raspberrypi,pico-mipi-dbi-pio
Description
These nodes are “mipi-dbi” bus nodes.
MIPI-DBI Mode B controller. It emulates MIPI DBI mode B
(8080 parallel interface) using PIO peripherals.
Properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
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Data/command GPIO pin. Set to low when sending a command, or high when sending data.
This property is required. |
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Reset GPIO pin. Set high to reset the display.
This property is required. |
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Write GPIO pin for type B (Intel 8080) mode.
This property is required. |
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Chip-select GPIO pin.
This property is required. |
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Pin assignment for parallel data bus. Pins can be split in up to 4 pairs. The sum
of consecutive pins of all splits must be equal to the bits specified in the selected
mipi-mode.
For example a 16 Bit parallel data bus with pins assigned in 4 splits:
mipi_dbi: mipi_dbi {
compatible = "raspberrypi,pico-mipi-dbi-pio";
...
data-pin-splits = <&mipi_dbi 2 8>, // base pin = 2 consecutive pins = 8
<&mipi_dbi 12 4>, // base pin = 12 consecutive pins = 4
<&mipi_dbi 20 2>, // base pin = 20 consecutive pins = 2
<&mipi_dbi 25 2>; // base pin = 25 consecutive pins = 2
...
#data-pin-split-cells = <2>;
};
This property is required. |
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Constant value: |
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Clock divisor for PIO state machine
Range [1, 65536]
Rather than slowing the system clock itself, the clock divider
redefines how many system clock periods are considered to be
"one cycle", for execution purposes. This is useful if the display
driver needs a slower clock speed to meet its specifications.
The implementation needs four pio instructions to send a bit. Each
instruction takes exactly one cycle. This means the clock speed
seen by the display driver is already system clock divided by 4.
Bits are shifted out with the following speed:
Bit output shift rate [MHz] = system clock [MHz] / pio-clock-div / 4
For example:
system clock = 125 MHz
pio-clock-div = 1
The pios clock is as fast as the system clock. Each cycle takes 8ns.
Each bit takes 4 pio clock cycles, this results in 32ns or 31.25MHz
system clock = 125 MHz
pio-clock-div = 2
The pios clock is half the speed of the system clock. Each cycle takes 16ns.
Each bit takes 4 pio clock cycles, this results in 64ns or 15.625MHz
Default value: |
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Clock frequency of the SCL signal of the MBI-DBI peripheral, in Hz
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Pin configuration/s for the first state. Content is specific to the
selected pin controller driver implementation.
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Pin configuration/s for the second state. See pinctrl-0.
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Pin configuration/s for the third state. See pinctrl-0.
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Pin configuration/s for the fourth state. See pinctrl-0.
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Pin configuration/s for the fifth state. See pinctrl-0.
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Names for the provided states. The number of names needs to match the
number of states.
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Deprecated properties not inherited from the base binding file.
(None)
Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “raspberrypi,pico-mipi-dbi-pio” compatible.
Name |
Type |
Details |
|---|---|---|
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This property encodes the number of <u32> cells used by address fields
in "reg" properties in this node's children.
For details, see "2.3.5 #address-cells and #size-cells" in Devicetree
Specification v0.4.
This property is required. Constant value: |
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This property encodes the number of <u32> cells used by size fields in
"reg" properties in this node's children.
For details, see "2.3.5 #address-cells and #size-cells" in Devicetree
Specification v0.4.
This property is required. |
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Indicates the operational status of the hardware or other
resource that the node represents. In particular:
- "okay" means the resource is operational and, for example,
can be used by device drivers
- "disabled" means the resource is not operational and the system
should treat it as if it is not present
For details, see "2.3.4 status" in Devicetree Specification v0.4.
Legal values: See Important properties for more information. |
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This property is a list of strings that essentially define what
type of hardware or other resource this devicetree node
represents. Each device driver checks for specific compatible
property values to find the devicetree nodes that represent
resources that the driver should manage.
The recommended format is "vendor,device", The "vendor" part is
an abbreviated name of the vendor. The "device" is usually from
the datasheet.
The compatible property can have multiple values, ordered from
most- to least-specific. Having additional values is useful when the
device is a specific instance of a more general family, to allow the
system to match the most specific driver available.
For details, see "2.3.1 compatible" in Devicetree Specification v0.4.
This property is required. See Important properties for more information. |
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Information used to address the device. The value is specific to
the device (i.e. is different depending on the compatible
property).
The "reg" property is typically a sequence of (address, length) pairs.
Each pair is called a "register block". Values are
conventionally written in hex.
For details, see "2.3.6 reg" in Devicetree Specification v0.4.
See Important properties for more information. |
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Optional names given to each register block in the "reg" property.
For example:
/ {
soc {
#address-cells = <1>;
#size-cells = <1>;
uart@1000 {
reg = <0x1000 0x2000>, <0x3000 0x4000>;
reg-names = "foo", "bar";
};
};
};
The uart@1000 node has two register blocks:
- one with base address 0x1000, size 0x2000, and name "foo"
- another with base address 0x3000, size 0x4000, and name "bar"
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Information about interrupts generated by the device, encoded as an array
of one or more interrupt specifiers. The format of the data in this property
varies by where the device appears in the interrupt tree. Devices with the same
"interrupt-parent" will use the same format in their interrupts properties.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
See Important properties for more information. |
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Extended interrupt specifier for device, used as an alternative to
the "interrupts" property.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
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Optional names given to each interrupt generated by a device.
The interrupts themselves are defined in either "interrupts" or
"interrupts-extended" properties.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
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If present, this refers to the node which handles interrupts generated
by this device.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
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Human readable string describing the device. Use of this property is
deprecated except as needed on a case-by-case basis.
For details, see "4.1.2 Miscellaneous Properties" in Devicetree
Specification v0.4.
See Important properties for more information. |
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Information about the device's clock providers. In general, this property
should follow conventions established in the dt-schema binding:
https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/clock/clock.yaml
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Optional names given to each clock provider in the "clocks" property.
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DMA channel specifiers relevant to the device.
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Optional names given to the DMA channel specifiers in the "dmas" property.
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IO channel specifiers relevant to the device.
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Optional names given to the IO channel specifiers in the "io-channels" property.
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Mailbox / IPM channel specifiers relevant to the device.
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Optional names given to the mbox specifiers in the "mboxes" property.
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Power domain specifiers relevant to the device.
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Optional names given to the power domain specifiers in the "power-domains" property.
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Number of cells in power-domains property
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HW spinlock id relevant to the device.
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Optional names given to the hwlock specifiers in the "hwlocks" property.
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
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Property to identify that a device can be used as wake up source.
When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.
Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.
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Automatically configure the device for runtime power management after the
init function runs.
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List of power states that will disable this device power.
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Specifier cell names
data-pin-split cells: base_pin, consecutive_pins