[U-Boot] [PATCH v2 4/8] x86: slimbootloader: Add serial driver

[Bin Meng]

Hi Aiden,

On Wed, Jun 26, 2019 at 7:19 AM Park, Aiden <aiden.park at intel.com> wrote:
>
> - Get serial port information from the serial port info hob

Again, the same question: does this serial port info hob apply to FSP
based board? (eg: newer FSP produces such hob for bootloader to use?)
If yes, we probably need rename the driver to something more generic,
like "intel,hob-uart"?


> - Leverage ns16550 driver with slimbootloader specific platform data
>
> Signed-off-by: Aiden Park <aiden.park at intel.com>
> ---
>  arch/x86/cpu/slimbootloader/Makefile          |  2 +-
>  arch/x86/cpu/slimbootloader/serial.c          | 62 +++++++++++++++++++
>  .../asm/arch-slimbootloader/slimbootloader.h  | 33 ++++++++++
>  3 files changed, 96 insertions(+), 1 deletion(-)
>  create mode 100644 arch/x86/cpu/slimbootloader/serial.c
>
> diff --git a/arch/x86/cpu/slimbootloader/Makefile b/arch/x86/cpu/slimbootloader/Makefile
> index 4b0b3e71c9..3e62f564cd 100644
> --- a/arch/x86/cpu/slimbootloader/Makefile
> +++ b/arch/x86/cpu/slimbootloader/Makefile
> @@ -2,4 +2,4 @@
>  #
>  # Copyright (C) 2019 Intel Corporation <www.intel.com>
>
> -obj-y += car.o slimbootloader.o hob.o dram.o
> +obj-y += car.o slimbootloader.o hob.o dram.o serial.o
> diff --git a/arch/x86/cpu/slimbootloader/serial.c b/arch/x86/cpu/slimbootloader/serial.c
> new file mode 100644
> index 0000000000..186c7a79ef
> --- /dev/null
> +++ b/arch/x86/cpu/slimbootloader/serial.c
> @@ -0,0 +1,62 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2019 Intel Corporation <www.intel.com>
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <ns16550.h>
> +#include <serial.h>
> +#include <asm/arch/slimbootloader.h>
> +
> +int slimbootloader_serial_ofdata_to_platdata(struct udevice *dev)
> +{
> +       const struct efi_guid guid = LOADER_SERIAL_PORT_INFO_GUID;
> +       struct serial_port_info *serial_info = NULL;
> +       struct ns16550_platdata *plat = dev->platdata;
> +
> +       serial_info = (struct serial_port_info *)
> +           get_next_guid_hob_data(&guid, gd->arch.hob_list);
> +
> +       if (!serial_info) {
> +               debug("failed to get serial port information\n");
> +               return -ENOENT;
> +       }
> +       debug("type:%d base=0x%08x baudrate=%d stride=%d clk=%d\n",
> +             serial_info->type,
> +             serial_info->base,
> +             serial_info->baud,
> +             serial_info->stride,
> +             serial_info->clk);
> +
> +       /*
> +        * The serial_info->type provides port io or mmio access type info,
> +        * but the access type will be controlled by
> +        * CONFIG_SYS_NS16550_PORT_MAPPED or CONFIG_SYS_NS16550_MEM32.
> +        *
> +        * TBD: ns16550 access type configuration in runtime.
> +        *      ex) plat->access_type = serial_info->type
> +        */
> +       plat->base = serial_info->base;
> +       /* ns16550 uses reg_shift, then covert stride to shift */
> +       plat->reg_shift = (serial_info->stride >> 1);
> +       plat->clock = serial_info->clk;
> +
> +       return 0;
> +}
> +
> +static const struct udevice_id slimbootloader_serial_ids[] = {
> +       { .compatible = "intel,slimbootloader-uart" },
> +       {}
> +};
> +
> +U_BOOT_DRIVER(serial_slimbootloader) = {
> +       .name   = "serial_slimbootloader",
> +       .id     = UCLASS_SERIAL,
> +       .of_match = slimbootloader_serial_ids,
> +       .ofdata_to_platdata = slimbootloader_serial_ofdata_to_platdata,
> +       .platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
> +       .priv_auto_alloc_size = sizeof(struct NS16550),
> +       .probe  = ns16550_serial_probe,
> +       .ops    = &ns16550_serial_ops,
> +};
> diff --git a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
> index c85201e711..b05e527148 100644
> --- a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
> +++ b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
> @@ -16,6 +16,12 @@
>         { 0xa9, 0xe4, 0x92, 0xf3, 0x57, 0xd1, 0x28, 0x32 } \
>         }
>
> +#define LOADER_SERIAL_PORT_INFO_GUID \
> +       { \
> +       0x6c6872fe, 0x56a9, 0x4403, \
> +       { 0xbb, 0x98, 0x95, 0x8d, 0x62, 0xde, 0x87, 0xf1 } \
> +       }
> +
>  /**
>   * A single entry of memory map information
>   *
> @@ -48,6 +54,33 @@ struct memory_map_info {
>         struct memory_map_entry entry[0];
>  } __packed;
>
> +/**
> + * This includes serial port info which has already been initialized in previous
> + * Slim Bootloader stage.
> + * The Slim Bootloader initializes serial port regardless of debug/release build
> + * modes, and it passes the information to a payload thru hob. So, a payload can
> + * re-use the serial information without re-initializing serial port.
> + *
> + * @rev   : revision of serial_port_info structure. currently 1.
> + * @rsvd  : padding for alignment
> + * @type  : port io: 1, mmio: 2
> + * @base  : io base address. ex) 0x3f8, 0x80001000
> + * @baud  : uart baud rate
> + * @stride: register stride in Bytes
> + * @clk   : uart frequency in Hz
> + * @rsvd1 : reserved
> + */
> +struct serial_port_info {
> +       u8      rev;
> +       u8      rsvd[3];
> +       u32     type;
> +       u32     base;
> +       u32     baud;
> +       u32     stride;
> +       u32     clk;
> +       u32     rsvd1;
> +} __packed;
> +
>  /**
>   * This returns a pointer to hob data buffer if the given guid hob is found.
>   *
> --
> 2.20.1
>