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For nearly all commands in U-Boot the '?' variable is handled the same way with 0 meaning success, 1 meaning any failure. Explain this in the general rules section of the cmdline documentation (with a link to a counter example) and then remove the redundant wording from most commands. We retain a section about the return value in a number of places where we are doing something such as always returning a specific value or we have useful additional information to go along with the normal return codes. Signed-off-by: Tom Rini <trini@konsulko.com> Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
140 lines
3.7 KiB
ReStructuredText
140 lines
3.7 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
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.. index::
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single: i3c (command)
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i3c command
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===========
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Synopsis
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--------
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::
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i3c <host_controller>
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i3c current
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i3c list
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i3c device_list
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i3c write <mem_addr> <length> <device_number>
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i3c read <mem_addr> <length> <device_number>
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Description
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-----------
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The ``i3c`` command is used to probe the i3c host controller and perform
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read and write operations on the connected i3c devices.
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i3c current
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------------
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Display the currently selected i3c host controller.
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i3c list
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---------
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List all the i3c hosts defined in the device-tree.
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i3c device_list
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----------------
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List all the i3c devices' device number, static address, dynamic address,
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PID, BCR, DCR, Max Write Speed, and Max Read Speed of the probed i3c host
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controller.
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i3c write
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----------
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Perform a write operation from memory to the connected i3c device. The data
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is read from a specified memory address and written to the selected i3c
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device, which is identified by its device number.
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You need to provide the memory address (``mem_addr``), the length of data
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to be written (``length``), and the device number (``device_number``). The
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data in memory will be transferred to the device in the specified order.
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i3c read
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---------
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Perform a read operation from the connected i3c device to memory. The data
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is read from the selected i3c device and stored at the specified memory
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address. You need to provide the memory address (``mem_addr``), the length
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of data to be read (``length``), and the device number (``device_number``).
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The device will send the requested data, which is then written to the memory
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location you specified. This operation allows you to retrieve information
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from the device and use it in your application. The data is read in the
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order specified and can be multiple bytes.
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host_controller
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The name of the i3c host controller defined in the device-tree.
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length
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The size of the data to be read or written.
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device_number
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The device number in the driver model of the device connected to the i3c
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host controller.
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mem_addr
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The start address in memory from which to read or write the data.
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Examples
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--------
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Probe the ``i3c0`` controller::
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=> i3c i3c0
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Display the current i3c host controller::
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=> i3c current
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Check the device number and PID of the connected devices::
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=> i3c device_list
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Perform write operations on the connected i3c device (device 0) from memory::
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=> i3c write 0x1000 4 0
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This command reads 4 bytes of data from memory starting at address
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``0x1000`` and writes them to device 0, which is identified by its device
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number in the driver model. Example data from memory could look like this:
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```
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Data at 0x1000: 0xAA 0xBB 0xCC 0xDD
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```
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The bytes `0xAA`, `0xBB`, `0xCC`, and `0xDD` will be written to device 0.
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Perform a read operation from device 0 to memory (multiple bytes)::
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=> i3c read 0x1000 4 0
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This command reads 4 bytes of data from device 0 and writes them to
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memory starting at address ``0x1000``.
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Example output after reading 4 bytes from device 0:
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```
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i3c Read:
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00000000 AA BB CC DD
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```
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The bytes `0xAA`, `0xBB`, `0xCC`, and `0xDD` are read from device 0
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and written to memory at address `0x1000`.
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Configuration
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-------------
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The ``i3c`` command is only available if CONFIG_CMD_I3C=y.
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Note
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----
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When specifying the data to be written to the i3c device (for example, with
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the ``i3c write`` command), the data can be provided in either uppercase
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or lowercase hexadecimal format. Both are valid and will be processed
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correctly. Similarly, when reading data with ``i3c read``, the data will be
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retrieved in the specified length and can include multiple bytes, all
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formatted in the same way. |