(bus, np);
+
+		/* Fallback to standard phy registration if no phy were
+		 * found during dt phy registration
+		 */
+		if (!ret && !phy_find_first(bus)) {
+			for (i = 0; i < PHY_MAX_ADDR; i++) {
+				struct phy_device *phydev;
+
+				phydev = mdiobus_scan(bus, i);
+				if (IS_ERR(phydev) &&
+				    PTR_ERR(phydev) != -ENODEV) {
+					ret = PTR_ERR(phydev);
+					break;
+				}
+			}
+
+			if (ret)
+				goto err_out_unregister_bus;
+		}
+	} else {
+		for (i = 0; i < PHY_MAX_ADDR; i++)
+			bus->irq[i] = PHY_POLL;
+
+		ret = of_mdiobus_register(bus, np);
+	}
+
+	if (ret)
+		goto err_out_free_mdio_irq;
+
+	return 0;
+
+err_out_unregister_bus:
+	mdiobus_unregister(bus);
+err_out_free_mdio_irq:
+	kfree(bus->irq);
+err_disable_pclk:
+	clk_disable_unprepare(bp->pclk);
+	clk_disable_unprepare(bp->hclk);
+err_out_free_mdiobus:
+	mdiobus_free(bus);
+	return ret;
+}
+
+static int macb_mdio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = platform_get_drvdata(pdev);
+	struct macb_mdio_data *bp = bus->priv;
+	u32 config;
+
+	/* Disable management port */
+	config = macb_mdio_readl(bp, NCR);
+	config &= ~MACB_BIT(MPE);
+	macb_mdio_writel(bp, NCR, config);
+	mdiobus_unregister(bus);
+	clk_disable_unprepare(bp->hclk);
+	clk_disable_unprepare(bp->pclk);
+	mdiobus_free(bus);
+
+	return 0;
+}
+
+static const struct of_device_id macb_mdio_dt_ids[] = {
+	{ .compatible = "cdns,macb-mdio" },
+
+};
+MODULE_DEVICE_TABLE(of, macb_mdio_dt_ids);
+
+static struct platform_driver macb_mdio_driver = {
+	.probe = macb_mdio_probe,
+	.remove = macb_mdio_remove,
+	.driver = {
+		.name = "macb-mdio",
+		.of_match_table = macb_mdio_dt_ids,
+	},
+};
+
+module_platform_driver(macb_mdio_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cadence MACB MDIO driver");
+MODULE_AUTHOR("Xilinx");
-- 
1.7.9.5

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[RFC PATCH 0/2] net: macb: Add mdio driver for accessing multiple phy devices

[Punnaiah Choudary Kalluri]

This patch is to add support for the design that has multiple ethernet
mac controllers and single mdio bus connected to multiple phy devices.
i.e mdio lines are connected to any of the ethernet mac controller and
all the phy devices will be accessed using the phy maintenance interface
in that mac controller.

 ______                   _____
|      |                 |PHY0 |
| MAC0 |-----------------|     |
|______|       |         |_____|
               |           
 ______        |          _____
|      |       |         |     |
| MAC1 |       |_________|PHY1 | 
|______|                 |____ |

So, i come up with two implementations for addressing the above configuration.

Implementation 1:
 Have separate driver for mdio bus
 Create a DT node for all the PHY devices connected to the mdio bus
 This driver will share the register space of the mac controller that has
 mdio bus connected.  

Implementation 2:
 Add new property "has-mdio" and it should be 1 for the mac that has mdio bus
 connected.
 Create the mdio bus only when the has-mdio property is 1

Please review the two implementations and suggest which one is better to proceed
further. In my opinion implementation 1 will be the ideal one.

Currently i have tested the patches with single mac and single phy
configuration. I need to take care of few more cases before releasing the final patch
but before that i would like to have your opinion on the above implementations
and finalize one implementation. so that i can enhance it further.

