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>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/cpu/mtk_cpu.c b/drivers/cpu/mtk_cpu.c
new file mode 100644
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,
+};