It is useful to be able to keep track of the available CPUs in a multi-CPU system. This uclass is mostly intended for use with SMP systems.
The uclass provides methods for getting basic information about each CPU.
Signed-off-by: Simon Glass sjg@chromium.org ---
drivers/Kconfig | 2 ++ drivers/Makefile | 1 + drivers/cpu/Kconfig | 8 +++++ drivers/cpu/Makefile | 7 ++++ drivers/cpu/cpu-uclass.c | 61 +++++++++++++++++++++++++++++++++++ include/cpu.h | 84 ++++++++++++++++++++++++++++++++++++++++++++++++ include/dm/uclass-id.h | 1 + 7 files changed, 164 insertions(+) create mode 100644 drivers/cpu/Kconfig create mode 100644 drivers/cpu/Makefile create mode 100644 drivers/cpu/cpu-uclass.c create mode 100644 include/cpu.h
diff --git a/drivers/Kconfig b/drivers/Kconfig index 941aa0c..1f40887 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -2,6 +2,8 @@ menu "Device Drivers"
source "drivers/core/Kconfig"
+source "drivers/cpu/Kconfig" + source "drivers/demo/Kconfig"
source "drivers/pci/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 5ef58c0..405b64b 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -3,6 +3,7 @@ obj-$(CONFIG_DM_DEMO) += demo/ obj-$(CONFIG_BIOSEMU) += bios_emulator/ obj-y += block/ obj-$(CONFIG_BOOTCOUNT_LIMIT) += bootcount/ +obj-$(CONFIG_CPU) += cpu/ obj-y += crypto/ obj-$(CONFIG_FPGA) += fpga/ obj-y += hwmon/ diff --git a/drivers/cpu/Kconfig b/drivers/cpu/Kconfig new file mode 100644 index 0000000..23745e3 --- /dev/null +++ b/drivers/cpu/Kconfig @@ -0,0 +1,8 @@ +config CPU + bool "Enable CPU drivers using Driver Model" + help + This allows drivers to be provided for CPUs and their type to be + specified in the board's device tree. For boards which support + multiple CPUs, they normally have to be set up in U-Boot so that + they can work correctly in the OS. This provides a framework for + finding out information about available CPUs and making changes. diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile new file mode 100644 index 0000000..8710160 --- /dev/null +++ b/drivers/cpu/Makefile @@ -0,0 +1,7 @@ +# +# Copyright (c) 2015 Google, Inc +# Wolfgang Denk, DENX Software Engineering, wd@denx.de. +# +# SPDX-License-Identifier: GPL-2.0+ +# +obj-$(CONFIG_CPU) += cpu-uclass.o diff --git a/drivers/cpu/cpu-uclass.c b/drivers/cpu/cpu-uclass.c new file mode 100644 index 0000000..ab18ee2 --- /dev/null +++ b/drivers/cpu/cpu-uclass.c @@ -0,0 +1,61 @@ +/* + * Copyright (C) 2015 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <cpu.h> +#include <dm.h> +#include <dm/lists.h> +#include <dm/root.h> + +int cpu_get_desc(struct udevice *dev, char *buf, int size) +{ + struct cpu_ops *ops = cpu_get_ops(dev); + + if (!ops->get_desc) + return -ENOSYS; + + return ops->get_desc(dev, buf, size); +} + +int cpu_get_info(struct udevice *dev, struct cpu_info *info) +{ + struct cpu_ops *ops = cpu_get_ops(dev); + + if (!ops->get_desc) + return -ENOSYS; + + return ops->get_info(dev, info); +} + +U_BOOT_DRIVER(cpu_bus) = { + .name = "cpu_bus", + .id = UCLASS_SIMPLE_BUS, + .per_child_platdata_auto_alloc_size = sizeof(struct cpu_platdata), +}; + +static int uclass_cpu_init(struct uclass *uc) +{ + struct udevice *dev; + int node; + int ret; + + node = fdt_path_offset(gd->fdt_blob, "/cpus"); + if (node < 0) + return 0; + + ret = device_bind_driver_to_node(dm_root(), "cpu_bus", "cpus", node, + &dev); + + return ret; +} + +UCLASS_DRIVER(cpu) = { + .id = UCLASS_CPU, + .name = "cpu", + .flags = DM_UC_FLAG_SEQ_ALIAS, + .init = uclass_cpu_init, +}; diff --git a/include/cpu.h b/include/cpu.h new file mode 100644 index 0000000..46467d0 --- /dev/null +++ b/include/cpu.h @@ -0,0 +1,84 @@ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __cpu_h +#define __cpu_h + +/** + * struct cpu_platdata - platform data for a CPU + * + * This can be accessed with dev_get_parent_platdata() for any UCLASS_CPU + * device. + * + * @cpu_id: Platform-specific way of identifying the CPU. + */ +struct cpu_platdata { + int cpu_id; +}; + +/* CPU features - mostly just a placeholder for now */ +enum { + CPU_FEAT_L1_CACHE = 0, /* Supports level 1 cache */ + CPU_FEAT_MMU = 1, /* Supports virtual memory */ + + CPU_FEAT_COUNT, +}; + +/** + * struct cpu_info - Information about a CPU + * + * @cpu_freq: Current CPU frequency in Hz + * @features: Flags for supported CPU features + */ +struct cpu_info { + ulong cpu_freq; + ulong features; +}; + +struct cpu_ops { + /** + * get_desc() - Get a description string for a CPU + * + * @dev: Device to check (UCLASS_CPU) + * @buf: Buffer to place string + * @size: Size of string space + * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error + */ + int (*get_desc)(struct udevice *dev, char *buf, int size); + + /** + * get_info() - Get information about a CPU + * + * @dev: Device to check (UCLASS_CPU) + * @info: Returns CPU info + * @return 0 if OK, -ve on error + */ + int (*get_info)(struct udevice *dev, struct cpu_info *info); +}; + +#define cpu_get_ops(dev) ((struct cpu_ops *)(dev)->driver->ops) + +/** + * cpu_get_desc() - Get a description string for a CPU + * + * @dev: Device to check (UCLASS_CPU) + * @buf: Buffer to place string + * @size: Size of string space + * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error + */ +int cpu_get_desc(struct udevice *dev, char *buf, int size); + +/** + * get_info() - Get information about a CPU + * + * @dev: Device to check (UCLASS_CPU) + * @info: Returns CPU info + * @return 0 if OK, -ve on error + */ +int cpu_get_info(struct udevice *dev, struct cpu_info *info); + +#endif diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index fddfd35..395e25a 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -45,6 +45,7 @@ enum uclass_id { UCLASS_USB_HUB, /* USB hub */ UCLASS_USB_DEV_GENERIC, /* USB generic device */ UCLASS_MASS_STORAGE, /* Mass storage device */ + UCLASS_CPU, /* CPU, typically part of an SoC */
UCLASS_COUNT, UCLASS_INVALID = -1,