[2/2] net: ks8851: Register MDIO bus and the internal PHY

The KS8851 has a reduced internal PHY, which is accessible through its
registers at offset 0xe4. The PHY is compatible with KS886x PHY present
in Micrel switches, except the PHY ID Low/High registers are swapped.
Register MDIO bus so this PHY can be detected and probed by phylib.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Lukas Wunner <lukas@wunner.de>
To: netdev@vger.kernel.org
---
 drivers/net/ethernet/micrel/ks8851.h        |  1 +
 drivers/net/ethernet/micrel/ks8851_common.c | 69 ++++++++++++++++++++-
 2 files changed, 67 insertions(+), 3 deletions(-)

> +static int ks8851_mdio_read(struct mii_bus *bus, int phy_id, int reg)
> +{
> +	struct ks8851_net *ks = bus->priv;
> +
> +	if (phy_id != 0)
> +		return 0xffffffff;
> +

Please check for C45 and return -EOPNOTSUPP.

       Andrew

Hi Marek,

I love your patch! Perhaps something to improve:

[auto build test WARNING on net/master]
[also build test WARNING on net-next/master ipvs/master linus/master v5.11-rc1 next-20201223]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Marek-Vasut/net-phy-micrel-Add-KS8851-PHY-support/20201230-210003
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git 4bfc4714849d005e6835bcffa3c29ebd6e5ee35d
config: alpha-allmodconfig (attached as .config)
compiler: alpha-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/799aae00b2ec29ee4a86a2d8b8a8b0c1b816cb84
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Marek-Vasut/net-phy-micrel-Add-KS8851-PHY-support/20201230-210003
        git checkout 799aae00b2ec29ee4a86a2d8b8a8b0c1b816cb84
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/net/ethernet/micrel/ks8851_common.c: In function 'ks8851_register_mdiobus':
>> drivers/net/ethernet/micrel/ks8851_common.c:1082:22: warning: conversion from 'long unsigned int' to 'u32' {aka 'unsigned int'} changes value from '18446744073709551614' to '4294967294' [-Woverflow]

    1082 |  mii_bus->phy_mask = ~BIT(0);
         |                      ^


vim +1082 drivers/net/ethernet/micrel/ks8851_common.c

  1067	
  1068	static int ks8851_register_mdiobus(struct ks8851_net *ks, struct device *dev)
  1069	{
  1070		struct mii_bus *mii_bus;
  1071		int ret;
  1072	
  1073		mii_bus = mdiobus_alloc();
  1074		if (!mii_bus)
  1075			return -ENOMEM;
  1076	
  1077		mii_bus->name = "ks8851_eth_mii";
  1078		mii_bus->read = ks8851_mdio_read;
  1079		mii_bus->write = ks8851_mdio_write;
  1080		mii_bus->priv = ks;
  1081		mii_bus->parent = dev;
> 1082		mii_bus->phy_mask = ~BIT(0);

  1083		snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
  1084	
  1085		ret = mdiobus_register(mii_bus);
  1086		if (ret)
  1087			goto err_mdiobus_register;
  1088	
  1089		ks->mii_bus = mii_bus;
  1090	
  1091		return 0;
  1092	
  1093	err_mdiobus_register:
  1094		mdiobus_free(mii_bus);
  1095		return ret;
  1096	}
  1097	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

On 12/30/20 5:00 PM, Andrew Lunn wrote:
>> +static int ks8851_mdio_read(struct mii_bus *bus, int phy_id, int reg)

>> +{

>> +	struct ks8851_net *ks = bus->priv;

>> +

>> +	if (phy_id != 0)

>> +		return 0xffffffff;

>> +

> 

> Please check for C45 and return -EOPNOTSUPP.


The ks8851_reg_read() does all the register checking already.

On Sun, Jan 03, 2021 at 01:58:09PM +0100, Marek Vasut wrote:
> On 12/30/20 5:00 PM, Andrew Lunn wrote:

> > > +static int ks8851_mdio_read(struct mii_bus *bus, int phy_id, int reg)

> > > +{

> > > +	struct ks8851_net *ks = bus->priv;

> > > +

> > > +	if (phy_id != 0)

> > > +		return 0xffffffff;

> > > +

> > 

> > Please check for C45 and return -EOPNOTSUPP.

> 

> The ks8851_reg_read() does all the register checking already.


Not really.

static int ks8851_phy_read(struct net_device *dev, int phy_addr, int reg)
{
	struct ks8851_net *ks = netdev_priv(dev);
	unsigned long flags;
	int ksreg;
	int result;

	ksreg = ks8851_phy_reg(reg);
	if (!ksreg)
		return 0x0;	/* no error return allowed, so use zero */

	ks8851_lock(ks, &flags);
	result = ks8851_rdreg16(ks, ksreg);
	ks8851_unlock(ks, &flags);

	return result;
}

static int ks8851_phy_reg(int reg)
{
	switch (reg) {
	case MII_BMCR:
		return KS_P1MBCR;
	case MII_BMSR:
		return KS_P1MBSR;
	case MII_PHYSID1:
		return KS_PHY1ILR;
	case MII_PHYSID2:
		return KS_PHY1IHR;
	case MII_ADVERTISE:
		return KS_P1ANAR;
	case MII_LPA:
		return KS_P1ANLPR;
	}

	return 0x0;
}

So a C45 reg will cause 0 to be returned, not -EOPNOTSUPP.

   Andrew