net: macb: add support for high speed interface

This patch adds support for 10GBASE-R interface to the linux driver for
Cadence's ethernet controller.
This controller has separate MAC's and PCS'es for low and high speed paths.
High speed PCS supports 100M, 1G, 2.5G, 5G and 10G through rate adaptation
implementation. However, since it doesn't support auto negotiation, linux
driver is modified to support 10GBASE-R instead of USXGMII.
Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
Link: https://lore.kernel.org/r/1603975627-18338-1-git-send-email-pthombar@cadence.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/cadence/macb.h

@@ -77,10 +77,12 @@
 #define MACB_RBQPH		0x04D4
 
 /* GEM register offsets. */
+#define GEM_NCR			0x0000 /* Network Control */
 #define GEM_NCFGR		0x0004 /* Network Config */
 #define GEM_USRIO		0x000c /* User IO */
 #define GEM_DMACFG		0x0010 /* DMA Configuration */
 #define GEM_JML			0x0048 /* Jumbo Max Length */
+#define GEM_HS_MAC_CONFIG	0x0050 /* GEM high speed config */
 #define GEM_HRB			0x0080 /* Hash Bottom */
 #define GEM_HRT			0x0084 /* Hash Top */
 #define GEM_SA1B		0x0088 /* Specific1 Bottom */
@@ -166,6 +168,9 @@
 #define GEM_DCFG7		0x0298 /* Design Config 7 */
 #define GEM_DCFG8		0x029C /* Design Config 8 */
 #define GEM_DCFG10		0x02A4 /* Design Config 10 */
+#define GEM_DCFG12		0x02AC /* Design Config 12 */
+#define GEM_USX_CONTROL		0x0A80 /* High speed PCS control register */
+#define GEM_USX_STATUS		0x0A88 /* High speed PCS status register */
 
 #define GEM_TXBDCTRL	0x04cc /* TX Buffer Descriptor control register */
 #define GEM_RXBDCTRL	0x04d0 /* RX Buffer Descriptor control register */
@@ -272,11 +277,19 @@
 #define MACB_IRXFCS_OFFSET	19
 #define MACB_IRXFCS_SIZE	1
 
+/* GEM specific NCR bitfields. */
+#define GEM_ENABLE_HS_MAC_OFFSET	31
+#define GEM_ENABLE_HS_MAC_SIZE		1
+
 /* GEM specific NCFGR bitfields. */
+#define GEM_FD_OFFSET		1 /* Full duplex */
+#define GEM_FD_SIZE		1
 #define GEM_GBE_OFFSET		10 /* Gigabit mode enable */
 #define GEM_GBE_SIZE		1
 #define GEM_PCSSEL_OFFSET	11
 #define GEM_PCSSEL_SIZE		1
+#define GEM_PAE_OFFSET		13 /* Pause enable */
+#define GEM_PAE_SIZE		1
 #define GEM_CLK_OFFSET		18 /* MDC clock division */
 #define GEM_CLK_SIZE		3
 #define GEM_DBW_OFFSET		21 /* Data bus width */
@@ -461,11 +474,17 @@
 #define MACB_REV_OFFSET				0
 #define MACB_REV_SIZE				16
 
+/* Bitfield in HS_MAC_CONFIG */
+#define GEM_HS_MAC_SPEED_OFFSET			0
+#define GEM_HS_MAC_SPEED_SIZE			3
+
 /* Bitfields in DCFG1. */
 #define GEM_IRQCOR_OFFSET			23
 #define GEM_IRQCOR_SIZE				1
 #define GEM_DBWDEF_OFFSET			25
 #define GEM_DBWDEF_SIZE				3
+#define GEM_NO_PCS_OFFSET			0
+#define GEM_NO_PCS_SIZE				1
 
 /* Bitfields in DCFG2. */
 #define GEM_RX_PKT_BUFF_OFFSET			20
@@ -500,6 +519,28 @@
 #define GEM_RXBD_RDBUFF_OFFSET			8
 #define GEM_RXBD_RDBUFF_SIZE			4
 
