drivers: adc: make a copy of sequence struct

We should not be storing the sequence pointer, as
adc_read_async() returns immediately. The memory could
be heap allocated, or on a call stack. Make a copy of
it instead.

Fixes: #15039

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

drivers/adc/adc_context.h

@@ -54,7 +54,8 @@ struct adc_context {
 	bool asynchronous;
 #endif /* CONFIG_ADC_ASYNC */
 
-	const struct adc_sequence *sequence;
+	struct adc_sequence sequence;
+	struct adc_sequence_options options;
 	u16_t sampling_index;
 };
 
@@ -91,7 +92,7 @@ static inline void adc_context_request_next_sampling(struct adc_context *ctx)
 #ifdef ADC_CONTEXT_USES_KERNEL_TIMER
 static inline void adc_context_enable_timer(struct adc_context *ctx)
 {
-	u32_t interval_us = ctx->sequence->options->interval_us;
+	u32_t interval_us = ctx->options.interval_us;
 	u32_t interval_ms = ceiling_fraction(interval_us, 1000UL);
 
 	k_timer_start(&ctx->timer, 0, interval_ms);
@@ -181,13 +182,15 @@ static inline void adc_context_complete(struct adc_context *ctx, int status)
 static inline void adc_context_start_read(struct adc_context *ctx,
 					  const struct adc_sequence *sequence)
 {
-	ctx->sequence = sequence;
+	ctx->sequence = *sequence;
 	ctx->status = 0;
 
-	if (ctx->sequence->options) {
+	if (sequence->options) {
+		ctx->options = *sequence->options;
+		ctx->sequence.options = &ctx->options;
 		ctx->sampling_index = 0U;
 
-		if (ctx->sequence->options->interval_us != 0U) {
+		if (ctx->options.interval_us != 0U) {
 			atomic_set(&ctx->sampling_requested, 0);
 			adc_context_enable_timer(ctx);
 			return;
@@ -205,16 +208,15 @@ static inline void adc_context_start_read(struct adc_context *ctx,
 static inline void adc_context_on_sampling_done(struct adc_context *ctx,
 						struct device *dev)
 {
-	if (ctx->sequence->options) {
-		adc_sequence_callback callback =
-			ctx->sequence->options->callback;
+	if (ctx->sequence.options) {
+		adc_sequence_callback callback = ctx->options.callback;
 		enum adc_action action;
 		bool finish = false;
 		bool repeat = false;
 
 		if (callback) {
 			action = callback(dev,
-					  ctx->sequence,
+					  &ctx->sequence,
 					  ctx->sampling_index);
 		} else {
 			action = ADC_ACTION_CONTINUE;
@@ -229,7 +231,7 @@ static inline void adc_context_on_sampling_done(struct adc_context *ctx,
 			break;
 		default: /* ADC_ACTION_CONTINUE */
 			if (ctx->sampling_index <
-			    ctx->sequence->options->extra_samplings) {
+			    ctx->options.extra_samplings) {
 				++ctx->sampling_index;
 			} else {
 				finish = true;
@@ -244,7 +246,7 @@ static inline void adc_context_on_sampling_done(struct adc_context *ctx,
 			 * a zero interval or if the timer expired again while
 			 * the current sampling was in progress.
 			 */
-			if (ctx->sequence->options->interval_us == 0U) {
+			if (ctx->options.interval_us == 0U) {
 				adc_context_start_sampling(ctx);
 			} else if (atomic_dec(&ctx->sampling_requested) > 1) {
 				adc_context_start_sampling(ctx);
@@ -253,7 +255,7 @@ static inline void adc_context_on_sampling_done(struct adc_context *ctx,
 			return;
 		}
 
-		if (ctx->sequence->options->interval_us != 0U) {
+		if (ctx->options.interval_us != 0U) {
 			adc_context_disable_timer(ctx);
 		}
 	}

drivers/adc/adc_intel_quark_d2000.c

@@ -366,7 +366,7 @@ static void adc_context_start_sampling(struct adc_context *ctx)
 	struct adc_quark_d2000_info *info =
 		CONTAINER_OF(ctx, struct adc_quark_d2000_info, ctx);
 
-	info->channels = ctx->sequence->channels;
+	info->channels = ctx->sequence.channels;
 
 	adc_quark_d2000_start_conversion(info->dev);
 }
@@ -376,7 +376,7 @@ static void adc_context_update_buffer_pointer(struct adc_context *ctx,
 {
 	struct adc_quark_d2000_info *info =
 		CONTAINER_OF(ctx, struct adc_quark_d2000_info, ctx);
-	const struct adc_sequence *entry = ctx->sequence;
+	const struct adc_sequence *entry = &ctx->sequence;
 
 	if (repeat) {
 		info->buffer = (u16_t *)entry->buffer;

drivers/adc/adc_intel_quark_se_c1000_ss.c

@@ -441,7 +441,7 @@ static void adc_quark_se_ss_start_conversion(struct device *dev)
 {
 	struct adc_info *info = dev->driver_data;
 	const struct adc_config *config = info->dev->config->config_info;
-	const struct adc_sequence *entry = info->ctx.sequence;
+	const struct adc_sequence *entry = &info->ctx.sequence;
 	u32_t adc_base = config->reg_base;
 	u32_t ctrl, tmp_val, sample_window;
 
@@ -492,7 +492,7 @@ static void adc_context_start_sampling(struct adc_context *ctx)
 {
 	struct adc_info *info = CONTAINER_OF(ctx, struct adc_info, ctx);
 
-	info->channels = ctx->sequence->channels;
+	info->channels = ctx->sequence.channels;
 
 	adc_quark_se_ss_start_conversion(info->dev);
 }
@@ -501,7 +501,7 @@ static void adc_context_update_buffer_pointer(struct adc_context *ctx,
 					      bool repeat)
 {
 	struct adc_info *info = CONTAINER_OF(ctx, struct adc_info, ctx);
-	const struct adc_sequence *entry = ctx->sequence;
+	const struct adc_sequence *entry = &ctx->sequence;
 
 	if (repeat) {
 		info->buffer = (u16_t *)entry->buffer;
@@ -556,7 +556,7 @@ static void adc_quark_se_ss_rx_isr(void *arg)
 	struct device *dev = (struct device *)arg;
 	struct adc_info *info = dev->driver_data;
 	const struct adc_config *config = dev->config->config_info;
-	const struct adc_sequence *seq = info->ctx.sequence;
+	struct adc_sequence *seq = &info->ctx.sequence;
 	u32_t adc_base = config->reg_base;
 	u32_t reg_val;
 

drivers/adc/adc_mcux_adc16.c

@@ -183,7 +183,7 @@ static void adc_context_start_sampling(struct adc_context *ctx)
 	struct mcux_adc16_data *data =
 		CONTAINER_OF(ctx, struct mcux_adc16_data, ctx);
 
-	data->channels = ctx->sequence->channels;
+	data->channels = ctx->sequence.channels;
 	data->repeat_buffer = data->buffer;
 
 	mcux_adc16_start_channel(data->dev);

drivers/adc/adc_sam_afec.c

@@ -150,7 +150,7 @@ static void adc_context_start_sampling(struct adc_context *ctx)
 {
 	struct adc_sam_data *data = CONTAINER_OF(ctx, struct adc_sam_data, ctx);
 
-	data->channels = ctx->sequence->channels;
+	data->channels = ctx->sequence.channels;
 
 	adc_sam_start_conversion(data->dev);
 }