On 07/08/2016 02:07 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.
Signed-off-by: Linus Walleij <linus.wall...@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)) {
This could return -EPROBE_DEFER, which should probably not be ignored.
It might be better to use devm_gpiod_get_optional(). If you pass GPIOD_OUT_LOW
as parameter to that function, it should take the chip out of reset immediately.
See drivers/i2c/muxes/i2c-mux-pca954x.c for an example with a similar use case.
Guenter
+ 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))
