From: Roger Quadros <rogerq@ti.com>
To: Andrew Lunn <andrew@lunn.ch>
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 v2] mdio_bus: Issue GPIO RESET to PHYs.
Date: Thu, 20 Apr 2017 16:56:19 +0300 [thread overview]
Message-ID: <7a4ef761-f56b-0f4d-e092-211401a8ba30@ti.com> (raw)
In-Reply-To: <20170420131305.GB6152@lunn.ch>
On 20/04/17 16:13, Andrew Lunn wrote:
> On Thu, Apr 20, 2017 at 11:39:20AM +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.
>
> Hi Roger
>
> Networking patches should include in the subject line which tree they
> are for. In this case, net-next. So please make the Subject
>
> [patch v3 net-next] .....
>
>> [1] - am572x-idk, am571x-idk, a437x-idk
>>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>> v2:
>> - add device tree binding document (mdio.txt)
>> - specify default reset delay in of_mdio.c instead of mdio_bus.c
>>
>> Documentation/devicetree/bindings/net/mdio.txt | 20 ++++++++++++++++++++
>> drivers/net/phy/mdio_bus.c | 22 ++++++++++++++++++++++
>> drivers/of/of_mdio.c | 7 +++++++
>> include/linux/phy.h | 5 +++++
>> 4 files changed, 54 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/net/mdio.txt
>>
>> diff --git a/Documentation/devicetree/bindings/net/mdio.txt b/Documentation/devicetree/bindings/net/mdio.txt
>> new file mode 100644
>> index 0000000..6e703d7
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/net/mdio.txt
>> @@ -0,0 +1,20 @@
>> +Common MDIO bus properties.
>> +
>> +These are generic properties that can apply to any MDIO bus.
>> +
>> +Optional properties:
>> +- reset-gpios: List of one or more GPIOs that control the RESET lines
>> + of the PHYs on that MDIO bus.
>> +- reset-delay-us: RESET pulse width as per PHY datasheet.
>
> It would be good to explicitly say that it is in uS as part of the
> comment.
>
> Also, please document that we expect a list of child nodes, one per
> device on the bus. These should follow the generic phy.txt, or a
> device specific binding document.
>
>> +
>> +Example :
>> +
>
> It would be good to say something like:
>
> This example shows these optional properties, plus other properties
> required for the TI Davinci MDIO driver.
>
> Pointing this out may stop people cut/past the ti,hwmods property.
>
>> + davinci_mdio: ethernet@0x5c030000 {
>> + compatible = "ti,davinci_mdio";
>> + ti,hwmods = "davinci_mdio";
>> + reg = <0x5c030000 0x1000>;
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + reset-gpios = <&gpio2 5 GPIO_ACTIVE_LOW>;
>> + reset-delay-us = <2>; /* PHY datasheet states 1uS min */
>> + };
>
> And please include at least one PHY on the bus.
>
> Sorry for asking for so much in the documentation. That is the problem
> with the documentation being missing to start with.
>
> The code looks good now.
>
OK Andrew. I'll post a v3 with your suggestions.
cheers,
-roger
next prev parent reply other threads:[~2017-04-20 13:57 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
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 [this message]
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=7a4ef761-f56b-0f4d-e092-211401a8ba30@ti.com \
--to=rogerq@ti.com \
--cc=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=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).