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[87.92.251.137]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5ad6957a6a2sm908946e87.46.2026.06.23.08.56.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jun 2026 08:56:01 -0700 (PDT) From: Md Shofiqul Islam To: linux-iio@vger.kernel.org Cc: jic23@kernel.org, dlechner@baylibre.com, nuno.sa@analog.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, devicetree@vger.kernel.org, joshua.crofts1@gmail.com, Md Shofiqul Islam Subject: [PATCH v2 2/3] iio: health: add MAX86150 ECG and PPG biosensor driver Date: Tue, 23 Jun 2026 18:55:55 +0300 Message-ID: <20260623155556.13701-3-shofiqtest@gmail.com> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20260623155556.13701-1-shofiqtest@gmail.com> References: <20260623140113.12574-1-shofiqtest@gmail.com> <20260623155556.13701-1-shofiqtest@gmail.com> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The MAX86150 (Maxim/Analog Devices) integrates two PPG optical channels (Red/IR LED) and one ECG biopotential channel in a single I2C device. Data is captured via a 32-entry hardware FIFO with a configurable almost-full interrupt. The driver exposes three IIO channels: - in_intensity_red_raw (PPG Red, 19-bit unsigned) - in_intensity_ir_raw (PPG IR, 19-bit unsigned) - in_voltage0_raw (ECG, 18-bit signed) A hardware trigger is registered when an interrupt GPIO is provided in the device tree, enabling the IIO triggered buffer path for continuous low-overhead capture. The trigger enable/disable is driven by the set_trigger_state callback to prevent the interrupt line from asserting before the handler is ready. FIFO reads use regmap_noinc_read() to burst-read 9 bytes (3 slots x 3 bytes) from the streaming FIFO_DATA register in a single I2C transaction. Signed-off-by: Md Shofiqul Islam --- drivers/iio/health/Kconfig | 23 ++ drivers/iio/health/Makefile | 1 + drivers/iio/health/max86150.c | 612 ++++++++++++++++++++++++++++++++++ 3 files changed, 636 insertions(+) create mode 100755 drivers/iio/health/max86150.c diff --git a/drivers/iio/health/Kconfig b/drivers/iio/health/Kconfig index a89f3abf11f4..6496cf55290c 100644 --- a/drivers/iio/health/Kconfig +++ b/drivers/iio/health/Kconfig @@ -13,6 +13,7 @@ config AFE4403 depends on SPI_MASTER select REGMAP_SPI select IIO_BUFFER + select IIO_TRIGGER select IIO_TRIGGERED_BUFFER help Say yes to choose the Texas Instruments AFE4403 @@ -26,6 +27,7 @@ config AFE4404 depends on I2C select REGMAP_I2C select IIO_BUFFER + select IIO_TRIGGER select IIO_TRIGGERED_BUFFER help Say yes to choose the Texas Instruments AFE4404 @@ -39,6 +41,7 @@ config MAX30100 depends on I2C select REGMAP_I2C select IIO_BUFFER + select IIO_TRIGGER select IIO_KFIFO_BUF help Say Y here to build I2C interface support for the Maxim @@ -52,6 +55,7 @@ config MAX30102 depends on I2C select REGMAP_I2C select IIO_BUFFER + select IIO_TRIGGER select IIO_KFIFO_BUF help Say Y here to build I2C interface support for the Maxim @@ -62,4 +66,23 @@ config MAX30102 endmenu + +config MAX86150 + tristate "MAX86150 ECG and PPG biosensor" + depends on I2C + select IIO_BUFFER + select IIO_TRIGGER + select IIO_TRIGGERED_BUFFER + 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 910817112258..04fc73c58444 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 100755 index 000000000000..70c51ccb4672 --- /dev/null +++ b/drivers/iio/health/max86150.c @@ -0,0 +1,612 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MAX86150 combined