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511 lines
12 KiB
511 lines
12 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* max30100.c - Support for MAX30100 heart rate and pulse oximeter sensor |
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* |
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* Copyright (C) 2015, 2018 |
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* Author: Matt Ranostay <[email protected]> |
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* |
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* TODO: enable pulse length controls via device tree properties |
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*/ |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/interrupt.h> |
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#include <linux/delay.h> |
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#include <linux/err.h> |
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#include <linux/irq.h> |
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#include <linux/i2c.h> |
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#include <linux/mutex.h> |
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#include <linux/property.h> |
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#include <linux/regmap.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/buffer.h> |
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#include <linux/iio/kfifo_buf.h> |
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#define MAX30100_REGMAP_NAME "max30100_regmap" |
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#define MAX30100_DRV_NAME "max30100" |
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#define MAX30100_REG_INT_STATUS 0x00 |
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#define MAX30100_REG_INT_STATUS_PWR_RDY BIT(0) |
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#define MAX30100_REG_INT_STATUS_SPO2_RDY BIT(4) |
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#define MAX30100_REG_INT_STATUS_HR_RDY BIT(5) |
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#define MAX30100_REG_INT_STATUS_FIFO_RDY BIT(7) |
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#define MAX30100_REG_INT_ENABLE 0x01 |
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#define MAX30100_REG_INT_ENABLE_SPO2_EN BIT(0) |
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#define MAX30100_REG_INT_ENABLE_HR_EN BIT(1) |
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#define MAX30100_REG_INT_ENABLE_FIFO_EN BIT(3) |
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#define MAX30100_REG_INT_ENABLE_MASK 0xf0 |
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#define MAX30100_REG_INT_ENABLE_MASK_SHIFT 4 |
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#define MAX30100_REG_FIFO_WR_PTR 0x02 |
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#define MAX30100_REG_FIFO_OVR_CTR 0x03 |
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#define MAX30100_REG_FIFO_RD_PTR 0x04 |
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#define MAX30100_REG_FIFO_DATA 0x05 |
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#define MAX30100_REG_FIFO_DATA_ENTRY_COUNT 16 |
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#define MAX30100_REG_FIFO_DATA_ENTRY_LEN 4 |
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#define MAX30100_REG_MODE_CONFIG 0x06 |
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#define MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN BIT(0) |
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#define MAX30100_REG_MODE_CONFIG_MODE_HR_EN BIT(1) |
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#define MAX30100_REG_MODE_CONFIG_MODE_MASK 0x03 |
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#define MAX30100_REG_MODE_CONFIG_TEMP_EN BIT(3) |
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#define MAX30100_REG_MODE_CONFIG_PWR BIT(7) |
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#define MAX30100_REG_SPO2_CONFIG 0x07 |
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#define MAX30100_REG_SPO2_CONFIG_100HZ BIT(2) |
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#define MAX30100_REG_SPO2_CONFIG_HI_RES_EN BIT(6) |
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#define MAX30100_REG_SPO2_CONFIG_1600US 0x3 |
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#define MAX30100_REG_LED_CONFIG 0x09 |
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#define MAX30100_REG_LED_CONFIG_LED_MASK 0x0f |
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#define MAX30100_REG_LED_CONFIG_RED_LED_SHIFT 4 |
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#define MAX30100_REG_LED_CONFIG_24MA 0x07 |
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#define MAX30100_REG_LED_CONFIG_50MA 0x0f |
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#define MAX30100_REG_TEMP_INTEGER 0x16 |
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#define MAX30100_REG_TEMP_FRACTION 0x17 |
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struct max30100_data { |
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struct i2c_client *client; |
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struct iio_dev *indio_dev; |
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struct mutex lock; |
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struct regmap *regmap; |
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__be16 buffer[2]; /* 2 16-bit channels */ |
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}; |
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static bool max30100_is_volatile_reg(struct device *dev, unsigned int reg) |
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{ |
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switch (reg) { |
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case MAX30100_REG_INT_STATUS: |
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case MAX30100_REG_MODE_CONFIG: |
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case MAX30100_REG_FIFO_WR_PTR: |
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case MAX30100_REG_FIFO_OVR_CTR: |
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case MAX30100_REG_FIFO_RD_PTR: |
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case MAX30100_REG_FIFO_DATA: |
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case MAX30100_REG_TEMP_INTEGER: |
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case MAX30100_REG_TEMP_FRACTION: |
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return true; |
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default: |
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return false; |
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} |
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} |
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static const struct regmap_config max30100_regmap_config = { |
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.name = MAX30100_REGMAP_NAME, |
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.reg_bits = 8, |
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.val_bits = 8, |
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.max_register = MAX30100_REG_TEMP_FRACTION, |
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.cache_type = REGCACHE_FLAT, |
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.volatile_reg = max30100_is_volatile_reg, |
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}; |
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static const unsigned int max30100_led_current_mapping[] = { |
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4400, 7600, 11000, 14200, 17400, |
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20800, 24000, 27100, 30600, 33800, |
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37000, 40200, 43600, 46800, 50000 |
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}; |
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static const unsigned long max30100_scan_masks[] = {0x3, 0}; |
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static const struct iio_chan_spec max30100_channels[] = { |
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{ |
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.type = IIO_INTENSITY, |
