drivers: adc: add driver for AD5592

Add MFD subdriver for the built-in ADC controller
in AD5592 chip.

Signed-off-by: Bartosz Bilas <b.bilas@grinn-global.com>

CODEOWNERS

@@ -245,6 +245,7 @@
 /drivers/adc/adc_rpi_pico.c               @soburi
 /drivers/adc/*ads114s0x*                  @benediktibk
 /drivers/adc/*max11102_17*                @benediktibk
+/drivers/adc/adc_ad5592.c                 @bbilas
 /drivers/audio/*nrfx*                     @anangl
 /drivers/auxdisplay/*pt6314*              @xingrz
 /drivers/auxdisplay/*                      @thedjnK

drivers/adc/CMakeLists.txt

@@ -46,3 +46,4 @@ zephyr_library_sources_ifdef(CONFIG_ADC_TLA2021         adc_tla2021.c)
 zephyr_library_sources_ifdef(CONFIG_ADC_NXP_S32_ADC_SAR	adc_nxp_s32_adc_sar.c)
 zephyr_library_sources_ifdef(CONFIG_ADC_MAX1125X	adc_max1125x.c)
 zephyr_library_sources_ifdef(CONFIG_ADC_MAX11102_17	adc_max11102_17.c)
+zephyr_library_sources_ifdef(CONFIG_ADC_AD5592	        adc_ad5592.c)

drivers/adc/Kconfig

@@ -116,4 +116,6 @@ source "drivers/adc/Kconfig.max1125x"
 
 source "drivers/adc/Kconfig.max11102_17"
 
+source "drivers/adc/Kconfig.ad5592"
+
 endif # ADC

drivers/adc/Kconfig.ad5592

@@ -0,0 +1,25 @@
+# Copyright (c) 2023 Grinn
+# SPDX -License-Identifier: Apache-2.0
+
+config ADC_AD5592
+	bool "AD5592 ADC driver"
+	default y
+	depends on DT_HAS_ADI_AD5592_ADC_ENABLED
+	select MFD
+	help
+	  Enable the AD5592 ADC driver.
+
+config ADC_AD5592_ACQUISITION_THREAD_STACK_SIZE
+	int "Stack size for the ADC data acquisition thread"
+	depends on ADC_AD5592
+	default 384
+	help
+	  Size of the stack used for the internal data acquisition
+	  thread.
+
+config ADC_AD5592_ACQUISITION_THREAD_PRIO
+	int "Priority for the ADC data acquisition thread"
+	depends on ADC_AD5592
+	default 0
+	help
+	  Priority level for the internal ADC data acquisition thread.

