Commit 3a30ae6e authored by Richard Leitner's avatar Richard Leitner Committed by David S. Miller
Browse files

phylib: Add device reset delay support 



Some PHYs need a minimum time after the reset gpio was asserted and/or
deasserted. To ensure we meet these timing requirements add two new
optional devicetree parameters for the phy: reset-delay-us and
reset-post-delay-us.

Signed-off-by: default avatarRichard Leitner <richard.leitner@skidata.com>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9cca5d2f

Documentation/devicetree/bindings/net/phy.txt

+10 −0
Original line number Diff line number Diff line
@@ -55,6 +55,12 @@ Optional Properties: 


- reset-gpios: The GPIO phandle and specifier for the PHY reset signal.



- reset-delay-us: Delay after the reset was asserted in microseconds.

  If this property is missing the delay will be skipped.



- reset-post-delay-us: Delay after the reset was deasserted in microseconds.

  If this property is missing the delay will be skipped.



Example:



ethernet-phy@0 {
@@ -62,4 +68,8 @@ ethernet-phy@0 { 
	interrupt-parent = <&PIC>;

	interrupts = <35 IRQ_TYPE_EDGE_RISING>;

	reg = <0>;



	reset-gpios = <&gpio1 4 GPIO_ACTIVE_LOW>;

	reset-delay-us = <1000>;

	reset-post-delay-us = <2000>;

};

drivers/net/phy/mdio_device.c

+11 −2
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/slab.h>

#include <linux/string.h>

#include <linux/unistd.h>

#include <linux/delay.h>



void mdio_device_free(struct mdio_device *mdiodev)

{
@@ -118,8 +119,16 @@ EXPORT_SYMBOL(mdio_device_remove); 


void mdio_device_reset(struct mdio_device *mdiodev, int value)

{

	if (mdiodev->reset)

	unsigned int d;



	if (!mdiodev->reset)

		return;



	gpiod_set_value(mdiodev->reset, value);



	d = value ? mdiodev->reset_delay : mdiodev->reset_post_delay;

	if (d)

		usleep_range(d, d + max_t(unsigned int, d / 10, 100));

}

EXPORT_SYMBOL(mdio_device_reset);

drivers/of/of_mdio.c

+4 −0
Original line number Diff line number Diff line
@@ -77,6 +77,10 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio, 
	if (of_property_read_bool(child, "broken-turn-around"))

		mdio->phy_ignore_ta_mask |= 1 << addr;



	of_property_read_u32(child, "reset-delay-us", &phy->mdio.reset_delay);

	of_property_read_u32(child, "reset-post-delay-us",

			     &phy->mdio.reset_post_delay);



	/* Associate the OF node with the device structure so it

	 * can be looked up later */

	of_node_get(child);

include/linux/mdio.h

+2 −0
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ struct mdio_device { 
	int addr;

	int flags;

	struct gpio_desc *reset;

	unsigned int reset_delay;

	unsigned int reset_post_delay;

};

#define to_mdio_device(d) container_of(d, struct mdio_device, dev)

CRA Git | Maintained and supported by SUSTech CRA and CCSE