mips: mtmips: add support for MediaTek MT7621 SoC

This patch adds support for MediaTek MT7621 SoC.
All files are dedicated for u-boot.

The default build target is u-boot-mt7621.bin.

The specification of this chip:
https://www.mediatek.com/products/homenetworking/mt7621

Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/mach-mtmips/mt7621/init.c b/arch/mips/mach-mtmips/mt7621/init.c
new file mode 100644
index 0000000..d21848a
--- /dev/null
+++ b/arch/mips/mach-mtmips/mt7621/init.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 MediaTek Inc. All rights reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <dm/uclass.h>
+#include <dt-bindings/clock/mt7621-clk.h>
+#include <asm/global_data.h>
+#include <linux/io.h>
+#include <linux/bitfield.h>
+#include "mt7621.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static const char *const boot_mode[(CHIP_MODE_M >> CHIP_MODE_S) + 1] = {
+	[1] = "NAND 2K+64",
+	[2] = "SPI-NOR 3-Byte Addr",
+	[3] = "SPI-NOR 4-Byte Addr",
+	[10] = "NAND 2K+128",
+	[11] = "NAND 4K+128",
+	[12] = "NAND 4K+256",
+};
+
+int print_cpuinfo(void)
+{
+	void __iomem *sysc = ioremap_nocache(SYSCTL_BASE, SYSCTL_SIZE);
+	u32 val, ver, eco, pkg, core, dram, chipmode;
+	u32 cpu_clk, ddr_clk, bus_clk, xtal_clk;
+	struct udevice *clkdev;
+	const char *bootdev;
+	struct clk clk;
+	int ret;
+
+	val = readl(sysc + SYSCTL_CHIP_REV_ID_REG);
+	ver = FIELD_GET(VER_ID_M, val);
+	eco = FIELD_GET(ECO_ID_M, val);
+	pkg = FIELD_GET(PKG_ID, val);
+	core = FIELD_GET(CPU_ID, val);
+
+	val = readl(sysc + SYSCTL_SYSCFG0_REG);
+	dram = FIELD_GET(DRAM_TYPE, val);
+	chipmode = FIELD_GET(CHIP_MODE_M, val);
+
+	bootdev = boot_mode[chipmode];
+	if (!bootdev)
+		bootdev = "Unsupported boot mode";
+
+	printf("CPU:   MediaTek MT7621%c ver %u, eco %u\n",
+	       core ? (pkg ? 'A' : 'N') : 'S', ver, eco);
+
+	printf("Boot:  DDR%u, %s\n", dram ? 2 : 3, bootdev);
+
+	ret = uclass_get_device_by_driver(UCLASS_CLK, DM_DRIVER_GET(mt7621_clk),
+					  &clkdev);
+	if (ret)
+		return ret;
+
+	clk.dev = clkdev;
+
+	clk.id = MT7621_CLK_CPU;
+	cpu_clk = clk_get_rate(&clk);
+
+	clk.id = MT7621_CLK_BUS;
+	bus_clk = clk_get_rate(&clk);
+
+	clk.id = MT7621_CLK_DDR;
+	ddr_clk = clk_get_rate(&clk);
+
+	clk.id = MT7621_CLK_XTAL;
+	xtal_clk = clk_get_rate(&clk);
+
+	/* Set final timer frequency */
+	if (cpu_clk)
+		gd->arch.timer_freq = cpu_clk / 2;
+
+	printf("Clock: CPU: %uMHz, DDR: %uMT/s, Bus: %uMHz, XTAL: %uMHz\n",
+	       cpu_clk / 1000000, ddr_clk / 500000, bus_clk / 1000000,
+	       xtal_clk / 1000000);
+
+	return 0;
+}
+
+unsigned long get_xtal_mhz(void)
+{
+	void __iomem *sysc = ioremap_nocache(SYSCTL_BASE, SYSCTL_SIZE);