Punnaiah Choudary Kalluri (1):
  net: macb: Add mdio driver for accessing multiple phy devices
  net: macb: Add support for single mac managing more than one phy


 drivers/net/ethernet/cadence/Makefile    |    2 +-
 drivers/net/ethernet/cadence/macb.c      |   93 +-------------
 drivers/net/ethernet/cadence/macb.h      |    3 +-
 drivers/net/ethernet/cadence/macb_mdio.c |  204 ++++++++++++++++++++++++++++++
 4 files changed, 211 insertions(+), 91 deletions(-)
 create mode 100644 drivers/net/ethernet/cadence/macb_mdio.c

-- 
1.7.4

[RFC PATCH 1/2] net: macb: Add mdio driver for accessing multiple phy devices

[Punnaiah Choudary Kalluri]

This patch is to add spoort for the design that has multiple ethernet
mac controllers and single mdio bus connected to multiple phy devices.
i.e mdio lines are connected to any of the ethernet mac controller and
all the phy devices will be accessed using the phy maintainance interface
in that mac controller.

Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
---
 drivers/net/ethernet/cadence/Makefile    |    2 +-
 drivers/net/ethernet/cadence/macb.c      |   93 +-------------
 drivers/net/ethernet/cadence/macb.h      |    3 +-
 drivers/net/ethernet/cadence/macb_mdio.c |  204 ++++++++++++++++++++++++++++++
 4 files changed, 211 insertions(+), 91 deletions(-)
 create mode 100644 drivers/net/ethernet/cadence/macb_mdio.c

diff --git a/drivers/net/ethernet/cadence/Makefile b/drivers/net/ethernet/cadence/Makefile
index 9068b83..73504f4 100644
--- a/drivers/net/ethernet/cadence/Makefile
+++ b/drivers/net/ethernet/cadence/Makefile
@@ -3,4 +3,4 @@
 #
 
 obj-$(CONFIG_ARM_AT91_ETHER) += at91_ether.o
-obj-$(CONFIG_MACB) += macb.o
+obj-$(CONFIG_MACB) += macb.o macb_mdio.o
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 4833ba1..df1b928 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -320,7 +320,7 @@ static int macb_mii_probe(struct net_device *dev)
 	int phy_irq;
 	int ret;
 
-	phydev = phy_find_first(bp->mii_bus);
+	phydev = of_phy_find_device(bp->phy_node);
 	if (!phydev) {
 		netdev_err(dev, "no PHY found\n");
 		return -ENXIO;
@@ -359,89 +359,6 @@ static int macb_mii_probe(struct net_device *dev)
 	return 0;
 }
 
-int macb_mii_init(struct macb *bp)
-{
-	struct macb_platform_data *pdata;
-	struct device_node *np;
-	int err = -ENXIO, i;
-
-	/* Enable management port */
-	macb_writel(bp, NCR, MACB_BIT(MPE));
-
-	bp->mii_bus = mdiobus_alloc();
-	if (bp->mii_bus == NULL) {
-		err = -ENOMEM;
-		goto err_out;
-	}
-
-	bp->mii_bus->name = "MACB_mii_bus";
-	bp->mii_bus->read = &macb_mdio_read;
-	bp->mii_bus->write = &macb_mdio_write;
-	snprintf(bp->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
-		bp->pdev->name, bp->pdev->id);
-	bp->mii_bus->priv = bp;
-	bp->mii_bus->parent = &bp->dev->dev;
-	pdata = dev_get_platdata(&bp->pdev->dev);
-
-	bp->mii_bus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
-	if (!bp->mii_bus->irq) {
-		err = -ENOMEM;
-		goto err_out_free_mdiobus;
-	}
-
-	dev_set_drvdata(&bp->dev->dev, bp->mii_bus);
-
-	np = bp->pdev->dev.of_node;
-	if (np) {
-		/* try dt phy registration */
-		err = of_mdiobus_register(bp->mii_bus, np);
-
-		/* fallback to standard phy registration if no phy were
-		   found during dt phy registration */
-		if (!err && !phy_find_first(bp->mii_bus)) {
-			for (i = 0; i < PHY_MAX_ADDR; i++) {
-				struct phy_device *phydev;
-
-				phydev = mdiobus_scan(bp->mii_bus, i);
-				if (IS_ERR(phydev)) {
-					err = PTR_ERR(phydev);
-					break;
-				}
-			}
-
-			if (err)
-				goto err_out_unregister_bus;
-		}
-	} else {
-		for (i = 0; i < PHY_MAX_ADDR; i++)
-			bp->mii_bus->irq[i] = PHY_POLL;
-
-		if (pdata)
-			bp->mii_bus->phy_mask = pdata->phy_mask;
-
-		err = mdiobus_register(bp->mii_bus);
-	}
-
-	if (err)
-		goto err_out_free_mdio_irq;
-
-	err = macb_mii_probe(bp->dev);
-	if (err)
-		goto err_out_unregister_bus;
-
-	return 0;
-
-err_out_unregister_bus:
-	mdiobus_unregister(bp->mii_bus);
-err_out_free_mdio_irq:
-	kfree(bp->mii_bus->irq);
-err_out_free_mdiobus:
-	mdiobus_free(bp->mii_bus);
-err_out:
-	return err;
-}
-EXPORT_SYMBOL_GPL(macb_mii_init);
-
 static void macb_update_stats(struct macb *bp)
 {
 	u32 __iomem *reg = bp->regs + MACB_PFR;
@@ -2480,7 +2397,10 @@ static int macb_probe(struct platform_device *pdev)
 		goto err_out_free_netdev;
 	}
 