+/* Bitfields in DCFG12. */
+#define GEM_HIGH_SPEED_OFFSET			26
+#define GEM_HIGH_SPEED_SIZE			1
+
+/* Bitfields in USX_CONTROL. */
+#define GEM_USX_CTRL_SPEED_OFFSET		14
+#define GEM_USX_CTRL_SPEED_SIZE			3
+#define GEM_SERDES_RATE_OFFSET			12
+#define GEM_SERDES_RATE_SIZE			2
+#define GEM_RX_SCR_BYPASS_OFFSET		9
+#define GEM_RX_SCR_BYPASS_SIZE			1
+#define GEM_TX_SCR_BYPASS_OFFSET		8
+#define GEM_TX_SCR_BYPASS_SIZE			1
+#define GEM_TX_EN_OFFSET			1
+#define GEM_TX_EN_SIZE				1
+#define GEM_SIGNAL_OK_OFFSET			0
+#define GEM_SIGNAL_OK_SIZE			1
+
+/* Bitfields in USX_STATUS. */
+#define GEM_USX_BLOCK_LOCK_OFFSET		0
+#define GEM_USX_BLOCK_LOCK_SIZE			1
+
 /* Bitfields in TISUBN */
 #define GEM_SUBNSINCR_OFFSET			0
 #define GEM_SUBNSINCRL_OFFSET			24
@@ -663,6 +704,8 @@
 #define MACB_CAPS_GIGABIT_MODE_AVAILABLE	0x20000000
 #define MACB_CAPS_SG_DISABLED			0x40000000
 #define MACB_CAPS_MACB_IS_GEM			0x80000000
+#define MACB_CAPS_PCS				0x01000000
+#define MACB_CAPS_HIGH_SPEED			0x02000000
 
 /* LSO settings */
 #define MACB_LSO_UFO_ENABLE			0x01
@@ -1201,6 +1244,7 @@ struct macb {
 	struct mii_bus		*mii_bus;
 	struct phylink		*phylink;
 	struct phylink_config	phylink_config;
+	struct phylink_pcs	phylink_pcs;
 
 	u32			caps;
 	unsigned int		dma_burst_length;

drivers/net/ethernet/cadence/macb_main.c

@@ -84,6 +84,9 @@ struct sifive_fu540_macb_mgmt {
 #define MACB_WOL_HAS_MAGIC_PACKET	(0x1 << 0)
 #define MACB_WOL_ENABLED		(0x1 << 1)
 
+#define HS_SPEED_10000M			4
+#define MACB_SERDES_RATE_10G		1
+
 /* Graceful stop timeouts in us. We should allow up to
  * 1 frame time (10 Mbits/s, full-duplex, ignoring collisions)
  */
@@ -513,6 +516,7 @@ static void macb_validate(struct phylink_config *config,
 	    state->interface != PHY_INTERFACE_MODE_RMII &&
 	    state->interface != PHY_INTERFACE_MODE_GMII &&
 	    state->interface != PHY_INTERFACE_MODE_SGMII &&
+	    state->interface != PHY_INTERFACE_MODE_10GBASER &&
 	    !phy_interface_mode_is_rgmii(state->interface)) {
 		bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
 		return;
@@ -525,10 +529,31 @@ static void macb_validate(struct phylink_config *config,
 		return;
 	}
 
+	if (state->interface == PHY_INTERFACE_MODE_10GBASER &&
+	    !(bp->caps & MACB_CAPS_HIGH_SPEED &&
+	      bp->caps & MACB_CAPS_PCS)) {
+		bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
+		return;
+	}
+
 	phylink_set_port_modes(mask);
 	phylink_set(mask, Autoneg);
 	phylink_set(mask, Asym_Pause);
 