+	u32 bs, xtal_sel;
+
+	bs = readl(sysc + SYSCTL_SYSCFG0_REG);
+	xtal_sel = FIELD_GET(XTAL_MODE_SEL_M, bs);
+
+	if (xtal_sel <= 2)
+		return 20;
+	else if (xtal_sel <= 5)
+		return 40;
+	else
+		return 25;
+}
+
+static void xhci_config_40mhz(void __iomem *usbh)
+{
+	writel(FIELD_PREP(SSUSB_MAC3_SYS_CK_GATE_MASK_TIME_M, 0x20) |
+	       FIELD_PREP(SSUSB_MAC2_SYS_CK_GATE_MASK_TIME_M, 0x20) |
+	       FIELD_PREP(SSUSB_MAC3_SYS_CK_GATE_MODE_M, 2) |
+	       FIELD_PREP(SSUSB_MAC2_SYS_CK_GATE_MODE_M, 2) | 0x10,
+	       usbh + SSUSB_MAC_CK_CTRL_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_PREDIV_PE1D_M, 2) |
+	       FIELD_PREP(SSUSB_PLL_PREDIV_U3_M, 1) |
+	       FIELD_PREP(SSUSB_PLL_FBKDI_M, 4),
+	       usbh + DA_SSUSB_U3PHYA_10_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_FBKDIV_PE2H_M, 0x18) |
+	       FIELD_PREP(SSUSB_PLL_FBKDIV_PE1D_M, 0x18) |
+	       FIELD_PREP(SSUSB_PLL_FBKDIV_PE1H_M, 0x18) |
+	       FIELD_PREP(SSUSB_PLL_FBKDIV_U3_M, 0x1e),
+	       usbh + DA_SSUSB_PLL_FBKDIV_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_PCW_NCPO_U3_M, 0x1e400000),
+	       usbh + DA_SSUSB_PLL_PCW_NCPO_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_SSC_DELTA1_PE1H_M, 0x25) |
+	       FIELD_PREP(SSUSB_PLL_SSC_DELTA1_U3_M, 0x73),
+	       usbh + DA_SSUSB_PLL_SSC_DELTA1_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_SSC_DELTA_U3_M, 0x71) |
+	       FIELD_PREP(SSUSB_PLL_SSC_DELTA1_PE2D_M, 0x4a),
+	       usbh + DA_SSUSB_U3PHYA_21_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_SSC_PRD_M, 0x140),
+	       usbh + SSUSB_U3PHYA_9_REG);
+
+	writel(FIELD_PREP(SSUSB_SYSPLL_PCW_NCPO_M, 0x11c00000),
+	       usbh + SSUSB_U3PHYA_3_REG);
+
+	writel(FIELD_PREP(SSUSB_PCIE_CLKDRV_AMP_M, 4) |
+	       FIELD_PREP(SSUSB_SYSPLL_FBSEL_M, 1) |
+	       FIELD_PREP(SSUSB_SYSPLL_PREDIV_M, 1),
+	       usbh + SSUSB_U3PHYA_1_REG);
+
+	writel(FIELD_PREP(SSUSB_SYSPLL_FBDIV_M, 0x12) |
+	       SSUSB_SYSPLL_VCO_DIV_SEL | SSUSB_SYSPLL_FPEN |
+	       SSUSB_SYSPLL_MONCK_EN | SSUSB_SYSPLL_VOD_EN,
+	       usbh + SSUSB_U3PHYA_2_REG);
+
+	writel(SSUSB_EQ_CURSEL | FIELD_PREP(SSUSB_RX_DAC_MUX_M, 8) |
+	       FIELD_PREP(SSUSB_PCIE_SIGDET_VTH_M, 1) |
+	       FIELD_PREP(SSUSB_PCIE_SIGDET_LPF_M, 1),
+	       usbh + SSUSB_U3PHYA_11_REG);
+
+	writel(FIELD_PREP(SSUSB_RING_OSC_CNTEND_M, 0x1ff) |
+	       FIELD_PREP(SSUSB_XTAL_OSC_CNTEND_M, 0x7f) |
+	       SSUSB_RING_BYPASS_DET,
+	       usbh + SSUSB_B2_ROSC_0_REG);
+
+	writel(FIELD_PREP(SSUSB_RING_OSC_FRC_RECAL_M, 3) |
+	       SSUSB_RING_OSC_FRC_SEL,
+	       usbh + SSUSB_B2_ROSC_1_REG);
+}
+
+static void xhci_config_25mhz(void __iomem *usbh)
+{