ECG and PPG biosensor driver + * + * Copyright (C) 2026 Md Shofiqul Islam + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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 /* FD1[3:0] FD2[7:4] */ +#define MAX86150_REG_FIFO_DCTRL2 0x0A /* FD3[3:0] FD4[7:4] */ +#define MAX86150_REG_SYS_CTRL 0x0D +#define MAX86150_REG_PPG_CONFIG1 0x10 +#define MAX86150_REG_PPG_CONFIG2 0x11 +#define MAX86150_REG_LED1_PA 0x14 /* Red LED pulse amplitude */ +#define MAX86150_REG_LED2_PA 0x15 /* IR LED pulse amplitude */ +#define MAX86150_REG_ECG_CONFIG1 0x3C +#define MAX86150_REG_ECG_CONFIG3 0x3E +#define MAX86150_REG_PART_ID 0xFF + +/* Field masks */ +#define MAX86150_PART_ID_VAL 0x1E + +/* INT_STATUS1 / INT_ENABLE1 */ +#define MAX86150_INT_A_FULL BIT(7) /* FIFO almost full */ +#define MAX86150_INT_PPG_RDY BIT(6) /* new PPG sample ready */ + +/* SYS_CTRL */ +#define MAX86150_SYS_SHDN BIT(1) +#define MAX86150_SYS_RESET BIT(0) + +/* FIFO_CONFIG */ +#define MAX86150_FIFO_SMP_AVE GENMASK(7, 5) +#define MAX86150_FIFO_ROLLOVER_EN BIT(4) +#define MAX86150_FIFO_A_FULL GENMASK(3, 0) + +/* FIFO slot data-type codes */ +#define MAX86150_FD_NONE 0x0 +#define MAX86150_FD_LED1 0x1 /* Red PPG */ +#define MAX86150_FD_LED2 0x2 /* IR PPG */ +#define MAX86150_FD_ECG 0x9 +#define MAX86150_FIFO_FD1 GENMASK(3, 0) +#define MAX86150_FIFO_FD2 GENMASK(7, 4) +#define MAX86150_FIFO_FD3 GENMASK(3, 0) +#define MAX86150_FIFO_FD4 GENMASK(7, 4) + +/* PPG_CONFIG1 */ +#define MAX86150_PPG_ADC_RGE GENMASK(7, 6) +#define MAX86150_PPG_SR GENMASK(5, 1) + +/* Geometry */ +#define MAX86150_FIFO_DEPTH 32 +#define MAX86150_BYTES_PER_SLOT 3 /* 24-bit word per slot */ +#define MAX86150_NUM_SLOTS 3 /* Red, IR, ECG */ +#define MAX86150_SAMPLE_BYTES (MAX86150_NUM_SLOTS * MAX86150_BYTES_PER_SLOT) + +/* Default hardware configuration */ +#define MAX86150_LED_PA_DEFAULT 0x3F /* ~50 mA */ +#define MAX86150_PPG_SR_100HZ 4 /* PPG_SR field value for 100 Hz */ +#define MAX86150_PPG_ADC_RGE_16384 2 /* 16384 nA full scale */ +/* Fire A_FULL when 17 slots remain (32 - 15 = 17 samples in FIFO) */ +#define MAX86150_FIFO_A_FULL_VAL 15 + +/* Scan element indices */ +enum max86150_scan_idx { + MAX86150_IDX_PPG_RED = 0, + MAX86150_IDX_PPG_IR = 1, + MAX86150_IDX_ECG = 2, + MAX86150_IDX_TS, +}; + +/** + * struct max86150_data - driver private state + * @regmap: register map for this device + * @dev: parent device (for dev_err logging) + * @trig: IIO hardware trigger backed by the device interrupt line + * @buf: DMA-safe capture buffer sized for worst-case (all 3 channels + * active): 3 x s32 (12 bytes) + 4-byte pad + s64 timestamp = 24 + * bytes. __aligned(8) satisfies iio_push_to_buffers_with_timestamp(). + */ +struct max86150_data { + struct regmap *regmap; + struct device *dev; + struct iio_trigger *trig; + s32 buf[6] __aligned(8); +}; + +/* IIO channel specification */ + +static const struct iio_chan_spec max86150_channels[] = { + { + /* PPG Red LED - optical intensity, 19-bit unsigned */ + .type = IIO_INTENSITY, + .modified = 1, + .channel2 = IIO_MOD_LIGHT_RED, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = MAX86150_IDX_PPG_RED, + .scan_type = { + .sign = 'u', + .realbits = 19, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, + { + /* PPG IR LED - optical intensity, 19-bit unsigned */ + .type = IIO_INTENSITY, + .modified = 1, + .channel2 = IIO_MOD_LIGHT_IR, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = MAX86150_IDX_PPG_IR, + .scan_type = { + .sign = 