[PATCH v3 0/3] net: add reset-controller driven PHY reset

[PATCH v3 0/3] net: add reset-controller driven PHY reset

[David Bauer]

This patchset adds support for a PHY reset driven by a reset-controller.
Currently, only GPIO driven resets are supported by the PHY subsystem.
It also renames the reset-gpio from 'reset' to 'reset_gpio' to
better differentiate between resets wired to a GPIO and resets wired to
a reset-controller driven pin.

Some systems have the PHY reset-line wired to a pin controlled by a
reset-controller (eg. some Atheros AR9132 based boards). In case the
bootloader asserts reset before loading the kernel, we currently do not
have a clean way of deasserting reset to probe the PHY.

v3:
 - add missing newline in mdio_bus.c

v2:
 - fixed missed rename of "reset" in at803x.c
 - move initial reset to mdio_device_reset


David Bauer (3):
  dt-bindings: net: add PHY reset controller binding
  net: phy: add support for reset-controller
  net: mdio: rename mdio_device reset to reset_gpio

 Documentation/devicetree/bindings/net/phy.txt |  6 ++++
 drivers/net/phy/at803x.c                      |  2 +-
 drivers/net/phy/mdio_bus.c                    | 33 ++++++++++++++++---
 drivers/net/phy/mdio_device.c                 | 13 ++++++--
 include/linux/mdio.h                          |  3 +-
 5 files changed, 48 insertions(+), 9 deletions(-)

-- 
2.21.0

[PATCH v3 1/3] dt-bindings: net: add PHY reset controller binding

[David Bauer]

Add the documentation for PHY reset lines controlled by a reset controller.

Signed-off-by: David Bauer <mail@david-bauer.net>
---
 Documentation/devicetree/bindings/net/phy.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/phy.txt b/Documentation/devicetree/bindings/net/phy.txt
index 17c1d2bd00f6..9b9e5b1765dd 100644
--- a/Documentation/devicetree/bindings/net/phy.txt
+++ b/Documentation/devicetree/bindings/net/phy.txt
@@ -51,6 +51,10 @@ Optional Properties:
   to ensure the integrated PHY is used. The absence of this property indicates
   the muxers should be configured so that the external PHY is used.
 
+- resets: The reset-controller phandle and specifier for the PHY reset signal.
+
+- reset-names: Must be "phy" for the PHY reset signal.
+
 - reset-gpios: The GPIO phandle and specifier for the PHY reset signal.
 
 - reset-assert-us: Delay after the reset was asserted in microseconds.
@@ -67,6 +71,8 @@ ethernet-phy@0 {
 	interrupts = <35 IRQ_TYPE_EDGE_RISING>;
 	reg = <0>;
 
+	resets = <&rst 8>;
+	reset-names = "phy";
 	reset-gpios = <&gpio1 4 GPIO_ACTIVE_LOW>;
 	reset-assert-us = <1000>;
 	reset-deassert-us = <2000>;
-- 
2.21.0

[PATCH v3 2/3] net: phy: add support for reset-controller

[David Bauer]

This commit adds support for PHY reset pins handled by a reset controller.

Signed-off-by: David Bauer <mail@david-bauer.net>
---
 drivers/net/phy/mdio_bus.c    | 27 +++++++++++++++++++++++++--
 drivers/net/phy/mdio_device.c | 13 +++++++++++--
 include/linux/mdio.h          |  1 +
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 4be4cc09eb90..ba3d2523808b 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -24,6 +24,7 @@
 #include <linux/of_gpio.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
+#include <linux/reset.h>
 #include <linux/skbuff.h>
 #include <linux/spinlock.h>
 #include <linux/mm.h>
@@ -57,8 +58,23 @@ static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 
 	mdiodev->reset = gpiod;
 
-	/* Assert the reset signal again */
-	mdio_device_reset(mdiodev, 1);
+	return 0;
+}
+
+static int mdiobus_register_reset(struct mdio_device *mdiodev)
+{
+	struct reset_control *reset = NULL;
+
+	if (mdiodev->dev.of_node)
+		reset = devm_reset_control_get_exclusive(&mdiodev->dev,
+							 "phy");
+	if (PTR_ERR(reset) == -ENOENT ||
+	    PTR_ERR(reset) == -ENOTSUPP)
+		reset = NULL;
+	else if (IS_ERR(reset))
+		return PTR_ERR(reset);
+
+	mdiodev->reset_ctrl = reset;
 
 	return 0;
 }
@@ -74,6 +90,13 @@ int mdiobus_register_device(struct mdio_device *mdiodev)
 		err = mdiobus_register_gpiod(mdiodev);
 		if (err)
 			return err;
+
+		err = mdiobus_register_reset(mdiodev);
+		if (err)
+			return err;
+
+		/* Assert the reset signal */
+		mdio_device_reset(mdiodev, 1);
 	}
 
 	mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index 887076292e50..57668e0f9256 100644
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
@@ -16,6 +16,7 @@
 #include <linux/mii.h>
 #include <linux/module.h>
 #include <linux/phy.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/unistd.h>
@@ -116,10 +117,18 @@ void mdio_device_reset(struct mdio_device *mdiodev, int value)
 {
 	unsigned int d;
 
-	if (!mdiodev->reset)
+	if (!mdiodev->reset && !mdiodev->reset_ctrl)
 		return;
 
