soc: atmel_sam0: Implement fixup.h for ADC driver

The ADC driver now supports three different implementations. To maintain
readability, this patch implements an adc_fixup.h that permits more
generic access to relevant registers.

This patch also introduces support for a new third shape ADC - as found
in the SAML21 for example.

Signed-off-by: Attie Grande <attie.grande@argentum-systems.co.uk>

drivers/adc/adc_sam0.c

@@ -60,13 +60,8 @@ struct adc_sam0_cfg {
 
 static void wait_synchronization(Adc *const adc)
 {
-#if defined(ADC_SYNCBUSY_MASK)
-	while ((adc->SYNCBUSY.reg & ADC_SYNCBUSY_MASK) != 0) {
+	while ((ADC_SYNC(adc) & ADC_SYNC_MASK) != 0) {
 	}
-#else
-	while ((adc->STATUS.reg & ADC_STATUS_SYNCBUSY) != 0) {
-	}
-#endif
 }
 
 static int adc_sam0_acquisition_to_clocks(const struct device *dev,
@@ -141,26 +136,16 @@ static int adc_sam0_channel_setup(const struct device *dev,
 
 	switch (channel_cfg->reference) {
 	case ADC_REF_INTERNAL:
-#ifdef ADC_REFCTRL_REFSEL_INTREF
-		REFCTRL = ADC_REFCTRL_REFSEL_INTREF | ADC_REFCTRL_REFCOMP;
-		/* Enable the internal reference, defaulting to 1V */
-		SUPC->VREF.bit.VREFOE = 1;
-#else
-		REFCTRL = ADC_REFCTRL_REFSEL_INT1V | ADC_REFCTRL_REFCOMP;
+		REFCTRL = ADC_REFCTRL_REFSEL_INTERNAL | ADC_REFCTRL_REFCOMP;
 		/* Enable the internal bandgap reference */
-		SYSCTRL->VREF.bit.BGOUTEN = 1;
-#endif
+		ADC_BGEN = 1;
 		break;
 	case ADC_REF_VDD_1_2:
-#ifdef ADC_REFCTRL_REFSEL_INTVCC0
-		REFCTRL = ADC_REFCTRL_REFSEL_INTVCC0 | ADC_REFCTRL_REFCOMP;
-#else
-		REFCTRL = ADC_REFCTRL_REFSEL_INTVCC1 | ADC_REFCTRL_REFCOMP;
-#endif
+		REFCTRL = ADC_REFCTRL_REFSEL_VDD_1_2 | ADC_REFCTRL_REFCOMP;
 		break;
-#ifdef ADC_REFCTRL_REFSEL_INTVCC1
+#ifdef ADC_REFCTRL_REFSEL_VDD_1
 	case ADC_REF_VDD_1:
-		REFCTRL = ADC_REFCTRL_REFSEL_INTVCC1 | ADC_REFCTRL_REFCOMP;
+		REFCTRL = ADC_REFCTRL_REFSEL_VDD_1 | ADC_REFCTRL_REFCOMP;
 		break;
 #endif
 	case ADC_REF_EXTERNAL0:
@@ -226,20 +211,13 @@ static int adc_sam0_channel_setup(const struct device *dev,
 	if (channel_cfg->differential) {
 		INPUTCTRL |= ADC_INPUTCTRL_MUXNEG(channel_cfg->input_negative);
 
-#ifdef ADC_INPUTCTRL_DIFFMODE
-		INPUTCTRL |= ADC_INPUTCTRL_DIFFMODE;
-#else
-		adc->CTRLB.bit.DIFFMODE = 1;
-		wait_synchronization(adc);
-#endif
+		ADC_DIFF(adc) |= ADC_DIFF_MASK;
 	} else {
 		INPUTCTRL |= ADC_INPUTCTRL_MUXNEG_GND;
 