'u', + .realbits = 19, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, + { + /* ECG biopotential - voltage, 18-bit signed two's complement */ + .type = IIO_VOLTAGE, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = MAX86150_IDX_ECG, + .scan_type = { + .sign = 's', + .realbits = 18, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(MAX86150_IDX_TS), +}; + +/* Regmap configuration */ + +static const struct regmap_config max86150_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = MAX86150_REG_PART_ID, +}; + +/* FIFO helper */ + +/** + * max86150_read_one_sample - burst-read one complete 3-slot FIFO entry + * @data: driver state + * @ppg_red: out - 19-bit PPG Red ADC value (unsigned) + * @ppg_ir: out - 19-bit PPG IR ADC value (unsigned) + * @ecg: out - 18-bit ECG ADC value (sign-extended to s32) + * + * Each FIFO entry is 9 bytes (3 slots x 3 bytes). FIFO_DATA is a + * streaming register - the address does not auto-increment on each + * byte, so regmap_noinc_read() is used instead of regmap_bulk_read(). + * + * Byte layout in the 24-bit FIFO word (MSB first): + * PPG 19-bit unsigned: bits [18:0], top 5 bits are always zero + * ECG 18-bit signed: bits [17:0], top 6 bits are sign extension + */ +static int max86150_read_one_sample(struct max86150_data *data, + u32 *ppg_red, u32 *ppg_ir, s32 *ecg) +{ + u8 buf[MAX86150_SAMPLE_BYTES]; /* 9 bytes */ + int ret; + + ret = regmap_noinc_read(data->regmap, MAX86150_REG_FIFO_DATA, + buf, sizeof(buf)); + if (ret) + return ret; + + /* Bytes [0..2]: PPG Red - 19-bit value in bits [18:0] */ + *ppg_red = (u32)(buf[0] & 0x07) << 16 | (u32)buf[1] << 8 | buf[2]; + + /* Bytes [3..5]: PPG IR - same format */ + *ppg_ir = (u32)(buf[3] & 0x07) << 16 | (u32)buf[4] << 8 | buf[5]; + + /* Bytes [6..8]: ECG - 18-bit signed, sign-extend to s32 */ + *ecg = sign_extend32((u32)(buf[6] & 0x03) << 16 | + (u32)buf[7] << 8 | buf[8], 17); + + return 0; +} + +/* IIO read_raw */ + +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); + u32 ppg_red, ppg_ir; + s32 ecg; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + /* + * Claim direct mode to prevent concurrent sysfs reads from + * corrupting the FIFO pointers while a triggered buffer + * capture is active. + */ + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + /* + * Single-shot path: reset FIFO pointers so the next sample + * read is one that arrived after this call. + */ + ret = regmap_write(data->regmap, MAX86150_REG_FIFO_WR_PTR, 0); + if (!ret) + ret = regmap_write(data->regmap, + MAX86150_REG_OVF_COUNTER, 0); + if (!ret) + ret = regmap_write(data->regmap, + MAX86150_REG_FIFO_RD_PTR, 0); + if (ret) { + iio_device_release_direct(indio_dev); + return ret; + } + + /* Wait for one complete sample period at 100 Hz (<= 10 ms) */ + usleep_range(11000, 13000); + + ret = max86150_read_one_sample(data, &ppg_red, &ppg_ir, &ecg); + 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; + + case IIO_CHAN_INFO_SCALE: + /* + * TODO: return the hardware scale factor based on the + * configured PPG ADC range (PPG_ADC_RGE) and ECG PGA gain + * (ECG_PGA_GAIN). For PPG, scale is nA/LSB; for ECG, uV/LSB. + */ + return -EINVAL; + + default: + return -EINVAL; + } +} + +static const struct iio_info max86150_iio_info = { + .read_raw = max86150_read_raw, +}; + +/* Trigger */ + +/* + * Enable or disable the FIFO almost-full interrupt when the IIO triggered + * buffer is started or stopped. Keeping the interrupt masked until capture + * is active