[PATCH v2.1 3/9] net: arc_emac: support the phy reset for emac driver

From: Caesar Wang
Date: Sun Mar 13 2016 - 06:06:30 EST


This patch adds to support the emac phy reset.

Different boards may require different phy reset duration. Add property
phy-reset-duration for emac driver, so that the boards that need
a longer reset duration can specify it in their device tree.

Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>

---

Changes in v2.1:
- missing the include head file.

Changes in v2:
- As the pervious version, Sergei and Heiko comments on
https://patchwork.kernel.org/patch/8564571/.
- Nevermind, add signed-off since Heiko the original patch,
refer the Heiko's test patch on
https://github.com/mmind/linux-rockchip/commit/a943c588783438ff1c508dfa8c79f1709aa5775e
:)

drivers/net/ethernet/arc/emac.h | 6 ++++++
drivers/net/ethernet/arc/emac_mdio.c | 37 ++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+)

diff --git a/drivers/net/ethernet/arc/emac.h b/drivers/net/ethernet/arc/emac.h
index dae1ac3..1a40403 100644
--- a/drivers/net/ethernet/arc/emac.h
+++ b/drivers/net/ethernet/arc/emac.h
@@ -102,6 +102,11 @@ struct buffer_state {
DEFINE_DMA_UNMAP_LEN(len);
};

+struct arc_emac_mdio_bus_data {
+ struct gpio_desc *reset_gpio;
+ int msec;
+};
+
/**
* struct arc_emac_priv - Storage of EMAC's private information.
* @dev: Pointer to the current device.
@@ -131,6 +136,7 @@ struct arc_emac_priv {
struct device *dev;
struct phy_device *phy_dev;
struct mii_bus *bus;
+ struct arc_emac_mdio_bus_data bus_data;

void __iomem *regs;
struct clk *clk;
diff --git a/drivers/net/ethernet/arc/emac_mdio.c b/drivers/net/ethernet/arc/emac_mdio.c
index d5ee986..0ab62d4 100644
--- a/drivers/net/ethernet/arc/emac_mdio.c
+++ b/drivers/net/ethernet/arc/emac_mdio.c
@@ -7,6 +7,7 @@
#include <linux/delay.h>
#include <linux/of_mdio.h>
#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>

#include "emac.h"

@@ -99,6 +100,25 @@ static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
}

/**
+ * arc_mdio_reset
+ * @bus: points to the mii_bus structure
+ * Description: reset the MII bus
+ */
+int arc_mdio_reset(struct mii_bus *bus)
+{
+ struct arc_emac_priv *priv = bus->priv;
+ struct arc_emac_mdio_bus_data *data = &priv->bus_data;
+
+ if (data->reset_gpio) {
+ gpiod_set_value_cansleep(data->reset_gpio, 1);
+ msleep(data->msec);
+ gpiod_set_value_cansleep(data->reset_gpio, 0);
+ }
+
+ return 0;
+}
+
+/**
* arc_mdio_probe - MDIO probe function.
* @priv: Pointer to ARC EMAC private data structure.
*
@@ -109,6 +129,8 @@ static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
*/
int arc_mdio_probe(struct arc_emac_priv *priv)
{
+ struct arc_emac_mdio_bus_data *data = &priv->bus_data;
+ struct device_node *np = priv->dev->of_node;
struct mii_bus *bus;
int error;

@@ -122,6 +144,21 @@ int arc_mdio_probe(struct arc_emac_priv *priv)
bus->name = "Synopsys MII Bus",
bus->read = &arc_mdio_read;
bus->write = &arc_mdio_write;
+ bus->reset = &arc_mdio_reset;
+
+ /* optional reset-related properties */
+ data->reset_gpio = devm_gpiod_get_optional(priv->dev, "reset",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(data->reset_gpio)) {
+ error = PTR_ERR(data->reset_gpio);
+ dev_err(priv->dev, "Failed to request gpio: %d\n", error);
+ return error;
+ }
+
+ of_property_read_u32(np, "phy-reset-duration", &data->msec);
+ /* A sane reset duration should not be longer than 1s */
+ if (data->msec > 1000)
+ data->msec = 1;

snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);

--
1.9.1