[PATCH v7 0/3] iio: health: add MAX86150 ECG and PPG biosensor driver

[PATCH v7 0/3] iio: health: add MAX86150 ECG and PPG biosensor driver

[Md Shofiqul Islam]

Changes in v7 (Jonathan Cameron's review of v5 driver):
- Switch from triggered buffer to kfifo buffer (like MAX30100/MAX30102)
  and remove the IIO trigger framework from this driver entirely
- Remove spurious 'select IIO_TRIGGER' added to AFE4403, AFE4404,
  MAX30100, MAX30102 in the Kconfig patch
- Rename all register field macros to include the parent register name
  and a _MASK suffix (e.g. MAX86150_PPG_CONFIG1_ADC_RGE_MASK)
- Use IIO_DMA_MINALIGN instead of ARCH_DMA_MINALIGN
- Use IIO_DECLARE_BUFFER_WITH_TS() macro for the push buffer
- Fix regmap_noinc_read() length: use MAX86150_SAMPLE_BYTES (9) not
  sizeof(fifo_raw) (64) -- the padded size is for DMA alignment only;
  using it would over-read the FIFO by 7 extra samples per call
- Use get_unaligned_be24() with a single mask for 24-bit FIFO reads
- Use regmap_set_bits() / regmap_clear_bits() instead of regmap_update_bits
- Use iio_push_to_buffers_with_ts() (new name)
- Use fsleep() instead of usleep_range() after software reset
- Use 10 * NSEC_PER_MSEC instead of bare 10000000
- Replace if (!ret) chains with goto-based error handling
- Remove all code-section comments (/* Trigger */, /* Probe */, etc.)
- Remove forced variable declaration alignment
- Print a warning (not -ENODEV) for unexpected part ID
- Remove IRQ trigger type fallback; honour DT specification only
- Remove memset of push buffer before packing
- Drop overflow timestamp reconstruction; flush FIFO and discard samples
- Remove struct device *dev field (unused after removing trigger)
- Rename LED_PA_DEFAULT to LED_PA_50MA to make the value self-describing
- Remove vref regulator (not a supply pin per the datasheet); keep vdd
  and vled; change to non-optional devm_regulator_get_enable()

Changes in v6 (Jonathan Cameron's review of v5 DT binding):
- Remove "SoC" from description; spell out "photoplethysmography (PPG)"
  and "electrocardiogram (ECG)" in full
- Remove the I2C fast-mode (400 kHz) line
- Simplify interrupt description to a single sentence

Changes in v5:
- Rebase on iio/testing
- Adjust FIFO slot descriptor defines
- Fix scan_type for ECG (signed 18-bit)

v4 and earlier: initial submission and review iterations

Md Shofiqul Islam (3):
  dt-bindings: iio: health: add adi,max86150
  iio: health: add MAX86150 ECG and PPG biosensor driver
  MAINTAINERS: add entry for MAX86150 IIO health driver

 .../bindings/iio/health/adi,max86150.yaml     |  65 +++
 MAINTAINERS                                   |   7 +
 drivers/iio/health/Kconfig                    |  18 +
 drivers/iio/health/Makefile                   |   1 +
 drivers/iio/health/max86150.c                 | 533 ++++++++++++++++++
 5 files changed, 624 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/health/adi,max86150.yaml
 create mode 100644 drivers/iio/health/max86150.c

--
2.51.1

[PATCH v7 v7 1/3] dt-bindings: iio: health: add adi,max86150

[Md Shofiqul Islam]

Add Device Tree binding schema for the Analog Devices MAX86150
integrated ECG and PPG biosensor.

The device exposes two PPG channels (Red LED and IR LED) and one ECG
channel over I2C, with a 32-entry hardware FIFO and an active-low
interrupt.

