From: Andrew Lunn <andrew@lunn.ch>
To: Roger Quadros <rogerq@ti.com>
Cc: davem@davemloft.net, Florian Fainelli <f.fainelli@gmail.com>,
tony@atomide.com, nsekhar@ti.com, jsarha@ti.com,
netdev@vger.kernel.org, linux-omap@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mdio_bus: Issue GPIO RESET to PHYs.
Date: Wed, 19 Apr 2017 13:39:51 +0200 [thread overview]
Message-ID: <20170419113951.GA31908@lunn.ch> (raw)
In-Reply-To: <64d6494d-41d2-0faf-a434-057f796637fe@ti.com>
On Wed, Apr 19, 2017 at 12:24:26PM +0300, Roger Quadros wrote:
> Some boards [1] leave the PHYs at an invalid state
> during system power-up or reset thus causing unreliability
> issues with the PHY which manifests as PHY not being detected
> or link not functional. To fix this, these PHYs need to be RESET
> via a GPIO connected to the PHY's RESET pin.
>
> Some boards have a single GPIO controlling the PHY RESET pin of all
> PHYs on the bus whereas some others have separate GPIOs controlling
> individual PHY RESETs.
>
> In both cases, the RESET de-assertion cannot be done in the PHY driver
> as the PHY will not probe till its reset is de-asserted.
> So do the RESET de-assertion in the MDIO bus driver.
>
> [1] - am572x-idk, am571x-idk, a437x-idk
>
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
> drivers/net/phy/mdio_bus.c | 26 ++++++++++++++++++++++++++
> drivers/of/of_mdio.c | 4 ++++
> include/linux/phy.h | 5 +++++
> 3 files changed, 35 insertions(+)
Hi Roger
Thanks for making this generic.
Please add device tree binding documentation. I think that actually
means you have to document MDIO in general, since there currently is
not a binding document.
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index fa7d51f..25fda2b 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -22,8 +22,11 @@
> #include <linux/init.h>
> #include <linux/delay.h>
> #include <linux/device.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/of_device.h>
> #include <linux/of_mdio.h>
> +#include <linux/of_gpio.h>
> #include <linux/netdevice.h>
> #include <linux/etherdevice.h>
> #include <linux/skbuff.h>
> @@ -43,6 +46,8 @@
>
> #include "mdio-boardinfo.h"
>
> +#define DEFAULT_GPIO_RESET_DELAY 10 /* in microseconds */
> +
> int mdiobus_register_device(struct mdio_device *mdiodev)
> {
> if (mdiodev->bus->mdio_map[mdiodev->addr])
> @@ -307,6 +312,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
> {
> struct mdio_device *mdiodev;
> int i, err;
> + struct gpio_desc *gpiod;
>
> if (NULL == bus || NULL == bus->name ||
> NULL == bus->read || NULL == bus->write)
> @@ -333,6 +339,26 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
> if (bus->reset)
> bus->reset(bus);
>
> + /* de-assert bus level PHY GPIO resets */
> + for (i = 0; i < bus->num_reset_gpios; i++) {
> + gpiod = devm_gpiod_get_index(&bus->dev, "reset", i,
> + GPIOD_OUT_LOW);
> + if (IS_ERR(gpiod)) {
> + err = PTR_ERR(gpiod);
> + if (err != -ENOENT) {
> + pr_err("mii_bus %s couldn't get reset GPIO\n",
> + bus->id);
> + return err;
> + }
> + } else {
> + gpiod_set_value_cansleep(gpiod, 1);
> + if (!bus->reset_delay_us)
> + bus->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
Maybe do this once, where you read the device tree property.
> + udelay(bus->reset_delay_us);
> + gpiod_set_value_cansleep(gpiod, 0);
> + }
> + }
> +
> for (i = 0; i < PHY_MAX_ADDR; i++) {
> if ((bus->phy_mask & (1 << i)) == 0) {
> struct phy_device *phydev;
> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> index 0b29798..83a62e4 100644
> --- a/drivers/of/of_mdio.c
> +++ b/drivers/of/of_mdio.c
> @@ -221,6 +221,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>
> mdio->dev.of_node = np;
>
> + /* Get bus level PHY reset GPIO details */
> + of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
If the property does not exist, it is guaranteed mdio->reset_delay_us
is not changed. So you can set it to the default value before, then do
this call.
Andrew
next prev parent reply other threads:[~2017-04-19 11:40 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-05 8:33 [PATCH] net: davinci_mdio: add GPIO reset logic Roger Quadros
2017-04-05 15:03 ` Andrew Lunn
2017-04-06 9:15 ` Roger Quadros
2017-04-06 12:05 ` Andrew Lunn
2017-04-06 16:48 ` Roger Quadros
2017-04-08 13:55 ` David Miller
2017-04-08 15:10 ` Andrew Lunn
2017-04-08 15:18 ` Florian Fainelli
2017-04-10 7:52 ` Roger Quadros
2017-04-19 9:24 ` [PATCH] mdio_bus: Issue GPIO RESET to PHYs Roger Quadros
2017-04-19 11:39 ` Andrew Lunn [this message]
2017-04-19 11:56 ` Roger Quadros
2017-04-19 13:38 ` Andrew Lunn
2017-04-20 7:58 ` Roger Quadros
2017-04-20 8:39 ` [PATCH v2] " Roger Quadros
2017-04-20 13:13 ` Andrew Lunn
2017-04-20 13:56 ` Roger Quadros
2017-04-20 14:11 ` [PATCH v3 net-next] " Roger Quadros
2017-04-21 1:12 ` Andrew Lunn
2017-04-21 1:23 ` Florian Fainelli
2017-04-21 1:38 ` Andrew Lunn
2017-04-21 8:04 ` Roger Quadros
2017-04-21 13:15 ` [PATCH v4 " Roger Quadros
2017-04-21 13:31 ` Lars-Peter Clausen
2017-04-23 23:35 ` Andrew Lunn
2017-04-24 9:04 ` Roger Quadros
2017-04-24 16:32 ` Florian Fainelli
2017-04-25 16:22 ` Lars-Peter Clausen
2017-04-25 16:31 ` Florian Fainelli
2017-04-26 10:46 ` Roger Quadros
2017-04-26 12:27 ` Andrew Lunn
2017-04-26 10:43 ` Roger Quadros
2017-04-24 16:40 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170419113951.GA31908@lunn.ch \
--to=andrew@lunn.ch \
--cc=davem@davemloft.net \
--cc=f.fainelli@gmail.com \
--cc=jsarha@ti.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=nsekhar@ti.com \
--cc=rogerq@ti.com \
--cc=tony@atomide.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).