-#ifndef ADC_INPUTCTRL_DIFFMODE
-		adc->CTRLB.bit.DIFFMODE = 0;
-		wait_synchronization(adc);
-#endif
+		ADC_DIFF(adc) &= ~ADC_DIFF_MASK;
 	}
+	wait_synchronization(adc);
 
 	adc->INPUTCTRL.reg = INPUTCTRL;
 	wait_synchronization(adc);
@@ -248,25 +226,21 @@ static int adc_sam0_channel_setup(const struct device *dev,
 	switch (channel_cfg->input_positive) {
 #ifdef ADC_INPUTCTRL_MUXPOS_TEMP_Val
 	case ADC_INPUTCTRL_MUXPOS_TEMP_Val:
-		SYSCTRL->VREF.bit.TSEN = 1;
+		ADC_TSEN = 1;
 		break;
 #endif
 #ifdef ADC_INPUTCTRL_MUXPOS_PTAT_Val
 	case ADC_INPUTCTRL_MUXPOS_PTAT_Val:
-		SUPC->VREF.bit.TSEN = 1;
+		ADC_TSEN = 1;
 		break;
 #endif
 #ifdef ADC_INPUTCTRL_MUXPOS_CTAT_Val
 	case ADC_INPUTCTRL_MUXPOS_CTAT_Val:
-		SUPC->VREF.bit.TSEN = 1;
+		ADC_TSEN = 1;
 		break;
 #endif
 	case ADC_INPUTCTRL_MUXPOS_BANDGAP_Val:
-#ifdef ADC_REFCTRL_REFSEL_INTREF
-		SUPC->VREF.bit.VREFOE = 1;
-#else
-		SYSCTRL->VREF.bit.BGOUTEN = 1;
-#endif
+		ADC_BGEN = 1;
 		break;
 	default:
 		break;
@@ -361,7 +335,7 @@ static int start_read(const struct device *dev,
 			return -EINVAL;
 		}
 
-		adc->CTRLB.bit.RESSEL = ADC_CTRLB_RESSEL_8BIT_Val;
+		ADC_RESSEL(adc) = ADC_RESSEL_8BIT;
 		break;
 	case 10:
 		if (sequence->oversampling) {
@@ -369,15 +343,14 @@ static int start_read(const struct device *dev,
 			return -EINVAL;
 		}
 
-		adc->CTRLB.bit.RESSEL = ADC_CTRLB_RESSEL_10BIT_Val;
+		ADC_RESSEL(adc) = ADC_RESSEL_10BIT;
 		break;
 	case 12:
 		if (sequence->oversampling) {
-			adc->CTRLB.bit.RESSEL = ADC_CTRLB_RESSEL_16BIT_Val;
+			ADC_RESSEL(adc) = ADC_RESSEL_16BIT;
 		} else {
-			adc->CTRLB.bit.RESSEL = ADC_CTRLB_RESSEL_12BIT_Val;
+			ADC_RESSEL(adc) = ADC_RESSEL_12BIT;
 		}
-
 		break;
 	default:
 		LOG_ERR("ADC resolution value %d is not valid",
@@ -473,11 +446,7 @@ static int adc_sam0_init(const struct device *dev)
 	GCLK->CLKCTRL.reg = cfg->gclk | GCLK_CLKCTRL_CLKEN;
 #endif
 
-#ifdef ADC_CTRLA_PRESCALER_Pos
-	adc->CTRLA.reg = cfg->prescaler;
-#else
-	adc->CTRLB.reg = cfg->prescaler;
-#endif
+	ADC_PRESCALER(adc) = cfg->prescaler;
 	wait_synchronization(adc);
 