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.channel2 = IIO_MOD_LIGHT_IR, |
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.modified = 1, |
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.scan_index = 0, |
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.scan_type = { |
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.sign = 'u', |
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.realbits = 16, |
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.storagebits = 16, |
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.endianness = IIO_BE, |
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}, |
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}, |
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{ |
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.type = IIO_INTENSITY, |
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.channel2 = IIO_MOD_LIGHT_RED, |
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.modified = 1, |
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.scan_index = 1, |
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.scan_type = { |
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.sign = 'u', |
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.realbits = 16, |
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.storagebits = 16, |
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.endianness = IIO_BE, |
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}, |
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}, |
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{ |
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.type = IIO_TEMP, |
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.info_mask_separate = |
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BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), |
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.scan_index = -1, |
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}, |
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}; |
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static int max30100_set_powermode(struct max30100_data *data, bool state) |
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{ |
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return regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, |
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MAX30100_REG_MODE_CONFIG_PWR, |
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state ? 0 : MAX30100_REG_MODE_CONFIG_PWR); |
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} |
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static int max30100_clear_fifo(struct max30100_data *data) |
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{ |
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int ret; |
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ret = regmap_write(data->regmap, MAX30100_REG_FIFO_WR_PTR, 0); |
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if (ret) |
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return ret; |
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ret = regmap_write(data->regmap, MAX30100_REG_FIFO_OVR_CTR, 0); |
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if (ret) |
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return ret; |
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return regmap_write(data->regmap, MAX30100_REG_FIFO_RD_PTR, 0); |
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} |
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static int max30100_buffer_postenable(struct iio_dev *indio_dev) |
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{ |
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struct max30100_data *data = iio_priv(indio_dev); |
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int ret; |
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ret = max30100_set_powermode(data, true); |
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if (ret) |
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return ret; |
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return max30100_clear_fifo(data); |
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} |
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static int max30100_buffer_predisable(struct iio_dev *indio_dev) |
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{ |
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struct max30100_data *data = iio_priv(indio_dev); |
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return max30100_set_powermode(data, false); |
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} |
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static const struct iio_buffer_setup_ops max30100_buffer_setup_ops = { |
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.postenable = max30100_buffer_postenable, |
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.predisable = max30100_buffer_predisable, |
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}; |
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static inline int max30100_fifo_count(struct max30100_data *data) |
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{ |
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unsigned int val; |
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int ret; |
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ret = regmap_read(data->regmap, MAX30100_REG_INT_STATUS, &val); |
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if (ret) |
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return ret; |
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/* FIFO is almost full */ |
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if (val & MAX30100_REG_INT_STATUS_FIFO_RDY) |
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return MAX30100_REG_FIFO_DATA_ENTRY_COUNT - 1; |
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return 0; |
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} |
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static int max30100_read_measurement(struct max30100_data *data) |
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{ |
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int ret; |
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ret = i2c_smbus_read_i2c_block_data(data->client, |
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MAX30100_REG_FIFO_DATA, |
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MAX30100_REG_FIFO_DATA_ENTRY_LEN, |
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(u8 *) &data->buffer); |
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return (ret == MAX30100_REG_FIFO_DATA_ENTRY_LEN) ? 0 : ret; |
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} |
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static irqreturn_t max30100_interrupt_handler(int irq, void *private) |
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{ |
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struct iio_dev *indio_dev = private; |
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struct max30100_data *data = iio_priv(indio_dev); |
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int ret, cnt = 0; |
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mutex_lock(&data->lock); |
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while (cnt || (cnt = max30100_fifo_count(data)) > 0) { |
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ret = max30100_read_measurement(data); |
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if (ret) |
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break; |
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iio_push_to_buffers(data->indio_dev, data->buffer); |
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cnt--; |
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} |
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mutex_unlock(&data->lock); |
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return IRQ_HANDLED; |
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} |
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static int max30100_get_current_idx(unsigned int val, int *reg) |
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{ |
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int idx; |
