netdev - [PATCH 2/3 v2] net: smsc911x: request and deassert optional RESET GPIO

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Date:   Wed, 24 Aug 2016 14:59:41 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     netdev@...r.kernel.org, "David S . Miller" <davem@...emloft.net>,
        Steve Glendinning <steve.glendinning@...c.com>
Cc:     Guenter Roeck <linux@...ck-us.net>,
        Jeremy Linton <jeremy.linton@....com>,
        Kamlakant Patel <kamlakant.patel@...adcom.com>,
        Pavel Fedin <p.fedin@...sung.com>,
        Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH 2/3 v2] net: smsc911x: request and deassert optional RESET GPIO

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@...aro.org>
---
ChangeLog v1->v2:
- Use devm_gpiod_request_optiona() and request the line with
  GPIOD_OUT_LOW so it is deasserted immediately if active.
---
 drivers/net/ethernet/smsc/smsc911x.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
index ca3134540d2d..8ab8d4b9614b 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"
 
@@ -147,6 +148,9 @@ struct smsc911x_data {
 	/* regulators */
 	struct regulator_bulk_data supplies[SMSC911X_NUM_SUPPLIES];
 
+	/* Reset GPIO */
+	struct gpio_desc *reset_gpiod;
+
 	/* clock */
 	struct clk *clk;
 };
@@ -438,6 +442,11 @@ 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_optional(&pdev->dev,
+						     "reset",
+						     GPIOD_OUT_LOW);
+
 	/* Request clock */
 	pdata->clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pdata->clk))
-- 
2.7.4