Signed-off-by: Md Shofiqul Islam <shofiqtest@gmail.com>
---
 .../bindings/iio/health/adi,max86150.yaml     | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/health/adi,max86150.yaml

diff --git a/Documentation/devicetree/bindings/iio/health/adi,max86150.yaml b/Documentation/devicetree/bindings/iio/health/adi,max86150.yaml
new file mode 100644
index 0000000000000..b0ae7d2ecfcec
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/health/adi,max86150.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/health/adi,max86150.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices MAX86150 ECG and PPG Biosensor
+
+maintainers:
+  - Md Shofiqul Islam <shofiqtest@gmail.com>
+
+description: |
+  The MAX86150 is an integrated biosensor that combines two
+  photoplethysmography (PPG) channels (Red LED and IR LED) and one
+  electrocardiogram (ECG) channel for biopotential recording. Samples
+  are buffered in a 32-entry hardware FIFO with a configurable
+  almost-full interrupt.
+
+  Datasheet:
+    https://www.analog.com/media/en/technical-documentation/data-sheets/MAX86150.pdf
+
+properties:
+  compatible:
+    const: adi,max86150
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+    description:
+      Interrupt line, asserted when the FIFO almost-full threshold is
+      reached.
+
+  vdd-supply:
+    description: VDD power supply (1.8 V).
+
+  vled-supply:
+    description: VLED LED anode supply (3.3 V to 5 V).
+
+required:
+  - compatible
+  - reg
+  - vdd-supply
+  - vled-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        heart-rate@5e {
+            compatible = "adi,max86150";
+            reg = <0x5e>;
+            interrupt-parent = <&gpio1>;
+            interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
+            vdd-supply = <&vdd_1v8>;
+            vled-supply = <&vdd_3v3>;
+        };
+    };
-- 
2.51.1

[PATCH v7 v7 2/3] iio: health: add MAX86150 ECG and PPG biosensor driver

[Md Shofiqul Islam]

Add a new IIO driver for the Analog Devices MAX86150 integrated
biosensor, which combines two PPG optical channels (Red/IR LED) and
one ECG biopotential channel in a single I2C device.

The device has a 32-entry hardware FIFO with a configurable almost-full
interrupt.  Because all samples arrive via the FIFO, the driver uses a
kfifo buffer (like the sibling MAX30100 and MAX30102 drivers) rather
than the triggered-buffer framework.  The interrupt handler drains the
FIFO on each A_FULL event and timestamps samples back-calculated from
the interrupt arrival time by one sample_period_ns per step.

Key implementation details:
- FIFO draining via iio_buffer_setup_ops postenable/predisable
- DMA-safe FIFO read buffer aligned to IIO_DMA_MINALIGN
- IIO_DECLARE_BUFFER_WITH_TS for the push buffer
- 24-bit FIFO words decoded via get_unaligned_be24()
- regmap_set_bits() / regmap_clear_bits() for single-direction writes
- Overflow drops all samples; timestamps are unreliable after overflow
- Device remains in shutdown between captures to suppress LED current
- vdd and vled regulators required per datasheet; vref is not a supply

Signed-off-by: Md Shofiqul Islam <shofiqtest@gmail.com>
---
 drivers/iio/health/Kconfig    |  18 ++
 drivers/iio/health/Makefile   |   1 +
 drivers/iio/health/max86150.c | 533 ++++++++++++++++++++++++++++++++++
 3 files changed, 552 insertions(+)
 create mode 100644 drivers/iio/health/max86150.c

diff --git a/drivers/iio/health/Kconfig b/drivers/iio/health/Kconfig
index a89f3abf11f4a..e5b8b6bb9351e 100644
--- a/drivers/iio/health/Kconfig
+++ b/drivers/iio/health/Kconfig
@@ -62,4 +62,22 @@ config MAX30102
 
