Hi Linus,
On 08/24/2016 07:59 AM, Linus Walleij wrote:
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.
Hmm, at least in our hardware case AFAIK (juno/lan9118) the hardware
reset line on the lan9118 is active low, but the chip itself is
documented as having internal pullups so that it may be left unconnected.
Which microchip/smsc chip are we talking about? because it seems that
you probably want the GPIO pin to be in any state (hi-Z, or just high)
besides the one you selected here.
Beyond that, is it not possible for the firmware to get the reset pin in
the correct configuration, so that linux doesn't have to mess with it?
Signed-off-by: Linus Walleij <linus.wall...@linaro.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))
