Implement various CPU related functions. I'm actually just using it to get cpu clock frequency.
Tested-by: Max Filippov jcmvbkbc@gmail.com Signed-off-by: Jiaxun Yang jiaxun.yang@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.yang@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, +};