drivers: mfd: add Maxim MAX20335 MFD driver

Maxim MAX20335 is a PMIC with Ultra-Low IQ Voltage Regulators and
Battery Chargers for Small Lithium Ion Systems.

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

CODEOWNERS

@@ -373,6 +373,7 @@
 /drivers/led_strip/                       @mbolivar-ampere
 /drivers/lora/                            @Mani-Sadhasivam
 /drivers/mbox/                            @carlocaione
+/drivers/mfd/mfd_max20335.c               @bbilas
 /drivers/misc/                            @tejlmand
 /drivers/misc/ft8xx/                      @hubertmis
 /drivers/mm/                              @dcpleung

drivers/mfd/CMakeLists.txt

@@ -3,6 +3,7 @@
 
 zephyr_library()
 
+zephyr_library_sources_ifdef(CONFIG_MFD_MAX20335 mfd_max20335.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_NCT38XX mfd_nct38xx.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_NPM1300 mfd_npm1300.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_NPM6001 mfd_npm6001.c)

drivers/mfd/Kconfig

@@ -19,6 +19,7 @@ config MFD_INIT_PRIORITY
 	  Multi-function devices initialization priority.
 
 source "drivers/mfd/Kconfig.axp192"
+source "drivers/mfd/Kconfig.max20335"
 source "drivers/mfd/Kconfig.nct38xx"
 source "drivers/mfd/Kconfig.npm1300"
 source "drivers/mfd/Kconfig.npm6001"

drivers/mfd/Kconfig.max20335

@@ -0,0 +1,10 @@
+# Copyright (c) 2023 Grinn
+# SPDX -License-Identifier: Apache-2.0
+
+config MFD_MAX20335
+	bool "MAX20335 PMIC multi-function device driver"
+	default y
+	depends on DT_HAS_MAXIM_MAX20335_ENABLED
+	select I2C
+	help
+	  Enable the Maxim MAX20335 PMIC multi-function device driver

drivers/mfd/mfd_max20335.c

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2023 Grinn
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT maxim_max20335
+
+#include <errno.h>
+
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/sys/util.h>
+
+#define MAX20335_REG_CHIP_ID 0x00
+#define MAX20335_CHIP_ID_VAL 0x04
+
+struct mfd_max20335_config {
+	struct i2c_dt_spec bus;
+};
+
+static int mfd_max20335_init(const struct device *dev)
+{
+	const struct mfd_max20335_config *config = dev->config;
+	uint8_t val;
+	int ret;
+
+	if (!i2c_is_ready_dt(&config->bus)) {
+		return -ENODEV;
+	}
+
+	ret = i2c_reg_read_byte_dt(&config->bus, MAX20335_REG_CHIP_ID, &val);
+	if (ret < 0) {
+		return ret;
+	}
+
+	if (val != MAX20335_CHIP_ID_VAL) {
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+#define MFD_MA20335_DEFINE(inst)					\
+	static const struct mfd_max20335_config mfd_max20335_config##inst = { \
+		.bus = I2C_DT_SPEC_INST_GET(inst),			\
+	};								\
+									\
+	DEVICE_DT_INST_DEFINE(inst, mfd_max20335_init, NULL, NULL,	\
+			      &mfd_max20335_config##inst, POST_KERNEL,	\
+			      CONFIG_MFD_INIT_PRIORITY, NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(MFD_MA20335_DEFINE)

dts/bindings/mfd/maxim,max20335.yaml

@@ -0,0 +1,12 @@
+# Copyright (c) 2023 Grinn
+# SPDX-License-Identifier: Apache-2.0
+
+description: Maxim MAX20335
+
+compatible: "maxim,max20335"
+
+include: i2c-device.yaml
+
+properties:
+  reg:
+    required: true