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/* LED turned off */ |
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if (val == 0) { |
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*reg = 0; |
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return 0; |
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} |
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for (idx = 0; idx < ARRAY_SIZE(max30100_led_current_mapping); idx++) { |
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if (max30100_led_current_mapping[idx] == val) { |
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*reg = idx + 1; |
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return 0; |
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} |
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} |
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return -EINVAL; |
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} |
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static int max30100_led_init(struct max30100_data *data) |
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{ |
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struct device *dev = &data->client->dev; |
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unsigned int val[2]; |
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int reg, ret; |
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ret = device_property_read_u32_array(dev, "maxim,led-current-microamp", |
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(unsigned int *) &val, 2); |
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if (ret) { |
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/* Default to 24 mA RED LED, 50 mA IR LED */ |
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reg = (MAX30100_REG_LED_CONFIG_24MA << |
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MAX30100_REG_LED_CONFIG_RED_LED_SHIFT) | |
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MAX30100_REG_LED_CONFIG_50MA; |
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dev_warn(dev, "no led-current-microamp set"); |
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return regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, reg); |
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} |
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/* RED LED current */ |
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ret = max30100_get_current_idx(val[0], ®); |
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if (ret) { |
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dev_err(dev, "invalid RED current setting %d", val[0]); |
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return ret; |
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} |
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ret = regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG, |
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MAX30100_REG_LED_CONFIG_LED_MASK << |
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MAX30100_REG_LED_CONFIG_RED_LED_SHIFT, |
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reg << MAX30100_REG_LED_CONFIG_RED_LED_SHIFT); |
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if (ret) |
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return ret; |
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/* IR LED current */ |
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ret = max30100_get_current_idx(val[1], ®); |
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if (ret) { |
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dev_err(dev, "invalid IR current setting %d", val[1]); |
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return ret; |
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} |
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return regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG, |
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MAX30100_REG_LED_CONFIG_LED_MASK, reg); |
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} |
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static int max30100_chip_init(struct max30100_data *data) |
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{ |
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int ret; |
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/* setup LED current settings */ |
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ret = max30100_led_init(data); |
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if (ret) |
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return ret; |
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/* enable hi-res SPO2 readings at 100Hz */ |
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ret = regmap_write(data->regmap, MAX30100_REG_SPO2_CONFIG, |
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MAX30100_REG_SPO2_CONFIG_HI_RES_EN | |
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MAX30100_REG_SPO2_CONFIG_100HZ); |
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if (ret) |
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return ret; |
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/* enable SPO2 mode */ |
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ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, |
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MAX30100_REG_MODE_CONFIG_MODE_MASK, |
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MAX30100_REG_MODE_CONFIG_MODE_HR_EN | |
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MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN); |
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if (ret) |
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return ret; |
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/* enable FIFO interrupt */ |
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return regmap_update_bits(data->regmap, MAX30100_REG_INT_ENABLE, |
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MAX30100_REG_INT_ENABLE_MASK, |
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MAX30100_REG_INT_ENABLE_FIFO_EN |
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<< MAX30100_REG_INT_ENABLE_MASK_SHIFT); |
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} |
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static int max30100_read_temp(struct max30100_data *data, int *val) |
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{ |
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int ret; |
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unsigned int reg; |
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ret = regmap_read(data->regmap, MAX30100_REG_TEMP_INTEGER, ®); |
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if (ret < 0) |
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return ret; |
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*val = reg << 4; |
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ret = regmap_read(data->regmap, MAX30100_REG_TEMP_FRACTION, ®); |
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if (ret < 0) |
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return ret; |
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*val |= reg & 0xf; |
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*val = sign_extend32(*val, 11); |
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return 0; |
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} |
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static int max30100_get_temp(struct max30100_data *data, int *val) |
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{ |
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int ret; |
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/* start acquisition */ |
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ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, |
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MAX30100_REG_MODE_CONFIG_TEMP_EN, |
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MAX30100_REG_MODE_CONFIG_TEMP_EN); |
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if (ret) |
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return ret; |
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msleep(35); |
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return max30100_read_temp(data, val); |
