[PATCH] net: stmmac: Support gpio high-level reset for devices requiring it

[Lizhe]

some devices only reset when the GPIO is at a high level, but the
current function lacks support for such devices. add high-level
reset functionality to the function to support devices that require
high-level triggering for reset

Signed-off-by: Lizhe <sensor1010@xxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index 836f2848dfeb..cb989e6d7eac 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -458,6 +458,7 @@ int stmmac_mdio_reset(struct mii_bus *bus)
 
 #ifdef CONFIG_OF
 	if (priv->device->of_node) {
+		int active_low = 0;
 		struct gpio_desc *reset_gpio;
 		u32 delays[3] = { 0, 0, 0 };
 
@@ -467,6 +468,9 @@ int stmmac_mdio_reset(struct mii_bus *bus)
 		if (IS_ERR(reset_gpio))
 			return PTR_ERR(reset_gpio);
 
+		if (reset_gpio)
+			active_low = gpiod_is_active_low(reset_gpio);
+
 		device_property_read_u32_array(priv->device,
 					       "snps,reset-delays-us",
 					       delays, ARRAY_SIZE(delays));
@@ -474,11 +478,11 @@ int stmmac_mdio_reset(struct mii_bus *bus)
 		if (delays[0])
 			msleep(DIV_ROUND_UP(delays[0], 1000));
 
-		gpiod_set_value_cansleep(reset_gpio, 1);
+		gpiod_set_value_cansleep(reset_gpio, active_low ? 1 : 0);
 		if (delays[1])
 			msleep(DIV_ROUND_UP(delays[1], 1000));
 
-		gpiod_set_value_cansleep(reset_gpio, 0);
+		gpiod_set_value_cansleep(reset_gpio, active_low ? 0 : 1);
 		if (delays[2])
 			msleep(DIV_ROUND_UP(delays[2], 1000));
 	}
-- 
2.17.1