> -----Original Message----- > From: Andrew Lunn [mailto:and...@lunn.ch] > Sent: Friday, July 28, 2017 7:22 AM > To: Antoine Tenart <antoine.ten...@free-electrons.com> > Cc: da...@davemloft.net; ja...@lakedaemon.net; gregory.clement@free- > electrons.com; sebastian.hesselba...@gmail.com; thomas.petazzoni@free- > electrons.com; Nadav Haklai <nad...@marvell.com>; li...@armlinux.org.uk; > m...@semihalf.com; Stefan Chulski <stef...@marvell.com>; > netdev@vger.kernel.org; linux-arm-ker...@lists.infradead.org > Subject: [EXT] Re: [PATCH net-next 03/18] net: mvpp2: set the SMI PHY address > when connecting to the PHY > > External Email > > ---------------------------------------------------------------------- > On Thu, Jul 27, 2017 at 06:49:05PM -0700, Antoine Tenart wrote: > > Hi Andrew, > > > > On Wed, Jul 26, 2017 at 06:08:06PM +0200, Andrew Lunn wrote: > > > On Mon, Jul 24, 2017 at 03:48:33PM +0200, Antoine Tenart wrote: > > > > > > > > + if (priv->hw_version != MVPP22) > > > > + return 0; > > > > + > > > > + /* Set the SMI PHY address */ > > > > + if (of_property_read_u32(port->phy_node, "reg", &phy_addr)) { > > > > + netdev_err(port->dev, "cannot find the PHY address\n"); > > > > + return -EINVAL; > > > > + } > > > > + > > > > + writel(phy_addr, priv->iface_base + > > > > +MVPP22_SMI_PHY_ADDR(port->gop_id)); > > > > return 0; > > > > } > > > > > > You could use phy_dev->mdiodev->addr, rather than parse the DT. > > > > OK. > > > > > Why does the MAC need to know this address? The phylib and PHY > > > driver should be the only thing accessing the PHY, otherwise you are > > > asking for trouble. > > > > This is part of the SMI/xSMI interface. I added into the mvpp2 driver > > and not in the mvmdio one because the GoP port number must be known to > > set this register (so that would be even less clean to do it). > > Hi Antoine > > It is still not clear to my why you need to program the address into the > hardware. Is the hardware talking to the PHY? > > Andrew
Hi Andrew, This register configures SMI(Serial Management Interface) hardware unit, not PPv2(Packet Processor) hardware unit. The SB incorporates the following SMI management interfaces: MDC - Serial Management Interface Clock , MDIO - Serial Management Interface Data and complies with IEEE 802.3 Clause 22. SMI interface used for: 1. PHY register read/write. The device provides a mechanism for PHY registers read and write access. 2. Auto-Negotiation with PHY devices connected to the GMAC ports. The device uses a standard master Serial Management Interface for reading from/writing to the PHY registers. In addition, the PHY polling unit performs Auto-Negotiation status update with PHY devices attached to the Network ports via the Master SMI Interface. The device polls the Status register of each PHY in a round-robin manner. If the device detects a change in the link from down to up on 1 of the ports, it performs a series of register reads from the PHY and updates the Auto-Negotiation results in the device's registers. The Port MAC Status register is updated with these results only if Auto-Negotiation is enabled. So SMI interface should know GoP(MAC) id. Regards, Stefan.