drivers/adc/adc_ad5592.c

@@ -0,0 +1,255 @@
+/*
+ * Copyright (c) 2023 Grinn
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT adi_ad5592_adc
+
+#include <zephyr/drivers/adc.h>
+#include <zephyr/kernel.h>
+#include <zephyr/sys/byteorder.h>
+
+#include <zephyr/drivers/mfd/ad5592.h>
+
+#define ADC_CONTEXT_USES_KERNEL_TIMER
+#include "adc_context.h"
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(adc_ad5592, CONFIG_ADC_LOG_LEVEL);
+
+#define AD5592_ADC_RESOLUTION 12U
+#define AD5592_ADC_MAX_VAL 4096
+
+struct adc_ad5592_config {
+	const struct device *mfd_dev;
+};
+
+struct adc_ad5592_data {
+	struct adc_context ctx;
+	const struct device *dev;
+	uint8_t adc_conf;
+	uint16_t *buffer;
+	uint16_t *repeat_buffer;
+	uint8_t channels;
+	struct k_thread thread;
+	struct k_sem sem;
+
+	K_KERNEL_STACK_MEMBER(stack, CONFIG_ADC_AD5592_ACQUISITION_THREAD_STACK_SIZE);
+};
+
+static int adc_ad5592_channel_setup(const struct device *dev,
+				    const struct adc_channel_cfg *channel_cfg)
+{
+	const struct adc_ad5592_config *config = dev->config;
+	struct adc_ad5592_data *data = dev->data;
+
+	if (channel_cfg->channel_id >= AD5592_PIN_MAX) {
+		LOG_ERR("invalid channel id %d", channel_cfg->channel_id);
+		return -EINVAL;
+	}
+
+	data->adc_conf |= BIT(channel_cfg->channel_id);
+
+	return mfd_ad5592_write_reg(config->mfd_dev, AD5592_REG_ADC_CONFIG, data->adc_conf);
+}
+
+static int adc_ad5592_validate_buffer_size(const struct device *dev,
+					   const struct adc_sequence *sequence)
+{
+	uint8_t channels;
+	size_t needed;
+
+	channels = POPCOUNT(sequence->channels);
+	needed = channels * sizeof(uint16_t);
+
+	if (sequence->buffer_size < needed) {
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int adc_ad5592_start_read(const struct device *dev, const struct adc_sequence *sequence)
+{
+	struct adc_ad5592_data *data = dev->data;
+	int ret;
+
+	if (sequence->resolution != AD5592_ADC_RESOLUTION) {
+		LOG_ERR("invalid resolution %d", sequence->resolution);
+		return -EINVAL;
+	}
+
+	if (find_msb_set(sequence->channels) > AD5592_PIN_MAX) {
+		LOG_ERR("invalid channels in mask: 0x%08x", sequence->channels);
+		return -EINVAL;
+	}
+
+	ret = adc_ad5592_validate_buffer_size(dev, sequence);
+	if (ret < 0) {
+		LOG_ERR("insufficient buffer size");
+		return ret;
+	}
+
+	data->buffer = sequence->buffer;
+	adc_context_start_read(&data->ctx, sequence);
+
+	return adc_context_wait_for_completion(&data->ctx);
+}
+
+static int adc_ad5592_read_channel(const struct device *dev, uint8_t channel, uint16_t *result)
+{
+	const struct adc_ad5592_config *config = dev->config;
+	uint16_t val;
+	int ret;
+
+	ret = mfd_ad5592_write_reg(config->mfd_dev, AD5592_REG_SEQ_ADC, BIT(channel));
+	if (ret < 0) {
+		return ret;
+	}
+
+	/*
+	 * Invalid data:
+	 * See Figure 46. Single-Channel ADC Conversion Sequence.
+	 * The first conversion result always returns invalid data.
+	 */
+	(void) mfd_ad5592_read_raw(config->mfd_dev, &val);
+
+	ret = mfd_ad5592_read_raw(config->mfd_dev, &val);
+	if (ret < 0) {
+		return ret;
+	}
+
+	val = sys_be16_to_cpu(val);
+	if (channel >= 1) {
+		val -= channel * AD5592_ADC_MAX_VAL;
+	}
+
+	*result = val;
+
+	return 0;
+}
+
+static void adc_context_start_sampling(struct adc_context *ctx)
+{
+	struct adc_ad5592_data *data = CONTAINER_OF(ctx, struct adc_ad5592_data, ctx);
+
+	data->channels = ctx->sequence.channels;
+	data->repeat_buffer = data->buffer;
+
+	k_sem_give(&data->sem);
+}
+
+static void adc_context_update_buffer_pointer(struct adc_context *ctx,
+					      bool repeat_sampling)
+{
+	struct adc_ad5592_data *data = CONTAINER_OF(ctx, struct adc_ad5592_data, ctx);
+
+	if (repeat_sampling) {
+		data->buffer = data->repeat_buffer;
+	}
+}
+
+static void adc_ad5592_acquisition_thread(struct adc_ad5592_data *data)
+{
+	uint16_t result;
+	uint8_t channel;
+	int ret;
+
+	while (true) {
+		k_sem_take(&data->sem, K_FOREVER);
+
+		while (data->channels != 0) {
+			channel = find_lsb_set(data->channels) - 1;
+
+			ret = adc_ad5592_read_channel(data->dev, channel, &result);
+			if (ret < 0) {
+				LOG_ERR("failed to read channel %d (ret %d)", channel, ret);
+				adc_context_complete(&data->ctx, ret);
+				break;
+			}
+
+			*data->buffer++ = result;
+			WRITE_BIT(data->channels, channel, 0);
+		}
+
+		adc_context_on_sampling_done(&data->ctx, data->dev);
+	}
+}
+
+static int adc_ad5592_read_async(const struct device *dev,
+				 const struct adc_sequence *sequence,
+				 struct k_poll_signal *async)
+{
+	struct adc_ad5592_data *data = dev->data;
+	int ret;
+
+	adc_context_lock(&data->ctx, async ? true : false, async);
+	ret = adc_ad5592_start_read(dev, sequence);
+	adc_context_release(&data->ctx, ret);
+
+	return ret;
+}
+
+static int adc_ad5592_read(const struct device *dev,
+			   const struct adc_sequence *sequence)
+{
+	return adc_ad5592_read_async(dev, sequence, NULL);
+}
+
+static int adc_ad5592_init(const struct device *dev)
+{
+	const struct adc_ad5592_config *config = dev->config;
+	struct adc_ad5592_data *data = dev->data;
+	k_tid_t tid;
+	int ret;
+
+	if (!device_is_ready(config->mfd_dev)) {
+		return -ENODEV;
+	}
+
+	ret = mfd_ad5592_write_reg(config->mfd_dev, AD5592_REG_PD_REF_CTRL, AD5592_EN_REF);
+	if (ret < 0) {
+		return ret;
+	}
+
+	data->dev = dev;
+
+	k_sem_init(&data->sem, 0, 1);
+	adc_context_init(&data->ctx);
+
+	tid = k_thread_create(&data->thread, data->stack,
+			CONFIG_ADC_AD5592_ACQUISITION_THREAD_STACK_SIZE,
+			(k_thread_entry_t)adc_ad5592_acquisition_thread, data, NULL, NULL,
+			CONFIG_ADC_AD5592_ACQUISITION_THREAD_PRIO, 0, K_NO_WAIT);
+
+	ret = k_thread_name_set(tid, "adc_ad5592");
+	if (ret < 0) {
+		return ret;
+	}
+
+	adc_context_unlock_unconditionally(&data->ctx);
+
+	return 0;
+}
+
+static const struct adc_driver_api adc_ad5592_api = {
+	.channel_setup = adc_ad5592_channel_setup,
+	.read = adc_ad5592_read,
+#ifdef CONFIG_ADC_ASYNC
+	.read_async = adc_ad5592_read_async,
+#endif
+};
+
+#define ADC_AD5592_DEFINE(inst)							\
+	static const struct adc_ad5592_config adc_ad5592_config##inst = {	\
+		.mfd_dev = DEVICE_DT_GET(DT_INST_PARENT(inst)),			\
+	};									\
+										\
+	struct adc_ad5592_data adc_ad5592_data##inst;				\
+										\
+	DEVICE_DT_INST_DEFINE(inst, adc_ad5592_init, NULL,			\
+			      &adc_ad5592_data##inst, &adc_ad5592_config##inst, \
+			      POST_KERNEL, CONFIG_MFD_INIT_PRIORITY,		\
+			      &adc_ad5592_api);
+
+DT_INST_FOREACH_STATUS_OKAY(ADC_AD5592_DEFINE)