prevents a pre-existing FIFO fill from asserting the line before + * the handler is ready to clear it. + */ +static int max86150_set_trigger_state(struct iio_trigger *trig, bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct max86150_data *data = iio_priv(indio_dev); + unsigned int mask = state ? MAX86150_INT_A_FULL : 0; + + return regmap_write(data->regmap, MAX86150_REG_INT_ENABLE1, mask); +} + +static const struct iio_trigger_ops max86150_trigger_ops = { + .set_trigger_state = max86150_set_trigger_state, +}; + +/* Triggered buffer */ + +/** + * max86150_trigger_handler - threaded IRQ handler for FIFO almost-full + * + * Called by the IIO buffer infrastructure when the hardware trigger fires. + * Reads INT_STATUS1 to de-assert the interrupt, then drains all available + * FIFO samples into the IIO push buffer, packing only the channels that + * are currently enabled in active_scan_mask. + */ +static irqreturn_t max86150_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *idev = pf->indio_dev; + struct max86150_data *data = iio_priv(idev); + unsigned int status, wr_ptr, rd_ptr, ovf, available; + u32 ppg_red, ppg_ir; + s32 ecg; + int ret, j; + + /* + * Reading INT_STATUS1 clears the interrupt. Do this before touching + * the FIFO so the pin is de-asserted while we drain samples. + */ + ret = regmap_read(data->regmap, MAX86150_REG_INT_STATUS1, &status); + if (ret) + goto done; + + ret = regmap_read(data->regmap, MAX86150_REG_FIFO_WR_PTR, &wr_ptr); + if (ret) + goto done; + ret = regmap_read(data->regmap, MAX86150_REG_FIFO_RD_PTR, &rd_ptr); + if (ret) + goto done; + + /* + * Read OVF_COUNTER to distinguish a full FIFO from an empty one: + * both produce wr_ptr == rd_ptr after the pointers wrap around. + * If OVF_COUNTER is non-zero the FIFO has saturated; treat all 32 + * slots as available so we drain the entire FIFO and clear the + * interrupt condition. + */ + ret = regmap_read(data->regmap, MAX86150_REG_OVF_COUNTER, &ovf); + if (ret) + goto done; + + if (ovf > 0) + available = MAX86150_FIFO_DEPTH; + else + available = (wr_ptr - rd_ptr) & (MAX86150_FIFO_DEPTH - 1); + + while (available--) { + ret = max86150_read_one_sample(data, &ppg_red, &ppg_ir, &ecg); + if (ret) + break; + + /* + * Pack only active channels at consecutive positions [0..j-1]. + * iio_push_to_buffers_with_timestamp() uses scan_bytes (which + * accounts for the active channel count) to place the timestamp, + * so static indexing would misplace it when fewer than 3 + * channels are enabled. + */ + j = 0; + if (test_bit(MAX86150_IDX_PPG_RED, idev->active_scan_mask)) + data->buf[j++] = ppg_red; + if (test_bit(MAX86150_IDX_PPG_IR, idev->active_scan_mask)) + data->buf[j++] = ppg_ir; + if (test_bit(MAX86150_IDX_ECG, idev->active_scan_mask)) + data->buf[j++] = ecg; + + iio_push_to_buffers_with_timestamp(idev, data->buf, + iio_get_time_ns(idev)); + } + +done: + iio_trigger_notify_done(idev->trig); + return IRQ_HANDLED; +} + +/* Chip initialisation / teardown */ + +static void max86150_powerdown(void *arg) +{ + struct max86150_data *data = arg; + + regmap_write(data->regmap, MAX86150_REG_INT_ENABLE1, 0); + regmap_write(data->regmap, MAX86150_REG_SYS_CTRL, MAX86150_SYS_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_RESET); + if (ret) + return ret; + usleep_range(1000, 2000); + + /* + * FIFO: no sample averaging, rollover enabled, assert A_FULL when + * 17 samples are in the FIFO (32 - 15 = 17 available to read). + */ + ret = regmap_write(data->regmap, MAX86150_REG_FIFO_CONFIG, + MAX86150_FIFO_ROLLOVER_EN | + FIELD_PREP(MAX86150_FIFO_A_FULL, + 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_FD1, MAX86150_FD_LED1) | + FIELD_PREP(MAX86150_FIFO_FD2, 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_FD3, MAX86150_FD_ECG) | + FIELD_PREP(MAX86150_FIFO_FD4, 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_ADC_RGE, + MAX86150_PPG_ADC_RGE_16384) | + FIELD_PREP(MAX86150_PPG_SR, + MAX86150_PPG_SR_100HZ)); + if (ret) + return ret; + + /* LED pulse amplitudes (~50 mA) */ + ret = regmap_write(data->regmap, MAX86150_REG_LED1_PA, + MAX86150_LED_PA_DEFAULT); + if (ret) + return ret; + + return regmap_write(data->regmap, MAX86150_REG_LED2_PA, + MAX86150_LED_PA_DEFAULT); + /* + * Do NOT enable the A_FULL interrupt here. It is enabled and + * disabled via max86150_set_trigger_state() when the IIO triggered + * buffer is started and stopped, which prevents the edge-triggered + * interrupt line from asserting before the handler is registered. + */ +} + +static void max86150_trigger_put(void *trig) +{ + iio_trigger_put(trig); +} + +/* Probe */ + +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); + data->dev = &client->dev; + + /* + * Enable power supplies before any I2C access. Both are optional + * in the device tree (devm_regulator_get_enable returns 0 when the + * supply is not described), but must be present and stable on real + * hardware before the first register read. + */ + 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, "leds"); + if (ret) + return dev_err_probe(&client->dev, ret, + "Failed to get/enable leds 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) + return dev_err_probe(&client->dev, -ENODEV, + "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 the device tree provides an interrupt, set up a hardware + * trigger so userspace can use the FIFO almost-full signal to + * drive capture without polling. + */ + if (client->irq > 0) { + data->trig = devm_iio_trigger_alloc(&client->dev, + "%s-dev%d", + indio_dev->name, + iio_device_id(indio_dev)); + if (!data->trig) + return -ENOMEM; + + data->trig->ops = &max86150_trigger_ops; + iio_trigger_set_drvdata(data->trig, indio_dev); + + /* + * iio_trigger_generic_data_rdy_poll is a hard-IRQ handler + * that calls iio_trigger_poll() and returns IRQ_HANDLED. + * No IRQF_ONESHOT is needed for this edge-triggered line. + */ + ret = devm_request_irq(&client->dev, client->irq, + iio_trigger_generic_data_rdy_poll, + IRQF_TRIGGER_FALLING, + "max86150", data->trig); + if (ret) + return dev_err_probe(&client->dev, ret, + "Cannot request IRQ %d\n", + client->irq); + + ret = devm_iio_trigger_register(&client->dev, data->trig); + if (ret) + return dev_err_probe(&client->dev, ret, + "Cannot register trigger\n"); + + indio_dev->trig = iio_trigger_get(data->trig); + ret = devm_add_action_or_reset(&client->dev, + max86150_trigger_put, + data->trig); + if (ret) + return ret; + } + + ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, + iio_pollfunc_store_time, + max86150_trigger_handler, + NULL); + if (ret) + return dev_err_probe(&client->dev, ret, + "Cannot setup triggered buffer\n"); + + return devm_iio_device_register(&client->dev, indio_dev); +} + +/* I2C driver table */ + +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 = "maxim,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 "); +MODULE_DESCRIPTION("MAX86150 ECG and PPG biosensor driver"); +MODULE_LICENSE("GPL"); -- 2.51.1