-	gpiod_set_value(mdiodev->reset, value);
+	if (mdiodev->reset)
+		gpiod_set_value(mdiodev->reset, value);
+
+	if (mdiodev->reset_ctrl) {
+		if (value)
+			reset_control_assert(mdiodev->reset_ctrl);
+		else
+			reset_control_deassert(mdiodev->reset_ctrl);
+	}
 
 	d = value ? mdiodev->reset_assert_delay : mdiodev->reset_deassert_delay;
 	if (d)
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 3e99ae3ed87f..6eaf71500ef6 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -40,6 +40,7 @@ struct mdio_device {
 	int addr;
 	int flags;
 	struct gpio_desc *reset;
+	struct reset_control *reset_ctrl;
 	unsigned int reset_assert_delay;
 	unsigned int reset_deassert_delay;
 };
-- 
2.21.0

[PATCH v3 3/3] net: mdio: rename mdio_device reset to reset_gpio

[David Bauer]

This renames the GPIO reset of mdio devices from 'reset' to
'reset_gpio' to better differentiate between GPIO and
reset-controller driven reset line.

Signed-off-by: David Bauer <mail@david-bauer.net>
---
 drivers/net/phy/at803x.c      | 2 +-
 drivers/net/phy/mdio_bus.c    | 6 +++---
 drivers/net/phy/mdio_device.c | 6 +++---
 include/linux/mdio.h          | 2 +-
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index f3e96191eb6f..16c5a83e2a60 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -334,7 +334,7 @@ static void at803x_link_change_notify(struct phy_device *phydev)
 	 * cannot recover from by software.
 	 */
 	if (phydev->state == PHY_NOLINK) {
-		if (phydev->mdio.reset && !priv->phy_reset) {
+		if (phydev->mdio.reset_gpio && !priv->phy_reset) {
 			struct at803x_context context;
 
 			at803x_context_save(phydev, &context);
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index ba3d2523808b..bd04fe762056 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -56,7 +56,7 @@ static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 			return PTR_ERR(gpiod);
 	}
 
-	mdiodev->reset = gpiod;
+	mdiodev->reset_gpio = gpiod;
 
 	return 0;
 }
@@ -469,8 +469,8 @@ void mdiobus_unregister(struct mii_bus *bus)
 		if (!mdiodev)
 			continue;
 
-		if (mdiodev->reset)
-			gpiod_put(mdiodev->reset);
+		if (mdiodev->reset_gpio)
+			gpiod_put(mdiodev->reset_gpio);
 
 		mdiodev->device_remove(mdiodev);
 		mdiodev->device_free(mdiodev);
diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index 57668e0f9256..e282600bd83e 100644
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
@@ -117,11 +117,11 @@ void mdio_device_reset(struct mdio_device *mdiodev, int value)
 {
 	unsigned int d;
 
-	if (!mdiodev->reset && !mdiodev->reset_ctrl)
+	if (!mdiodev->reset_gpio && !mdiodev->reset_ctrl)
 		return;
 
-	if (mdiodev->reset)
-		gpiod_set_value(mdiodev->reset, value);
+	if (mdiodev->reset_gpio)
+		gpiod_set_value(mdiodev->reset_gpio, value);
 
 	if (mdiodev->reset_ctrl) {
 		if (value)
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 6eaf71500ef6..9dc16d5705a1 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -39,7 +39,7 @@ struct mdio_device {
 	/* Bus address of the MDIO device (0-31) */
 	int addr;
 	int flags;
-	struct gpio_desc *reset;
+	struct gpio_desc *reset_gpio;
 	struct reset_control *reset_ctrl;
 	unsigned int reset_assert_delay;
 	unsigned int reset_deassert_delay;
-- 
2.21.0

Re: [PATCH v3 1/3] dt-bindings: net: add PHY reset controller binding

[Andrew Lunn]

On Wed, Apr 17, 2019 at 11:59:20PM +0200, David Bauer wrote:
> Add the documentation for PHY reset lines controlled by a reset controller.
> 
> Signed-off-by: David Bauer <mail@david-bauer.net>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH v3 2/3] net: phy: add support for reset-controller

[Andrew Lunn]

On Wed, Apr 17, 2019 at 11:59:21PM +0200, David Bauer wrote:
> This commit adds support for PHY reset pins handled by a reset controller.
> 
> Signed-off-by: David Bauer <mail@david-bauer.net>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH v3 3/3] net: mdio: rename mdio_device reset to reset_gpio

[Andrew Lunn]

On Wed, Apr 17, 2019 at 11:59:22PM +0200, David Bauer wrote:
> This renames the GPIO reset of mdio devices from 'reset' to
> 'reset_gpio' to better differentiate between GPIO and
> reset-controller driven reset line.
> 
> Signed-off-by: David Bauer <mail@david-bauer.net>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH v3 0/3] net: add reset-controller driven PHY reset

[David Miller]

From: David Bauer <mail@david-bauer.net>
Date: Wed, 17 Apr 2019 23:59:19 +0200

> This patchset adds support for a PHY reset driven by a reset-controller.
> Currently, only GPIO driven resets are supported by the PHY subsystem.
> It also renames the reset-gpio from 'reset' to 'reset_gpio' to
> better differentiate between resets wired to a GPIO and resets wired to
> a reset-controller driven pin.
> 
> Some systems have the PHY reset-line wired to a pin controlled by a
> reset-controller (eg. some Atheros AR9132 based boards). In case the
> bootloader asserts reset before loading the kernel, we currently do not
> have a clean way of deasserting reset to probe the PHY.
> 
> v3:
>  - add missing newline in mdio_bus.c
> 
> v2:
>  - fixed missed rename of "reset" in at803x.c
>  - move initial reset to mdio_device_reset

Series applied to net-next, thanks.