 	adc->INTENCLR.reg = ADC_INTENCLR_MASK;
@@ -532,34 +501,16 @@ static const struct adc_driver_api adc_sam0_api = {
 	.gclk_mask = UTIL_CAT(GCLK_PCHCTRL_GEN_GCLK,			\
 			      DT_INST_PROP(n, gclk)),			\
 	.gclk_id = DT_INST_CLOCKS_CELL_BY_NAME(n, gclk, periph_ch),	\
-	.prescaler = UTIL_CAT(ADC_CTRLA_PRESCALER_DIV,			\
-			      DT_INST_PROP(n, prescaler)),
-
-#define ADC_SAM0_BIASCOMP_SHIFT(n)					\
-	(ADC0_FUSES_BIASCOMP_Pos + DT_INST_PROP(n, calib_offset))
-#define ADC_SAM0_BIASCOMP(n)						\
-	(((*(uint32_t *)NVMCTRL_SW0) >> ADC_SAM0_BIASCOMP_SHIFT(n)) & 0x7)
-
-#define ADC_SAM0_BIASR2R_SHIFT(n)					\
-	(ADC0_FUSES_BIASR2R_Pos + DT_INST_PROP(n, calib_offset))
-#define ADC_SAM0_BIASR2R(n)						\
-	(((*(uint32_t *)NVMCTRL_SW0) >> ADC_SAM0_BIASR2R_SHIFT(n)) & 0x7)
-
-#define ADC_SAM0_BIASREFBUF_SHIFT(n)					\
-	(ADC0_FUSES_BIASREFBUF_Pos + DT_INST_PROP(n, calib_offset))
-#define ADC_SAM0_BIASREFBUF(n)						\
-	(((*(uint32_t *)NVMCTRL_SW0) >> ADC_SAM0_BIASREFBUF_SHIFT(n)) & 0x7)
+	.prescaler = UTIL_CAT(ADC_CTRLx_PRESCALER_DIV,			\
+			      UTIL_CAT(DT_INST_PROP(n, prescaler), _Val)),
 
 #define ADC_SAM0_CONFIGURE(n)						\
 do {									\
 	const struct adc_sam0_cfg *const cfg = dev->config;		\
 	Adc * const adc = cfg->regs;					\
-	uint32_t comp = ADC_SAM0_BIASCOMP(n);				\
-	uint32_t r2r = ADC_SAM0_BIASR2R(n);				\
-	uint32_t rbuf = ADC_SAM0_BIASREFBUF(n);				\
-	adc->CALIB.reg = ADC_CALIB_BIASCOMP(comp) |			\
-			 ADC_CALIB_BIASR2R(r2r) |			\
-			 ADC_CALIB_BIASREFBUF(rbuf);			\
+	adc->CALIB.reg = ADC_SAM0_BIASCOMP(n)				\
+			 | ADC_SAM0_BIASR2R(n)				\
+			 | ADC_SAM0_BIASREFBUF(n);			\
 } while (0)
 
 #else
@@ -567,8 +518,8 @@ do {									\
 #define ADC_SAM0_CLOCK_CONTROL(n)					\
 	.gclk = UTIL_CAT(GCLK_CLKCTRL_GEN_GCLK,	DT_INST_PROP(n, gclk)) |\
 			 GCLK_CLKCTRL_ID_ADC,				\
-	.prescaler = UTIL_CAT(ADC_CTRLB_PRESCALER_DIV,			\
-			      DT_INST_PROP(n, prescaler)),		\
+	.prescaler = UTIL_CAT(ADC_CTRLx_PRESCALER_DIV,			\
+			      UTIL_CAT(DT_INST_PROP(n, prescaler), _Val)),
 
