cpu: add basic cpu driver for MediaTek ARM chips

Add basic CPU driver used to retrieve CPU model information.

Tested-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile
index 20884b1..3b38ba9 100644 (file)
--- 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_CPU_MICROBLAZE) += microblaze_cpu.o

diff --git a/drivers/cpu/mtk_cpu.c b/drivers/cpu/mtk_cpu.c
new file mode 100644 (file)
index 0000000..2a08be9
--- /dev/null
+++ b/drivers/cpu/mtk_cpu.c
@@ -0,0 +1,86 @@
+// 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 <regmap.h>
+#include <syscon.h>
+#include <asm/global_data.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct mtk_cpu_plat {
+       struct regmap *hwver;
+};
+
+static int mtk_cpu_get_desc(const struct udevice *dev, char *buf, int size)
+{
+       struct mtk_cpu_plat *plat = dev_get_plat(dev);
+       uint val;
+
+       regmap_read(plat->hwver, 0, &val);
+
+       snprintf(buf, size, "MediaTek MT%04X", val);
+
+       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);
+       struct ofnode_phandle_args args;
+       int ret;
+
+       ret = dev_read_phandle_with_args(dev, "mediatek,hwver", NULL, 0, 0,
+                                        &args);
+       if (ret)
+               return ret;
+
+       plat->hwver = syscon_node_to_regmap(args.node);
+       if (IS_ERR(plat->hwver))
+               return PTR_ERR(plat->hwver);
+
+       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,
+};