net: cpsw: Add support to drive gpios for ethernet to be functional

On DRA72 EVM, cpsw slaves may be muxed with other modules. This
selection is controlled by a pcf gpio line. Add support for cpsw driver
to acquire mode-gpios and select the appropriate slave using gpio APIs.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>
diff --git a/drivers/net/cpsw.c b/drivers/net/cpsw.c
index 2ce4ec6..774b021 100644
--- a/drivers/net/cpsw.c
+++ b/drivers/net/cpsw.c
@@ -22,6 +22,7 @@
 #include <netdev.h>
 #include <cpsw.h>
 #include <asm/errno.h>
+#include <asm/gpio.h>
 #include <asm/io.h>
 #include <phy.h>
 #include <asm/arch/cpu.h>
@@ -1152,12 +1153,14 @@
 {
 	struct eth_pdata *pdata = dev_get_platdata(dev);
 	struct cpsw_priv *priv = dev_get_priv(dev);
+	struct gpio_desc *mode_gpios;
 	const char *phy_mode;
 	const void *fdt = gd->fdt_blob;
 	int node = dev->of_offset;
 	int subnode;
 	int slave_index = 0;
 	int active_slave;
+	int num_mode_gpios;
 	int ret;
 
 	pdata->iobase = dev_get_addr(dev);
@@ -1203,6 +1206,15 @@
 		return -ENOENT;
 	}
 
+	num_mode_gpios = gpio_get_list_count(dev, "mode-gpios");
+	if (num_mode_gpios > 0) {
+		mode_gpios = malloc(sizeof(struct gpio_desc) *
+				    num_mode_gpios);
+		gpio_request_list_by_name(dev, "mode-gpios", mode_gpios,
+					  num_mode_gpios, GPIOD_IS_OUT);
+		free(mode_gpios);
+	}
+
 	active_slave = fdtdec_get_int(fdt, node, "active_slave", 0);
 	priv->data.active_slave = active_slave;