| /* |
| * max30100.c - Support for MAX30100 heart rate and pulse oximeter sensor |
| * |
| * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * TODO: enable pulse length controls via device tree properties |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/irq.h> |
| #include <linux/i2c.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/regmap.h> |
| #include <linux/iio/iio.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/kfifo_buf.h> |
| |
| #define MAX30100_REGMAP_NAME "max30100_regmap" |
| #define MAX30100_DRV_NAME "max30100" |
| |
| #define MAX30100_REG_INT_STATUS 0x00 |
| #define MAX30100_REG_INT_STATUS_PWR_RDY BIT(0) |
| #define MAX30100_REG_INT_STATUS_SPO2_RDY BIT(4) |
| #define MAX30100_REG_INT_STATUS_HR_RDY BIT(5) |
| #define MAX30100_REG_INT_STATUS_FIFO_RDY BIT(7) |
| |
| #define MAX30100_REG_INT_ENABLE 0x01 |
| #define MAX30100_REG_INT_ENABLE_SPO2_EN BIT(0) |
| #define MAX30100_REG_INT_ENABLE_HR_EN BIT(1) |
| #define MAX30100_REG_INT_ENABLE_FIFO_EN BIT(3) |
| #define MAX30100_REG_INT_ENABLE_MASK 0xf0 |
| #define MAX30100_REG_INT_ENABLE_MASK_SHIFT 4 |
| |
| #define MAX30100_REG_FIFO_WR_PTR 0x02 |
| #define MAX30100_REG_FIFO_OVR_CTR 0x03 |
| #define MAX30100_REG_FIFO_RD_PTR 0x04 |
| #define MAX30100_REG_FIFO_DATA 0x05 |
| #define MAX30100_REG_FIFO_DATA_ENTRY_COUNT 16 |
| #define MAX30100_REG_FIFO_DATA_ENTRY_LEN 4 |
| |
| #define MAX30100_REG_MODE_CONFIG 0x06 |
| #define MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN BIT(0) |
| #define MAX30100_REG_MODE_CONFIG_MODE_HR_EN BIT(1) |
| #define MAX30100_REG_MODE_CONFIG_MODE_MASK 0x03 |
| #define MAX30100_REG_MODE_CONFIG_TEMP_EN BIT(3) |
| #define MAX30100_REG_MODE_CONFIG_PWR BIT(7) |
| |
| #define MAX30100_REG_SPO2_CONFIG 0x07 |
| #define MAX30100_REG_SPO2_CONFIG_100HZ BIT(2) |
| #define MAX30100_REG_SPO2_CONFIG_HI_RES_EN BIT(6) |
| #define MAX30100_REG_SPO2_CONFIG_1600US 0x3 |
| |
| #define MAX30100_REG_LED_CONFIG 0x09 |
| #define MAX30100_REG_LED_CONFIG_LED_MASK 0x0f |
| #define MAX30100_REG_LED_CONFIG_RED_LED_SHIFT 4 |
| |
| #define MAX30100_REG_LED_CONFIG_24MA 0x07 |
| #define MAX30100_REG_LED_CONFIG_50MA 0x0f |
| |
| #define MAX30100_REG_TEMP_INTEGER 0x16 |
| #define MAX30100_REG_TEMP_FRACTION 0x17 |
| |
| struct max30100_data { |
| struct i2c_client *client; |
| struct iio_dev *indio_dev; |
| struct mutex lock; |
| struct regmap *regmap; |
| |
| __be16 buffer[2]; /* 2 16-bit channels */ |
| }; |
| |
| static bool max30100_is_volatile_reg(struct device *dev, unsigned int reg) |
| { |
| switch (reg) { |
| case MAX30100_REG_INT_STATUS: |
| case MAX30100_REG_MODE_CONFIG: |
| case MAX30100_REG_FIFO_WR_PTR: |
| case MAX30100_REG_FIFO_OVR_CTR: |
| case MAX30100_REG_FIFO_RD_PTR: |
| case MAX30100_REG_FIFO_DATA: |
| case MAX30100_REG_TEMP_INTEGER: |
| case MAX30100_REG_TEMP_FRACTION: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| static const struct regmap_config max30100_regmap_config = { |
| .name = MAX30100_REGMAP_NAME, |
| |
| .reg_bits = 8, |
| .val_bits = 8, |
| |
| .max_register = MAX30100_REG_TEMP_FRACTION, |