+	if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE &&
+	    (state->interface == PHY_INTERFACE_MODE_NA ||
+	     state->interface == PHY_INTERFACE_MODE_10GBASER)) {
+		phylink_set(mask, 10000baseCR_Full);
+		phylink_set(mask, 10000baseER_Full);
+		phylink_set(mask, 10000baseKR_Full);
+		phylink_set(mask, 10000baseLR_Full);
+		phylink_set(mask, 10000baseLRM_Full);
+		phylink_set(mask, 10000baseSR_Full);
+		phylink_set(mask, 10000baseT_Full);
+		if (state->interface != PHY_INTERFACE_MODE_NA)
+			goto out;
+	}
+
 	phylink_set(mask, 10baseT_Half);
 	phylink_set(mask, 10baseT_Full);
 	phylink_set(mask, 100baseT_Half);
@@ -545,23 +570,80 @@ static void macb_validate(struct phylink_config *config,
 		if (!(bp->caps & MACB_CAPS_NO_GIGABIT_HALF))
 			phylink_set(mask, 1000baseT_Half);
 	}
-
+out:
 	bitmap_and(supported, supported, mask, __ETHTOOL_LINK_MODE_MASK_NBITS);
 	bitmap_and(state->advertising, state->advertising, mask,
 		   __ETHTOOL_LINK_MODE_MASK_NBITS);
 }
 
-static void macb_mac_pcs_get_state(struct phylink_config *config,
+static void macb_usx_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
+				 phy_interface_t interface, int speed,
+				 int duplex)
+{
+	struct macb *bp = container_of(pcs, struct macb, phylink_pcs);
+	u32 config;
+
+	config = gem_readl(bp, USX_CONTROL);
+	config = GEM_BFINS(SERDES_RATE, MACB_SERDES_RATE_10G, config);
+	config = GEM_BFINS(USX_CTRL_SPEED, HS_SPEED_10000M, config);
+	config &= ~(GEM_BIT(TX_SCR_BYPASS) | GEM_BIT(RX_SCR_BYPASS));
+	config |= GEM_BIT(TX_EN);
+	gem_writel(bp, USX_CONTROL, config);
+}
+
+static void macb_usx_pcs_get_state(struct phylink_pcs *pcs,
+				   struct phylink_link_state *state)
+{
+	struct macb *bp = container_of(pcs, struct macb, phylink_pcs);
+	u32 val;
+
+	state->speed = SPEED_10000;
+	state->duplex = 1;
+	state->an_complete = 1;
+
+	val = gem_readl(bp, USX_STATUS);
+	state->link = !!(val & GEM_BIT(USX_BLOCK_LOCK));
+	val = gem_readl(bp, NCFGR);
+	if (val & GEM_BIT(PAE))
+		state->pause = MLO_PAUSE_RX;
+}
+
+static int macb_usx_pcs_config(struct phylink_pcs *pcs,
+			       unsigned int mode,
+			       phy_interface_t interface,
+			       const unsigned long *advertising,
+			       bool permit_pause_to_mac)
+{
+	struct macb *bp = container_of(pcs, struct macb, phylink_pcs);
+
+	gem_writel(bp, USX_CONTROL, gem_readl(bp, USX_CONTROL) |
+		   GEM_BIT(SIGNAL_OK));
+
+	return 0;
+}
+
+static void macb_pcs_get_state(struct phylink_pcs *pcs,
 			       struct phylink_link_state *state)
 {
 	state->link = 0;
 }
 
-static void macb_mac_an_restart(struct phylink_config *config)
+static void macb_pcs_an_restart(struct phylink_pcs *pcs)
 {
 	/* Not supported */
 }
 
+static const struct phylink_pcs_ops macb_phylink_usx_pcs_ops = {
+	.pcs_get_state = macb_usx_pcs_get_state,
+	.pcs_config = macb_usx_pcs_config,
+	.pcs_link_up = macb_usx_pcs_link_up,
+};
+
+static const struct phylink_pcs_ops macb_phylink_pcs_ops = {
+	.pcs_get_state = macb_pcs_get_state,
+	.pcs_an_restart = macb_pcs_an_restart,
+};
+
 static void macb_mac_config(struct phylink_config *config, unsigned int mode,
 			    const struct phylink_link_state *state)
 {
@@ -569,25 +651,35 @@ static void macb_mac_config(struct phylink_config *config, unsigned int mode,
 	struct macb *bp = netdev_priv(ndev);
 	unsigned long flags;
 	u32 old_ctrl, ctrl;
+	u32 old_ncr, ncr;
 
 	spin_lock_irqsave(&bp->lock, flags);
 
 	old_ctrl = ctrl = macb_or_gem_readl(bp, NCFGR);
+	old_ncr = ncr = macb_or_gem_readl(bp, NCR);
 
 	if (bp->caps & MACB_CAPS_MACB_IS_EMAC) {
 		if (state->interface == PHY_INTERFACE_MODE_RMII)
 			ctrl |= MACB_BIT(RM9200_RMII);
 	} else if (macb_is_gem(bp)) {
 		ctrl &= ~(GEM_BIT(SGMIIEN) | GEM_BIT(PCSSEL));
+		ncr &= ~GEM_BIT(ENABLE_HS_MAC);
 
