[U-Boot] [PATCH v5 6/8] net: macb: Extend MACB driver for SiFive Unleashed board

[Anup Patel]

The SiFive MACB ethernet has a custom TX_CLK_SEL register to select
different TX clock for 1000mbps vs 10/100mbps.

This patch adds SiFive MACB compatible string and extends the MACB
ethernet driver to change TX clock using TX_CLK_SEL register for
SiFive MACB.

Signed-off-by: Anup Patel <anup.patel at wdc.com>
---
 drivers/net/macb.c | 53 +++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 45 insertions(+), 8 deletions(-)

diff --git a/drivers/net/macb.c b/drivers/net/macb.c
index c072f99d8f..6a29ee3064 100644
--- a/drivers/net/macb.c
+++ b/drivers/net/macb.c
@@ -83,6 +83,9 @@ struct macb_dma_desc {
 
 struct macb_device {
 	void			*regs;
+	void			*regs_sifive_gemgxl;
+
+	bool			skip_dma_config;
 	unsigned int		dma_burst_length;
 
 	unsigned int		rx_tail;
@@ -122,7 +125,9 @@ struct macb_device {
 };
 
 struct macb_config {
+	bool			skip_dma_config;
 	unsigned int		dma_burst_length;
+	bool			has_sifive_gemgxl;
 };
 
 #ifndef CONFIG_DM_ETH
@@ -486,18 +491,11 @@ static int macb_phy_find(struct macb_device *macb, const char *name)
 int __weak macb_linkspd_cb(struct udevice *dev, unsigned int speed)
 {
 #ifdef CONFIG_CLK
+	struct macb_device *macb = dev_get_priv(dev);
 	struct clk tx_clk;
 	ulong rate;
 	int ret;
 
-	/*
-	 * "tx_clk" is an optional clock source for MACB.
-	 * Ignore if it does not exist in DT.
-	 */
-	ret = clk_get_by_name(dev, "tx_clk", &tx_clk);
-	if (ret)
-		return 0;
-
 	switch (speed) {
 	case _10BASET:
 		rate = 2500000;		/* 2.5 MHz */
@@ -513,6 +511,26 @@ int __weak macb_linkspd_cb(struct udevice *dev, unsigned int speed)
 		return 0;
 	}
 
+	if (macb->regs_sifive_gemgxl) {
+		/*
+		 * SiFive GEMGXL TX clock operation mode:
+		 *
+		 * 0 = GMII mode. Use 125 MHz gemgxlclk from PRCI in TX logic
+		 *     and output clock on GMII output signal GTX_CLK
+		 * 1 = MII mode. Use MII input signal TX_CLK in TX logic
+		 */
+		writel(rate != 125000000, macb->regs_sifive_gemgxl);
+		return 0;
+	}
+
+	/*
+	 * "tx_clk" is an optional clock source for MACB.
+	 * Ignore if it does not exist in DT.
+	 */
+	ret = clk_get_by_name(dev, "tx_clk", &tx_clk);
+	if (ret)
+		return 0;
+
 	if (tx_clk.dev) {
 		ret = clk_set_rate(&tx_clk, rate);
 		if (ret)
@@ -701,6 +719,9 @@ static void gmac_configure_dma(struct macb_device *macb)
 	u32 buffer_size;
 	u32 dmacfg;
 
+	if (macb->skip_dma_config)
+		return;
+
 	buffer_size = 128 / RX_BUFFER_MULTIPLE;
 	dmacfg = gem_readl(macb, DMACFG) & ~GEM_BF(RXBS, -1L);
 	dmacfg |= GEM_BF(RXBS, buffer_size);
@@ -1178,6 +1199,7 @@ static int macb_eth_probe(struct udevice *dev)
 	struct macb_device *macb = dev_get_priv(dev);
 	const char *phy_mode;
 	__maybe_unused int ret;
+	fdt_addr_t addr;
 
 	phy_mode = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), "phy-mode",
 			       NULL);
@@ -1194,6 +1216,7 @@ static int macb_eth_probe(struct udevice *dev)
 	if (!macb_config)
 		macb_config = &default_gem_config;
 
+	macb->skip_dma_config = macb_config->skip_dma_config;
 	macb->dma_burst_length = macb_config->dma_burst_length;
 #ifdef CONFIG_CLK
 	ret = macb_enable_clk(dev);
@@ -1201,6 +1224,13 @@ static int macb_eth_probe(struct udevice *dev)
 		return ret;
 #endif
 
+	if (macb_config->has_sifive_gemgxl) {
+		addr = dev_read_addr_index(dev, 1);
+		if (addr == FDT_ADDR_T_NONE)
+			return -ENODEV;
+		macb->regs_sifive_gemgxl = (void __iomem *)addr;
+	}
+
 	_macb_eth_initialize(macb);
 
 #if defined(CONFIG_CMD_MII) || defined(CONFIG_PHYLIB)
@@ -1259,6 +1289,12 @@ static const struct macb_config sama5d4_config = {
 	.dma_burst_length = 4,
 };
 
+static const struct macb_config sifive_config = {
+	.skip_dma_config = true,
+	.dma_burst_length = 0,
+	.has_sifive_gemgxl = true,
+};
+
 static const struct udevice_id macb_eth_ids[] = {
 	{ .compatible = "cdns,macb" },
 	{ .compatible = "cdns,at91sam9260-macb" },
@@ -1266,6 +1302,7 @@ static const struct udevice_id macb_eth_ids[] = {
 	{ .compatible = "atmel,sama5d3-gem" },
 	{ .compatible = "atmel,sama5d4-gem", .data = (ulong)&sama5d4_config },
 	{ .compatible = "cdns,zynq-gem" },
+	{ .compatible = "sifive,fu540-macb", .data = (ulong)&sifive_config },
 	{ }
 };
 
-- 
2.17.1