 endmenu
 
+
+config MAX86150
+	tristate "MAX86150 ECG and PPG biosensor"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_KFIFO_BUF
+	select REGMAP_I2C
+	help
+	  Say Y here to enable support for the Maxim MAX86150 combined
+	  ECG and photoplethysmography (PPG) biosensor.
+
+	  The driver exposes three IIO channels: two PPG optical channels
+	  (Red and IR LED) for heart rate and SpO2 monitoring, and one
+	  ECG channel for biopotential recording.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called max86150.
+
 endmenu
diff --git a/drivers/iio/health/Makefile b/drivers/iio/health/Makefile
index 9108171122588..04fc73c584449 100644
--- a/drivers/iio/health/Makefile
+++ b/drivers/iio/health/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_AFE4403)		+= afe4403.o
 obj-$(CONFIG_AFE4404)		+= afe4404.o
 obj-$(CONFIG_MAX30100)		+= max30100.o
 obj-$(CONFIG_MAX30102)		+= max30102.o
+obj-$(CONFIG_MAX86150)		+= max86150.o
diff --git a/drivers/iio/health/max86150.c b/drivers/iio/health/max86150.c
new file mode 100644
index 0000000000000..1e3d28cb41b70
--- /dev/null
+++ b/drivers/iio/health/max86150.c
@@ -0,0 +1,533 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MAX86150 combined ECG and PPG biosensor driver
+ *
+ * Copyright (C) 2026 Md Shofiqul Islam <shofiqtest@gmail.com>
+ *
+ * The MAX86150 integrates two PPG optical channels (Red/IR LED) and one
+ * ECG biopotential channel in a single I2C device.  Data is captured
+ * through a 32-entry hardware FIFO with a configurable almost-full
+ * interrupt, making it well-suited for continuous monitoring with a
+ * low-power host.
+ *
+ * Datasheet:
+ *   https://www.analog.com/media/en/technical-documentation/data-sheets/MAX86150.pdf
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/unaligned.h>
+
+/* Register addresses */
+#define MAX86150_REG_INT_STATUS1	0x00
+#define MAX86150_REG_INT_STATUS2	0x01
+#define MAX86150_REG_INT_ENABLE1	0x02
+#define MAX86150_REG_INT_ENABLE2	0x03
+#define MAX86150_REG_FIFO_WR_PTR	0x04
+#define MAX86150_REG_OVF_COUNTER	0x05
+#define MAX86150_REG_FIFO_RD_PTR	0x06
+#define MAX86150_REG_FIFO_DATA		0x07
+#define MAX86150_REG_FIFO_CONFIG	0x08
+#define MAX86150_REG_FIFO_DCTRL1	0x09
+#define MAX86150_REG_FIFO_DCTRL2	0x0A
+#define MAX86150_REG_SYS_CTRL		0x0D
+#define MAX86150_REG_PPG_CONFIG1	0x10
+#define MAX86150_REG_PPG_CONFIG2	0x11
+#define MAX86150_REG_LED1_PA		0x14
+#define MAX86150_REG_LED2_PA		0x15
+#define MAX86150_REG_ECG_CONFIG1	0x3C
+#define MAX86150_REG_ECG_CONFIG3	0x3E
+#define MAX86150_REG_PART_ID		0xFF
+
+#define MAX86150_PART_ID_VAL		0x1E
+
+/* INT_STATUS1 / INT_ENABLE1 */
+#define MAX86150_INT_A_FULL		BIT(7)
+#define MAX86150_INT_PPG_RDY		BIT(6)
+
+/* SYS_CTRL */
+#define MAX86150_SYS_CTRL_SHDN		BIT(1)
+#define MAX86150_SYS_CTRL_RESET		BIT(0)
+
+/* FIFO_CONFIG */
+#define MAX86150_FIFO_CONFIG_SMP_AVE_MASK	GENMASK(7, 5)
+#define MAX86150_FIFO_CONFIG_ROLLOVER_EN	BIT(4)
+#define MAX86150_FIFO_CONFIG_A_FULL_MASK	GENMASK(3, 0)
+
+/* FIFO slot data-type codes */
+#define MAX86150_FD_NONE		0x0
+#define MAX86150_FD_LED1		0x1
+#define MAX86150_FD_LED2		0x2
+#define MAX86150_FD_ECG			0x9
