Re: [PATCH RFC net-next 1/5] net: dsa: mt7530: Convert to PHYLINK API

[Vladimir Oltean <olteanv@gmail.com>]

Hi Russell,

On 6/24/19 6:39 PM, Russell King - ARM Linux admin wrote:
> Hi,
> 
> On Mon, Jun 24, 2019 at 04:52:47PM +0200, René van Dorst wrote:
>> Convert mt7530 to PHYLINK API
>>
>> Signed-off-by: René van Dorst <opensource@vdorst.com>
>> ---
>>   drivers/net/dsa/mt7530.c | 237 +++++++++++++++++++++++++++++----------
>>   drivers/net/dsa/mt7530.h |   9 ++
>>   2 files changed, 187 insertions(+), 59 deletions(-)
>>
>> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
>> index 3181e95586d6..9c5e4dd00826 100644
>> --- a/drivers/net/dsa/mt7530.c
>> +++ b/drivers/net/dsa/mt7530.c
>> @@ -13,7 +13,7 @@
>>   #include <linux/of_mdio.h>
>>   #include <linux/of_net.h>
>>   #include <linux/of_platform.h>
>> -#include <linux/phy.h>
>> +#include <linux/phylink.h>
>>   #include <linux/regmap.h>
>>   #include <linux/regulator/consumer.h>
>>   #include <linux/reset.h>
>> @@ -633,63 +633,6 @@ mt7530_get_sset_count(struct dsa_switch *ds, int port, int sset)
>>   	return ARRAY_SIZE(mt7530_mib);
>>   }
>>   
>> -static void mt7530_adjust_link(struct dsa_switch *ds, int port,
>> -			       struct phy_device *phydev)
>> -{
>> -	struct mt7530_priv *priv = ds->priv;
>> -
>> -	if (phy_is_pseudo_fixed_link(phydev)) {
>> -		dev_dbg(priv->dev, "phy-mode for master device = %x\n",
>> -			phydev->interface);
>> -
>> -		/* Setup TX circuit incluing relevant PAD and driving */
>> -		mt7530_pad_clk_setup(ds, phydev->interface);
>> -
>> -		if (priv->id == ID_MT7530) {
>> -			/* Setup RX circuit, relevant PAD and driving on the
>> -			 * host which must be placed after the setup on the
>> -			 * device side is all finished.
>> -			 */
>> -			mt7623_pad_clk_setup(ds);
>> -		}
>> -	} else {
>> -		u16 lcl_adv = 0, rmt_adv = 0;
>> -		u8 flowctrl;
>> -		u32 mcr = PMCR_USERP_LINK | PMCR_FORCE_MODE;
>> -
>> -		switch (phydev->speed) {
>> -		case SPEED_1000:
>> -			mcr |= PMCR_FORCE_SPEED_1000;
>> -			break;
>> -		case SPEED_100:
>> -			mcr |= PMCR_FORCE_SPEED_100;
>> -			break;
>> -		}
>> -
>> -		if (phydev->link)
>> -			mcr |= PMCR_FORCE_LNK;
>> -
>> -		if (phydev->duplex) {
>> -			mcr |= PMCR_FORCE_FDX;
>> -
>> -			if (phydev->pause)
>> -				rmt_adv = LPA_PAUSE_CAP;
>> -			if (phydev->asym_pause)
>> -				rmt_adv |= LPA_PAUSE_ASYM;
>> -
>> -			lcl_adv = linkmode_adv_to_lcl_adv_t(
>> -				phydev->advertising);
>> -			flowctrl = mii_resolve_flowctrl_fdx(lcl_adv, rmt_adv);
>> -
>> -			if (flowctrl & FLOW_CTRL_TX)
>> -				mcr |= PMCR_TX_FC_EN;
>> -			if (flowctrl & FLOW_CTRL_RX)
>> -				mcr |= PMCR_RX_FC_EN;
>> -		}
>> -		mt7530_write(priv, MT7530_PMCR_P(port), mcr);
>> -	}
>> -}
>> -
>>   static int
>>   mt7530_cpu_port_enable(struct mt7530_priv *priv,
>>   		       int port)
