[U-Boot,08/20] dm: Implement a CPU uclass

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

Hi Simon,

On Tue, Apr 28, 2015 at 6:48 AM, Simon Glass <sjg@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@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-$(CONFIG_FPGA) += fpga/
>  obj-y += hwmon/
> diff --git a/drivers/cpu/Kconfig b/drivers/cpu/Kconfig
> new file mode 100644
> index 0000000..23745e3
> --- /dev/null
> +++ b/drivers/cpu/Kconfig
> @@ -0,0 +1,8 @@
> +config CPU
> +       bool "Enable CPU drivers using Driver Model"
> +       help
> +         This allows drivers to be provided for CPUs and their type to be
> +         specified in the board's device tree. For boards which support
> +         multiple CPUs, they normally have to be set up in U-Boot so that
> +         they can work correctly in the OS. This provides a framework for
> +         finding out information about available CPUs and making changes.
> diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile
> new file mode 100644
> index 0000000..8710160
> --- /dev/null
> +++ b/drivers/cpu/Makefile
> @@ -0,0 +1,7 @@
> +#
> +# Copyright (c) 2015 Google, Inc
> +# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
> +#
> +# SPDX-License-Identifier:      GPL-2.0+
> +#
> +obj-$(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

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