+
+/* FIFO_DCTRL1 / FIFO_DCTRL2 */
+#define MAX86150_FIFO_DCTRL_FD_LO_MASK	GENMASK(3, 0)
+#define MAX86150_FIFO_DCTRL_FD_HI_MASK	GENMASK(7, 4)
+
+/* PPG_CONFIG1 */
+#define MAX86150_PPG_CONFIG1_ADC_RGE_MASK	GENMASK(7, 6)
+#define MAX86150_PPG_CONFIG1_SR_MASK		GENMASK(5, 1)
+
+#define MAX86150_FIFO_DEPTH		32
+#define MAX86150_BYTES_PER_SLOT		3
+#define MAX86150_NUM_SLOTS		3
+#define MAX86150_SAMPLE_BYTES		(MAX86150_NUM_SLOTS * MAX86150_BYTES_PER_SLOT)
+
+/* Fire A_FULL when 17 slots are available (32 - 15 = 17) */
+#define MAX86150_FIFO_A_FULL_VAL	15
+
+#define MAX86150_LED_PA_50MA		0x3F
+#define MAX86150_PPG_SR_100HZ		4
+#define MAX86150_PPG_ADC_RGE_16384	2
+
+enum max86150_scan_idx {
+	MAX86150_IDX_PPG_RED = 0,
+	MAX86150_IDX_PPG_IR  = 1,
+	MAX86150_IDX_ECG     = 2,
+	MAX86150_IDX_TS,
+};
+
+struct max86150_data {
+	struct regmap *regmap;
+	u32 sample_period_ns;
+	u8 fifo_raw[ALIGN(MAX86150_SAMPLE_BYTES, IIO_DMA_MINALIGN)]
+		__aligned(IIO_DMA_MINALIGN);
+	IIO_DECLARE_BUFFER_WITH_TS(s32, buf, 3);
+};
+
+static const struct iio_chan_spec max86150_channels[] = {
+	{
+		.type               = IIO_INTENSITY,
+		.modified           = 1,
+		.channel2           = IIO_MOD_LIGHT_RED,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index         = MAX86150_IDX_PPG_RED,
+		.scan_type = {
+			.sign        = 'u',
+			.realbits    = 19,
+			.storagebits = 32,
+			.endianness  = IIO_CPU,
+		},
+	},
+	{
+		.type               = IIO_INTENSITY,
+		.modified           = 1,
+		.channel2           = IIO_MOD_LIGHT_IR,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index         = MAX86150_IDX_PPG_IR,
+		.scan_type = {
+			.sign        = 'u',
+			.realbits    = 19,
+			.storagebits = 32,
+			.endianness  = IIO_CPU,
+		},
+	},
+	{
+		.type               = IIO_VOLTAGE,
+		.channel            = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index         = MAX86150_IDX_ECG,
+		.scan_type = {
+			.sign        = 's',
+			.realbits    = 18,
+			.storagebits = 32,
+			.endianness  = IIO_CPU,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(MAX86150_IDX_TS),
+};
+
+static const struct regmap_config max86150_regmap_config = {
+	.reg_bits     = 8,
+	.val_bits     = 8,
+	.max_register = MAX86150_REG_PART_ID,
+};
+
+static int max86150_read_one_sample(struct max86150_data *data,
+				    u32 *ppg_red, u32 *ppg_ir, s32 *ecg)
+{
+	int ret;
+
+	ret = regmap_noinc_read(data->regmap, MAX86150_REG_FIFO_DATA,
+				data->fifo_raw, MAX86150_SAMPLE_BYTES);
+	if (ret)
+		return ret;
+
+	*ppg_red = get_unaligned_be24(&data->fifo_raw[0]) & GENMASK(18, 0);
+	*ppg_ir  = get_unaligned_be24(&data->fifo_raw[3]) & GENMASK(18, 0);
+	*ecg = sign_extend32(get_unaligned_be24(&data->fifo_raw[6]) &
+			     GENMASK(17, 0), 17);
+
+	return 0;
+}
+
+static int max86150_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct max86150_data *data = iio_priv(indio_dev);
+	unsigned int ppg_rdy_status;
+	u32 ppg_red, ppg_ir;
+	s32 ecg;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (!iio_device_claim_direct(indio_dev))
+			return -EBUSY;
+
+		ret = regmap_clear_bits(data->regmap, MAX86150_REG_SYS_CTRL,
