Re: [PATCH net-next 1/2] net: dsa: mt7530-mdio: read PHY address of switch from device tree

[Daniel Golle]

On Sun, Apr 14, 2024 at 01:08:19AM +0300, Arınç ÜNAL via B4 Relay wrote:
> From: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
> 
> Read the PHY address the switch listens on from the reg property of the
> switch node on the device tree. This change brings support for MT7530
> switches on boards with such bootstrapping configuration where the switch
> listens on a different PHY address than the hardcoded PHY address on the
> driver, 31.
> 
> As described on the "MT7621 Programming Guide v0.4" document, the MT7530
> switch and its PHYs can be configured to listen on the range of 7-12,
> 15-20, 23-28, and 31 and 0-4 PHY addresses.
> 
> There are operations where the switch PHY registers are used. For the PHY
> address of the control PHY, transform the MT753X_CTRL_PHY_ADDR constant
> into a macro and use it. The PHY address for the control PHY is 0 when the
> switch listens on 31. In any other case, it is one greater than the PHY
> address the switch listens on.
> 
> Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>

See minor nit inline below.

Reviewed-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
Tested-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
(only MT7530 and MT7531 on address 0x1f has been tested, I don't have
any board configuring the switch to any other base-address)

> ---
>  drivers/net/dsa/mt7530-mdio.c | 28 ++++++++++++++--------------
>  drivers/net/dsa/mt7530.c      | 35 ++++++++++++++++++++++-------------
>  drivers/net/dsa/mt7530.h      |  4 +++-
>  3 files changed, 39 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/net/dsa/mt7530-mdio.c b/drivers/net/dsa/mt7530-mdio.c
> index fa3ee85a99c1..599b28c8a340 100644
> --- a/drivers/net/dsa/mt7530-mdio.c
> +++ b/drivers/net/dsa/mt7530-mdio.c
> @@ -18,7 +18,8 @@
>  static int
>  mt7530_regmap_write(void *context, unsigned int reg, unsigned int val)
>  {
> -	struct mii_bus *bus = context;
> +	struct mt7530_priv *priv = context;
> +	struct mii_bus *bus = priv->bus;
>  	u16 page, r, lo, hi;
>  	int ret;
>  
> @@ -27,36 +28,35 @@ mt7530_regmap_write(void *context, unsigned int reg, unsigned int val)
>  	lo = val & 0xffff;
>  	hi = val >> 16;
>  
> -	/* MT7530 uses 31 as the pseudo port */
> -	ret = bus->write(bus, 0x1f, 0x1f, page);
> +	ret = bus->write(bus, priv->phy_addr, 0x1f, page);
>  	if (ret < 0)
>  		return ret;
>  
> -	ret = bus->write(bus, 0x1f, r,  lo);
> +	ret = bus->write(bus, priv->phy_addr, r, lo);
>  	if (ret < 0)
>  		return ret;
>  
> -	ret = bus->write(bus, 0x1f, 0x10, hi);
> +	ret = bus->write(bus, priv->phy_addr, 0x10, hi);
>  	return ret;
>  }
>  
>  static int
>  mt7530_regmap_read(void *context, unsigned int reg, unsigned int *val)
>  {
> -	struct mii_bus *bus = context;
> +	struct mt7530_priv *priv = context;
> +	struct mii_bus *bus = priv->bus;
>  	u16 page, r, lo, hi;
>  	int ret;
>  
>  	page = (reg >> 6) & 0x3ff;
>  	r = (reg >> 2) & 0xf;
>  
> -	/* MT7530 uses 31 as the pseudo port */
> -	ret = bus->write(bus, 0x1f, 0x1f, page);
> +	ret = bus->write(bus, priv->phy_addr, 0x1f, page);
>  	if (ret < 0)
>  		return ret;
>  
> -	lo = bus->read(bus, 0x1f, r);
> -	hi = bus->read(bus, 0x1f, 0x10);
> +	lo = bus->read(bus, priv->phy_addr, r);
> +	hi = bus->read(bus, priv->phy_addr, 0x10);
>  
>  	*val = (hi << 16) | (lo & 0xffff);
>  
> @@ -107,8 +107,7 @@ mt7531_create_sgmii(struct mt7530_priv *priv)
>  		mt7531_pcs_config[i]->unlock = mt7530_mdio_regmap_unlock;
>  		mt7531_pcs_config[i]->lock_arg = &priv->bus->mdio_lock;
>  
> -		regmap = devm_regmap_init(priv->dev,
> -					  &mt7530_regmap_bus, priv->bus,
> +		regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus, priv,
>  					  mt7531_pcs_config[i]);
>  		if (IS_ERR(regmap)) {
>  			ret = PTR_ERR(regmap);
> @@ -153,6 +152,7 @@ mt7530_probe(struct mdio_device *mdiodev)
>  
>  	priv->bus = mdiodev->bus;
>  	priv->dev = &mdiodev->dev;
> +	priv->phy_addr = mdiodev->addr;
>  
>  	ret = mt7530_probe_common(priv);
>  	if (ret)
> @@ -203,8 +203,8 @@ mt7530_probe(struct mdio_device *mdiodev)
>  	regmap_config->reg_stride = 4;
>  	regmap_config->max_register = MT7530_CREV;
>  	regmap_config->disable_locking = true;
> -	priv->regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus,
> -					priv->bus, regmap_config);
> +	priv->regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus, priv,
> +					regmap_config);
>  	if (IS_ERR(priv->regmap))
>  		return PTR_ERR(priv->regmap);
