drivers: mfd: add support for MAX2221X multi-function device

drivers/mfd/CMakeLists.txt

@@ -28,3 +28,4 @@ zephyr_library_sources_ifdef(CONFIG_MFD_MCHP_SAM_FLEXCOM mfd_mchp_sam_flexcom.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_PF1550 mfd_pf1550.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_PCA9422 mfd_pca9422.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_MOTOROLA_MC146818 mfd_mc146818.c)
+zephyr_library_sources_ifdef(CONFIG_MFD_MAX2221X mfd_max2221x.c)

drivers/mfd/Kconfig

@@ -27,6 +27,7 @@ source "drivers/mfd/Kconfig.bd8lb600fs"
 source "drivers/mfd/Kconfig.ds3231"
 source "drivers/mfd/Kconfig.max20335"
 source "drivers/mfd/Kconfig.max22017"
+source "drivers/mfd/Kconfig.max2221x"
 source "drivers/mfd/Kconfig.max31790"
 source "drivers/mfd/Kconfig.maxq10xx"
 source "drivers/mfd/Kconfig.mchp_sam"

drivers/mfd/Kconfig.max2221x

@@ -0,0 +1,10 @@
+# Copyright (c) 2025 Analog Devices Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config MFD_MAX2221X
+	bool "Analog Devices MAX2221X multi-function device driver"
+	default y
+	depends on SPI
+	depends on DT_HAS_ADI_MAX2221X_ENABLED
+	help
+	  Enable the driver for the Analog Devices MAX2221X multi-function device driver

drivers/mfd/mfd_max2221x.c

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2025 Analog Devices Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT adi_max2221x
+
+#include <zephyr/drivers/mfd/max2221x.h>
+#include <zephyr/device.h>
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/spi.h>
+#include <zephyr/sys/util.h>
+#include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/__assert.h>
+#include <zephyr/logging/log.h>
+
+LOG_MODULE_REGISTER(MFD_MAX2221X, CONFIG_MFD_LOG_LEVEL);
+
+struct mfd_max2221x_config {
+	struct spi_dt_spec spi;
+};
+
+int max2221x_reg_read(const struct device *dev, uint8_t addr, uint16_t *value)
+{
+	int ret;
+	const struct mfd_max2221x_config *config = dev->config;
+	uint8_t rxbuffer[3] = {0};
+	size_t rx_len = 3;
+
+	*value = 0;
+	addr = FIELD_PREP(MAX2221X_SPI_TRANS_ADDR, addr) | FIELD_PREP(MAX2221X_SPI_TRANS_DIR, 0);
+
+	const struct spi_buf txb[] = {
+		{
+			.buf = &addr,
+			.len = 1,
+		},
+	};
+
+	const struct spi_buf rxb[] = {
+		{
+			.buf = rxbuffer,
+			.len = rx_len,
+		},
+	};
+
+	struct spi_buf_set tx = {
+		.buffers = txb,
+		.count = ARRAY_SIZE(txb),
+	};
+
+	struct spi_buf_set rx = {
+		.buffers = rxb,
+		.count = ARRAY_SIZE(rxb),
+	};
+
+	ret = spi_transceive_dt(&config->spi, &tx, &rx);
+	if (ret) {
+		return ret;
+	}
+
+	memset(rxbuffer, 0, sizeof(rxbuffer));
+
+	ret = spi_transceive_dt(&config->spi, &tx, &rx);
+	if (ret) {
+		return ret;
+	}
+
+	*value = sys_be16_to_cpu(*(uint16_t *)&rxbuffer[1]);
+	return 0;
+}
+
+int max2221x_reg_write(const struct device *dev, uint8_t addr, uint16_t value)
+{
+	const struct mfd_max2221x_config *config = dev->config;
+
+	addr = FIELD_PREP(MAX2221X_SPI_TRANS_ADDR, addr) | FIELD_PREP(MAX2221X_SPI_TRANS_DIR, 1);
+	value = sys_cpu_to_be16(value);
+
+	const struct spi_buf buf[] = {
+		{
+			.buf = &addr,
+			.len = 1,
+		},
+		{
+			.buf = &value,
+			.len = 2,
+		},
+	};
+
+	struct spi_buf_set tx = {
+		.buffers = buf,
+		.count = ARRAY_SIZE(buf),
+	};
+
+	return spi_write_dt(&config->spi, &tx);
+}
+
+int max2221x_reg_update(const struct device *dev, uint8_t addr, uint16_t mask, uint16_t val)
+{
+	uint16_t tmp;
+	int ret;
+
+	ret = max2221x_reg_read(dev, addr, &tmp);
+	if (ret) {
+		return ret;
+	}
+
+	tmp = (tmp & ~mask) | FIELD_PREP(mask, val);
+
+	return max2221x_reg_write(dev, addr, tmp);
+}
+
+static int max2221x_init(const struct device *dev)
+{
+	const struct mfd_max2221x_config *config = dev->config;
+
+	if (!spi_is_ready_dt(&config->spi)) {
+		LOG_ERR("SPI device %s not ready", config->spi.bus->name);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+#define MAX2221X_DEFINE(inst)                                                                      \
+	static const struct mfd_max2221x_config mfd_max2221x_config_##inst = {                     \
+		.spi = SPI_DT_SPEC_INST_GET(inst, SPI_WORD_SET(8) | SPI_TRANSFER_MSB, 0),          \
+	};                                                                                         \
+                                                                                                   \
+	DEVICE_DT_INST_DEFINE(inst, max2221x_init, NULL, NULL, &mfd_max2221x_config_##inst,        \
+			      POST_KERNEL, CONFIG_MFD_INIT_PRIORITY, NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(MAX2221X_DEFINE)

