mips: mtmips: add support for MediaTek MT7620 SoC

This patch adds support for MediaTek MT7620 SoC.
All files are dedicated for u-boot.

Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/arch/mips/mach-mtmips/mt7620/sysc.c b/arch/mips/mach-mtmips/mt7620/sysc.c
new file mode 100644
index 0000000..296a9be
--- /dev/null
+++ b/arch/mips/mach-mtmips/mt7620/sysc.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * Author:  Weijie Gao <weijie.gao@mediatek.com>
+ *
+ * Misc driver for manipulating System control registers
+ */
+
+#include <dm.h>
+#include <misc.h>
+#include <asm/io.h>
+#include <asm/addrspace.h>
+#include <dm/device_compat.h>
+#include <mach/mt7620-sysc.h>
+#include "mt7620.h"
+
+struct mt7620_sysc_priv {
+	void __iomem *base;
+};
+
+static int mt7620_sysc_read(struct udevice *dev, int offset, void *buf,
+			    int size)
+{
+	struct mt7620_sysc_priv *priv = dev_get_priv(dev);
+	u32 val;
+
+	if (offset % sizeof(u32) || size != sizeof(u32) ||
+	    offset >= SYSCTL_SIZE)
+		return -EINVAL;
+
+	val = readl(priv->base + offset);
+
+	if (buf)
+		*(u32 *)buf = val;
+
+	return 0;
+}
+
+static int mt7620_sysc_write(struct udevice *dev, int offset, const void *buf,
+			     int size)
+{
+	struct mt7620_sysc_priv *priv = dev_get_priv(dev);
+	u32 val;
+
+	if (offset % sizeof(u32) || size != sizeof(u32) ||
+	    offset >= SYSCTL_SIZE || !buf)
+		return -EINVAL;
+
+	val = *(u32 *)buf;
+	writel(val, priv->base + offset);
+
+	return 0;
+}
+
+static int mt7620_sysc_ioctl(struct udevice *dev, unsigned long request,
+			     void *buf)
+{
+	struct mt7620_sysc_priv *priv = dev_get_priv(dev);
+	struct mt7620_sysc_chip_rev *chip_rev;
+	struct mt7620_sysc_clks *clks;
+	u32 val, shift;
+
+	if (!buf)
+		return -EINVAL;
+
+	switch (request) {
+	case MT7620_SYSC_IOCTL_GET_CLK:
+		clks = buf;
+		mt7620_get_clks(&clks->cpu_clk, &clks->sys_clk,
+				&clks->xtal_clk);
+
+		val = readl(priv->base + SYSCTL_CLKCFG0_REG);
+		if (val & PERI_CLK_SEL)
+			clks->peri_clk = clks->xtal_clk;
+		else
+			clks->peri_clk = 40000000;
+
+		return 0;
+
+	case MT7620_SYSC_IOCTL_GET_CHIP_REV:
+		chip_rev = buf;
+
+		val = readl(priv->base + SYSCTL_CHIP_REV_ID_REG);
+
+		chip_rev->bga = !!(val & PKG_ID);
+		chip_rev->ver = (val & VER_M) >> VER_S;
+		chip_rev->eco = (val & ECO_M) >> ECO_S;
+
+		return 0;
+
+	case MT7620_SYSC_IOCTL_SET_GE1_MODE:
+	case MT7620_SYSC_IOCTL_SET_GE2_MODE:
+		val = *(u32 *)buf;
+
+		if (val > MT7620_SYSC_GE_ESW_PHY)
+			return -EINVAL;
+
+		if (request == MT7620_SYSC_IOCTL_SET_GE1_MODE)
+			shift = GE1_MODE_S;
+		else
+			shift = GE2_MODE_S;
+
+		clrsetbits_32(priv->base + SYSCTL_SYSCFG1_REG,
+			      GE_MODE_M << shift, val << shift);
+
+		return 0;
+
+	case MT7620_SYSC_IOCTL_SET_USB_MODE:
+		val = *(u32 *)buf;
+
+		if (val == MT7620_SYSC_USB_DEVICE_MODE)
+			val = 0;
+		else if (val == MT7620_SYSC_USB_HOST_MODE)
+			val = USB0_HOST_MODE;
+
+		clrsetbits_32(priv->base + SYSCTL_SYSCFG1_REG,
+			      USB0_HOST_MODE, val);
+
+		return 0;
+
+	case MT7620_SYSC_IOCTL_SET_PCIE_MODE:
+		val = *(u32 *)buf;
+
+		if (val == MT7620_SYSC_PCIE_EP_MODE)
+			val = 0;
+		else if (val == MT7620_SYSC_PCIE_RC_MODE)
+			val = PCIE_RC_MODE;
+
+		clrsetbits_32(priv->base + SYSCTL_SYSCFG1_REG,
+			      PCIE_RC_MODE, val);
+
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mt7620_sysc_probe(struct udevice *dev)
+{
+	struct mt7620_sysc_priv *priv = dev_get_priv(dev);
+
+	priv->base = dev_remap_addr_index(dev, 0);
+	if (!priv->base) {
+		dev_err(dev, "failed to map sysc registers\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct misc_ops mt7620_sysc_ops = {
+	.read = mt7620_sysc_read,
+	.write = mt7620_sysc_write,
+	.ioctl = mt7620_sysc_ioctl,
+};
+
+static const struct udevice_id mt7620_sysc_ids[] = {
+	{ .compatible = "mediatek,mt7620-sysc" },
+	{ }
+};
+
+U_BOOT_DRIVER(mt7620_sysc) = {
+	.name		= "mt7620_sysc",
+	.id		= UCLASS_MISC,
+	.of_match	= mt7620_sysc_ids,
+	.probe		= mt7620_sysc_probe,
+	.ops		= &mt7620_sysc_ops,
+	.priv_auto	= sizeof(struct mt7620_sysc_priv),
+	.flags = DM_FLAG_PRE_RELOC,
+};