arch/arm/src/samv7: add DMA and TC trigger support to AFEC driver

This commit adds DMA and TC support to SAMV7 AFEC driver. The AFEC (ADC)
can now be triggered by Timer/counter at chosen frewuency and samples can
be transfered via DMA with configurable number of samples. Timer/counter
trigger is now set as a default option with the possibility to change it
to software generated trigger.

DMA is inspired by SAMA5 driver and also uses ping pong buffers.

Signed-off-by: Michal Lenc <michallenc@seznam.cz>

arch/arm/src/samv7/Kconfig

@@ -314,10 +314,16 @@ config SAMV7_ADC
 	bool "12-bit ADC Controller (ADC)"
 	default n
 
-config SAMV7_AFEC0
+config SAMV7_AFEC_TIOATRIG
+	bool
+	default n
+
+menuconfig SAMV7_AFEC0
 	bool "Analog Front End 0 (AFEC0)"
 	default n
 	select SAMV7_AFEC
+	---help---
+		Support for AFEC0 (ADC) driver.
 
 if SAMV7_AFEC0
 
@@ -332,12 +338,65 @@ config SAMV7_AFEC0_RES
 		3		OSR16
 		4		OSR64
 		5		OSR256
-endif
 
-config SAMV7_AFEC1
+config SAMV7_AFEC_DMA
+	bool "DMA Support"
+	default n
+	depends on SAMV7_XDMAC
+	---help---
+		Enables transfer of converted data over DMA.
+
+config SAMV7_AFEC_DMASAMPLES
+	int "Number of DMA samples"
+	default 2
+	depends on SAMV7_AFEC_DMA
+	---help---
+		Number of DMA samples to be transfered. Number of samples less than
+		2 might be inneficient.
+
+choice
+	prompt "AFEC Trigger mode"
+	default SAMV7_AFEC0_TIOATRIG
+
+config SAMV7_AFEC0_TIOATRIG
+	bool "Timer/counter trigger"
+	select SAMV7_AFEC_TIOATRIG
+	---help---
+		Use output of Timer/Counter as a trigger.
+
+config SAMV7_AFEC0_SWTRIG
+	bool "Software trigger"
+	---help---
+		Use software trigger.
+
+endchoice
+
+if SAMV7_AFEC0_TIOATRIG
+
+config SAMV7_AFEC0_TIOAFREQ
+	int "AFEC sampling frequency"
+	default 1000
+	---help---
+		This setting provides the rate at which the timer will driver AFEC
+		sampling.
+
+config SAMV7_AFEC0_TIOACHAN
+	int "Timer/counter channel number"
+	default 0
+	range 0 2
+	---help---
+		Number of TC channel to trigger the AFEC conversion.
+
+endif #SAMV7_AFEC0_TIOATRIG
+
+endif # SAMV7_AFEC0
+
+menuconfig SAMV7_AFEC1
 	bool "Analog Front End 1 (AFEC1)"
 	default n
 	select SAMV7_AFEC
+	---help---
+		Support for AFEC1 (ADC) driver.
 
 if SAMV7_AFEC1
 
@@ -352,7 +411,58 @@ config SAMV7_AFEC1_RES
 		3		OSR16
 		4		OSR64
 		5		OSR256
-endif
+
+config SAMV7_AFEC_DMA
+	bool "DMA Support"
+	default n
+	depends on SAMV7_XDMAC
+	---help---
+		Enables transfer of converted data over DMA.
+
+config SAMV7_AFEC_DMASAMPLES
+	int "Number of DMA samples"
+	default 2
+	depends on SAMV7_AFEC_DMA
+	---help---
+		Number of DMA samples to be transfered. Number of samples less than
+		2 might be inneficient.
+
+choice
+	prompt "AFEC Trigger mode"
+	default SAMV7_AFEC1_TIOATRIG
+
+config SAMV7_AFEC1_TIOATRIG
+	bool "Timer/counter trigger"
+	select SAMV7_AFEC_TIOATRIG
+	---help---
+		Use output of Timer/Counter as a trigger.
+
+config SAMV7_AFEC1_SWTRIG
+	bool "Software trigger"
+	---help---
+		Use software trigger.
+
+endchoice
+
+if SAMV7_AFEC1_TIOATRIG
+
+config SAMV7_AFEC1_TIOAFREQ
+	int "AFEC sampling frequency"
+	default 1000
+	---help---
+		This setting provides the rate at which the timer will driver ADC
+		sampling.
+
+config SAMV7_AFEC1_TIOACHAN
+	int "Timer/counter channel number"
+	default 3
+	range 3 5
+	---help---
+		Number of TC channel to trigger the AFEC conversion.
+
+endif #SAMV7_AFEC1_TIOATRIG
+
+endif # SAMV7_AFEC1
 
 config SAMV7_MCAN0
 	bool "CAN controller 0 (MCAN0)"