>> @@ -1323,6 +1266,178 @@ mt7530_setup(struct dsa_switch *ds)
>>   	return 0;
>>   }
>>   
>> +static void mt7530_phylink_mac_config(struct dsa_switch *ds, int port,
>> +				      unsigned int mode,
>> +				      const struct phylink_link_state *state)
>> +{
>> +	struct mt7530_priv *priv = ds->priv;
>> +	u32 mcr = PMCR_IFG_XMIT(1) | PMCR_MAC_MODE | PMCR_BACKOFF_EN |
>> +		  PMCR_BACKPR_EN | PMCR_TX_EN | PMCR_RX_EN;
>> +
>> +	switch (port) {
>> +	case 0: /* Internal phy */
>> +	case 1:
>> +	case 2:
>> +	case 3:
>> +	case 4:
>> +		if (state->interface != PHY_INTERFACE_MODE_GMII)
>> +			goto unsupported;
>> +		break;
>> +	/* case 5: Port 5 is not supported! */
>> +	case 6: /* 1st cpu port */
>> +		if (state->interface != PHY_INTERFACE_MODE_RGMII &&
>> +		    state->interface != PHY_INTERFACE_MODE_TRGMII)
>> +			goto unsupported;
>> +
>> +		/* Setup TX circuit incluing relevant PAD and driving */
>> +		mt7530_pad_clk_setup(ds, state->interface);
>> +
>> +		if (priv->id == ID_MT7530) {
>> +			/* Setup RX circuit, relevant PAD and driving on the
>> +			 * host which must be placed after the setup on the
>> +			 * device side is all finished.
>> +			 */
>> +			mt7623_pad_clk_setup(ds);
>> +		}
>> +		break;
>> +	default:
>> +		dev_err(ds->dev, "%s: unsupported port: %i\n", __func__, port);
>> +		return;
>> +	}
>> +
>> +	if (!state->an_enabled || mode == MLO_AN_FIXED) {
>> +		mcr |= PMCR_FORCE_MODE;
>> +
>> +		if (state->speed == SPEED_1000)
>> +			mcr |= PMCR_FORCE_SPEED_1000;
>> +		if (state->speed == SPEED_100)
>> +			mcr |= PMCR_FORCE_SPEED_100;
>> +		if (state->duplex == DUPLEX_FULL)
>> +			mcr |= PMCR_FORCE_FDX;
>> +		if (state->link || mode == MLO_AN_FIXED)
>> +			mcr |= PMCR_FORCE_LNK;
> 
> This should be removed - state->link is not for use in mac_config.
> Even in fixed mode, the link can be brought up/down by means of a
> gpio, and this should be dealt with via the mac_link_* functions.
> 

What do you mean exactly that state->link is not for use, is that true 
in general?
In drivers/net/dsa/sja1105/sja1105_main.c, if I remove the "if 
(!state->link)" guard, I see PHYLINK calls with a SPEED_UNKNOWN argument 
for ports that are BR_STATE_DISABLED. Is that normal?

>> +		if (state->pause || phylink_test(state->advertising, Pause))
>> +			mcr |= PMCR_TX_FC_EN | PMCR_RX_FC_EN;
>> +		if (state->pause & MLO_PAUSE_TX)
>> +			mcr |= PMCR_TX_FC_EN;
>> +		if (state->pause & MLO_PAUSE_RX)
>> +			mcr |= PMCR_RX_FC_EN;
> 
> This is clearly wrong - if any bit in state->pause is set, then we
> end up with both PMCR_TX_FC_EN | PMCR_RX_FC_EN set.  If we have Pause
> Pause set in the advertising mask, then both are set.  This doesn't
> seem right - are these bits setting the advertisement, or are they
> telling the MAC to use flow control?
