From: Roger Quadros <rogerq@ti.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: <davem@davemloft.net>, <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] net: davinci_mdio: add GPIO reset logic
Date: Thu, 6 Apr 2017 12:15:10 +0300 [thread overview]
Message-ID: <485433e3-1a9f-71f6-afc9-88e646cf43d1@ti.com> (raw)
In-Reply-To: <20170405150334.GI13449@lunn.ch>
Hi,
On 05/04/17 18:03, Andrew Lunn wrote:
> On Wed, Apr 05, 2017 at 11:33:57AM +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 like not being detected by the mdio bus
>> or link not functional. To work around these boards have
>> a GPIO connected to the PHY's reset pin.
>>
>> Implement GPIO reset handling for such cases.
>>
>> [1] - am572x-idk, am571x-idk, a437x-idk.
>>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> Signed-off-by: Sekhar Nori <nsekhar@ti.com>
>> ---
>> .../devicetree/bindings/net/davinci-mdio.txt | 2 +
>> drivers/net/ethernet/ti/davinci_mdio.c | 68 +++++++++++++++++++---
>> 2 files changed, 62 insertions(+), 8 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/net/davinci-mdio.txt b/Documentation/devicetree/bindings/net/davinci-mdio.txt
>> index 621156c..fd6ebe7 100644
>> --- a/Documentation/devicetree/bindings/net/davinci-mdio.txt
>> +++ b/Documentation/devicetree/bindings/net/davinci-mdio.txt
>> @@ -12,6 +12,8 @@ Required properties:
>>
>> Optional properties:
>> - ti,hwmods : Must be "davinci_mdio"
>> +- reset-gpios : array of GPIO specifier for PHY hardware reset control
>> +- reset-delay-us : reset assertion time [in microseconds]
>>
>> Note: "ti,hwmods" field is used to fetch the base address and irq
>> resources from TI, omap hwmod data base during device registration.
>> diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
>> index 33df340..c6f9e55 100644
>> --- a/drivers/net/ethernet/ti/davinci_mdio.c
>> +++ b/drivers/net/ethernet/ti/davinci_mdio.c
>> @@ -40,6 +40,9 @@
>> #include <linux/of_device.h>
>> #include <linux/of_mdio.h>
>> #include <linux/pinctrl/consumer.h>
>> +#include <linux/gpio.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/of_gpio.h>
>>
>> /*
>> * This timeout definition is a worst-case ultra defensive measure against
>> @@ -53,6 +56,8 @@
>>
>> #define DEF_OUT_FREQ 2200000 /* 2.2 MHz */
>>
>> +#define DEFAULT_GPIO_RESET_DELAY 10 /* in microseconds */
>> +
>> struct davinci_mdio_of_param {
>> int autosuspend_delay_ms;
>> };
>> @@ -104,6 +109,9 @@ struct davinci_mdio_data {
>> */
>> bool skip_scan;
>> u32 clk_div;
>> + struct gpio_desc **gpio_reset;
>> + int num_gpios;
>> + int reset_delay_us;
>> };
>>
>> static void davinci_mdio_init_clk(struct davinci_mdio_data *data)
>> @@ -142,6 +150,20 @@ static void davinci_mdio_enable(struct davinci_mdio_data *data)
>> __raw_writel(data->clk_div | CONTROL_ENABLE, &data->regs->control);
>> }
>>
>> +static void __davinci_gpio_reset(struct davinci_mdio_data *data)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < data->num_gpios; i++) {
>> + if (!data->gpio_reset[i])
>> + continue;
>> +
>> + gpiod_set_value_cansleep(data->gpio_reset[i], 1);
>> + udelay(data->reset_delay_us);
>> + gpiod_set_value_cansleep(data->gpio_reset[i], 0);
>> + }
>> +}
>
> Do you really need more than one GPIO? A single gpio would make all
> this code a lot simpler.
>
Yes we need. Some of our boards have separate GPIO RESET lines for
different PHYs on the same MDIO bus.
cheers,
-roger
next prev parent reply other threads:[~2017-04-06 9:20 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 [this message]
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
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=485433e3-1a9f-71f6-afc9-88e646cf43d1@ti.com \
--to=rogerq@ti.com \
--cc=andrew@lunn.ch \
--cc=davem@davemloft.net \
--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=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).