Implement a driver for LoongArch CPU solely for gathering
some information bits from FDT and CPU level config registers.
Signed-off-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
---
drivers/cpu/Kconfig | 6 ++
drivers/cpu/Makefile | 1 +
drivers/cpu/loongarch_cpu.c | 148 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 155 insertions(+)
diff --git a/drivers/cpu/Kconfig b/drivers/cpu/Kconfig
index 1c3c810651ef..9cee9285194b 100644
--- a/drivers/cpu/Kconfig
+++ b/drivers/cpu/Kconfig
@@ -13,6 +13,12 @@ config CPU_IMX
help
Support CPU cores for SoCs of the i.MX series.
+config CPU_LOONGARCH
+ bool "Enable LoongArch CPU driver"
+ depends on CPU && LOONGARCH
+ help
+ Support CPU cores for LoongArch processors.
+
config CPU_MPC83XX
bool "Enable MPC83xx CPU driver"
depends on CPU && MPC83xx
diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile
index d4bbf6fa5e05..914819712f79 100644
--- a/drivers/cpu/Makefile
+++ b/drivers/cpu/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_ARCH_IMX8) += imx8_cpu.o
obj-$(CONFIG_ARCH_AT91) += at91_cpu.o
obj-$(CONFIG_ARCH_MEDIATEK) += mtk_cpu.o
obj-$(CONFIG_CPU_IMX) += imx8_cpu.o
+obj-$(CONFIG_CPU_LOONGARCH) += loongarch_cpu.o
obj-$(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/loongarch_cpu.c b/drivers/cpu/loongarch_cpu.c
new file mode 100644
index 000000000000..8ce6746054ff
--- /dev/null
+++ b/drivers/cpu/loongarch_cpu.c
@@ -0,0 +1,148 @@
+// 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 <log.h>
+#include <asm/loongarch.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+
+static int loongarch_cpu_get_desc(const struct udevice *dev, char *buf, int
size)
+{
+ const char *cpu;
+
+ /* We try to get CPU name from IOCSR first */
+ if ((read_cpucfg(LOONGARCH_CPUCFG1) & CPUCFG1_IOCSR)) {
+ int i;
+ char vendor_buf[9] = { 0 };
+ char name_buf[9] = { 0 };
+ u64 vendor = iocsr_read64(LOONGARCH_IOCSR_VENDOR);
+ u64 name = iocsr_read64(LOONGARCH_IOCSR_CPUNAME);
+
+ if (!vendor || !name)
+ goto get_desc_dt;
+
+ for (i = 0; i < sizeof(u64); i++) {
+ vendor_buf[i] = vendor & 0xff;
+ name_buf[i] = name & 0xff;
+ vendor >>= 8;
+ name >>= 8;
+ }
+
+ snprintf(buf, size, "%s-%s", vendor_buf, name_buf);
+
+ return 0;
+ }
+
+get_desc_dt:
+ cpu = dev_read_string(dev, "compatible");
+ if (!cpu || size < (strlen(cpu) + 1))
+ return -ENOSPC;
+
+ strcpy(buf, cpu);
+
+ return 0;
+}
+
+static int loongarch_cpu_get_info(const struct udevice *dev, struct cpu_info
*info)
+{
+ int ret;
+ struct clk clk;
+
+ /* First try getting the frequency from the assigned clock */
+ ret = clk_get_by_index((struct udevice *)dev, 0, &clk);
+ if (!ret) {
+ ret = clk_get_rate(&clk);
+ if (!IS_ERR_VALUE(ret))
+ info->cpu_freq = ret;
+ }
+
+ if (!info->cpu_freq)
+ dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq);
+
+ if (read_cpucfg(LOONGARCH_CPUCFG1) & CPUCFG1_PAGING)
+ info->features |= BIT(CPU_FEAT_MMU);
+
+ if (read_cpucfg(LOONGARCH_CPUCFG16) & CPUCFG16_L1_IUPRE)
+ info->features |= BIT(CPU_FEAT_L1_CACHE);
+
+ return 0;
+}
+
+static int loongarch_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 core 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 loongarch_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 loongarch_cpu_probe(struct udevice *dev)
+{
+ int ret = 0;
+ struct clk clk;
+
+ /* Get a clock if it exists */
+ ret = clk_get_by_index(dev, 0, &clk);
+ if (ret)
+ return 0;
+
+ ret = clk_enable(&clk);
+ if (ret == -ENOSYS || ret == -ENOTSUPP)
+ return 0;
+ else
+ return ret;
+}
+
+static const struct cpu_ops loongarch_cpu_ops = {
+ .get_desc = loongarch_cpu_get_desc,
+ .get_info = loongarch_cpu_get_info,
+ .get_count = loongarch_cpu_get_count,
+};
+
+static const struct udevice_id loongarch_cpu_ids[] = {
+ { .compatible = "loongarch,Loongson-3A5000" }, /* From QEMU,
undocumented */
+ { .compatible = "loongson,la264" },
+ { .compatible = "loongson,la364" },
+ { }
+};
+
+U_BOOT_DRIVER(loongarch_cpu) = {
+ .name = "loongarch_cpu",
+ .id = UCLASS_CPU,
+ .of_match = loongarch_cpu_ids,
+ .bind = loongarch_cpu_bind,
+ .probe = loongarch_cpu_probe,
+ .ops = &loongarch_cpu_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
--
2.43.0
