[PATCH net-next v4 13/12] net: lan865x: optional hardware reset

Ramón Nordin Rodriguez
2024-04-28T21:16:36Z

From c65e42982684d5fd8b2294eb6acf755aa0fcab83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ram=C3=B3n=20Nordin=20Rodriguez?=
<ramon.nordin.rodriguez@ferroamp.se>
Date: Sun, 28 Apr 2024 22:25:12 +0200
Subject: [PATCH net-next v4 13/12] net: lan865x: optional hardware reset
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This commit optionally enables a hardware reset of the lan8650/1
mac-phy. These chips have a software reset that is discourage from use
in the manual since it only resets the internal phy.

Signed-off-by: Ramón Nordin Rodriguez <ramon.nordin.rodriguez@ferroamp.se>
---
.../bindings/net/microchip,lan865x.yaml | 4 +++
.../net/ethernet/microchip/lan865x/lan865x.c | 28 +++++++++++++++++++
2 files changed, 32 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/microchip,lan865x.yaml b/Documentation/devicetree/bindings/net/microchip,lan865x.yaml
index 4fdec0ba3532..0f11f431df06 100644
--- a/Documentation/devicetree/bindings/net/microchip,lan865x.yaml
+++ b/Documentation/devicetree/bindings/net/microchip,lan865x.yaml
@@ -44,6 +44,9 @@ properties:
minimum: 15000000
maximum: 25000000

+ reset-gpios:
+ maxItems: 1
+
"#address-cells":
const: 1

@@ -76,5 +79,6 @@ examples:
interrupts = <6 IRQ_TYPE_EDGE_FALLING>;
local-mac-address = [04 05 06 01 02 03];
spi-max-frequency = <15000000>;
+ reset-gpios = <&gpio2 8 GPIO_ACTIVE_HIGH>;
};
};
diff --git a/drivers/net/ethernet/microchip/lan865x/lan865x.c b/drivers/net/ethernet/microchip/lan865x/lan865x.c
index 9abefa8b9d9f..bed9033574b2 100644
--- a/drivers/net/ethernet/microchip/lan865x/lan865x.c
+++ b/drivers/net/ethernet/microchip/lan865x/lan865x.c
@@ -9,6 +9,7 @@
#include <linux/kernel.h>
#include <linux/phy.h>
#include <linux/oa_tc6.h>
+#include <linux/gpio/driver.h>

#define DRV_NAME "lan865x"

@@ -33,6 +34,7 @@

struct lan865x_priv {
struct work_struct multicast_work;
+ struct gpio_desc *reset_gpio;
struct net_device *netdev;
struct spi_device *spi;
struct oa_tc6 *tc6;
@@ -283,6 +285,24 @@ static int lan865x_set_zarfe(struct lan865x_priv *priv)
return oa_tc6_write_register(priv->tc6, OA_TC6_REG_CONFIG0, regval);
}

+static int lan865x_probe_reset_gpio(struct lan865x_priv *priv)
+{
+ priv->reset_gpio = devm_gpiod_get_optional(&priv->spi->dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(priv->reset_gpio))
+ return PTR_ERR(priv->reset_gpio);
+
+ return 0;
+}
+
+static void lan865x_hw_reset(struct lan865x_priv *priv)
+{
+ gpiod_set_value_cansleep(priv->reset_gpio, 1);
+ // section 9.6.3 RESET_N Timing specifies a minimum hold of 5us
+ usleep_range(5, 10);
+ gpiod_set_value_cansleep(priv->reset_gpio, 0);
+}
+
static int lan865x_probe(struct spi_device *spi)
{
struct net_device *netdev;
@@ -297,6 +317,14 @@ static int lan865x_probe(struct spi_device *spi)
priv->netdev = netdev;
priv->spi = spi;
spi_set_drvdata(spi, priv);
+ if (lan865x_probe_reset_gpio(priv)) {
+ dev_err(&spi->dev, "failed to probe reset pin");
+ ret = -ENODEV;
+ goto free_netdev;
+ }
+
+ if (priv->reset_gpio)
+ lan865x_hw_reset(priv);
INIT_WORK(&priv->multicast_work, lan865x_multicast_work_handler);

priv->tc6 = oa_tc6_init(spi, netdev);
--
2.43.0