+	writel(FIELD_PREP(SSUSB_MAC3_SYS_CK_GATE_MASK_TIME_M, 0x20) |
+	       FIELD_PREP(SSUSB_MAC2_SYS_CK_GATE_MASK_TIME_M, 0x20) |
+	       FIELD_PREP(SSUSB_MAC3_SYS_CK_GATE_MODE_M, 2) |
+	       FIELD_PREP(SSUSB_MAC2_SYS_CK_GATE_MODE_M, 2) | 0x10,
+	       usbh + SSUSB_MAC_CK_CTRL_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_PREDIV_PE1D_M, 2) |
+	       FIELD_PREP(SSUSB_PLL_FBKDI_M, 4),
+	       usbh + DA_SSUSB_U3PHYA_10_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_FBKDIV_PE2H_M, 0x18) |
+	       FIELD_PREP(SSUSB_PLL_FBKDIV_PE1D_M, 0x18) |
+	       FIELD_PREP(SSUSB_PLL_FBKDIV_PE1H_M, 0x18) |
+	       FIELD_PREP(SSUSB_PLL_FBKDIV_U3_M, 0x19),
+	       usbh + DA_SSUSB_PLL_FBKDIV_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_PCW_NCPO_U3_M, 0x18000000),
+	       usbh + DA_SSUSB_PLL_PCW_NCPO_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_SSC_DELTA1_PE1H_M, 0x25) |
+	       FIELD_PREP(SSUSB_PLL_SSC_DELTA1_U3_M, 0x4a),
+	       usbh + DA_SSUSB_PLL_SSC_DELTA1_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_SSC_DELTA_U3_M, 0x48) |
+	       FIELD_PREP(SSUSB_PLL_SSC_DELTA1_PE2D_M, 0x4a),
+	       usbh + DA_SSUSB_U3PHYA_21_REG);
+
+	writel(FIELD_PREP(SSUSB_PLL_SSC_PRD_M, 0x190),
+	       usbh + SSUSB_U3PHYA_9_REG);
+
+	writel(FIELD_PREP(SSUSB_SYSPLL_PCW_NCPO_M, 0xe000000),
+	       usbh + SSUSB_U3PHYA_3_REG);
+
+	writel(FIELD_PREP(SSUSB_PCIE_CLKDRV_AMP_M, 4) |
+	       FIELD_PREP(SSUSB_SYSPLL_FBSEL_M, 1),
+	       usbh + SSUSB_U3PHYA_1_REG);
+
+	writel(FIELD_PREP(SSUSB_SYSPLL_FBDIV_M, 0xf) |
+	       SSUSB_SYSPLL_VCO_DIV_SEL | SSUSB_SYSPLL_FPEN |
+	       SSUSB_SYSPLL_MONCK_EN | SSUSB_SYSPLL_VOD_EN,
+	       usbh + SSUSB_U3PHYA_2_REG);
+
+	writel(SSUSB_EQ_CURSEL | FIELD_PREP(SSUSB_RX_DAC_MUX_M, 8) |
+	       FIELD_PREP(SSUSB_PCIE_SIGDET_VTH_M, 1) |
+	       FIELD_PREP(SSUSB_PCIE_SIGDET_LPF_M, 1),
+	       usbh + SSUSB_U3PHYA_11_REG);
+
+	writel(FIELD_PREP(SSUSB_RING_OSC_CNTEND_M, 0x1ff) |
+	       FIELD_PREP(SSUSB_XTAL_OSC_CNTEND_M, 0x7f) |
+	       SSUSB_RING_BYPASS_DET,
+	       usbh + SSUSB_B2_ROSC_0_REG);
+
+	writel(FIELD_PREP(SSUSB_RING_OSC_FRC_RECAL_M, 3) |
+	       SSUSB_RING_OSC_FRC_SEL,
+	       usbh + SSUSB_B2_ROSC_1_REG);
+}
+
+void lowlevel_init(void)
+{
+	void __iomem *usbh = ioremap_nocache(SSUSB_BASE, SSUSB_SIZE);
+	u32 xtal = get_xtal_mhz();
+
+	/* Setup USB xHCI */
+	if (xtal == 40)
+		xhci_config_40mhz(usbh);
+	else if (xtal == 25)
+		xhci_config_25mhz(usbh);
+}
+
+ulong notrace get_tbclk(void)
+{
+	return gd->arch.timer_freq;
+}
+
+void _machine_restart(void)
+{
+	void __iomem *sysc = ioremap_nocache(SYSCTL_BASE, SYSCTL_SIZE);
+
+	while (1)
+		writel(SYS_RST, sysc + SYSCTL_RSTCTL_REG);
+}