Implement various CPU related functions.
I'm actually just using it to get cpu clock frequency.
Signed-off-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
---
drivers/cpu/Kconfig | 6 +++
drivers/cpu/Makefile | 1 +
drivers/cpu/xtensa_cpu.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 124 insertions(+)
diff --git a/drivers/cpu/Kconfig b/drivers/cpu/Kconfig
index 1c3c810651ef..5c06cd9f60e8 100644
--- a/drivers/cpu/Kconfig
+++ b/drivers/cpu/Kconfig
@@ -33,3 +33,9 @@ config CPU_MICROBLAZE
select XILINX_MICROBLAZE0_PVR
help
Support CPU cores for Microblaze architecture.
+
+config CPU_XTENSA
+ bool "Enable Xtensa CPU driver"
+ depends on CPU && XTENSA
+ help
+ Support CPU cores for Xtensa architecture.
diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile
index d4bbf6fa5e05..bc75d9b974e8 100644
--- a/drivers/cpu/Makefile
+++ b/drivers/cpu/Makefile
@@ -14,4 +14,5 @@ obj-$(CONFIG_CPU_IMX) += imx8_cpu.o
obj-$(CONFIG_CPU_MPC83XX) += mpc83xx_cpu.o
obj-$(CONFIG_CPU_RISCV) += riscv_cpu.o
obj-$(CONFIG_CPU_MICROBLAZE) += microblaze_cpu.o
+obj-$(CONFIG_CPU_XTENSA) += xtensa_cpu.o
obj-$(CONFIG_SANDBOX) += cpu_sandbox.o
diff --git a/drivers/cpu/xtensa_cpu.c b/drivers/cpu/xtensa_cpu.c
new file mode 100644
index 000000000000..fbb561dd6128
--- /dev/null
+++ b/drivers/cpu/xtensa_cpu.c
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2024 Jiaxun Yang <jiaxun.y...@flygoat.com>
+ */
+
+#include <clk.h>
+#include <cpu.h>
+#include <dm.h>
+#include <errno.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+
+#include <asm/arch/core.h>
+
+static int xtensa_cpu_get_desc(const struct udevice *dev, char *buf, int size)
+{
+ const char *cpu = XCHAL_CORE_ID;
+
+ if (!cpu || size < (strlen(cpu) + 1))
+ return -ENOSPC;
+
+ strcpy(buf, cpu);
+
+ return 0;
+}
+
+static int xtensa_cpu_get_info(const struct udevice *dev, struct cpu_info
*info)
+{
+ struct cpu_plat *plat = dev_get_parent_plat(dev);
+
+ info->cpu_freq = plat->timebase_freq;
+
+#if XCHAL_HAVE_PTP_MMU
+ info->features |= BIT(CPU_FEAT_MMU);
+#endif
+#if XCHAL_ICACHE_SIZE || XCHAL_DCACHE_SIZE
+ info->features |= BIT(CPU_FEAT_L1_CACHE);
+#endif
+
+ return 0;
+}
+
+static int xtensa_cpu_get_count(const struct udevice *dev)
+{
+ ofnode node;
+ int num = 0;
+
+ ofnode_for_each_subnode(node, dev_ofnode(dev->parent)) {
+ const char *device_type;
+
+ /* skip if hart is marked as not available in the device tree */
+ if (!ofnode_is_enabled(node))
+ continue;
+
+ device_type = ofnode_read_string(node, "device_type");
+ if (!device_type)
+ continue;
+ if (strcmp(device_type, "cpu") == 0)
+ num++;
+ }
+
+ return num;
+}
+
+static int xtensa_cpu_bind(struct udevice *dev)
+{
+ struct cpu_plat *plat = dev_get_parent_plat(dev);
+
+ plat->cpu_id = dev_read_addr(dev);
+
+ return 0;
+}
+
+static int xtensa_cpu_probe(struct udevice *dev)
+{
+ int ret = 0;
+ struct clk clk;
+ struct cpu_plat *plat = dev_get_parent_plat(dev);
+
+ asm volatile ("rsr %0, 176\n"
+ "rsr %1, 208\n"
+ : "=r"(plat->id[0]), "=r"(plat->id[1]));
+
+ /* Get a clock if it exists */
+ ret = clk_get_by_index(dev, 0, &clk);
+ if (!ret) {
+ ret = clk_enable(&clk);
+ if (ret && (ret != -ENOSYS || ret != -ENOTSUPP))
+ return ret;
+ ret = clk_get_rate(&clk);
+ if (!IS_ERR_VALUE(ret))
+ plat->timebase_freq = ret;
+ }
+
+ return 0;
+}
+
+static const struct cpu_ops xtensa_cpu_ops = {
+ .get_desc = xtensa_cpu_get_desc,
+ .get_info = xtensa_cpu_get_info,
+ .get_count = xtensa_cpu_get_count,
+};
+
+static const struct udevice_id xtensa_cpu_ids[] = {
+ { .compatible = "cdns,xtensa-cpu" },
+ { }
+};
+
+U_BOOT_DRIVER(xtensa_cpu) = {
+ .name = "xtensa_cpu",
+ .id = UCLASS_CPU,
+ .of_match = xtensa_cpu_ids,
+ .bind = xtensa_cpu_bind,
+ .probe = xtensa_cpu_probe,
+ .ops = &xtensa_cpu_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
--
2.43.0
