From e3c707d23a3a5bc1ba9b8c03731a32c3714ae56a Mon Sep 17 00:00:00 2001
From: Weijie Gao <weijie.gao@mediatek.com>
Date: Wed, 31 Aug 2022 19:05:20 +0800
Subject: [PATCH 28/32] cpu: add basic cpu driver for MediaTek ARM chips

Add basic CPU driver used to retrieve CPU model information.

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
---
 drivers/cpu/Makefile  |   1 +
 drivers/cpu/mtk_cpu.c | 106 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 drivers/cpu/mtk_cpu.c

--- a/drivers/cpu/Makefile
+++ b/drivers/cpu/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_CPU) += cpu-uclass.o
 obj-$(CONFIG_ARCH_BMIPS) += bmips_cpu.o
 obj-$(CONFIG_ARCH_IMX8) += imx8_cpu.o
 obj-$(CONFIG_ARCH_AT91) += at91_cpu.o
+obj-$(CONFIG_ARCH_MEDIATEK) += mtk_cpu.o
 obj-$(CONFIG_CPU_MPC83XX) += mpc83xx_cpu.o
 obj-$(CONFIG_CPU_RISCV) += riscv_cpu.o
 obj-$(CONFIG_SANDBOX) += cpu_sandbox.o
--- /dev/null
+++ b/drivers/cpu/mtk_cpu.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 MediaTek Inc. All rights reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include <linux/types.h>
+#include <cpu.h>
+#include <dm.h>
+#include <fdt_support.h>
+#include <mapmem.h>
+#include <asm/global_data.h>
+#include <linux/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct mtk_cpu_plat {
+	void __iomem *hwver_base;
+};
+
+static int mtk_cpu_get_desc(const struct udevice *dev, char *buf, int size)
+{
+	struct mtk_cpu_plat *plat = dev_get_plat(dev);
+
+	snprintf(buf, size, "MediaTek MT%04X", readl(plat->hwver_base));
+
+	return 0;
+}
+
+static int mtk_cpu_get_count(const struct udevice *dev)
+{
+	return 1;
+}
+
+static int mtk_cpu_get_vendor(const struct udevice *dev, char *buf, int size)
+{
+	snprintf(buf, size, "MediaTek");
+
+	return 0;
+}
+
+static int mtk_cpu_probe(struct udevice *dev)
+{
+	struct mtk_cpu_plat *plat = dev_get_plat(dev);
+	const void *fdt = gd->fdt_blob, *reg;
+	int offset, parent, len, na, ns;
+	u64 addr;
+
+	if (!fdt)
+		return -ENODEV;
+
+	offset = fdt_path_offset(fdt, "/hwver");
+	if (offset < 0)
+		return -ENODEV;
+
+	parent = fdt_parent_offset(fdt, offset);
+	if (parent < 0)
+		return -ENODEV;
+
+	na = fdt_address_cells(fdt, parent);
+	if (na < 1)
+		return -ENODEV;
+
+	ns = fdt_size_cells(gd->fdt_blob, parent);
+	if (ns < 0)
+		return -ENODEV;
+
+	reg = fdt_getprop(gd->fdt_blob, offset, "reg", &len);
+	if (!reg)
+		return -ENODEV;
+
+	if (ns)
+		addr = fdt_translate_address(fdt, offset, reg);
+	else
+		addr = fdt_read_number(reg, na);
+
+	plat->hwver_base = map_sysmem(addr, 0);
+	if (!plat->hwver_base)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct cpu_ops mtk_cpu_ops = {
+	.get_desc	= mtk_cpu_get_desc,
+	.get_count	= mtk_cpu_get_count,
+	.get_vendor	= mtk_cpu_get_vendor,
+};
+
+static const struct udevice_id mtk_cpu_ids[] = {
+	{ .compatible = "arm,cortex-a7" },
+	{ .compatible = "arm,cortex-a53" },
+	{ .compatible = "arm,cortex-a73" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(cpu_mtk) = {
+	.name		= "mtk-cpu",
+	.id		= UCLASS_CPU,
+	.of_match	= mtk_cpu_ids,
+	.ops		= &mtk_cpu_ops,
+	.probe		= mtk_cpu_probe,
+	.plat_auto	= sizeof(struct mtk_cpu_plat),
+	.flags		= DM_FLAG_PRE_RELOC,
+};