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Add descriptors used in mikroBUS manifest #4

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Add descriptors used in mikroBUS manifest #4

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171 changes: 170 additions & 1 deletion source/intf_info.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -156,7 +156,10 @@ values are described in Table :num:`table-descriptor-type`.
String 0x02
Bundle 0x03
CPort 0x04
(All other values reserved) 0x05..0xff
Mikrobus 0x05
Property 0x06
Device 0x07
(All other values reserved) 0x08..0xff
============================ ==========

..
Expand Down Expand Up @@ -449,6 +452,172 @@ typically should not be used.)

..

.. _mikrobus-descriptor:

Mikrobus Descriptor
^^^^^^^^^^^^^^^^

A mikroBUS describes a configuration of the corresponding pin on the mikroBUS addon board in a clockwise direction starting from the PWM pin omitting power (VCC and ground) pins as same as the default state of the pin.

There are mikroBUS addon boards that use some dedicated SPI, UART, PWM, and I2C pins as GPIO pins, so it is necessary to redefine the default pin configuration of that pins on the host system. Also, sometimes it is required the pull-up on the host pin for correct functionality. This descriptor provides that information to the host system.

The mikroBUS descriptor is of fixed size (12 bytes) and is defined in Table :num:`table-mikrobus-descriptor`.

.. figtable::
:nofig:
:label: table-mikrobus-descriptor
:caption: mikroBUS Descriptor
:alt: mikroBUS Descriptor
:spec: l l c c l

============ ============== ======== ========== =========================================
Offset Field Size Value Description
============ ============== ======== ========== =========================================
0 pwm-state 1 Number See Table :num:`table-mikrobus-pin-state`
1 int-state 1 Number See Table :num:`table-mikrobus-pin-state`
2 rx-state 1 Number See Table :num:`table-mikrobus-pin-state`
3 tx-state 1 Number See Table :num:`table-mikrobus-pin-state`
4 scl-state 1 Number See Table :num:`table-mikrobus-pin-state`
5 sda-state 1 Number See Table :num:`table-mikrobus-pin-state`
6 mosi-state 1 Number See Table :num:`table-mikrobus-pin-state`
7 miso-state 1 Number See Table :num:`table-mikrobus-pin-state`
8 sck-state 1 Number See Table :num:`table-mikrobus-pin-state`
9 cs-state 1 Number See Table :num:`table-mikrobus-pin-state`
10 rst-state 1 Number See Table :num:`table-mikrobus-pin-state`
11 an-state 1 Number See Table :num:`table-mikrobus-pin-state`
============ ============== ======== ========== =========================================

..

.. figtable::
:nofig:
:label: table-mikrobus-pin-state
:caption: mikroBUS Pin State Numbers
:alt: mikroBUS Pin State Numbers
:spec: l c

============================ ==========
Pin State Value
============================ ==========
Input 0x01
Output High 0x02
Output Low 0x03
PWM 0x04
SPI 0x05
I2C 0x06
UART 0x07
(All other values reserved) 0x08..0xff
============================ ==========

..

.. _property-descriptor:

Property Descriptor
^^^^^^^^^^^^^^^^^^^

A property descriptor describes named properties or named GPIOs to the host. The host system uses this information to properly configure specific mikroBUS addon board drivers by passing the properties and GPIO name. There can be multiple instances of property descriptors per add-on board manifest.

The property descriptor is of variable size and is defined in Table :num:`table-property-descriptor`.

.. figtable::
:nofig:
:label: table-property-descriptor
:caption: Property Descriptor
:alt: Property Descriptor
:spec: l l c c l

============ ============== ================== ========== =========================================
Offset Field Size Value Description
============ ============== ================== ========== =========================================
0 length 1 Number Nuber of values in the property
1 id 1 ID Property ID
2 name-id 1 ID String ID for the property name
3 type 1 Number See Table :num:`table-property-type`
4 value length * type_size type Value of the property
============ ============== ================== ========== =========================================

..

.. figtable::
:nofig:
:label: table-property-type
:caption: Property Type Numbers
:alt: Property Type Numbers
:spec: l c

====================================================== ==========
Type Value
====================================================== ==========
mikroBUS 0x00
Property (array of references to children properties) 0x01
GPIO (array of references pio names string descriptor) 0x02
U8 0x03
U16 0x04
U32 0x05
U64 0x06
(All other values reserved) 0x07..0xff
====================================================== ==========

..

.. _device-descritor:

Device Descriptor
^^^^^^^^^^^^^^^^^

A Device Descriptor describes a device on the mikroBUS port. The device descriptor is a fixed-length descriptor, and there can be multiple instances of device descriptors in an add-on board manifest in cases where the add-on board presents more than one device to the host.

The device descriptor is defined in Table :num:`table-device-descriptor`.

.. figtable::
:nofig:
:label: table-device-descriptor
:caption: Device Descriptor
:alt: Device Descriptor
:spec: l l c c l

============ ============== ================== ========== =========================================
Offset Field Size Value Description
============ ============== ================== ========== =========================================
0 id 1 ID Device Descriptor ID
1 driver_id 1 ID String ID for the device driver id
2 protocol 1 Number See Table :num:`table-device-protocol`
3 reg 1 Number i2c device address or alternative CS pin for SPI
4 speed_hz 4 Number max SPI speed in HZ
8 irq 1 Number relative position for GPIO interrupt if exists
9 irq_type 1 Number a type of interrupt
10 mode 1 Number SPI mode of operation
11 prop_link 1 ID Property ID that contains a list of properties
12 gpio_link 1 ID Property ID that contains a list of GPIO pin names
13 reg_link 1 ID Property ID that contains a list of regulators
14 clock_link 1 ID Property ID that contains a list of clocks
15 (pad) 1 0 Reserved (pad to 8 bytes)
============ ============== ================== ========== =========================================

..

.. figtable::
:nofig:
:label: table-device-protocol
:caption: Device Protocol Numbers
:alt: Device Protocol Numbers
:spec: l c

====== ==========
Type Value
====== ==========
GPIO 0x02
I2C 0x03
UART 0x04
PWM 0x09
SPI 0x0b
RAW 0xfe
VENDOR 0xfe
====== ==========

..

.. _greybus-interface-attributes:

Greybus Interface Attributes
Expand Down