[U-Boot] [PATCH 08/20] dm: Implement a CPU uclass
Bin Meng
bmeng.cn at gmail.com
Tue Apr 28 09:24:01 CEST 2015
Hi Simon,
On Tue, Apr 28, 2015 at 6:48 AM, Simon Glass <sjg at chromium.org> wrote:
> 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 at 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/
Should it be CONFIG_DM_CPU?
> obj-y += crypto/
> obj-$(CONFIG_FPGA) += fpga/
> obj-y += hwmon/
> diff --git a/drivers/cpu/Kconfig b/drivers/cpu/Kconfig
> new file mode 100644
> index 0000000..23745e3
> --- /dev/null
> +++ b/drivers/cpu/Kconfig
> @@ -0,0 +1,8 @@
> +config CPU
> + bool "Enable CPU drivers using Driver Model"
> + help
> + This allows drivers to be provided for CPUs and their type to be
> + specified in the board's device tree. For boards which support
> + multiple CPUs, they normally have to be set up in U-Boot so that
> + they can work correctly in the OS. This provides a framework for
> + finding out information about available CPUs and making changes.
> diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile
> new file mode 100644
> index 0000000..8710160
> --- /dev/null
> +++ b/drivers/cpu/Makefile
> @@ -0,0 +1,7 @@
> +#
> +# Copyright (c) 2015 Google, Inc
> +# Wolfgang Denk, DENX Software Engineering, wd at denx.de.
> +#
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +obj-$(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 at 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 at chromium.org>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#ifndef __cpu_h
> +#define __cpu_h
Should be capital letters.
> +
> +/**
> + * 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
cpu_get_info()
> + *
> + * @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,
> --
Regards,
Bin
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