-	err = macb_mii_init(bp);
+	bp->phy_node = of_parse_phandle(bp->pdev->dev.of_node,
+						"phy-handle", 0);
+
+	err = macb_mii_probe(bp->dev);
 	if (err)
 		goto err_out_unregister_netdev;
 
@@ -2524,9 +2444,6 @@ static int macb_remove(struct platform_device *pdev)
 		bp = netdev_priv(dev);
 		if (bp->phy_dev)
 			phy_disconnect(bp->phy_dev);
-		mdiobus_unregister(bp->mii_bus);
-		kfree(bp->mii_bus->irq);
-		mdiobus_free(bp->mii_bus);
 		unregister_netdev(dev);
 		if (!IS_ERR(bp->tx_clk))
 			clk_disable_unprepare(bp->tx_clk);
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index f0aa177..ba515ab 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -825,13 +825,12 @@ struct macb {
 	unsigned int		rx_frm_len_mask;
 	unsigned int		jumbo_max_len;
 	bool			isjumbo;
-
+	struct device_node *phy_node;
 	u64			ethtool_stats[GEM_STATS_LEN];
 };
 
 extern const struct ethtool_ops macb_ethtool_ops;
 
-int macb_mii_init(struct macb *bp);
 int macb_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
 struct net_device_stats *macb_get_stats(struct net_device *dev);
 void macb_set_rx_mode(struct net_device *dev);
diff --git a/drivers/net/ethernet/cadence/macb_mdio.c b/drivers/net/ethernet/cadence/macb_mdio.c
new file mode 100644
index 0000000..563ac52
--- /dev/null
+++ b/drivers/net/ethernet/cadence/macb_mdio.c
@@ -0,0 +1,204 @@
+/*
+ * Cadence Macb mdio controller driver
+ *
+ * Copyright (C) 2014 - 2015 Xilinx, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include "macb.h"
+
+struct macb_mdio_data {
+	void __iomem *regs;
+	struct clk *pclk;
+	struct clk *hclk;
+};
+
+static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+	struct macb_mdio_data *bp = bus->priv;
+	int value;
+
+	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
+			      | MACB_BF(RW, MACB_MAN_READ)
+			      | MACB_BF(PHYA, mii_id)
+			      | MACB_BF(REGA, regnum)
+			      | MACB_BF(CODE, MACB_MAN_CODE)));
+
+	/* wait for end of transfer */
+	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
+		cpu_relax();
+
+	value = MACB_BFEXT(DATA, macb_readl(bp, MAN));
+
+	return value;
+}
+
+static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+			   u16 value)
+{
+	struct macb_mdio_data *bp = bus->priv;
+
+	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
+			      | MACB_BF(RW, MACB_MAN_WRITE)
+			      | MACB_BF(PHYA, mii_id)
+			      | MACB_BF(REGA, regnum)
+			      | MACB_BF(CODE, MACB_MAN_CODE)
+			      | MACB_BF(DATA, value)));
+
+	/* wait for end of transfer */
+	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
+		cpu_relax();
+
+	return 0;
+}
+
+static u32 gem_mdc_clk_div(struct macb_mdio_data *bp)
+{
+	u32 config;
+	unsigned long pclk_hz = clk_get_rate(bp->pclk);
+
+	if (pclk_hz <= 20000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV8);
+	else if (pclk_hz <= 40000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV16);
+	else if (pclk_hz <= 80000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV32);