+					MAX86150_SYS_CTRL_SHDN);
+		if (ret)
+			goto out_shutdown;
+
+		ret = regmap_write(data->regmap, MAX86150_REG_FIFO_WR_PTR, 0);
+		if (ret)
+			goto out_shutdown;
+		ret = regmap_write(data->regmap, MAX86150_REG_OVF_COUNTER, 0);
+		if (ret)
+			goto out_shutdown;
+		ret = regmap_write(data->regmap, MAX86150_REG_FIFO_RD_PTR, 0);
+		if (ret)
+			goto out_shutdown;
+
+		/*
+		 * Poll PPG_RDY rather than sleeping a fixed interval -- the
+		 * internal oscillator may start slower than nominal, leaving
+		 * the FIFO empty if we read too early.
+		 */
+		ret = regmap_read_poll_timeout(data->regmap,
+					       MAX86150_REG_INT_STATUS1,
+					       ppg_rdy_status,
+					       ppg_rdy_status & MAX86150_INT_PPG_RDY,
+					       1000, 25000);
+		if (ret)
+			goto out_shutdown;
+
+		ret = max86150_read_one_sample(data, &ppg_red, &ppg_ir, &ecg);
+
+out_shutdown:
+		regmap_set_bits(data->regmap, MAX86150_REG_SYS_CTRL,
+				MAX86150_SYS_CTRL_SHDN);
+		iio_device_release_direct(indio_dev);
+
+		if (ret)
+			return ret;
+
+		switch (chan->scan_index) {
+		case MAX86150_IDX_PPG_RED:
+			*val = ppg_red;
+			break;
+		case MAX86150_IDX_PPG_IR:
+			*val = ppg_ir;
+			break;
+		case MAX86150_IDX_ECG:
+			*val = ecg;
+			break;
+		default:
+			return -EINVAL;
+		}
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info max86150_iio_info = {
+	.read_raw = max86150_read_raw,
+};
+
+static int max86150_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct max86150_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = regmap_clear_bits(data->regmap, MAX86150_REG_SYS_CTRL,
+				MAX86150_SYS_CTRL_SHDN);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(data->regmap, MAX86150_REG_FIFO_WR_PTR, 0);
+	if (ret)
+		goto err_shutdown;
+	ret = regmap_write(data->regmap, MAX86150_REG_OVF_COUNTER, 0);
+	if (ret)
+		goto err_shutdown;
+	ret = regmap_write(data->regmap, MAX86150_REG_FIFO_RD_PTR, 0);
+	if (ret)
+		goto err_shutdown;
+	ret = regmap_write(data->regmap, MAX86150_REG_INT_ENABLE1,
+			   MAX86150_INT_A_FULL);
+	if (ret)
+		goto err_shutdown;
+	return 0;
+
+err_shutdown:
+	regmap_set_bits(data->regmap, MAX86150_REG_SYS_CTRL,
+			MAX86150_SYS_CTRL_SHDN);
+	return ret;
+}
+
+static int max86150_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct max86150_data *data = iio_priv(indio_dev);
+
+	regmap_write(data->regmap, MAX86150_REG_INT_ENABLE1, 0);
+	regmap_set_bits(data->regmap, MAX86150_REG_SYS_CTRL,
+			MAX86150_SYS_CTRL_SHDN);
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops max86150_buffer_setup_ops = {
+	.postenable = max86150_buffer_postenable,
+	.predisable = max86150_buffer_predisable,
+};
+
+static irqreturn_t max86150_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct max86150_data *data = iio_priv(indio_dev);
+	unsigned int status, wr_ptr, rd_ptr, ovf;
+	u32 ppg_red, ppg_ir;
+	s32 ecg;
+	s64 ts;
+	int ret, n_avail, i, j;
+
+	ret = regmap_read(data->regmap, MAX86150_REG_INT_STATUS1, &status);
+	if (ret)
+		return IRQ_HANDLED;
+
+	if (!(status & MAX86150_INT_A_FULL))
+		return IRQ_NONE;
+
+	ret = regmap_read(data->regmap, MAX86150_REG_OVF_COUNTER, &ovf);
+	if (ret)