drivers/adc/adc_shell.c

@@ -104,6 +104,7 @@ static struct adc_hdl {
 	DT_FOREACH_STATUS_OKAY(maxim_max11115, ADC_HDL_LIST_ENTRY)
 	DT_FOREACH_STATUS_OKAY(maxim_max11116, ADC_HDL_LIST_ENTRY)
 	DT_FOREACH_STATUS_OKAY(maxim_max11117, ADC_HDL_LIST_ENTRY)
+	DT_FOREACH_STATUS_OKAY(adi_ad5592_adc, ADC_HDL_LIST_ENTRY)
 };
 
 static struct adc_hdl *get_adc(const char *device_label)

dts/bindings/adc/adi,ad5592-adc.yaml

@@ -0,0 +1,15 @@
+# Copyright (c) 2023 Grinn
+# SPDX-License-Identifier: Apache-2.0
+
+description: AD5592 ADC Controller
+
+compatible: "adi,ad5592-adc"
+
+include: adc-controller.yaml
+
+properties:
+  "#io-channel-cells":
+    const: 1
+
+io-channel-cells:
+  - input

tests/drivers/build_all/adc/app.overlay

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2023 Grinn
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Application overlay for testing driver builds
+ *
+ * Names in this file should be chosen in a way that won't conflict
+ * with real-world devicetree nodes, to allow these tests to run on
+ * (and be extended to test) real hardware.
+ */
+
+/ {
+	test {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		test_gpio: gpio@deadbeef {
+			compatible = "vnd,gpio";
+			gpio-controller;
+			reg = <0xdeadbeef 0x1000>;
+			#gpio-cells = <0x2>;
+			status = "okay";
+		};
+
+		test_spi: spi@33334444 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			compatible = "vnd,spi";
+			reg = <0x33334444 0x1000>;
+			status = "okay";
+			clock-frequency = <2000000>;
+
+			cs-gpios = <&test_gpio 0 0>;
+
+			test_spi_ad5592: ad5592@0 {
+				compatible = "adi,ad5592";
+				status = "okay";
+				reg = <0x0>;
+				spi-max-frequency = <0>;
+				reset-gpios = <&test_gpio 0 0>;
+
+				ad5592_adc: adc-controller {
+					compatible = "adi,ad5592-adc";
+					#io-channel-cells = <1>;
+				};
+			};
+		};
+	};
+};

tests/drivers/build_all/adc/prj.conf

@@ -4,3 +4,4 @@ CONFIG_ADC=y
 CONFIG_MAX_THREAD_BYTES=4
 CONFIG_ADC_INIT_PRIORITY=80
 CONFIG_KOBJECT_RODATA_AREA_EXTRA_BYTES=256
+CONFIG_SPI=y