Thread (14 messages) 14 messages, 5 authors, 2016-03-18
STALE3755d
Revisions (3)
  1. v2 [diff vs current]
  2. v2 [diff vs current]
  3. v3 current

[PATCH v3 3/9] net: arc_emac: support the phy reset for emac driver

From: Caesar Wang <hidden>
Date: 2016-03-14 08:05:51
Also in: linux-rockchip, lkml
Subsystem: networking drivers, the rest · Maintainers: Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

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 <redacted>
Signed-off-by: Caesar Wang <redacted>
Cc: "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Alexander Kochetkov <redacted>
Cc: Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>

---

Changes in v3:
- Caused the build error since the missing include head file.
- %s/reset/phy-reset to match the device tree.
- Add the Cc people

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..caf7042 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, "phy-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
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