>  
> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> index c0d0bce0b594..fefa6dd151fa 100644
> --- a/drivers/net/dsa/mt7530.c
> +++ b/drivers/net/dsa/mt7530.c
> @@ -86,22 +86,26 @@ core_read_mmd_indirect(struct mt7530_priv *priv, int prtad, int devad)
>  	int value, ret;
>  
>  	/* Write the desired MMD Devad */
> -	ret = bus->write(bus, 0, MII_MMD_CTRL, devad);
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_CTRL, devad);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Write the desired MMD register address */
> -	ret = bus->write(bus, 0, MII_MMD_DATA, prtad);
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_DATA, prtad);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Select the Function : DATA with no post increment */
> -	ret = bus->write(bus, 0, MII_MMD_CTRL, (devad | MII_MMD_CTRL_NOINCR));
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_CTRL, devad | MII_MMD_CTRL_NOINCR);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Read the content of the MMD's selected register */
> -	value = bus->read(bus, 0, MII_MMD_DATA);
> +	value = bus->read(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			  MII_MMD_DATA);
>  
>  	return value;
>  err:
> @@ -118,22 +122,26 @@ core_write_mmd_indirect(struct mt7530_priv *priv, int prtad,
>  	int ret;
>  
>  	/* Write the desired MMD Devad */
> -	ret = bus->write(bus, 0, MII_MMD_CTRL, devad);
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_CTRL, devad);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Write the desired MMD register address */
> -	ret = bus->write(bus, 0, MII_MMD_DATA, prtad);
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_DATA, prtad);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Select the Function : DATA with no post increment */
> -	ret = bus->write(bus, 0, MII_MMD_CTRL, (devad | MII_MMD_CTRL_NOINCR));
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_CTRL, devad | MII_MMD_CTRL_NOINCR);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Write the data into MMD's selected register */
> -	ret = bus->write(bus, 0, MII_MMD_DATA, data);
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_DATA, data);
>  err:
>  	if (ret < 0)
>  		dev_err(&bus->dev,
> @@ -2671,16 +2679,17 @@ mt7531_setup(struct dsa_switch *ds)
>  	 * phy_[read,write]_mmd_indirect is called, we provide our own
>  	 * mt7531_ind_mmd_phy_[read,write] to complete this function.
>  	 */
> -	val = mt7531_ind_c45_phy_read(priv, MT753X_CTRL_PHY_ADDR,
> +	val = mt7531_ind_c45_phy_read(priv,
> +				      MT753X_CTRL_PHY_ADDR(priv->phy_addr),
>  				      MDIO_MMD_VEND2, CORE_PLL_GROUP4);
>  	val |= MT7531_RG_SYSPLL_DMY2 | MT7531_PHY_PLL_BYPASS_MODE;
>  	val &= ~MT7531_PHY_PLL_OFF;
> -	mt7531_ind_c45_phy_write(priv, MT753X_CTRL_PHY_ADDR, MDIO_MMD_VEND2,
> -				 CORE_PLL_GROUP4, val);
> +	mt7531_ind_c45_phy_write(priv, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +				 MDIO_MMD_VEND2, CORE_PLL_GROUP4, val);
>  
>  	/* Disable EEE advertisement on the switch PHYs. */
> -	for (i = MT753X_CTRL_PHY_ADDR;
> -	     i < MT753X_CTRL_PHY_ADDR + MT7530_NUM_PHYS; i++) {
> +	for (i = MT753X_CTRL_PHY_ADDR(priv->phy_addr);
> +	     i < MT753X_CTRL_PHY_ADDR(priv->phy_addr) + MT7530_NUM_PHYS; i++) {
>  		mt7531_ind_c45_phy_write(priv, i, MDIO_MMD_AN, MDIO_AN_EEE_ADV,
>  					 0);
>  	}
> diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
> index 585db03c0548..76adc9d21bcf 100644
> --- a/drivers/net/dsa/mt7530.h
> +++ b/drivers/net/dsa/mt7530.h
> @@ -625,7 +625,7 @@ enum mt7531_clk_skew {
>  #define  MT7531_PHY_PLL_OFF		BIT(5)
>  #define  MT7531_PHY_PLL_BYPASS_MODE	BIT(4)
>  
> -#define MT753X_CTRL_PHY_ADDR		0
> +#define MT753X_CTRL_PHY_ADDR(phy_addr)	(phy_addr == 0x1f ? 0 : phy_addr + 1)

#define MT753X_CTRL_PHY_ADDR(phy_addr)	(phy_addr + 1 & 0x1f)

It's shorter, and works without conditional operator which is expensive.

>  
>  #define CORE_PLL_GROUP5			0x404
>  #define  RG_LCDDS_PCW_NCPO1(x)		((x) & 0xffff)
> @@ -774,6 +774,7 @@ struct mt753x_info {
>   * @irq_enable:		IRQ enable bits, synced to SYS_INT_EN
>   * @create_sgmii:	Pointer to function creating SGMII PCS instance(s)
>   * @active_cpu_ports:	Holding the active CPU ports
> + * @phy_addr:		Holding the PHY address the switch listens on
>   */
>  struct mt7530_priv {
>  	struct device		*dev;
> @@ -800,6 +801,7 @@ struct mt7530_priv {
>  	u32 irq_enable;
>  	int (*create_sgmii)(struct mt7530_priv *priv);
>  	u8 active_cpu_ports;
> +	int phy_addr;
>  };
>  
>  struct mt7530_hw_vlan_entry {
> 
> -- 
> 2.40.1
> 
>