| .cache_type = REGCACHE_FLAT, |
| |
| .volatile_reg = max30100_is_volatile_reg, |
| }; |
| |
| static const unsigned int max30100_led_current_mapping[] = { |
| 4400, 7600, 11000, 14200, 17400, |
| 20800, 24000, 27100, 30600, 33800, |
| 37000, 40200, 43600, 46800, 50000 |
| }; |
| |
| static const unsigned long max30100_scan_masks[] = {0x3, 0}; |
| |
| static const struct iio_chan_spec max30100_channels[] = { |
| { |
| .type = IIO_INTENSITY, |
| .channel2 = IIO_MOD_LIGHT_IR, |
| .modified = 1, |
| |
| .scan_index = 0, |
| .scan_type = { |
| .sign = 'u', |
| .realbits = 16, |
| .storagebits = 16, |
| .endianness = IIO_BE, |
| }, |
| }, |
| { |
| .type = IIO_INTENSITY, |
| .channel2 = IIO_MOD_LIGHT_RED, |
| .modified = 1, |
| |
| .scan_index = 1, |
| .scan_type = { |
| .sign = 'u', |
| .realbits = 16, |
| .storagebits = 16, |
| .endianness = IIO_BE, |
| }, |
| }, |
| { |
| .type = IIO_TEMP, |
| .info_mask_separate = |
| BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), |
| .scan_index = -1, |
| }, |
| }; |
| |
| static int max30100_set_powermode(struct max30100_data *data, bool state) |
| { |
| return regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, |
| MAX30100_REG_MODE_CONFIG_PWR, |
| state ? 0 : MAX30100_REG_MODE_CONFIG_PWR); |
| } |
| |
| static int max30100_clear_fifo(struct max30100_data *data) |
| { |
| int ret; |
| |
| ret = regmap_write(data->regmap, MAX30100_REG_FIFO_WR_PTR, 0); |
| if (ret) |
| return ret; |
| |
| ret = regmap_write(data->regmap, MAX30100_REG_FIFO_OVR_CTR, 0); |
| if (ret) |
| return ret; |
| |
| return regmap_write(data->regmap, MAX30100_REG_FIFO_RD_PTR, 0); |
| } |
| |
| static int max30100_buffer_postenable(struct iio_dev *indio_dev) |
| { |
| struct max30100_data *data = iio_priv(indio_dev); |
| int ret; |
| |
| ret = max30100_set_powermode(data, true); |
| if (ret) |
| return ret; |
| |
| return max30100_clear_fifo(data); |
| } |
| |
| static int max30100_buffer_predisable(struct iio_dev *indio_dev) |
| { |
| struct max30100_data *data = iio_priv(indio_dev); |
| |
| return max30100_set_powermode(data, false); |
| } |
| |
| static const struct iio_buffer_setup_ops max30100_buffer_setup_ops = { |
| .postenable = max30100_buffer_postenable, |
| .predisable = max30100_buffer_predisable, |
| }; |
| |
| static inline int max30100_fifo_count(struct max30100_data *data) |
| { |
| unsigned int val; |
| int ret; |
| |
| ret = regmap_read(data->regmap, MAX30100_REG_INT_STATUS, &val); |
| if (ret) |
| return ret; |
| |
| /* FIFO is almost full */ |
| if (val & MAX30100_REG_INT_STATUS_FIFO_RDY) |
| return MAX30100_REG_FIFO_DATA_ENTRY_COUNT - 1; |
| |
| return 0; |
| } |
| |
| static int max30100_read_measurement(struct max30100_data *data) |
| { |
| int ret; |
| |
| ret = i2c_smbus_read_i2c_block_data(data->client, |
| MAX30100_REG_FIFO_DATA, |
| MAX30100_REG_FIFO_DATA_ENTRY_LEN, |
| (u8 *) &data->buffer); |
| |
| return (ret == MAX30100_REG_FIFO_DATA_ENTRY_LEN) ? 0 : ret; |
| } |
| |
| static irqreturn_t max30100_interrupt_handler(int irq, void *private) |
| { |