+	else if (pclk_hz <= 120000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV48);
+	else if (pclk_hz <= 160000000)
+		config = GEM_BF(CLK, GEM_CLK_DIV64);
+	else
+		config = GEM_BF(CLK, GEM_CLK_DIV96);
+
+	return config;
+}
+
+static int macb_mdio_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mii_bus *bus;
+	struct macb_mdio_data *bp;
+	struct resource *res;
+	int ret;
+	u32 config, i;
+
+	bus = mdiobus_alloc_size(sizeof(*bp));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "macb_mii_bus";
+	bus->read = &macb_mdio_read;
+	bus->write = &macb_mdio_write;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
+	bus->parent = &pdev->dev;
+	bus->irq = devm_kzalloc(&pdev->dev, sizeof(int) * PHY_MAX_ADDR,
+				GFP_KERNEL);
+	if (!bus->irq) {
+		ret = -ENOMEM;
+		goto err_out_free_mdiobus;
+	}
+
+	for (i = 0; i < PHY_MAX_ADDR; i++)
+		bus->irq[i] = PHY_POLL;
+
+	bp = bus->priv;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	bp->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(bp->regs)) {
+		ret = PTR_ERR(bp->regs);
+		goto err_out_free_mdiobus;
+	}
+
+	bp->pclk = devm_clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(bp->pclk)) {
+		ret = PTR_ERR(bp->pclk);
+		dev_err(&pdev->dev, "failed to get macb_clk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	bp->hclk = devm_clk_get(&pdev->dev, "hclk");
+	if (IS_ERR(bp->hclk)) {
+		ret = PTR_ERR(bp->hclk);
+		dev_err(&pdev->dev, "failed to get hclk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	ret = clk_prepare_enable(bp->pclk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable pclk (%u)\n", ret);
+		goto err_out_free_mdiobus;
+	}
+
+	ret = clk_prepare_enable(bp->hclk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable hclk (%u)\n", ret);
+		goto err_disable_pclk;
+	}
+
+	/* Enable management port */
+	macb_writel(bp, NCR, MACB_BIT(MPE));
+	config = gem_mdc_clk_div(bp);
+	macb_writel(bp, NCFGR, config);
+
+	ret = of_mdiobus_register(bus, np);
+	if (ret < 0)
+		goto err_out_free_mdiobus;
+
+	platform_set_drvdata(pdev, bus);
+
+	return 0;
+
+err_disable_pclk:
+	clk_disable_unprepare(bp->pclk);
+
+err_out_free_mdiobus:
+	mdiobus_free(bus);
+	return ret;
+}
+
+static int macb_mdio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = platform_get_drvdata(pdev);
+	struct macb_mdio_data *bp = bus->priv;
+
+	mdiobus_unregister(bus);
+	clk_disable_unprepare(bp->hclk);
+	clk_disable_unprepare(bp->pclk);
+	mdiobus_free(bus);
+
+	return 0;
+}
+
+static const struct of_device_id macb_mdio_dt_ids[] = {
+	{ .compatible = "cdns,macb-mdio" },
+
+};
+MODULE_DEVICE_TABLE(of, macb_mdio_dt_ids);
+
+static struct platform_driver macb_mdio_driver = {
+	.probe = macb_mdio_probe,
+	.remove = macb_mdio_remove,
+	.driver = {
+		.name = "macb-mdio",
+		.of_match_table = macb_mdio_dt_ids,
+	},
+};
+
+module_platform_driver(macb_mdio_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cadence MACB/GEM Ethernet driver");
+MODULE_AUTHOR("Xilinx");
-- 
1.7.4