> 
>> +	}
>> +
>> +	mt7530_write(priv, MT7530_PMCR_P(port), mcr);
>> +
>> +	return;
>> +
>> +unsupported:
>> +	dev_err(ds->dev, "%s: P%d: Unsupported phy_interface mode: %d (%s)\n",
>> +		__func__, port, state->interface, phy_modes(state->interface));
>> +}
>> +
>> +static void mt7530_phylink_mac_link_down(struct dsa_switch *ds, int port,
>> +					 unsigned int mode,
>> +					 phy_interface_t interface)
>> +{
>> +	/* Do nothing */
>> +}
>> +
>> +static void mt7530_phylink_mac_link_up(struct dsa_switch *ds, int port,
>> +				       unsigned int mode,
>> +				       phy_interface_t interface,
>> +				       struct phy_device *phydev)
>> +{
>> +	/* Do nothing */
>> +}
> 
> These two are where you should be forcing the link up or down if
> required (basically, inband modes should let the link come up/down
> irrespective of these functions, otherwise it should be forced.)
> 
>> +
>> +static void mt7530_phylink_validate(struct dsa_switch *ds, int port,
>> +				    unsigned long *supported,
>> +				    struct phylink_link_state *state)
>> +{
>> +	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
>> +
>> +	switch (port) {
>> +	case 0: /* Internal phy */
>> +	case 1:
>> +	case 2:
>> +	case 3:
>> +	case 4:
>> +		if (state->interface != PHY_INTERFACE_MODE_NA &&
>> +		    state->interface != PHY_INTERFACE_MODE_GMII)
>> +			goto unsupported;
>> +		break;
>> +	/* case 5: Port 5 not supported! */
>> +	case 6: /* 1st cpu port */
>> +		if (state->interface != PHY_INTERFACE_MODE_RGMII &&
>> +		    state->interface != PHY_INTERFACE_MODE_TRGMII)
> 
> PHY_INTERFACE_MODE_NA ?
> 
>> +			goto unsupported;
>> +		break;
>> +	default:
>> +		linkmode_zero(supported);
>> +		dev_err(ds->dev, "%s: unsupported port: %i\n", __func__, port);
>> +		return;
>> +	}
>> +
>> +	phylink_set(mask, Autoneg);
>> +	phylink_set(mask, Pause);
>> +	phylink_set(mask, Asym_Pause);
>> +	phylink_set(mask, MII);
>> +
>> +	phylink_set(mask, 10baseT_Half);
>> +	phylink_set(mask, 10baseT_Full);
>> +	phylink_set(mask, 100baseT_Half);
>> +	phylink_set(mask, 100baseT_Full);
>> +	phylink_set(mask, 1000baseT_Full);
>> +	phylink_set(mask, 1000baseT_Half);
> 
> You seem to be missing phylink_set_port_modes() here.
> 
>> +
>> +	linkmode_and(supported, supported, mask);
>> +	linkmode_and(state->advertising, state->advertising, mask);
>> +	return;
>> +
>> +unsupported:
>> +	linkmode_zero(supported);
>> +	dev_err(ds->dev, "%s: unsupported interface mode: [0x%x] %s\n",
>> +		__func__, state->interface, phy_modes(state->interface));
> 
> Not a good idea to print this at error level; sometimes we just probe
> for support.
> 
> Eg, think about a SFP cage, and a SFP is plugged in that uses a PHY
> interface mode that the MAC can't support - we detect that by the
> validation failing, and printing a more meaningful message in phylink
> itself.
