[PATCH 2/3] net: smsc911x: request and deassert optional RESET GPIO

[Linus Walleij <linus.walleij@linaro.org>]

On some systems (such as the Qualcomm APQ8060 Dragonboard) the
RESET signal of the SMSC911x is not pulled up by a resistor but
connected to a GPIO line, so that the operating system must
explicitly deassert RESET before use.

Support this in the SMSC911x driver so this ethernet connector
can be used on such targets.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/net/ethernet/smsc/smsc911x.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
index 8af25563f627..125d58ac22bd 100644
--- a/drivers/net/ethernet/smsc/smsc911x.c
+++ b/drivers/net/ethernet/smsc/smsc911x.c
@@ -62,6 +62,7 @@
 #include <linux/acpi.h>
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
+#include <linux/gpio/consumer.h>
 
 #include "smsc911x.h"
 
@@ -149,6 +150,9 @@ struct smsc911x_data {
 	/* regulators */
 	struct regulator_bulk_data supplies[SMSC911X_NUM_SUPPLIES];
 
+	/* Reset GPIO */
+	struct gpio_desc *reset_gpiod;
+
 	/* clock */
 	struct clk *clk;
 };
@@ -440,6 +444,15 @@ static int smsc911x_request_resources(struct platform_device *pdev)
 		netdev_err(ndev, "couldn't get regulators %d\n",
 				ret);
 
+	/* Request optional RESET GPIO */
+	pdata->reset_gpiod = devm_gpiod_get(&pdev->dev, "reset",
+					    GPIOD_OUT_HIGH);
+	/* Deassert the signal */
+	if (!IS_ERR(pdata->reset_gpiod)) {
+		dev_info(&pdev->dev, "release reset\n");
+		gpiod_set_value(pdata->reset_gpiod, 0);
+	}
+
 	/* Request clock */
 	pdata->clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pdata->clk))
-- 
2.7.4