 #define ADC_SAM0_CONFIGURE(n)						\
 do {									\

soc/arm/atmel_sam0/common/adc_fixup_sam0.h

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2021 Argentum Systems Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _ATMEL_SAM_ADC_FIXUP_H_
+#define _ATMEL_SAM_ADC_FIXUP_H_
+
+#if defined(ADC_SYNCBUSY_MASK)
+#define ADC_SYNC(adc) ((adc)->SYNCBUSY.reg)
+#define ADC_SYNC_MASK (ADC_SYNCBUSY_MASK)
+#elif defined(ADC_STATUS_SYNCBUSY)
+#define ADC_SYNC(adc) ((adc)->STATUS.reg)
+#define ADC_SYNC_MASK (ADC_STATUS_SYNCBUSY)
+#else
+#error ADC not supported...
+#endif
+
+#if defined(ADC_INPUTCTRL_DIFFMODE)
+#define ADC_DIFF(adc) (INPUTCTRL)
+#define ADC_DIFF_MASK (ADC_INPUTCTRL_DIFFMODE)
+#elif defined(ADC_CTRLB_DIFFMODE)
+#define ADC_DIFF(adc) ((adc)->CTRLB.reg)
+#define ADC_DIFF_MASK (ADC_CTRLB_DIFFMODE)
+#elif defined(ADC_CTRLC_DIFFMODE)
+#define ADC_DIFF(adc) ((adc)->CTRLC.reg)
+#define ADC_DIFF_MASK (ADC_CTRLC_DIFFMODE)
+#else
+#error ADC not supported...
+#endif
+
+#if defined(ADC_CTRLB_RESSEL)
+#define ADC_RESSEL(adc)  ((adc)->CTRLB.bit.RESSEL)
+#define ADC_RESSEL_8BIT  ADC_CTRLB_RESSEL_8BIT_Val
+#define ADC_RESSEL_10BIT ADC_CTRLB_RESSEL_10BIT_Val
+#define ADC_RESSEL_12BIT ADC_CTRLB_RESSEL_12BIT_Val
+#define ADC_RESSEL_16BIT ADC_CTRLB_RESSEL_16BIT_Val
+#elif defined(ADC_CTRLC_RESSEL)
+#define ADC_RESSEL(adc)  ((adc)->CTRLC.bit.RESSEL)
+#define ADC_RESSEL_8BIT  ADC_CTRLC_RESSEL_8BIT_Val
+#define ADC_RESSEL_10BIT ADC_CTRLC_RESSEL_10BIT_Val
+#define ADC_RESSEL_12BIT ADC_CTRLC_RESSEL_12BIT_Val
+#define ADC_RESSEL_16BIT ADC_CTRLC_RESSEL_16BIT_Val
+#else
+#error ADC not supported...
+#endif
+
+#if defined(ADC_CTRLA_PRESCALER)
+#define ADC_PRESCALER(adc) ((adc)->CTRLA.bit.PRESCALER)
+#define ADC_CTRLx_PRESCALER_DIV ADC_CTRLA_PRESCALER_DIV
+#elif defined(ADC_CTRLB_PRESCALER)
+#define ADC_PRESCALER(adc) ((adc)->CTRLB.bit.PRESCALER)
+#define ADC_CTRLx_PRESCALER_DIV ADC_CTRLB_PRESCALER_DIV
+#else
+#error ADC not supported...
+#endif
+
+#if defined(SYSCTRL_VREF_TSEN)
+#define ADC_TSEN (SYSCTRL->VREF.bit.TSEN)
+#elif defined(SUPC_VREF_TSEN)
+#define ADC_TSEN (SUPC->VREF.bit.TSEN)
+#else
+#error ADC not supported...
+#endif
+
+#if defined(SYSCTRL_VREF_BGOUTEN)
+#define ADC_BGEN (SYSCTRL->VREF.bit.BGOUTEN)
+#elif defined(SUPC_VREF_VREFOE)
+#define ADC_BGEN (SUPC->VREF.bit.VREFOE)
+#else
+#error ADC not supported...
+#endif
+
+#if defined(MCLK)
+/* a trailing underscore and/or lumpy concatenation is used to prevent expansion */
+#define ADC_SAM0_CALIB(prefix, val) \
+	UTIL_CAT(ADC_CALIB_, val)( \
+		(((*(uint32_t *)UTIL_CAT(UTIL_CAT(UTIL_CAT(prefix, FUSES_), val), _ADDR)) \
+		>> UTIL_CAT(UTIL_CAT(UTIL_CAT(prefix, FUSES_), val), _Pos)) \
+		& UTIL_CAT(UTIL_CAT(UTIL_CAT(prefix, FUSES_), val), _Msk)) \
+	)
+
+#if ADC_INST_NUM == 1
+#  define ADC_FUSES_PREFIX(n) ADC_
+#else
+#  define ADC_FUSES_PREFIX(n) UTIL_CAT(AD, UTIL_CAT(C, UTIL_CAT(n, _)))
+#endif
+
+#if defined(ADC_FUSES_BIASCOMP) || defined(ADC0_FUSES_BIASCOMP)
+#  define ADC_SAM0_BIASCOMP(n) ADC_SAM0_CALIB(ADC_FUSES_PREFIX(n), BIASCOMP)
+#else
+#  define ADC_SAM0_BIASCOMP(n) 0
+#endif
+
+#if defined(ADC_FUSES_BIASR2R) || defined(ADC0_FUSES_BIASR2R)
+#  define ADC_SAM0_BIASR2R(n) ADC_SAM0_CALIB(ADC_FUSES_PREFIX(n), BIASR2R)
+#else
+#  define ADC_SAM0_BIASR2R(n) 0
+#endif
+
+#if defined(ADC_FUSES_BIASREFBUF) || defined(ADC0_FUSES_BIASREFBUF)
+#  define ADC_SAM0_BIASREFBUF(n) ADC_SAM0_CALIB(ADC_FUSES_PREFIX(n), BIASREFBUF)
+#else
+#  define ADC_SAM0_BIASREFBUF(n) 0
+#endif
+#endif /* MCLK */
+
+#ifndef ADC_REFCTRL_REFSEL_INTERNAL
+#  ifdef ADC_REFCTRL_REFSEL_INTREF
+#    define ADC_REFCTRL_REFSEL_INTERNAL ADC_REFCTRL_REFSEL_INTREF
+#  else
+#    define ADC_REFCTRL_REFSEL_INTERNAL ADC_REFCTRL_REFSEL_INT1V
+#  endif
+#endif
+
+#ifndef ADC_REFCTRL_REFSEL_VDD_1_2
+#  ifdef ADC_REFCTRL_REFSEL_INTVCC0
+#    define ADC_REFCTRL_REFSEL_VDD_1_2 ADC_REFCTRL_REFSEL_INTVCC0
+#  else
+#    define ADC_REFCTRL_REFSEL_VDD_1_2 ADC_REFCTRL_REFSEL_INTVCC1
+#  endif
+#endif
+
+#ifndef ADC_REFCTRL_REFSEL_VDD_1
+#  ifdef ADC_REFCTRL_REFSEL_INTVCC1
+#    define ADC_REFCTRL_REFSEL_VDD_1 ADC_REFCTRL_REFSEL_INTVCC1
+#  endif
+#endif
+
+#endif /* _ATMEL_SAM0_ADC_FIXUP_H_ */

