net/macb: Update device tree binding for resetting PHY using GPIO

Instead of being at the MAC level the reset gpio preperty is moved at the
PHY child node level. It is still managed by the MAC, but from the point
of view of the binding it make more sense to be part of the PHY node.

This commit also fixes a build errors if GPIOLIB is not selected.
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/macb.txt

@@ -19,8 +19,8 @@ Required properties:
 	Optional elements: 'tx_clk'
 - clocks: Phandles to input clocks.
 
-Optional properties:
-- phy-reset-gpios : Should specify the gpio for phy reset
+Optional properties for PHY child node:
+- reset-gpios : Should specify the gpio for phy reset
 
 Examples:
 
@@ -32,4 +32,8 @@ Examples:
 		local-mac-address = [3a 0e 03 04 05 06];
 		clock-names = "pclk", "hclk", "tx_clk";
 		clocks = <&clkc 30>, <&clkc 30>, <&clkc 13>;
+		ethernet-phy@1 {
+			reg = <0x1>;
+			reset-gpios = <&pioE 6 1>;
+		};
 	};

drivers/net/ethernet/cadence/macb.c

@@ -19,6 +19,7 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
@@ -28,6 +29,7 @@
 #include <linux/phy.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/of_mdio.h>
 #include <linux/of_net.h>
 
@@ -2817,6 +2819,7 @@ static int macb_probe(struct platform_device *pdev)
 					      = macb_clk_init;
 	int (*init)(struct platform_device *) = macb_init;
 	struct device_node *np = pdev->dev.of_node;
+	struct device_node *phy_node;
 	const struct macb_config *macb_config = NULL;
 	struct clk *pclk, *hclk, *tx_clk;
 	unsigned int queue_mask, num_queues;
@@ -2905,8 +2908,14 @@ static int macb_probe(struct platform_device *pdev)
 		macb_get_hwaddr(bp);
 
 	/* Power up the PHY if there is a GPIO reset */
-	bp->reset_gpio = devm_gpiod_get_optional(&bp->pdev->dev, "phy-reset",
-						 GPIOD_OUT_HIGH);
+	phy_node =  of_get_next_available_child(np, NULL);
+	if (phy_node) {
+		int gpio = of_get_named_gpio(phy_node, "reset-gpios", 0);
+		if (gpio_is_valid(gpio))
+			bp->reset_gpio = gpio_to_desc(gpio);
+		gpiod_set_value(bp->reset_gpio, GPIOD_OUT_HIGH);
+	}
+	of_node_put(phy_node);
 
 	err = of_get_phy_mode(np);
 	if (err < 0) {
@@ -2976,7 +2985,7 @@ static int macb_remove(struct platform_device *pdev)
 		mdiobus_free(bp->mii_bus);
 
 		/* Shutdown the PHY if there is a GPIO reset */
-		gpiod_set_value(bp->reset_gpio, 0);
+		gpiod_set_value(bp->reset_gpio, GPIOD_OUT_LOW);
 
 		unregister_netdev(dev);
 		clk_disable_unprepare(bp->tx_clk);