Subject: [PATCH v2] net: Rework mdio-ofgpio driver to use of_mdio infrastructure

From: Mark Ware <[email-masked]>
Date: Tue, 21 Jul 2009 19:50:33 +1000

Changes to the fs_enet driver (aa73832c5a80d6c52c69b18af858d88fa595dd3c) cause kernel crashes when using the mdio-ofgpio driver.

The following patch replicates similar changes made to the fs_enet mii-bitbang drivers.
---

This version attempts to address Grant's comments below:

Grant Likely wrote:
 >
 > You should refactor mdio_gpio_bus_init() to not call
 > mdiobus_register() at all, and instead just return a pointer to the
 > unregistered new_bus.  Then mdio_gpio_probe() and mdio_ofgpio_probe()
 > can call the correct register variant directly.  Fewer ugly #ifdefs
 > this way.  It also eliminates the need to cast the void* pointer.
 >

  drivers/net/phy/mdio-gpio.c |   77 ++++++++++++++++++++-----------------------
  1 files changed, 36 insertions(+), 41 deletions(-)

diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
index 33984b7..22cdd45 100644
--- a/drivers/net/phy/mdio-gpio.c
+++ b/drivers/net/phy/mdio-gpio.c
@@ -30,6 +30,7 @@

  #ifdef CONFIG_OF_GPIO
  #include <linux/of_gpio.h>
+#include <linux/of_mdio.h>
  #include <linux/of_platform.h>
  #endif

@@ -81,13 +82,12 @@ static struct mdiobb_ops mdio_gpio_ops = {
  	.get_mdio_data = mdio_get,
  };

-static int __devinit mdio_gpio_bus_init(struct device *dev,
+static struct mii_bus * __devinit mdio_gpio_bus_init(struct device *dev,
  					struct mdio_gpio_platform_data *pdata,
  					int bus_id)
  {
  	struct mii_bus *new_bus;
  	struct mdio_gpio_info *bitbang;
-	int ret = -ENOMEM;
  	int i;

  	bitbang = kzalloc(sizeof(*bitbang), GFP_KERNEL);
@@ -104,8 +104,6 @@ static int __devinit mdio_gpio_bus_init(struct device *dev,

  	new_bus->name = "GPIO Bitbanged MDIO",

-	ret = -ENODEV;
-
  	new_bus->phy_mask = pdata->phy_mask;
  	new_bus->irq = pdata->irqs;
  	new_bus->parent = dev;
@@ -129,15 +127,8 @@ static int __devinit mdio_gpio_bus_init(struct device *dev,

  	dev_set_drvdata(dev, new_bus);

-	ret = mdiobus_register(new_bus);
-	if (ret)
-		goto out_free_all;
-
-	return 0;
+	return new_bus;

-out_free_all:
-	dev_set_drvdata(dev, NULL);
-	gpio_free(bitbang->mdio);
  out_free_mdc:
  	gpio_free(bitbang->mdc);
  out_free_bus:
@@ -145,30 +136,47 @@ out_free_bus:
  out_free_bitbang:
  	kfree(bitbang);
  out:
-	return ret;
+	return NULL;
  }

-static void __devexit mdio_gpio_bus_destroy(struct device *dev)
+static void __devinit mdio_gpio_bus_deinit(struct device *dev)
  {
  	struct mii_bus *bus = dev_get_drvdata(dev);
  	struct mdio_gpio_info *bitbang = bus->priv;

-	mdiobus_unregister(bus);
-	free_mdio_bitbang(bus);
  	dev_set_drvdata(dev, NULL);
-	gpio_free(bitbang->mdc);
  	gpio_free(bitbang->mdio);
+	gpio_free(bitbang->mdc);
+	free_mdio_bitbang(bus);
  	kfree(bitbang);
  }

+static void __devexit mdio_gpio_bus_destroy(struct device *dev)
+{
+	struct mii_bus *bus = dev_get_drvdata(dev);
+
+	mdiobus_unregister(bus);
+	mdio_gpio_bus_deinit(dev);
+}
+
  static int __devinit mdio_gpio_probe(struct platform_device *pdev)
  {
  	struct mdio_gpio_platform_data *pdata = pdev->dev.platform_data;
+	struct mii_bus *new_bus;
+	int ret;

  	if (!pdata)
  		return -ENODEV;

-	return mdio_gpio_bus_init(&pdev->dev, pdata, pdev->id);
+	new_bus = mdio_gpio_bus_init(&pdev->dev, pdata, pdev->id);
+	if (!new_bus)
+		return -ENODEV;
+
+	ret = mdiobus_register(new_bus);
+	if (ret)
+		mdio_gpio_bus_deinit(&pdev->dev);
+
+	return ret;
  }

  static int __devexit mdio_gpio_remove(struct platform_device *pdev)
@@ -179,29 +187,12 @@ static int __devexit mdio_gpio_remove(struct platform_device *pdev)
  }

  #ifdef CONFIG_OF_GPIO
-static void __devinit add_phy(struct mdio_gpio_platform_data *pdata,
-			      struct device_node *np)
-{
-	const u32 *data;
-	int len, id, irq;
-
-	data = of_get_property(np, "reg", &len);
-	if (!data || len != 4)
-		return;
-
-	id = *data;
-	pdata->phy_mask &= ~(1 << id);
-
-	irq = of_irq_to_resource(np, 0, NULL);
-	if (irq)
-		pdata->irqs[id] = irq;
-}

  static int __devinit mdio_ofgpio_probe(struct of_device *ofdev,
                                          const struct of_device_id *match)
  {
-	struct device_node *np = NULL;
  	struct mdio_gpio_platform_data *pdata;
+	struct mii_bus *new_bus;
  	int ret;

  	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
@@ -215,14 +206,18 @@ static int __devinit mdio_ofgpio_probe(struct of_device *ofdev,

  	ret = of_get_gpio(ofdev->node, 1);
  	if (ret < 0)
-                goto out_free;
+		goto out_free;
  	pdata->mdio = ret;

-	while ((np = of_get_next_child(ofdev->node, np)))
-		if (!strcmp(np->type, "ethernet-phy"))
-			add_phy(pdata, np);
+	new_bus = mdio_gpio_bus_init(&ofdev->dev, pdata, pdata->mdc);
+	if (!new_bus)
+		return -ENODEV;

-	return mdio_gpio_bus_init(&ofdev->dev, pdata, pdata->mdc);
+	ret = of_mdiobus_register(new_bus, ofdev->node);
+	if (ret)
+		mdio_gpio_bus_deinit(&ofdev->dev);
+
+	return ret;

  out_free:
  	kfree(pdata);
-- 
1.5.6.5