tests/drivers: pwm_api: Document how to tune test for stm32 targets

The way the test is implemented requires some adaptation to be effective on all STM32 boards. I'm not adding per board code on purpose, as this would be a never ending story. Fixes #31582 Signed-off-by: Erwan Gouriou <[email protected]>
zephyrproject-rtos · Jan 26, 2021 · 3d267ee · 3d267ee
1 parent 7592863
commit 3d267ee
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/tests/drivers/pwm/pwm_api/src/test_pwm.c b/tests/drivers/pwm/pwm_api/src/test_pwm.c
@@ -76,6 +76,15 @@
 #elif defined CONFIG_BOARD_ADAFRUIT_ITSYBITSY_M4_EXPRESS
 #define DEFAULT_PWM_PORT 2 /* TCC1/WO[2] on PA18 (D7) */
 #elif DT_HAS_COMPAT_STATUS_OKAY(st_stm32_pwm)
+/* Default port should be adapted per board to fit the channel
+ * associated to the PWM pin. For intsance, for following device,
+ *      pwm1: pwm {
+ *              status = "okay";
+ *              pinctrl-0 = <&tim1_ch3_pe13>;
+ *      };
+ * the following should be used:
+ * #define DEFAULT_PWM_PORT 3
+ */
 #define DEFAULT_PWM_PORT 1
 #else
 #define DEFAULT_PWM_PORT 0