net: stmmac: dwmac-loongson: Add Loongson GNET support

The new generation Loongson LS2K2000 SoC and LS7A2000 chipset are
equipped with the network controllers called Loongson GNET. It's the
single and multi DMA-channels Loongson GMAC but with a PHY attached.
Here is the summary of the DW GMAC features the controller has:

   DW GMAC IP-core: v3.73a
   Speeds: 10/100/1000Mbps
   Duplex: Full (both versions), Half (LS2K2000 GNET only)
   DMA-descriptors type: enhanced
   L3/L4 filters availability: Y
   VLAN hash table filter: Y
   PHY-interface: GMII (PHY is integrated into the chips)
   Remote Wake-up support: Y
   Mac Management Counters (MMC): Y
   Number of additional MAC addresses: 5
   MAC Hash-based filter: Y
   Hash Table Size: 256
   AV feature: Y (LS2K2000 GNET only)
   DMA channels: 8 (LS2K2000 GNET), 1 (LS7A2000 GNET)

Let's update the Loongson DWMAC driver to supporting the new Loongson
GNET controller. The change is mainly trivial: the driver shall be
bound to the PCIe device with DID 0x7a13, and the device-specific
setup() method shall be called for it. The only peculiarity concerns
the integrated PHY speed change procedure. The PHY has a weird problem
with switching from the low speeds to 1000Mbps mode. The speedup
procedure requires the PHY-link re-negotiation. So the suggested
change provide the device-specific fix_mac_speed() method to overcome
the problem.
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Yinggang Gu <guyinggang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c

@@ -65,11 +65,13 @@
 					 DMA_STATUS_MSK_COMMON_LOONGSON)
 
 #define PCI_DEVICE_ID_LOONGSON_GMAC	0x7a03
+#define PCI_DEVICE_ID_LOONGSON_GNET	0x7a13
 #define DWMAC_CORE_LS_MULTICHAN	0x10	/* Loongson custom ID */
 #define CHANNEL_NUM			8
 
 struct loongson_data {
 	u32 loongson_id;
+	struct device *dev;
 };
 
 struct stmmac_pci_info {
@@ -147,6 +149,60 @@ static struct stmmac_pci_info loongson_gmac_pci_info = {
 	.setup = loongson_gmac_data,
 };
 
+static void loongson_gnet_fix_speed(void *priv, unsigned int speed,
+				    unsigned int mode)
+{
+	struct loongson_data *ld = (struct loongson_data *)priv;
+	struct net_device *ndev = dev_get_drvdata(ld->dev);
+	struct stmmac_priv *ptr = netdev_priv(ndev);
+
+	/* The integrated PHY has a weird problem with switching from the low
+	 * speeds to 1000Mbps mode. The speedup procedure requires the PHY-link
+	 * re-negotiation.
+	 */
+	if (speed == SPEED_1000) {
+		if (readl(ptr->ioaddr + MAC_CTRL_REG) &
+		    GMAC_CONTROL_PS)
+			/* Word around hardware bug, restart autoneg */
+			phy_restart_aneg(ndev->phydev);
+	}
+}
+
+static int loongson_gnet_data(struct pci_dev *pdev,
+			      struct plat_stmmacenet_data *plat)
+{
+	struct loongson_data *ld;
+	int i;
+
+	ld = plat->bsp_priv;
+
+	loongson_default_data(pdev, plat);
+
+	if (ld->loongson_id == DWMAC_CORE_LS_MULTICHAN) {
+		plat->rx_queues_to_use = CHANNEL_NUM;
+		plat->tx_queues_to_use = CHANNEL_NUM;
+
+		/* Only channel 0 supports checksum,
+		 * so turn off checksum to enable multiple channels.
+		 */
+		for (i = 1; i < CHANNEL_NUM; i++)
+			plat->tx_queues_cfg[i].coe_unsupported = 1;
+	} else {
+		plat->tx_queues_to_use = 1;
+		plat->rx_queues_to_use = 1;
+	}
+
+	plat->phy_interface = PHY_INTERFACE_MODE_GMII;
+	plat->mdio_bus_data->phy_mask = ~(u32)BIT(2);
+	plat->fix_mac_speed = loongson_gnet_fix_speed;
+
+	return 0;
+}
+
+static struct stmmac_pci_info loongson_gnet_pci_info = {
+	.setup = loongson_gnet_data,
+};
+
 static void loongson_dwmac_dma_init_channel(struct stmmac_priv *priv,
 					    void __iomem *ioaddr,
 					    struct stmmac_dma_cfg *dma_cfg,
@@ -279,8 +335,10 @@ static struct mac_device_info *loongson_dwmac_setup(void *apriv)
 	struct mac_device_info *mac;
 	struct stmmac_dma_ops *dma;
 	struct loongson_data *ld;
+	struct pci_dev *pdev;
 
 	ld = priv->plat->bsp_priv;
+	pdev = to_pci_dev(priv->device);
 
 	mac = devm_kzalloc(priv->device, sizeof(*mac), GFP_KERNEL);
 	if (!mac)
@@ -290,7 +348,7 @@ static struct mac_device_info *loongson_dwmac_setup(void *apriv)
 	if (!dma)
 		return NULL;
 
-	/* The Loongson GMAC devices are based on the DW GMAC
+	/* The Loongson GMAC and GNET devices are based on the DW GMAC
 	 * v3.50a and v3.73a IP-cores. But the HW designers have changed the
 	 * GMAC_VERSION.SNPSVER field to the custom 0x10 value on the
 	 * network controllers with the multi-channels feature
@@ -319,8 +377,19 @@ static struct mac_device_info *loongson_dwmac_setup(void *apriv)
 	if (mac->multicast_filter_bins)
 		mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
 
-	/* Loongson GMAC doesn't support the flow control. */
+	/* Loongson GMAC doesn't support the flow control. LS2K2000
+	 * GNET doesn't support the half-duplex link mode.
+	 */
+	if (pdev->device == PCI_DEVICE_ID_LOONGSON_GMAC) {
 		mac->link.caps = MAC_10 | MAC_100 | MAC_1000;
+	} else {
+		if (ld->loongson_id == DWMAC_CORE_LS_MULTICHAN)
+			mac->link.caps = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
+					 MAC_10 | MAC_100 | MAC_1000;
+		else
+			mac->link.caps = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
+					 MAC_10FD | MAC_100FD | MAC_1000FD;
+	}
 
 	mac->link.duplex = GMAC_CONTROL_DM;
 	mac->link.speed10 = GMAC_CONTROL_PS;
@@ -497,6 +566,7 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
 
 	plat->bsp_priv = ld;
 	plat->setup = loongson_dwmac_setup;
+	ld->dev = &pdev->dev;
 	ld->loongson_id = readl(res.addr + GMAC_VERSION) & 0xff;
 
 	info = (struct stmmac_pci_info *)id->driver_data;
@@ -597,6 +667,7 @@ static SIMPLE_DEV_PM_OPS(loongson_dwmac_pm_ops, loongson_dwmac_suspend,
 
 static const struct pci_device_id loongson_dwmac_id_table[] = {
 	{ PCI_DEVICE_DATA(LOONGSON, GMAC, &loongson_gmac_pci_info) },
+	{ PCI_DEVICE_DATA(LOONGSON, GNET, &loongson_gnet_pci_info) },
 	{}
 };
 MODULE_DEVICE_TABLE(pci, loongson_dwmac_id_table);