arch/arm/am67: Add eCAP APWM lower-half driver

Documentation/platforms/arm/am67/boards/t3-gem-o1/index.rst

@@ -103,6 +103,8 @@ main-domain R5F core:
 - **I2C:** WKUP_I2C0 master, registered as /dev/i2c2.
 - **PWM:** EPWM0 and EPWM1, channels A and B each, registered as /dev/pwm0
   and /dev/pwm1.
+- **eCAP:** eCAP1 and eCAP2 in APWM mode, registered as /dev/ecap1 and
+  /dev/ecap2.
 
 Installation
 ============

arch/arm/src/am67/Kconfig

@@ -34,6 +34,38 @@ config AM67_EPWM1
 		supported.
 
 
+config AM67_ECAP0
+	bool "AM67 eCAP0 APWM driver"
+	default n
+	depends on PWM
+	---help---
+		Enable the eCAP0 module as a single-channel Auxiliary PWM
+		(APWM) output.  Registered as /dev/ecap0 (kept out of the
+		/dev/pwmN namespace, which belongs to the EPWM instances).
+		The default output pad is ball A23 (mode 8 =
+		ECAP0_IN_APWM0_OUT), chosen to avoid the C20 collision with
+		EPWM0_B; confirm it reaches the HAT header before relying on
+		it.
+
+config AM67_ECAP1
+	bool "AM67 eCAP1 APWM driver"
+	default n
+	depends on PWM
+	---help---
+		Enable the eCAP1 module as a single-channel APWM output,
+		registered as /dev/ecap1.  Output pad selection is a board TODO
+		(candidates collide with I2C0); see am67_pinmux.c.
+
+config AM67_ECAP2
+	bool "AM67 eCAP2 APWM driver"
+	default n
+	depends on PWM
+	---help---
+		Enable the eCAP2 module as a single-channel APWM output,
+		registered as /dev/ecap2.  Output pad selection is a board TODO
+		(candidates collide with I2C0); see am67_pinmux.c.
+
+
 config AM67_MCSPI0
 	bool "AM67 MCU_MCSPI0 master driver"
 	default n

arch/arm/src/am67/Make.defs

@@ -36,6 +36,9 @@ endif
 ifeq ($(CONFIG_AM67_EPWM0),y)
 CHIP_CSRCS += am67_pwm.c
 endif
+ifneq ($(filter y,$(CONFIG_AM67_ECAP0) $(CONFIG_AM67_ECAP1) $(CONFIG_AM67_ECAP2)),)
+CHIP_CSRCS += am67_ecap.c
+endif
 ifeq ($(CONFIG_AM67_MCSPI0),y)
 CHIP_CSRCS += am67_mcspi.c
 endif