zephyr: docs: Add references to the Zephyr devicetree intro

Add references to the Zephyr devicetree introduction documents upstream.
Also add direct references to the "node label" definition, as this is a
common source of confusion for new users.

BUG=b:207403708
BRANCH=none
TEST=View docs with gitiles

Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: I6fad8781cfe51a0d7741cd7eb2ba13b5e744661d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3579985
Reviewed-by: Denis Brockus <dbrockus@chromium.org>

4 files changed, 15 insertions, 9 deletions

diff --git a/docs/zephyr/zephyr_battery.md b/docs/zephyr/zephyr_battery.md
index 6b084bf95f..99f70a9c10 100644
--- a/docs/zephyr/zephyr_battery.md
+++ b/docs/zephyr/zephyr_battery.md
@@ -50,7 +50,7 @@ Example:
 
 ```
 
-Here `vendor_part` will be the default battery type. If this node label is
+Here `vendor_part` will be the default battery type. If this [*node label*] is
 present in the overlay, the [DEFAULT_BATTERY_TYPE] is set in the battery shim
 code with the labeled battery type. The `vendor` and `part` references must
 match an existing battery defined in [battery bindings directory].
@@ -183,3 +183,4 @@ shutdown_soc:4 %
 [battery-smart enum]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/dts/bindings/battery/battery-smart.yaml?q=%22enum:%22&ss=chromiumos
 [cros-ec-i2c-port-base.yaml]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/dts/bindings/i2c/cros-ec-i2c-port-base.yaml
 [task]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/shim/include/shimmed_task_id.h
+[*node label*]: https://docs.zephyrproject.org/latest/build/dts/intro.html#dt-node-labels
diff --git a/docs/zephyr/zephyr_gpio.md b/docs/zephyr/zephyr_gpio.md
index 1d563513cd..5e70562ab9 100644
--- a/docs/zephyr/zephyr_gpio.md
+++ b/docs/zephyr/zephyr_gpio.md
@@ -24,7 +24,7 @@ the devicetree node with
 all GPIOs from this node (unless the `no-auto-init` property is present).
 Legacy C source code accesses GPIOs using the specified
 `enum-name` property as an enum name of the GPIO.
-Zephyr based code uses the node label, an alias, or other node reference
+Zephyr based code uses the [*node label*], an alias, or other node reference
 to identify the GPIO.
 
 Named GPIO properties:
@@ -41,7 +41,7 @@ initialization time, and selectively enabled by code at some later time.
 The file [gpio-enum-name.yaml] defines the list of valid `enum-name` values.
 
 In the GPIO declaration use the lowercase net name from the schematic as the
-*node name*, and the same net name prefixed with `gpio_` as *node label*.
+*node name*, and the same net name prefixed with `gpio_` as [*node label*].
 For example:
 
 ```
@@ -87,7 +87,7 @@ GPIOs references that are not in legacy common code should use the
 to access the GPIO.
 
 GPIOs are referenced in the `named-gpios` child nodes using the
-node label (if one exists), an alias to a node label, or
+[*node label*] (if one exists), an alias to a [*node label*], or
 indirectly as a node reference via as a `phandle` in another node.
 
 To facilitate this, all GPIO child nodes in `named-gpios`
@@ -97,7 +97,7 @@ These pointers are accessible via the following macros:
 
 Macro | Argument | Description
 :------- | :---------- | :-------
-`GPIO_DT_FROM_NODELABEL` | nodelabel | Uses a node label to reference the GPIO node.
+`GPIO_DT_FROM_NODELABEL` | nodelabel | Uses a [*node label*] to reference the GPIO node.
 `GPIO_DT_FROM_NODE` | node | Uses a node id (referenced as a `phandle` in another node).
 `GPIO_DT_FROM_ALIAS` | alias | Uses an alias to a label on the GPIO node.
 
