Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <056164ec-3525-479b-3b71-834af48d323c@gmail.com>
Date:   Fri, 29 Jul 2022 10:19:54 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.11.0
Subject: Re: [PATCH net-next v3 3/4] net: phy: Add helper to derive the number
 of ports from a phy mode
Content-Language: en-US
To:     Maxime Chevallier <maxime.chevallier@bootlin.com>,
        davem@davemloft.net, Rob Herring <robh+dt@kernel.org>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, thomas.petazzoni@bootlin.com,
        Andrew Lunn <andrew@lunn.ch>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        linux-arm-kernel@lists.infradead.org,
        Richard Cochran <richardcochran@gmail.com>,
        Horatiu.Vultur@microchip.com, Allan.Nielsen@microchip.com,
        UNGLinuxDriver@microchip.com
References: <20220729153356.581444-1-maxime.chevallier@bootlin.com>
 <20220729153356.581444-4-maxime.chevallier@bootlin.com>
From:   Florian Fainelli <f.fainelli@gmail.com>
In-Reply-To: <20220729153356.581444-4-maxime.chevallier@bootlin.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 7/29/22 08:33, Maxime Chevallier wrote:
> Some phy modes such as QSGMII multiplex several MAC<->PHY links on one
> single physical interface. QSGMII used to be the only one supported, but
> other modes such as QUSGMII also carry multiple links.
> 
> This helper allows getting the number of links that are multiplexed
> on a given interface.
> 
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---
> V1->V2 : New patch
> V2->V3 : Made PHY_INTERFACE_MODE_INTERNAL 1 port, and added the MAX
> case.
> 
>  drivers/net/phy/phy-core.c | 52 ++++++++++++++++++++++++++++++++++++++
>  include/linux/phy.h        |  2 ++
>  2 files changed, 54 insertions(+)
> 
> diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
> index 1f2531a1a876..f8ec12d3d6ae 100644
> --- a/drivers/net/phy/phy-core.c
> +++ b/drivers/net/phy/phy-core.c
> @@ -74,6 +74,58 @@ const char *phy_duplex_to_str(unsigned int duplex)
>  }
>  EXPORT_SYMBOL_GPL(phy_duplex_to_str);
>  
> +/**
> + * phy_interface_num_ports - Return the number of links that can be carried by
> + *			     a given MAC-PHY physical link. Returns 0 if this is
> + *			     unknown, the number of links else.
> + *
> + * @interface: The interface mode we want to get the number of ports
> + */
> +int phy_interface_num_ports(phy_interface_t interface)
> +{
> +	switch (interface) {
> +	case PHY_INTERFACE_MODE_NA:
> +		return 0;
> +	case PHY_INTERFACE_MODE_INTERNAL:

Maybe this was covered in the previous iteration, but cannot the default case return 1, and all of the cases that need an explicit non-1 return value are handled? Enumeration all of those that do need to return 1 does not really scale.
-- 
Florian