soc/arm/atmel_sam0/samd20/soc.h

@@ -54,6 +54,7 @@
 
 #endif /* _ASMLANGUAGE */
 
+#include "adc_fixup_sam0.h"
 #include "../common/soc_port.h"
 #include "../common/atmel_sam0_dt.h"
 

soc/arm/atmel_sam0/samd21/soc.h

@@ -48,6 +48,7 @@
 
 #endif /* _ASMLANGUAGE */
 
+#include "adc_fixup_sam0.h"
 #include "../common/soc_port.h"
 #include "../common/atmel_sam0_dt.h"
 

soc/arm/atmel_sam0/samd51/soc.h

@@ -40,6 +40,7 @@
 
 #include "sercom_fixup_samd5x.h"
 #include "tc_fixup_samd5x.h"
+#include "adc_fixup_sam0.h"
 #include "../common/soc_port.h"
 #include "../common/atmel_sam0_dt.h"
 

soc/arm/atmel_sam0/same51/soc.h

@@ -32,6 +32,7 @@
 
 #include "sercom_fixup_samd5x.h"
 #include "tc_fixup_samd5x.h"
+#include "adc_fixup_sam0.h"
 #include "../common/soc_port.h"
 #include "../common/atmel_sam0_dt.h"
 

soc/arm/atmel_sam0/same53/soc.h

@@ -33,6 +33,7 @@
 #include "sercom_fixup_samd5x.h"
 #include "tc_fixup_samd5x.h"
 #include "gmac_fixup_samd5x.h"
+#include "adc_fixup_sam0.h"
 #include "../common/soc_port.h"
 #include "../common/atmel_sam0_dt.h"
 

soc/arm/atmel_sam0/same54/soc.h

@@ -31,6 +31,7 @@
 #include "sercom_fixup_samd5x.h"
 #include "tc_fixup_samd5x.h"
 #include "gmac_fixup_samd5x.h"
+#include "adc_fixup_sam0.h"
 #include "../common/soc_port.h"
 #include "../common/atmel_sam0_dt.h"
 

soc/arm/atmel_sam0/samr21/soc.h

@@ -34,6 +34,7 @@
 
 #endif /* _ASMLANGUAGE */
 
+#include "adc_fixup_sam0.h"
 #include "../common/soc_port.h"
 #include "../common/atmel_sam0_dt.h"