@@ -279,7 +279,7 @@ Child nodes of this single node contain the following properties:
 
 Property | Description | Settings
 :------- | :---------- | :-------
-`irq-pin` | A reference via a node label to the named-gpio that is associated with this interrupt. | `<&gpio_label>`
+`irq-pin` | A reference via a [*node label*] to the named-gpio that is associated with this interrupt. | `<&gpio_label>`
 `flags` | The GPIO [interrupt flags](https://docs.zephyrproject.org/latest/reference/peripherals/gpio.html) that define how the interrupt is generated. | `GPIO_INT_<flags>`
 `handler` | The C name of the interrupt handler that handles the interrupt. | C function name.
 
@@ -431,7 +431,7 @@ property `GPIO_ENTERING_RW`.
     val = gpio_get_level(GPIO_ENTERING_RW);
 ```
 
-Use the `node label` to reference the GPIO in other devicetree nodes:
+Use the [*node label*] to reference the GPIO in other devicetree nodes:
 
 ```
 my_node: my-node {
@@ -456,3 +456,4 @@ project.
 [gpio.dts]: ../../zephyr/projects/volteer/volteer/gpio.dts
 [interrupts.dts]: ../../zephyr/projects/volteer/volteer/interrupts.dts
 [BUILD.py]: ../../zephyr/projects/volteer/volteer/BUILD.py
+[*node label*]: https://docs.zephyrproject.org/latest/build/dts/intro.html#dt-node-labels
\ No newline at end of file
diff --git a/docs/zephyr/zephyr_i2c.md b/docs/zephyr/zephyr_i2c.md
index 4f001e4408..da54a373a5 100644
--- a/docs/zephyr/zephyr_i2c.md
+++ b/docs/zephyr/zephyr_i2c.md
@@ -47,7 +47,7 @@ Example enabling I2C0 and I2C3 at 100 KHz and 1 MHz, respectively.
 Nuvoton ECs use two devicetree nodes to describe the I2C buses used, an I2C
 controller and an I2C port.
 
-Nuvoton I2C node labels use the following pattern:
+Nuvoton I2C [*node labels*] use the following pattern:
 - I2C controller: `&i2c_ctrl<controller>`
 - I2C port: `&i2c<controller>_<port>`
 
@@ -352,3 +352,4 @@ below:
 [`CONFIG_I2C_SHELL`]: https://docs.zephyrproject.org/latest/kconfig.html#CONFIG_I2C_SHELL
 [cros-ec-i2c-port-base.yaml]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/dts/bindings/i2c/cros-ec-i2c-port-base.yaml
 [volteer.dts]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/boards/arm/volteer/volteer.dts;
+[*node labels*]: https://docs.zephyrproject.org/latest/build/dts/intro.html#dt-node-labels
\ No newline at end of file
diff --git a/docs/zephyr/zephyr_new_board_checklist.md b/docs/zephyr/zephyr_new_board_checklist.md
index f83aa3a188..f2299a896d 100644
--- a/docs/zephyr/zephyr_new_board_checklist.md
+++ b/docs/zephyr/zephyr_new_board_checklist.md
@@ -25,7 +25,8 @@ Each feature includes the following sub-tasks:
   the feature. `Kconfig` options are enabled in one of the [project
   configuration files].
 - **Devicetree Nodes** - This section details the devicetree nodes and
-  properties required by the feature.
+  properties required by the feature. The [Zephyr Introduction to Devicetree]
+  provides a conceptual overview of devicetree and how Zephyr uses it.
 - **Board Specific Code** - When present, this section details any C code that
   your project must implement.
 - **Threads** - This section details the threads created by the feature and
@@ -66,3 +67,5 @@ EC Feature                                                                  | Ne
 [Configure BC1.2 Charger Detector (TODO)](./zephyr_template.md)             | no
 [Configure ADC](./zephyr_adc.md)                                            | no
 [Configure Temperature Sensors](./zephyr_temperature_sensor.md)             | no
+
+[Zephyr Introduction to Devicetree]: https://docs.zephyrproject.org/latest/build/dts/intro.html