mdio-gpio: Add reset functionality to mdio-gpio driver(v2).

This patch adds phy reset functionality to mdio-gpio driver. Now
mdio_gpio_platform_data has new member as function pointer which can be
filled at the bsp level for a callback from phy infrastructure. Also the
mdio-bitbang driver fills-in the reset function of mii_bus structure.

Without this patch the bsp level code has to takecare of the reseting
PHY's on the bus, which become bit hacky for every bsp and
phy-infrastructure is ignored aswell.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/mdio-bitbang.c

@@ -202,6 +202,14 @@ static int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val)
 	return 0;
 }
 
+static int mdiobb_reset(struct mii_bus *bus)
+{
+	struct mdiobb_ctrl *ctrl = bus->priv;
+	if (ctrl->reset)
+		ctrl->reset(bus);
+	return 0;
+}
+
 struct mii_bus *alloc_mdio_bitbang(struct mdiobb_ctrl *ctrl)
 {
 	struct mii_bus *bus;
@@ -214,6 +222,7 @@ struct mii_bus *alloc_mdio_bitbang(struct mdiobb_ctrl *ctrl)
 
 	bus->read = mdiobb_read;
 	bus->write = mdiobb_write;
+	bus->reset = mdiobb_reset;
 	bus->priv = ctrl;
 
 	return bus;

drivers/net/phy/mdio-gpio.c

@@ -95,6 +95,7 @@ static struct mii_bus * __devinit mdio_gpio_bus_init(struct device *dev,
 		goto out;
 
 	bitbang->ctrl.ops = &mdio_gpio_ops;
+	bitbang->ctrl.reset = pdata->reset;
 	bitbang->mdc = pdata->mdc;
 	bitbang->mdio = pdata->mdio;
 

include/linux/mdio-bitbang.h

@@ -32,6 +32,8 @@ struct mdiobb_ops {
 
 struct mdiobb_ctrl {
 	const struct mdiobb_ops *ops;
+	/* reset callback */
+	int (*reset)(struct mii_bus *bus);
 };
 
 /* The returned bus is not yet registered with the phy layer. */

include/linux/mdio-gpio.h

@@ -20,6 +20,8 @@ struct mdio_gpio_platform_data {
 
 	unsigned int phy_mask;
 	int irqs[PHY_MAX_ADDR];
+	/* reset callback */
+	int (*reset)(struct mii_bus *bus);
 };
 
 #endif /* __LINUX_MDIO_GPIO_H */