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path: root/drivers/cpu/riscv_cpu.c
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Diffstat (limited to 'drivers/cpu/riscv_cpu.c')
-rw-r--r--drivers/cpu/riscv_cpu.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c
new file mode 100644
index 0000000000..5e15df590e
--- /dev/null
+++ b/drivers/cpu/riscv_cpu.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <cpu.h>
+#include <dm.h>
+#include <errno.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+
+static int riscv_cpu_get_desc(struct udevice *dev, char *buf, int size)
+{
+ const char *isa;
+
+ isa = dev_read_string(dev, "riscv,isa");
+ if (size < (strlen(isa) + 1))
+ return -ENOSPC;
+
+ strcpy(buf, isa);
+
+ return 0;
+}
+
+static int riscv_cpu_get_info(struct udevice *dev, struct cpu_info *info)
+{
+ const char *mmu;
+
+ dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq);
+
+ mmu = dev_read_string(dev, "mmu-type");
+ if (!mmu)
+ info->features |= BIT(CPU_FEAT_MMU);
+
+ return 0;
+}
+
+static int riscv_cpu_get_count(struct udevice *dev)
+{
+ ofnode node;
+ int num = 0;
+
+ ofnode_for_each_subnode(node, dev_ofnode(dev->parent)) {
+ const char *device_type;
+
+ device_type = ofnode_read_string(node, "device_type");
+ if (!device_type)
+ continue;
+ if (strcmp(device_type, "cpu") == 0)
+ num++;
+ }
+
+ return num;
+}
+
+static int riscv_cpu_bind(struct udevice *dev)
+{
+ struct cpu_platdata *plat = dev_get_parent_platdata(dev);
+ struct driver *drv;
+ int ret;
+
+ /* save the hart id */
+ plat->cpu_id = dev_read_addr(dev);
+
+ /* first examine the property in current cpu node */
+ ret = dev_read_u32(dev, "timebase-frequency", &plat->timebase_freq);
+ /* if not found, then look at the parent /cpus node */
+ if (ret)
+ dev_read_u32(dev->parent, "timebase-frequency",
+ &plat->timebase_freq);
+
+ /*
+ * Bind riscv-timer driver on hart 0
+ *
+ * We only instantiate one timer device which is enough for U-Boot.
+ * Pass the "timebase-frequency" value as the driver data for the
+ * timer device.
+ *
+ * Return value is not checked since it's possible that the timer
+ * driver is not included.
+ */
+ if (!plat->cpu_id && plat->timebase_freq) {
+ drv = lists_driver_lookup_name("riscv_timer");
+ if (!drv) {
+ debug("Cannot find the timer driver, not included?\n");
+ return 0;
+ }
+
+ device_bind_with_driver_data(dev, drv, "riscv_timer",
+ plat->timebase_freq, ofnode_null(),
+ NULL);
+ }
+
+ return 0;
+}
+
+static const struct cpu_ops riscv_cpu_ops = {
+ .get_desc = riscv_cpu_get_desc,
+ .get_info = riscv_cpu_get_info,
+ .get_count = riscv_cpu_get_count,
+};
+
+static const struct udevice_id riscv_cpu_ids[] = {
+ { .compatible = "riscv" },
+ { }
+};
+
+U_BOOT_DRIVER(riscv_cpu) = {
+ .name = "riscv_cpu",
+ .id = UCLASS_CPU,
+ .of_match = riscv_cpu_ids,
+ .bind = riscv_cpu_bind,
+ .ops = &riscv_cpu_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};