> 
>> +}
>> +
>> +static int
>> +mt7530_phylink_mac_link_state(struct dsa_switch *ds, int port,
>> +			      struct phylink_link_state *state)
>> +{
>> +	struct mt7530_priv *priv = ds->priv;
>> +	u32 pmsr;
>> +
>> +	if (port < 0 || port >= MT7530_NUM_PORTS)
>> +		return -EINVAL;
>> +
>> +	pmsr = mt7530_read(priv, MT7530_PMSR_P(port));
>> +
>> +	state->link = (pmsr & PMSR_LINK);
>> +	state->an_complete = state->link;
>> +	state->duplex = (pmsr & PMSR_DPX) >> 1;
>> +
>> +	switch (pmsr & (PMSR_SPEED_1000 | PMSR_SPEED_100)) {
>> +	case 0:
>> +		state->speed = SPEED_10;
>> +		break;
>> +	case PMSR_SPEED_100:
>> +		state->speed = SPEED_100;
>> +		break;
>> +	case PMSR_SPEED_1000:
>> +		state->speed = SPEED_1000;
>> +		break;
>> +	default:
>> +		state->speed = SPEED_UNKNOWN;
>> +		break;
>> +	}
>> +
>> +	state->pause = 0;
>> +	if (pmsr & PMSR_RX_FC)
>> +		state->pause |= MLO_PAUSE_RX;
>> +	if (pmsr & PMSR_TX_FC)
>> +		state->pause |= MLO_PAUSE_TX;
>> +
>> +	return 1;
>> +}
>> +
>>   static const struct dsa_switch_ops mt7530_switch_ops = {
>>   	.get_tag_protocol	= mtk_get_tag_protocol,
>>   	.setup			= mt7530_setup,
>> @@ -1331,7 +1446,6 @@ static const struct dsa_switch_ops mt7530_switch_ops = {
>>   	.phy_write		= mt7530_phy_write,
>>   	.get_ethtool_stats	= mt7530_get_ethtool_stats,
>>   	.get_sset_count		= mt7530_get_sset_count,
>> -	.adjust_link		= mt7530_adjust_link,
>>   	.port_enable		= mt7530_port_enable,
>>   	.port_disable		= mt7530_port_disable,
>>   	.port_stp_state_set	= mt7530_stp_state_set,
>> @@ -1344,6 +1458,11 @@ static const struct dsa_switch_ops mt7530_switch_ops = {
>>   	.port_vlan_prepare	= mt7530_port_vlan_prepare,
>>   	.port_vlan_add		= mt7530_port_vlan_add,
>>   	.port_vlan_del		= mt7530_port_vlan_del,
>> +	.phylink_validate	= mt7530_phylink_validate,
>> +	.phylink_mac_link_state = mt7530_phylink_mac_link_state,
>> +	.phylink_mac_config	= mt7530_phylink_mac_config,
>> +	.phylink_mac_link_down	= mt7530_phylink_mac_link_down,
>> +	.phylink_mac_link_up	= mt7530_phylink_mac_link_up,
>>   };
>>   
>>   static const struct of_device_id mt7530_of_match[] = {
>> diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
>> index bfac90f48102..41d9a132ac70 100644
>> --- a/drivers/net/dsa/mt7530.h
>> +++ b/drivers/net/dsa/mt7530.h
>> @@ -198,6 +198,7 @@ enum mt7530_vlan_port_attr {
>>   #define  PMCR_FORCE_SPEED_100		BIT(2)
>>   #define  PMCR_FORCE_FDX			BIT(1)
>>   #define  PMCR_FORCE_LNK			BIT(0)
>> +#define  PMCR_FORCE_LNK_DOWN		PMCR_FORCE_MODE
>>   #define  PMCR_COMMON_LINK		(PMCR_IFG_XMIT(1) | PMCR_MAC_MODE | \
>>   					 PMCR_BACKOFF_EN | PMCR_BACKPR_EN | \
>>   					 PMCR_TX_EN | PMCR_RX_EN | \
>> @@ -218,6 +219,14 @@ enum mt7530_vlan_port_attr {
>>   					 PMCR_TX_FC_EN | PMCR_RX_FC_EN)
>>   
>>   #define MT7530_PMSR_P(x)		(0x3008 + (x) * 0x100)
>> +#define  PMSR_EEE1G			BIT(7)
>> +#define  PMSR_EEE100M			BIT(6)
>> +#define  PMSR_RX_FC			BIT(5)
>> +#define  PMSR_TX_FC			BIT(4)
>> +#define  PMSR_SPEED_1000		BIT(3)
>> +#define  PMSR_SPEED_100			BIT(2)
>> +#define  PMSR_DPX			BIT(1)
>> +#define  PMSR_LINK			BIT(0)
>>   
>>   /* Register for MIB */
>>   #define MT7530_PORT_MIB_COUNTER(x)	(0x4000 + (x) * 0x100)
>> -- 
>> 2.20.1
>>
>>
> 

Regards,
-Vladimir