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# Copyright (c) 2022 Espressif Systems (Shanghai) Co., Ltd.
# SPDX-License-Identifier: Apache-2.0
description: |
Espressif's LEDC controller Node
The LEDC controller is primarily designed to control the intensity of LEDs, although it can be
used to generate PWM signals for other purposes as well.
The mapping between the channel and GPIO is done through pinctrl
&ledc0 {
pinctrl-0 = <&ledc0_default>;
pinctrl-names = "default";
}
The 'ledc0_default' node state is defined in <board>-pinctrl.dtsi.
ledc0_default: ledc0_default {
group1 {
pinmux = <LEDC_CH0_GPIO0>,
<LEDC_CH1_GPIO2>,
<LEDC_CH2_GPIO4>;
output-enable;
};
};
If another GPIO mapping is desired, check if <board>-pinctrl.dtsi already have it defined,
otherwise, define the required mapping at your own application folder into a custom
<board>.overlay file.
The 'pinmux' property uses a macro defined in
https://github.com/zephyrproject-rtos/hal_espressif/tree/zephyr/include/dt-bindings/pinctrl
Before including a new node, check if the desired mapping is available according to the SoC.
As an example, the 'ledc0_custom' state below illustrates an alternate mapping using another set
of channels and pins in a custom overlay file.
&pinctrl {
ledc0_custom: ledc0_custom {
group1 {
pinmux = <LEDC_CH0_GPIO0>,
<LEDC_CH9_GPIO2>,
<LEDC_CH10_GPIO4>;
output-enable;
};
};
};
Use the child bindings to configure the desired channel:
&ledc0 {
pinctrl-0 = <&ledc0_custom>;
pinctrl-names = "default";
status = "okay";
#address-cells = <1>;
#size-cells = <0>;
channel0@0 {
reg = <0x0>;
timer = <0>;
};
channel9@9 {
reg = <0x9>;
timer = <0>;
};
channel10@a {
reg = <0xa>;
timer = <1>;
};
};
Note: The channel's 'reg' property defines the ID of the channel. It must match the channel used
in the 'pinmux'.
compatible: "espressif,esp32-ledc"
include: [pwm-controller.yaml, pinctrl-device.yaml, base.yaml]
properties:
"#pwm-cells":
const: 3
child-binding:
description: Channel configuration.
properties:
reg:
type: int
required: true
enum:
- 0
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
description: |
The ESP32 has 8 low speed channel and 8 high speed channels.
The low speed channel are mapped from channel 0 to 7, and the high speed are mapped from
channel 8 to 15.
High speed channels are only available in the ESP32 SoC. ESP32S2 and ESP32S3 have 8
available channels, and ESP32C3 has 6. In these SoCs there is no differentiation between
low or high speed.
timer:
type: int
required: true
enum:
- 0
- 1
- 2
- 3
description: |
Timer selection.
For maximum flexibility, the high-speed as well as the low-speed channels can be driven from
one of four high-speed/low-speed timers.
pwm-cells:
- channel
- period
- flags