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path: root/drivers/net/ethernet/smsc/smc91x.c
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Diffstat (limited to 'drivers/net/ethernet/smsc/smc91x.c')
-rw-r--r--drivers/net/ethernet/smsc/smc91x.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/net/ethernet/smsc/smc91x.c b/drivers/net/ethernet/smsc/smc91x.c
index 5e94d00..2c62208 100644
--- a/drivers/net/ethernet/smsc/smc91x.c
+++ b/drivers/net/ethernet/smsc/smc91x.c
@@ -81,6 +81,7 @@ static const char version[] =
#include <linux/workqueue.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_gpio.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
@@ -2188,6 +2189,41 @@ static const struct of_device_id smc91x_match[] = {
{},
};
MODULE_DEVICE_TABLE(of, smc91x_match);
+
+/**
+ * of_try_set_control_gpio - configure a gpio if it exists
+ */
+static int try_toggle_control_gpio(struct device *dev,
+ struct gpio_desc **desc,
+ const char *name, int index,
+ int value, unsigned int nsdelay)
+{
+ struct gpio_desc *gpio = *desc;
+ int res;
+
+ gpio = devm_gpiod_get_index(dev, name, index);
+ if (IS_ERR(gpio)) {
+ if (PTR_ERR(gpio) == -ENOENT) {
+ *desc = NULL;
+ return 0;
+ }
+
+ return PTR_ERR(gpio);
+ }
+ res = gpiod_direction_output(gpio, !value);
+ if (res) {
+ dev_err(dev, "unable to toggle gpio %s: %i\n", name, res);
+ devm_gpiod_put(dev, gpio);
+ gpio = NULL;
+ return res;
+ }
+ if (nsdelay)
+ usleep_range(nsdelay, 2 * nsdelay);
+ gpiod_set_value_cansleep(gpio, value);
+ *desc = gpio;
+
+ return 0;
+}
#endif
/*
@@ -2237,6 +2273,28 @@ static int smc_drv_probe(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
u32 val;
+ /* Optional pwrdwn GPIO configured? */
+ ret = try_toggle_control_gpio(&pdev->dev, &lp->power_gpio,
+ "power", 0, 0, 100);
+ if (ret)
+ return ret;
+
+ /*
+ * Optional reset GPIO configured? Minimum 100 ns reset needed
+ * according to LAN91C96 datasheet page 14.
+ */
+ ret = try_toggle_control_gpio(&pdev->dev, &lp->reset_gpio,
+ "reset", 0, 0, 100);
+ if (ret)
+ return ret;
+
+ /*
+ * Need to wait for optional EEPROM to load, max 750 us according
+ * to LAN91C96 datasheet page 55.
+ */
+ if (lp->reset_gpio)
+ usleep_range(750, 1000);
+
/* Combination of IO widths supported, default to 16-bit */
if (!of_property_read_u32(np, "reg-io-width", &val)) {
if (val & 1)
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