drivers/misc/CMakeLists.txt

@@ -15,5 +15,6 @@ add_subdirectory_ifdef(CONFIG_RENESAS_RX_DTC renesas_rx_dtc)
 add_subdirectory_ifdef(CONFIG_RENESAS_RX_EXTERNAL_INTERRUPT renesas_rx_external_interrupt)
 add_subdirectory_ifdef(CONFIG_NXP_RTXXX_DSP_CTRL nxp_rtxxx_dsp_ctrl)
 add_subdirectory_ifdef(CONFIG_STM32N6_AXISRAM stm32n6_axisram)
+add_subdirectory_ifdef(CONFIG_MISC_MAX2221X max2221x)
 
 add_subdirectory(interconn)

drivers/misc/Kconfig

@@ -22,5 +22,6 @@ source "drivers/misc/renesas_rx_external_interrupt/Kconfig"
 source "drivers/misc/nxp_rtxxx_dsp_ctrl/Kconfig"
 source "drivers/misc/stm32n6_axisram/Kconfig"
 source "drivers/misc/nxp_inputmux/Kconfig"
+source "drivers/misc/max2221x/Kconfig"
 
 endmenu

drivers/misc/max2221x/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources(max2221x.c)

drivers/misc/max2221x/Kconfig

@@ -0,0 +1,24 @@
+# Copyright (c) 2025 Analog Devices Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config MISC_MAX2221X
+	bool "Analog Devices MAX22216/MAX22217 Misc driver"
+	default y
+	depends on DT_HAS_ADI_MAX2221X_MISC_ENABLED
+	select MFD
+	help
+	  Enable driver for MAX2221X MISC.
+
+if MISC_MAX2221X
+
+config MISC_MAX2221X_INIT_PRIORITY
+	int "Init priority"
+	default 90
+	help
+	  Analog Devices MAX22216/MAX22217 Misc driver initialization priority.
+
+module = MISC_MAX2221X
+module-str = misc_max2221x
+source "subsys/logging/Kconfig.template.log_config"
+
+endif # MISC_MAX2221X