Re: [PATCH net-next v3 39/47] net: fman: memac: Add serdes support

[Sean Anderson <sean.anderson@seco.com>]

On 7/21/22 9:30 AM, Camelia Alexandra Groza wrote:
>> -----Original Message-----
>> From: Sean Anderson <sean.anderson@seco.com>
>> Sent: Saturday, July 16, 2022 1:00
>> To: David S . Miller <davem@davemloft.net>; Jakub Kicinski
>> <kuba@kernel.org>; Madalin Bucur <madalin.bucur@nxp.com>;
>> netdev@vger.kernel.org
>> Cc: Paolo Abeni <pabeni@redhat.com>; Eric Dumazet
>> <edumazet@google.com>; linux-arm-kernel@lists.infradead.org; Russell
>> King <linux@armlinux.org.uk>; linux-kernel@vger.kernel.org; Sean Anderson
>> <sean.anderson@seco.com>
>> Subject: [PATCH net-next v3 39/47] net: fman: memac: Add serdes support
>> 
>> This adds support for using a serdes which has to be configured. This is
>> primarly in preparation for the next commit, which will then change the
>> serdes mode dynamically.
>> 
>> Signed-off-by: Sean Anderson <sean.anderson@seco.com>
>> ---
>> 
>> (no changes since v1)
>> 
>>  .../net/ethernet/freescale/fman/fman_memac.c  | 48
>> ++++++++++++++++++-
>>  1 file changed, 46 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/net/ethernet/freescale/fman/fman_memac.c
>> b/drivers/net/ethernet/freescale/fman/fman_memac.c
>> index 02b3a0a2d5d1..a62fe860b1d0 100644
>> --- a/drivers/net/ethernet/freescale/fman/fman_memac.c
>> +++ b/drivers/net/ethernet/freescale/fman/fman_memac.c
>> @@ -13,6 +13,7 @@
>>  #include <linux/io.h>
>>  #include <linux/phy.h>
>>  #include <linux/phy_fixed.h>
>> +#include <linux/phy/phy.h>
>>  #include <linux/of_mdio.h>
>> 
>>  /* PCS registers */
>> @@ -324,6 +325,7 @@ struct fman_mac {
>>  	void *fm;
>>  	struct fman_rev_info fm_rev_info;
>>  	bool basex_if;
>> +	struct phy *serdes;
>>  	struct phy_device *pcsphy;
>>  	bool allmulti_enabled;
>>  };
>> @@ -1203,17 +1205,55 @@ int memac_initialization(struct mac_device
>> *mac_dev,
>>  		}
>>  	}
>> 
>> +	memac->serdes = devm_of_phy_get(mac_dev->dev, mac_node,
>> "serdes");
> 
> devm_of_phy_get returns -ENOSYS on PPC builds because CONFIG_GENERIC_PHY isn't
> enabled by default. Please add a dependency.
> 
>> +	if (PTR_ERR(memac->serdes) == -ENODEV) {

I think it is better to add -ENOSYS to the condition here. That way,
the phy subsystem stays optional.

--Sean

>> +		memac->serdes = NULL;
>> +	} else if (IS_ERR(memac->serdes)) {
>> +		err = PTR_ERR(memac->serdes);
>> +		dev_err_probe(mac_dev->dev, err, "could not get
>> serdes\n");
>> +		goto _return_fm_mac_free;
>> +	} else {
>> +		err = phy_init(memac->serdes);
>> +		if (err) {
>> +			dev_err_probe(mac_dev->dev, err,
>> +				      "could not initialize serdes\n");
>> +			goto _return_fm_mac_free;
>> +		}
>> +
>> +		err = phy_power_on(memac->serdes);
>> +		if (err) {
>> +			dev_err_probe(mac_dev->dev, err,
>> +				      "could not power on serdes\n");
>> +			goto _return_phy_exit;
>> +		}
>> +
>> +		if (memac->phy_if == PHY_INTERFACE_MODE_SGMII ||
>> +		    memac->phy_if == PHY_INTERFACE_MODE_1000BASEX ||
>> +		    memac->phy_if == PHY_INTERFACE_MODE_2500BASEX ||
>> +		    memac->phy_if == PHY_INTERFACE_MODE_QSGMII ||
>> +		    memac->phy_if == PHY_INTERFACE_MODE_XGMII) {
>> +			err = phy_set_mode_ext(memac->serdes,
>> PHY_MODE_ETHERNET,
>> +					       memac->phy_if);
>> +			if (err) {
>> +				dev_err_probe(mac_dev->dev, err,
>> +					      "could not set serdes mode
>> to %s\n",
>> +					      phy_modes(memac->phy_if));
>> +				goto _return_phy_power_off;
>> +			}
>> +		}
>> +	}
>> +
>>  	if (!mac_dev->phy_node && of_phy_is_fixed_link(mac_node)) {
>>  		struct phy_device *phy;
>> 
>>  		err = of_phy_register_fixed_link(mac_node);
>>  		if (err)
>> -			goto _return_fm_mac_free;
>> +			goto _return_phy_power_off;
>> 
>>  		fixed_link = kzalloc(sizeof(*fixed_link), GFP_KERNEL);
>>  		if (!fixed_link) {
>>  			err = -ENOMEM;
>> -			goto _return_fm_mac_free;
>> +			goto _return_phy_power_off;
>>  		}
>> 
>>  		mac_dev->phy_node = of_node_get(mac_node);
>> @@ -1242,6 +1282,10 @@ int memac_initialization(struct mac_device
>> *mac_dev,
>> 
>>  	goto _return;
>> 
>> +_return_phy_power_off:
>> +	phy_power_off(memac->serdes);
>> +_return_phy_exit:
>> +	phy_exit(memac->serdes);
>>  _return_fixed_link_free:
>>  	kfree(fixed_link);
> 
> _return_fixed_link_free should execute before _return_phy_power_off and _return_phy_exit
> 
>>  _return_fm_mac_free:
>> --
>> 2.35.1.1320.gc452695387.dirty
>