[RFC PATCH] doc: mmc man-page

[Heinrich Schuchardt]

On 2/26/21 11:01 AM, Jaehoon Chung wrote:
> Provide a man-pages for the mmc command.
>
> Signed-off-by: Jaehoon Chung <jh80.chung at samsung.com>
> ---
>   doc/usage/mmc.rst | 149 ++++++++++++++++++++++++++++++++++++++++++++++

Thanks a lot for providing a man-page for the mmc command.

You have to change doc/usage/index.rst too.

>   1 file changed, 149 insertions(+)
>   create mode 100644 doc/usage/mmc.rst
>
> diff --git a/doc/usage/mmc.rst b/doc/usage/mmc.rst
> new file mode 100644
> index 000000000000..30fee447d409
> --- /dev/null
> +++ b/doc/usage/mmc.rst
> @@ -0,0 +1,149 @@
> +.. SPDX-License-Identifier: GPL-2.0+:
> +
> +mmc command
> +============
> +
> +Synopsis
> +--------
> +
> +::
> +
> +    mmc info
> +    mmc read addr blk# cnt
> +    mmc write addr blk# cnt
> +    mmc erase blk# cnt
> +    mmc rescan
> +    mmc part
> +    mmc dev [dev] [part]
> +    mmc list
> +    mmc wp
> +    mmc bootbus <dev> <boot_bus_width> <reset_boot_bus_width> <boot_mode>
> +    mmc bootpart-resize <dev> <dev part size MB> <RPMB part size MB>
> +    mmc partconf <dev> [boot_ack boot_partition partition_access]

This sub-command is missing below.

> +    mmc rst-function <dev> <value>
> +
> +Description
> +-----------
> +
> +The mmc command is used to control MMC(eMMC/SD) device

Please, add missing full stops '.'.

> +
> +The *mmc info* displays information (Manufacturer ID, OEM, Name, Bus Speed, Mode, ...) of MMC device
> +
> +The *mmc read* command reads raw data to memory address from MMC device with block offset and count
> +
> +The *mmc write* write raw data to MMC device from memory address with block offset and count
> +    addr - memory address

Please format arguments like this:

addr
	memory address

You can check the formatting using 'make htmldocs'.

> +
> +    blk# - start block offset
> +
> +    cnt - block count
> +
> +The *mmc erase* erases MMC device from block offset until count
> +    blk# - start block offset
> +
> +    cnt - block count
> +
> +The *mmc rescan* scans the available MMC device
> +
> +The *mmc part* displays the list available partition on current mmc device
> +
> +The *mmc dev* show or set current mmc device
> +    [dev]

Please, remove the brackets.

> +        device number to change
> +    [part]
> +        partition number to change
> +
> +The *mmc list* displays the list avaiable devices

The *mmc list* command ...

> +
> +The *mmc wp* enables "power on write protect" function about boot partitions

The *mmc wp* command ...

%s/about/for/

Please, mention that power cycling is needed to lift the write protection.

> +
> +The *mmc bootbus* sets the BOOT_BUS_WIDTH feild

The *mmc bootbus* command ...

%s/feild/field/

> +    BOOTU_BUS_WIDTH[177] is one of EXT_CSD register. (*Refer to eMMC specification*)
> +
> +The *mmc-bootpart-resize* changes sizes of boot and RPMB partition

partitions.

> +    dev - device number
> +
> +    boot part size MB - Size to change boot partition

How about:

target size of boot partition

> +
> +    RPMB part size MB - Size to chagne RPMB partition

%s/chagne/change/

target size of RPMB partition

> +
> +The *mmc rst-function* change the RST_n_FUNCTION filed

field?

I think we should describe what a RST_n_FUNCTION is.

We should enumerate the allowable values. The eMMC specification (JEDEC
Standard No. 84-B51, 2014) has:

0x0: RST_n signal is temporarily disabled (default)
0x1: RST_n signal is permanently enabled
0x2: RST_n signal is permanently disabled

> +    **WARNING**: This is a write-once filed. (*Refer to eMMC specification*)

%s/filed/field/

> +
> +Example
> +-------
> +
> +The *mmc info* command displays device's capabilities:
> +::
> +
> +    => mmc info
> +    Device: EXYNOS DWMMC
> +    Manufacturer ID: 45
> +    OEM: 100
> +    Name: SDW16
> +    Bus Speed: 52000000
> +    Mode: MMC DDR52 (52MHz)
> +    Rd Block Len: 512
> +    MMC version 5.0
> +    High Capacity: Yes
> +    Capacity: 14.7 GiB
> +    Bus Width: 8-bit DDR
> +    Erase Group Size: 512 KiB
> +    HC WP Group Size: 8 MiB
> +    User Capacity: 14.7 GiB WRREL
> +    Boot Capacity: 4 MiB ENH
> +    RPMB Capacity: 4 MiB ENH
> +    Boot area 0 is not write protected
> +    Boot area 1 is not write protected
> +
> +The raw data can be read/written via *mmc read/write* command:
> +::
> +
> +    => mmc read 0x40000000 0x5000 0x100
> +    MMC read: dev # 0, block # 20480, count 256 ... 256 blocks read: OK
> +
> +    => mmc write 0x40000000 0x5000 0x10
> +    MMC write: dev # 0, block # 20480, count 256 ... 256 blocks written: OK
> +
> +The partition list can be shown via *mmc part* command:
> +::
> +
> +    => mmc part
> +    Partition Map for MMC device 0  --   Partition Type: DOS
> +
> +    Part    Start Sector    Num Sectors     UUID            Type
> +      1     8192            131072          dff8751a-01     0e Boot
> +      2     139264          6291456         dff8751a-02     83
> +      3     6430720         1048576         dff8751a-03     83
> +      4     7479296         23298048        dff8751a-04     05 Extd
> +      5     7481344         307200          dff8751a-05     83
> +      6     7790592         65536           dff8751a-06     83
> +      7     7858176         16384           dff8751a-07     83
> +      8     7876608         22900736        dff8751a-08     83
> +
> +The current device can be shown or set via *mmc dev* command:
> +::
> +
> +    => mmc dev
> +    switch to partitions #0, OK
> +    mmc0(part0) is current device
> +    => mmc dev 2 0
> +    switch to partitions #0, OK
> +    mmc2 is current device
> +
> +The list of available devices can be shown via *mmc list* command:
> +::
> +
> +    => mmc list
> +    mmc list
> +    EXYNOS DWMMC: 0 (eMMC)
> +    EXYNOS DWMMC: 2 (SD)
> +
> +Configuration
> +-------------
> +
> +The mmc command is only avaialble if CONFIG_CMD_MMC=y.
> +Some commands need to enable more configuration.

Some sub-command need require further configuration:

> +
> +* write / erase - CONFIG_MMC_WRITE

write, erase
	CONFIG_MMC_WRITE=y

> +* bootbus - CONFIG_SUPPORT_EMMC_BOOT=y
>

Best regards

Heinrich