+		return IRQ_HANDLED;
+
+	if (ovf > 0) {
+		/* FIFO overflowed; timestamps are unreliable - flush and discard */
+		regmap_write(data->regmap, MAX86150_REG_FIFO_WR_PTR, 0);
+		regmap_write(data->regmap, MAX86150_REG_OVF_COUNTER, 0);
+		regmap_write(data->regmap, MAX86150_REG_FIFO_RD_PTR, 0);
+		return IRQ_HANDLED;
+	}
+
+	ret = regmap_read(data->regmap, MAX86150_REG_FIFO_WR_PTR, &wr_ptr);
+	if (ret)
+		return IRQ_HANDLED;
+	ret = regmap_read(data->regmap, MAX86150_REG_FIFO_RD_PTR, &rd_ptr);
+	if (ret)
+		return IRQ_HANDLED;
+
+	n_avail = (wr_ptr - rd_ptr) & (MAX86150_FIFO_DEPTH - 1);
+	if (!n_avail)
+		return IRQ_HANDLED;
+
+	/*
+	 * Anchor timestamps to the interrupt time: sample (n_avail - 1) is
+	 * the newest and corresponds to ts; earlier samples are back-calculated
+	 * by one sample_period_ns per step.
+	 */
+	ts = ktime_get_ns();
+
+	for (i = 0; i < n_avail; i++) {
+		s64 sample_ts = ts -
+			(s64)(n_avail - 1 - i) * data->sample_period_ns;
+
+		ret = max86150_read_one_sample(data, &ppg_red, &ppg_ir, &ecg);
+		if (ret)
+			break;
+
+		j = 0;
+		if (test_bit(MAX86150_IDX_PPG_RED, indio_dev->active_scan_mask))
+			data->buf[j++] = ppg_red;
+		if (test_bit(MAX86150_IDX_PPG_IR, indio_dev->active_scan_mask))
+			data->buf[j++] = ppg_ir;
+		if (test_bit(MAX86150_IDX_ECG, indio_dev->active_scan_mask))
+			data->buf[j++] = ecg;
+
+		iio_push_to_buffers_with_ts(indio_dev, data->buf,
+					    sizeof(data->buf), sample_ts);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void max86150_powerdown(void *arg)
+{
+	struct max86150_data *data = arg;
+
+	regmap_write(data->regmap, MAX86150_REG_INT_ENABLE1, 0);
+	regmap_set_bits(data->regmap, MAX86150_REG_SYS_CTRL,
+			MAX86150_SYS_CTRL_SHDN);
+}
+
+static int max86150_chip_init(struct max86150_data *data)
+{
+	int ret;
+
+	/* Software reset; the bit self-clears within 1 ms */
+	ret = regmap_write(data->regmap, MAX86150_REG_SYS_CTRL,
+			   MAX86150_SYS_CTRL_RESET);
+	if (ret)
+		return ret;
+	fsleep(1000);
+
+	ret = regmap_write(data->regmap, MAX86150_REG_FIFO_CONFIG,
+			   MAX86150_FIFO_CONFIG_ROLLOVER_EN |
+			   FIELD_PREP(MAX86150_FIFO_CONFIG_A_FULL_MASK,
+				      MAX86150_FIFO_A_FULL_VAL));
+	if (ret)
+		return ret;
+
+	/* Slot 1 = PPG Red (LED1), Slot 2 = PPG IR (LED2) */
+	ret = regmap_write(data->regmap, MAX86150_REG_FIFO_DCTRL1,
+			   FIELD_PREP(MAX86150_FIFO_DCTRL_FD_LO_MASK,
+				      MAX86150_FD_LED1) |
+			   FIELD_PREP(MAX86150_FIFO_DCTRL_FD_HI_MASK,
+				      MAX86150_FD_LED2));
+	if (ret)
+		return ret;
+
+	/* Slot 3 = ECG, Slot 4 = disabled */
+	ret = regmap_write(data->regmap, MAX86150_REG_FIFO_DCTRL2,
+			   FIELD_PREP(MAX86150_FIFO_DCTRL_FD_LO_MASK,
+				      MAX86150_FD_ECG) |
+			   FIELD_PREP(MAX86150_FIFO_DCTRL_FD_HI_MASK,
+				      MAX86150_FD_NONE));
+	if (ret)
+		return ret;
+
+	/* PPG: 100 Hz sample rate, 16384 nA ADC full-scale range */
+	ret = regmap_write(data->regmap, MAX86150_REG_PPG_CONFIG1,
+			   FIELD_PREP(MAX86150_PPG_CONFIG1_ADC_RGE_MASK,
+				      MAX86150_PPG_ADC_RGE_16384) |
+			   FIELD_PREP(MAX86150_PPG_CONFIG1_SR_MASK,
+				      MAX86150_PPG_SR_100HZ));
+	if (ret)
+		return ret;