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} |
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static int max30100_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, int *val2, long mask) |
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{ |
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struct max30100_data *data = iio_priv(indio_dev); |
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int ret = -EINVAL; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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/* |
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* Temperature reading can only be acquired while engine |
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* is running |
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*/ |
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mutex_lock(&indio_dev->mlock); |
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if (!iio_buffer_enabled(indio_dev)) |
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ret = -EAGAIN; |
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else { |
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ret = max30100_get_temp(data, val); |
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if (!ret) |
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ret = IIO_VAL_INT; |
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} |
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mutex_unlock(&indio_dev->mlock); |
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break; |
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case IIO_CHAN_INFO_SCALE: |
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*val = 1; /* 0.0625 */ |
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*val2 = 16; |
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ret = IIO_VAL_FRACTIONAL; |
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break; |
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} |
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return ret; |
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} |
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static const struct iio_info max30100_info = { |
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.read_raw = max30100_read_raw, |
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}; |
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static int max30100_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct max30100_data *data; |
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struct iio_dev *indio_dev; |
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int ret; |
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
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if (!indio_dev) |
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return -ENOMEM; |
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indio_dev->name = MAX30100_DRV_NAME; |
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indio_dev->channels = max30100_channels; |
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indio_dev->info = &max30100_info; |
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indio_dev->num_channels = ARRAY_SIZE(max30100_channels); |
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indio_dev->available_scan_masks = max30100_scan_masks; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev, |
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INDIO_BUFFER_SOFTWARE, |
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&max30100_buffer_setup_ops); |
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if (ret) |
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return ret; |
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data = iio_priv(indio_dev); |
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data->indio_dev = indio_dev; |
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data->client = client; |
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mutex_init(&data->lock); |
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i2c_set_clientdata(client, indio_dev); |
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data->regmap = devm_regmap_init_i2c(client, &max30100_regmap_config); |
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if (IS_ERR(data->regmap)) { |
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dev_err(&client->dev, "regmap initialization failed.\n"); |
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return PTR_ERR(data->regmap); |
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} |
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max30100_set_powermode(data, false); |
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ret = max30100_chip_init(data); |
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if (ret) |
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return ret; |
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if (client->irq <= 0) { |
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dev_err(&client->dev, "no valid irq defined\n"); |
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return -EINVAL; |
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} |
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ret = devm_request_threaded_irq(&client->dev, client->irq, |
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NULL, max30100_interrupt_handler, |
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IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
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"max30100_irq", indio_dev); |
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if (ret) { |
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dev_err(&client->dev, "request irq (%d) failed\n", client->irq); |
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return ret; |
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} |
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return iio_device_register(indio_dev); |
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} |
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static int max30100_remove(struct i2c_client *client) |
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{ |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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struct max30100_data *data = iio_priv(indio_dev); |
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iio_device_unregister(indio_dev); |
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max30100_set_powermode(data, false); |
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return 0; |
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} |
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static const struct i2c_device_id max30100_id[] = { |
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{ "max30100", 0 }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(i2c, max30100_id); |
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static const struct of_device_id max30100_dt_ids[] = { |
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{ .compatible = "maxim,max30100" }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, max30100_dt_ids); |
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static struct i2c_driver max30100_driver = { |
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.driver = { |
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.name = MAX30100_DRV_NAME, |
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.of_match_table = max30100_dt_ids, |
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}, |
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.probe = max30100_probe, |
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.remove = max30100_remove, |
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.id_table = max30100_id, |
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}; |
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module_i2c_driver(max30100_driver); |
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MODULE_AUTHOR("Matt Ranostay <[email protected]>"); |
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MODULE_DESCRIPTION("MAX30100 heart rate and pulse oximeter sensor"); |
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MODULE_LICENSE("GPL");
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