-		if (state->interface == PHY_INTERFACE_MODE_SGMII)
+		if (state->interface == PHY_INTERFACE_MODE_SGMII) {
 			ctrl |= GEM_BIT(SGMIIEN) | GEM_BIT(PCSSEL);
+		} else if (state->interface == PHY_INTERFACE_MODE_10GBASER) {
+			ctrl |= GEM_BIT(PCSSEL);
+			ncr |= GEM_BIT(ENABLE_HS_MAC);
+		}
 	}
 
 	/* Apply the new configuration, if any */
 	if (old_ctrl ^ ctrl)
 		macb_or_gem_writel(bp, NCFGR, ctrl);
 
+	if (old_ncr ^ ncr)
+		macb_or_gem_writel(bp, NCR, ncr);
+
 	spin_unlock_irqrestore(&bp->lock, flags);
 }
 
@@ -664,6 +756,10 @@ static void macb_mac_link_up(struct phylink_config *config,
 
 	macb_or_gem_writel(bp, NCFGR, ctrl);
 
+	if (bp->phy_interface == PHY_INTERFACE_MODE_10GBASER)
+		gem_writel(bp, HS_MAC_CONFIG, GEM_BFINS(HS_MAC_SPEED, HS_SPEED_10000M,
+							gem_readl(bp, HS_MAC_CONFIG)));
+
 	spin_unlock_irqrestore(&bp->lock, flags);
 
 	/* Enable Rx and Tx */
@@ -672,10 +768,25 @@ static void macb_mac_link_up(struct phylink_config *config,
 	netif_tx_wake_all_queues(ndev);
 }
 
+static int macb_mac_prepare(struct phylink_config *config, unsigned int mode,
+			    phy_interface_t interface)
+{
+	struct net_device *ndev = to_net_dev(config->dev);
+	struct macb *bp = netdev_priv(ndev);
+
+	if (interface == PHY_INTERFACE_MODE_10GBASER)
+		bp->phylink_pcs.ops = &macb_phylink_usx_pcs_ops;
+	else
+		bp->phylink_pcs.ops = &macb_phylink_pcs_ops;
+
+	phylink_set_pcs(bp->phylink, &bp->phylink_pcs);
+
+	return 0;
+}
+
 static const struct phylink_mac_ops macb_phylink_ops = {
 	.validate = macb_validate,
-	.mac_pcs_get_state = macb_mac_pcs_get_state,
-	.mac_an_restart = macb_mac_an_restart,
+	.mac_prepare = macb_mac_prepare,
 	.mac_config = macb_mac_config,
 	.mac_link_down = macb_mac_link_down,
 	.mac_link_up = macb_mac_link_up,
@@ -3523,6 +3634,11 @@ static void macb_configure_caps(struct macb *bp,
 		dcfg = gem_readl(bp, DCFG1);
 		if (GEM_BFEXT(IRQCOR, dcfg) == 0)
 			bp->caps |= MACB_CAPS_ISR_CLEAR_ON_WRITE;
+		if (GEM_BFEXT(NO_PCS, dcfg) == 0)
+			bp->caps |= MACB_CAPS_PCS;
+		dcfg = gem_readl(bp, DCFG12);
+		if (GEM_BFEXT(HIGH_SPEED, dcfg) == 1)
+			bp->caps |= MACB_CAPS_HIGH_SPEED;
 		dcfg = gem_readl(bp, DCFG2);
 		if ((dcfg & (GEM_BIT(RX_PKT_BUFF) | GEM_BIT(TX_PKT_BUFF))) == 0)
 			bp->caps |= MACB_CAPS_FIFO_MODE;