Merge branch 'stmmac-regression-fix'

Merge branch 'stmmac-regression-fix'

Herve Codina says:

====================
net: stmmac: fix regression on SPEAr3xx SOC

The ethernet driver used on old SPEAr3xx soc was previously supported on old
kernel. Some regressions were introduced during the different updates leading
to a broken driver for this soc.

This series fixes these regressions and brings back ethernet on SPEAr3xx.
Tested on a SPEAr320 board.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/snps,dwmac.yaml

@@ -21,6 +21,7 @@ select:
       contains:
         enum:
           - snps,dwmac
+          - snps,dwmac-3.40a
           - snps,dwmac-3.50a
           - snps,dwmac-3.610
           - snps,dwmac-3.70a
@@ -76,6 +77,7 @@ properties:
         - rockchip,rk3399-gmac
         - rockchip,rv1108-gmac
         - snps,dwmac
+        - snps,dwmac-3.40a
         - snps,dwmac-3.50a
         - snps,dwmac-3.610
         - snps,dwmac-3.70a

arch/arm/boot/dts/spear3xx.dtsi

@@ -47,7 +47,7 @@ dma@fc400000 {
 		};
 
 		gmac: eth@e0800000 {
-			compatible = "st,spear600-gmac";
+			compatible = "snps,dwmac-3.40a";
 			reg = <0xe0800000 0x8000>;
 			interrupts = <23 22>;
 			interrupt-names = "macirq", "eth_wake_irq";

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

@@ -71,6 +71,7 @@ static int dwmac_generic_probe(struct platform_device *pdev)
 
 static const struct of_device_id dwmac_generic_match[] = {
 	{ .compatible = "st,spear600-gmac"},
+	{ .compatible = "snps,dwmac-3.40a"},
 	{ .compatible = "snps,dwmac-3.50a"},
 	{ .compatible = "snps,dwmac-3.610"},
 	{ .compatible = "snps,dwmac-3.70a"},

drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c

@@ -218,11 +218,18 @@ static void dwmac1000_dump_dma_regs(void __iomem *ioaddr, u32 *reg_space)
 				readl(ioaddr + DMA_BUS_MODE + i * 4);
 }
 
-static void dwmac1000_get_hw_feature(void __iomem *ioaddr,
+static int dwmac1000_get_hw_feature(void __iomem *ioaddr,
 				    struct dma_features *dma_cap)
 {
 	u32 hw_cap = readl(ioaddr + DMA_HW_FEATURE);
 
+	if (!hw_cap) {
+		/* 0x00000000 is the value read on old hardware that does not
+		 * implement this register
+		 */
+		return -EOPNOTSUPP;
+	}
+
 	dma_cap->mbps_10_100 = (hw_cap & DMA_HW_FEAT_MIISEL);
 	dma_cap->mbps_1000 = (hw_cap & DMA_HW_FEAT_GMIISEL) >> 1;
 	dma_cap->half_duplex = (hw_cap & DMA_HW_FEAT_HDSEL) >> 2;
@@ -252,6 +259,8 @@ static void dwmac1000_get_hw_feature(void __iomem *ioaddr,
 	dma_cap->number_tx_channel = (hw_cap & DMA_HW_FEAT_TXCHCNT) >> 22;
 	/* Alternate (enhanced) DESC mode */
 	dma_cap->enh_desc = (hw_cap & DMA_HW_FEAT_ENHDESSEL) >> 24;
+
+	return 0;
 }
 
 static void dwmac1000_rx_watchdog(void __iomem *ioaddr, u32 riwt,

drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c

@@ -347,7 +347,7 @@ static void dwmac4_dma_tx_chan_op_mode(void __iomem *ioaddr, int mode,
 	writel(mtl_tx_op, ioaddr +  MTL_CHAN_TX_OP_MODE(channel));
 }
 
-static void dwmac4_get_hw_feature(void __iomem *ioaddr,
+static int dwmac4_get_hw_feature(void __iomem *ioaddr,
 				 struct dma_features *dma_cap)
 {
 	u32 hw_cap = readl(ioaddr + GMAC_HW_FEATURE0);
@@ -437,6 +437,8 @@ static void dwmac4_get_hw_feature(void __iomem *ioaddr,
 	dma_cap->frpbs = (hw_cap & GMAC_HW_FEAT_FRPBS) >> 11;
 	dma_cap->frpsel = (hw_cap & GMAC_HW_FEAT_FRPSEL) >> 10;
 	dma_cap->dvlan = (hw_cap & GMAC_HW_FEAT_DVLAN) >> 5;
+
+	return 0;
 }
 
 /* Enable/disable TSO feature and set MSS */

drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c

@@ -371,7 +371,7 @@ static int dwxgmac2_dma_interrupt(void __iomem *ioaddr,
 	return ret;
 }
 
-static void dwxgmac2_get_hw_feature(void __iomem *ioaddr,
+static int dwxgmac2_get_hw_feature(void __iomem *ioaddr,
 				   struct dma_features *dma_cap)
 {
 	u32 hw_cap;
@@ -445,6 +445,8 @@ static void dwxgmac2_get_hw_feature(void __iomem *ioaddr,
 	dma_cap->frpes = (hw_cap & XGMAC_HWFEAT_FRPES) >> 11;
 	dma_cap->frpbs = (hw_cap & XGMAC_HWFEAT_FRPPB) >> 9;
 	dma_cap->frpsel = (hw_cap & XGMAC_HWFEAT_FRPSEL) >> 3;
+
+	return 0;
 }
 
 static void dwxgmac2_rx_watchdog(void __iomem *ioaddr, u32 riwt, u32 queue)

drivers/net/ethernet/stmicro/stmmac/hwif.h

@@ -203,7 +203,7 @@ struct stmmac_dma_ops {
 	int (*dma_interrupt) (void __iomem *ioaddr,
 			      struct stmmac_extra_stats *x, u32 chan, u32 dir);
 	/* If supported then get the optional core features */
-	void (*get_hw_feature)(void __iomem *ioaddr,
+	int (*get_hw_feature)(void __iomem *ioaddr,
 			      struct dma_features *dma_cap);
 	/* Program the HW RX Watchdog */
 	void (*rx_watchdog)(void __iomem *ioaddr, u32 riwt, u32 queue);
@@ -255,7 +255,7 @@ struct stmmac_dma_ops {
 #define stmmac_dma_interrupt_status(__priv, __args...) \
 	stmmac_do_callback(__priv, dma, dma_interrupt, __args)
 #define stmmac_get_hw_feature(__priv, __args...) \
-	stmmac_do_void_callback(__priv, dma, get_hw_feature, __args)
+	stmmac_do_callback(__priv, dma, get_hw_feature, __args)
 #define stmmac_rx_watchdog(__priv, __args...) \
 	stmmac_do_void_callback(__priv, dma, rx_watchdog, __args)
 #define stmmac_set_tx_ring_len(__priv, __args...) \

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c

@@ -508,6 +508,14 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
 		plat->pmt = 1;
 	}
 
+	if (of_device_is_compatible(np, "snps,dwmac-3.40a")) {
+		plat->has_gmac = 1;
+		plat->enh_desc = 1;
+		plat->tx_coe = 1;
+		plat->bugged_jumbo = 1;
+		plat->pmt = 1;
+	}
+
 	if (of_device_is_compatible(np, "snps,dwmac-4.00") ||
 	    of_device_is_compatible(np, "snps,dwmac-4.10a") ||
 	    of_device_is_compatible(np, "snps,dwmac-4.20a") ||