+
+	ret = regmap_write(data->regmap, MAX86150_REG_LED1_PA, MAX86150_LED_PA_50MA);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(data->regmap, MAX86150_REG_LED2_PA, MAX86150_LED_PA_50MA);
+	if (ret)
+		return ret;
+
+	data->sample_period_ns = 10 * NSEC_PER_MSEC;
+
+	return regmap_write(data->regmap, MAX86150_REG_SYS_CTRL,
+			    MAX86150_SYS_CTRL_SHDN);
+}
+
+static int max86150_probe(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev;
+	struct max86150_data *data;
+	unsigned int part_id;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+
+	ret = devm_regulator_get_enable(&client->dev, "vdd");
+	if (ret)
+		return dev_err_probe(&client->dev, ret,
+				     "Failed to get/enable vdd supply\n");
+
+	ret = devm_regulator_get_enable(&client->dev, "vled");
+	if (ret)
+		return dev_err_probe(&client->dev, ret,
+				     "Failed to get/enable vled supply\n");
+
+	data->regmap = devm_regmap_init_i2c(client, &max86150_regmap_config);
+	if (IS_ERR(data->regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(data->regmap),
+				     "Failed to initialise regmap\n");
+
+	ret = regmap_read(data->regmap, MAX86150_REG_PART_ID, &part_id);
+	if (ret)
+		return dev_err_probe(&client->dev, ret,
+				     "Cannot read part ID\n");
+
+	if (part_id != MAX86150_PART_ID_VAL)
+		dev_warn(&client->dev,
+			 "Unexpected part ID 0x%02x (expected 0x%02x)\n",
+			 part_id, MAX86150_PART_ID_VAL);
+
+	ret = max86150_chip_init(data);
+	if (ret)
+		return dev_err_probe(&client->dev, ret,
+				     "Chip initialisation failed\n");
+
+	ret = devm_add_action_or_reset(&client->dev, max86150_powerdown, data);
+	if (ret)
+		return ret;
+
+	indio_dev->name = "max86150";
+	indio_dev->channels = max86150_channels;
+	indio_dev->num_channels = ARRAY_SIZE(max86150_channels);
+	indio_dev->info = &max86150_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	if (client->irq > 0) {
+		unsigned long irq_trig = irq_get_trigger_type(client->irq);
+
+		ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
+						  &max86150_buffer_setup_ops);
+		if (ret)
+			return dev_err_probe(&client->dev, ret,
+					     "Cannot setup kfifo buffer\n");
+
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL,
+						max86150_interrupt_handler,
+						irq_trig | IRQF_ONESHOT,
+						"max86150", indio_dev);
+		if (ret)
+			return dev_err_probe(&client->dev, ret,
+					     "Cannot request IRQ %d\n",
+					     client->irq);
+	}
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id max86150_id[] = {
+	{ "max86150" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max86150_id);
+
+static const struct of_device_id max86150_of_match[] = {
+	{ .compatible = "adi,max86150" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max86150_of_match);
+
+static struct i2c_driver max86150_driver = {
+	.driver = {
+		.name = "max86150",
+		.of_match_table = max86150_of_match,
+	},
+	.probe = max86150_probe,
+	.id_table = max86150_id,
+};
+module_i2c_driver(max86150_driver);
+
+MODULE_AUTHOR("Md Shofiqul Islam <shofiqtest@gmail.com>");
+MODULE_DESCRIPTION("MAX86150 ECG and PPG biosensor driver");
+MODULE_LICENSE("GPL");
-- 
2.51.1

