public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Christian Lamparter <chunkeey@gmail•com>
To: Andrew Lunn <andrew@lunn•ch>
Cc: netdev@vger•kernel.org, Florian Fainelli <f.fainelli@gmail•com>,
	Vivien Didelot <vivien.didelot@gmail•com>
Subject: Re: [PATCH v1] net: dsa: qca8k: implement DT-based ports <-> phy translation
Date: Tue, 05 Feb 2019 13:48:43 +0100	[thread overview]
Message-ID: <24213401.HFHtFJUkrt@debian64> (raw)
In-Reply-To: <20190205024533.GB10838@lunn.ch>

On Tuesday, February 5, 2019 3:45:33 AM CET Andrew Lunn wrote:
> On Mon, Feb 04, 2019 at 10:35:55PM +0100, Christian Lamparter wrote:
> > The QCA8337 enumerates 5 PHYs on the MDC/MDIO access: PHY0-PHY4.
> > Based on the System Block Diagram in Section 1.2 of the
> > QCA8337's datasheet. These PHYs are internally connected
> > to MACs of PORT 1 - PORT 5. However, neither qca8k's slave
> > mdio access functions qca8k_phy_read()/qca8k_phy_write()
> > nor the dsa framework is set up for that.
> > 
> > This version of the patch uses the existing phy-handle
> > properties of each specified DSA Port in the DT to map
> > each PORT/MAC to its exposed PHY on the MDIO bus. This
> > is supported by the current binding document qca8k.txt
> > as well.
> 
> Hi Christian
> 
> Looking at Documentation/devicetree/bindings/net/dsa/qca8k.txt 
> 
> I think everything you need is already implemented. What problem do
> you actually have?

Thankfully, Florian's reply answered the question to me. The problem
has to do with the qca8k's slave qca8k_phy_read and qca8k_phy_write.
Here are the functions:

|qca8k_phy_read(struct dsa_switch *ds, int phy, int regnum)
|{
|	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
|
|	return mdiobus_read(priv->bus, phy, regnum);
|}
|
|static int
|qca8k_phy_write(struct dsa_switch *ds, int phy, int regnum, u16 val)
|{
|	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
|
|	return mdiobus_write(priv->bus, phy, regnum, val);
|}

The trick here is that priv->bus is not the internal
bus instead it's set to the SoC's (external) mii bus in qca8k_sw_probe()).
So this isn't a slave bus! And as stated in the qca8k, the the external
and internal PHY bus are not mapped 1:1.

From what I can tell from the datasheet, the QCA8337N does have
dedicated MDIO master control register which is what is
needed here. It's at 0x003C. So these mdiobus_read/writes on the
SoCs MDIO bus would either need to be converted to read and write
to 0x003c... Or the qca8k_phy_read() and qca8k_phy_write could be
dropped all together. I've tested it on the WPQ864 and driver
works without since it was never a real slave bus there to begin with.

Thanks,
Christian
---
diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 7e97e620bd44..a26850c888cf 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -620,22 +620,6 @@ qca8k_adjust_link(struct dsa_switch *ds, int port, struct phy_device *phy)
 	qca8k_port_set_status(priv, port, 1);
 }
 
-static int
-qca8k_phy_read(struct dsa_switch *ds, int phy, int regnum)
-{
-	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
-
-	return mdiobus_read(priv->bus, phy, regnum);
-}
-
-static int
-qca8k_phy_write(struct dsa_switch *ds, int phy, int regnum, u16 val)
-{
-	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
-
-	return mdiobus_write(priv->bus, phy, regnum, val);
-}
-
 static void
 qca8k_get_strings(struct dsa_switch *ds, int port, u32 stringset, uint8_t *data)
 {
@@ -876,8 +860,6 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
 	.setup			= qca8k_setup,
 	.adjust_link            = qca8k_adjust_link,
 	.get_strings		= qca8k_get_strings,
-	.phy_read		= qca8k_phy_read,
-	.phy_write		= qca8k_phy_write,
 	.get_ethtool_stats	= qca8k_get_ethtool_stats,
 	.get_sset_count		= qca8k_get_sset_count,
 	.get_mac_eee		= qca8k_get_mac_eee,








  reply	other threads:[~2019-02-05 12:48 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-04 21:35 [PATCH v1] net: dsa: qca8k: implement DT-based ports <-> phy translation Christian Lamparter
2019-02-04 22:11 ` Florian Fainelli
2019-02-04 22:26 ` Andrew Lunn
2019-02-04 23:55   ` Christian Lamparter
2019-02-05  2:45 ` Andrew Lunn
2019-02-05 12:48   ` Christian Lamparter [this message]
2019-02-05 13:09     ` Andrew Lunn
2019-02-05 21:08       ` Christian Lamparter
2019-02-05 21:29         ` Andrew Lunn
2019-02-05 22:12           ` Christian Lamparter
2019-02-05 22:29             ` Florian Fainelli
2019-02-06 21:57               ` Christian Lamparter
2019-02-06 22:29                 ` Florian Fainelli
2019-02-06 22:32                   ` Florian Fainelli
2019-02-07  0:43                   ` Christian Lamparter

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=24213401.HFHtFJUkrt@debian64 \
    --to=chunkeey@gmail$(echo .)com \
    --cc=andrew@lunn$(echo .)ch \
    --cc=f.fainelli@gmail$(echo .)com \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=vivien.didelot@gmail$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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