Improve TX power docs

Add a separate section in the porting guide with doxygen docs and link to NCS doc about TX power calcualtion. Signed-off-by: Chaitanya Tata <[email protected]>
nrfconnect · Dec 5, 2024 · c13291a · c13291a
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diff --git a/nrf70_bm_lib/docs/Doxyfile b/nrf70_bm_lib/docs/Doxyfile
@@ -865,6 +865,7 @@ WARN_LOGFILE           =
 # Note: If this tag is empty the current directory is searched.
 
 INPUT                  = ../include/nrf70_bm_lib.h \
+                         ../include/nrf70_tx_pwr_ceil_dk.h \
                          ../../../nrfxlib/nrf_wifi/fw_if/umac_if/inc \
                          ../../../nrfxlib/nrf_wifi/fw_if/umac_if/inc/radio_test \
                          ../../../nrfxlib/nrf_wifi/fw_if/umac_if/inc/default

diff --git a/nrf70_bm_lib/docs/source/nrf70_bm_porting_guide.rst b/nrf70_bm_lib/docs/source/nrf70_bm_porting_guide.rst
@@ -97,6 +97,38 @@ For more information, visit the `nRF Connect SDK nrfxlib repository <https://git
 
    The git submodule pulls in the entire repo, but only `nrf_wifi` directory is required for the BM driver.
 
+Transmit (TX) power configuration
+*********************************
+
+The maximum transmit output power achieved on an nRF70 Series device-based product depends on the frequency band and operating channel.
+This varies across different Printed Circuit Board (PCB) designs.
+
+Multiple calibrations and checks are implemented to ensure consistent TX output power across channels and devices.
+However, as the resulting TX output power depends on PCB design; Error Vector Magnitude (EVM) and spectral mask failures may occur, unless the TX output power ceilings are properly applied.
+The application developer can specify the TX power ceiling at which the EVM and spectral mask compliance is met for a given PCB design.
+
+The build-time parameters for the TX power ceilings are made available to nRF Wi-Fi driver through the respective `C` header file.
+The reference header files are located in the `nrf70_bm_lib/include` directory.
+
+The following files are used to configure the TX power ceilings for the official Nordic development and evaluation boards:
+
+- `nrf70_tx_pwr_ceil_dk.h`: Contains the TX power configuration for the nRF7002 Development Kit (DK).
+
+- `nrf70_tx_pwr_ceil_ek.h`: Contains the TX power configuration for the nRF7002 Evaluation Kit (EK).
+
+For a new nRF70-based PCB design, the developer may create a new header file with the same structure as the reference files and replace the values with the appropriate values for the designed PCB.
+The appropriate TX power ceiling values may be derived by running the radio test sample on the board and using a spectrum/vector signal analyzer to measure the output power, spectral mask, EVM and other parameters and then adjusting the TX power ceiling values to meet the requirements.
+The values are represented in 0.25 dB increments.
+
+For more information on TX power calculation, refer to the section `nRF70 TX power calculation <https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/drivers/wifi/nrf70_native.html#tx_power_calculation>`_.
+
+
+Reference header file structure
+-------------------------------
+
+.. doxygenfile:: nrf70_tx_pwr_ceil_dk.h
+
+
 nRF70 OS agnostic layers API documentation
 ==========================================
 

diff --git a/nrf70_bm_lib/include/nrf70_tx_pwr_ceil_dk.h b/nrf70_bm_lib/include/nrf70_tx_pwr_ceil_dk.h
@@ -7,24 +7,37 @@
 
 /** @file
  * @brief nRF7002 DK TX power ceiling configuration.
- */
-
-/*
+ *
  * The configuration applies to the nRF7002 DK board targets, as well as
  * to board targets for nRF7001 and nRF7000 IC variants emulated on the
  * nRF7002 DK.
- */
-
-/* The following macros are normally auto-generated from DeviceTree
+ *
+ * The following macros are normally auto-generated from DeviceTree
  * when building the nRF70 driver in a Zephyr environment. They are
  * copied here as standard preprocessor directives for ease of porting.
+ *
+ * The values are represented in 0.25 dB increments.The values for the
+ * other MCS rates are interpolated from the values for MCS0 and MCS7.
+ *
+ *
+ * @addtogroup nrf70_bm_txpower nRF70 Bare Metal library
  */
+
+/** Maximum power for 2.4 GHz DSSS. */
 #define MAX_PWR_2G_DSSS 0x54
+/** Maximum power for 2.4 GHz MCS0. */
 #define MAX_PWR_2G_MCS0 0x40
+/** Maximum power for 2.4 GHz MCS7. */
 #define MAX_PWR_2G_MCS7 0x40
+/** Maximum power for 5 GHz low band (5150-5330 MHz) MCS0. */
 #define MAX_PWR_5G_LOW_MCS0 0x24
+/** Maximum power for 5 GHz low band (5150-5330 MHz) MCS7. */
 #define MAX_PWR_5G_LOW_MCS7 0x24
+/** Maximum power for 5 GHz mid band (5330-5670 MHz) MCS0. */
 #define MAX_PWR_5G_MID_MCS0 0x2C
+/** Maximum power for 5 GHz mid band (5330-5670 MHz) MCS7. */
 #define MAX_PWR_5G_MID_MCS7 0x2C
+/** Maximum power for 5 GHz high band (5670-5895 MHz) MCS0. */
 #define MAX_PWR_5G_HIGH_MCS0 0x34
+/** Maximum power for 5 GHz high band (5670-5895 MHz) MCS7. */
 #define MAX_PWR_5G_HIGH_MCS7 0x34
diff --git a/nrf70_bm_lib/include/nrf70_tx_pwr_ceil_ek.h b/nrf70_bm_lib/include/nrf70_tx_pwr_ceil_ek.h
@@ -9,15 +9,16 @@
  * @brief nRF7002 EK TX power ceiling configuration.
  */
 
-/*
+/**
  * The configuration applies to the nRF7002 EK shield targets, as well as
  * to shield targets for nRF7001 and nRF7000 IC variants emulated on the
  * nRF7002 EK.
- */
-
-/* The following macros are normally auto-generated from DeviceTree
+ *
+ * The following macros are normally auto-generated from DeviceTree
  * when building the nRF70 driver in a Zephyr environment. They are
  * copied here as standard preprocessor directives for ease of porting.
+ *
+ * The values are represented in 0.25 dB increments.
  */
 #define MAX_PWR_2G_DSSS 0x54
 #define MAX_PWR_2G_MCS0 0x40