Commit db02fdc8 authored by Yunshao Chiang's avatar Yunshao Chiang Committed by Johan Hedberg
Browse files

drivers: adc: it51xxx: fix the ADC channels sampling flow 



The original code process causes the following two issues:

1. The first sample is always 0 because the `ctx` sequence in `data` is
   assigned the input sequence until the `adc_context_start_read`. As a
   result, the `while (channels) { ... }` loop is not executed, and
   `adc_enable_measurement` is not called.

2. Since the `ctx` sequence in `data` is assigned in
   `adc_context_start_read`, which occurs after the `while (channels) {
   ... }` loop, the ADC samples the previously set channel.

Signed-off-by: default avatarYunshao Chiang <Yunshao.Chiang@ite.com.tw>
parent 7ac7a0e0

drivers/adc/adc_ite_it51xxx.c

+16 −17
Original line number Diff line number Diff line
@@ -265,10 +265,7 @@ static int adc_it51xxx_start_read(const struct device *dev, const struct adc_seq 
{

	const struct adc_it51xxx_cfg *config = dev->config;

	struct adc_it51xxx_data *data = dev->data;

	struct adc_context *ctx = &data->ctx;

	uint32_t channels = ctx->sequence.channels;

	uint32_t channel_mask = sequence->channels;

	uint8_t channel_count = 0;



	if (!channel_mask || channel_mask & ~BIT_MASK(config->channel_count)) {

		LOG_ERR("Invalid selection of channels");
@@ -280,6 +277,21 @@ static int adc_it51xxx_start_read(const struct device *dev, const struct adc_seq 
		return -EINVAL;

	}



	data->buffer = sequence->buffer;



	adc_context_start_read(&data->ctx, sequence);



	return adc_context_wait_for_completion(&data->ctx);

}



static void adc_context_start_sampling(struct adc_context *ctx)

{

	struct adc_it51xxx_data *data = CONTAINER_OF(ctx, struct adc_it51xxx_data, ctx);

	uint32_t channels = ctx->sequence.channels;

	uint8_t channel_count = 0;



	data->repeat_buffer = data->buffer;



	/*

	 * The ADC sampling of it51xxx needs to read each channel

	 * in sequence.
@@ -294,22 +306,9 @@ static int adc_it51xxx_start_read(const struct device *dev, const struct adc_seq 
	}



	if (check_buffer_size(&ctx->sequence, channel_count)) {

		return -ENOMEM;

	}



	data->buffer = sequence->buffer;



	adc_context_start_read(&data->ctx, sequence);



	return adc_context_wait_for_completion(&data->ctx);

		return;

	}



static void adc_context_start_sampling(struct adc_context *ctx)

{

	struct adc_it51xxx_data *data = CONTAINER_OF(ctx, struct adc_it51xxx_data, ctx);



	data->repeat_buffer = data->buffer;



	adc_context_on_sampling_done(&data->ctx, DEVICE_DT_INST_GET(0));

}

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