[PATCH v7 v7 3/3] MAINTAINERS: add entry for MAX86150 IIO health driver

[Md Shofiqul Islam]

Signed-off-by: Md Shofiqul Islam <shofiqtest@gmail.com>
---
 MAINTAINERS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 3115538ce8291..361a7c8b99ead 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15863,6 +15863,13 @@ S:	Supported
 F:	Documentation/devicetree/bindings/power/supply/maxim,max77976.yaml
 F:	drivers/power/supply/max77976_charger.c
 
+MAX86150 ECG AND PPG BIOSENSOR DRIVER
+M:	Md Shofiqul Islam <shofiqtest@gmail.com>
+L:	linux-iio@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/iio/health/adi,max86150.yaml
+F:	drivers/iio/health/max86150.c
+
 MAXIM MUIC CHARGER DRIVERS FOR EXYNOS BASED BOARDS
 M:	Krzysztof Kozlowski <krzk@kernel.org>
 L:	linux-pm@vger.kernel.org
-- 
2.51.1

Re: [PATCH v7 v7 3/3] MAINTAINERS: add entry for MAX86150 IIO health driver

[Maxwell Doose]

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On Mon Jul 6, 2026 at 5:39 PM CDT
Md Shofiqul Islam <shofiqtest@gmail.com> wrote:

> Signed-off-by: Md Shofiqul Islam <shofiqtest@gmail.com>
> ---
>  MAINTAINERS | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3115538ce8291..361a7c8b99ead 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15863,6 +15863,13 @@ S:	Supported
>  F:	Documentation/devicetree/bindings/power/supply/maxim,max77976.yaml
>  F:	drivers/power/supply/max77976_charger.c
>  
> +MAX86150 ECG AND PPG BIOSENSOR DRIVER
> +M:	Md Shofiqul Islam <shofiqtest@gmail.com>
> +L:	linux-iio@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/iio/health/adi,max86150.yaml
> +F:	drivers/iio/health/max86150.c
> +
>  MAXIM MUIC CHARGER DRIVERS FOR EXYNOS BASED BOARDS
>  M:	Krzysztof Kozlowski <krzk@kernel.org>
>  L:	linux-pm@vger.kernel.org

This should probably be squashed into either the dt-bindings patch or
the driver file patch (or both, with just the yaml being put on the
entry in the dt-bindings patch and adding the .c file to the entry in
the second patch).

-- 
best regards,
max


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