| struct iio_dev *indio_dev = private; |
| struct max30100_data *data = iio_priv(indio_dev); |
| int ret, cnt = 0; |
| |
| mutex_lock(&data->lock); |
| |
| while (cnt-- || (cnt = max30100_fifo_count(data) > 0)) { |
| ret = max30100_read_measurement(data); |
| if (ret) |
| break; |
| |
| iio_push_to_buffers(data->indio_dev, data->buffer); |
| } |
| |
| mutex_unlock(&data->lock); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int max30100_get_current_idx(unsigned int val, int *reg) |
| { |
| int idx; |
| |
| /* LED turned off */ |
| if (val == 0) { |
| *reg = 0; |
| return 0; |
| } |
| |
| for (idx = 0; idx < ARRAY_SIZE(max30100_led_current_mapping); idx++) { |
| if (max30100_led_current_mapping[idx] == val) { |
| *reg = idx + 1; |
| return 0; |
| } |
| } |
| |
| return -EINVAL; |
| } |
| |
| static int max30100_led_init(struct max30100_data *data) |
| { |
| struct device *dev = &data->client->dev; |
| struct device_node *np = dev->of_node; |
| unsigned int val[2]; |
| int reg, ret; |
| |
| ret = of_property_read_u32_array(np, "maxim,led-current-microamp", |
| (unsigned int *) &val, 2); |
| if (ret) { |
| /* Default to 24 mA RED LED, 50 mA IR LED */ |
| reg = (MAX30100_REG_LED_CONFIG_24MA << |
| MAX30100_REG_LED_CONFIG_RED_LED_SHIFT) | |
| MAX30100_REG_LED_CONFIG_50MA; |
| dev_warn(dev, "no led-current-microamp set"); |
| |
| return regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, reg); |
| } |
| |
| /* RED LED current */ |
| ret = max30100_get_current_idx(val[0], ®); |
| if (ret) { |
| dev_err(dev, "invalid RED current setting %d", val[0]); |
| return ret; |
| } |
| |
| ret = regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG, |
| MAX30100_REG_LED_CONFIG_LED_MASK << |
| MAX30100_REG_LED_CONFIG_RED_LED_SHIFT, |
| reg << MAX30100_REG_LED_CONFIG_RED_LED_SHIFT); |
| if (ret) |
| return ret; |
| |
| /* IR LED current */ |
| ret = max30100_get_current_idx(val[1], ®); |
| if (ret) { |
| dev_err(dev, "invalid IR current setting %d", val[1]); |
| return ret; |
| } |
| |
| return regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG, |
| MAX30100_REG_LED_CONFIG_LED_MASK, reg); |
| } |
| |
| static int max30100_chip_init(struct max30100_data *data) |
| { |
| int ret; |
| |
| /* setup LED current settings */ |
| ret = max30100_led_init(data); |
| if (ret) |
| return ret; |
| |
| /* enable hi-res SPO2 readings at 100Hz */ |
| ret = regmap_write(data->regmap, MAX30100_REG_SPO2_CONFIG, |
| MAX30100_REG_SPO2_CONFIG_HI_RES_EN | |
| MAX30100_REG_SPO2_CONFIG_100HZ); |
| if (ret) |
| return ret; |
| |
| /* enable SPO2 mode */ |
| ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, |
| MAX30100_REG_MODE_CONFIG_MODE_MASK, |
| MAX30100_REG_MODE_CONFIG_MODE_HR_EN | |
| MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN); |
| if (ret) |
| return ret; |
| |
| /* enable FIFO interrupt */ |
| return regmap_update_bits(data->regmap, MAX30100_REG_INT_ENABLE, |
| MAX30100_REG_INT_ENABLE_MASK, |
| MAX30100_REG_INT_ENABLE_FIFO_EN |
| << MAX30100_REG_INT_ENABLE_MASK_SHIFT); |
| } |
| |
| static int max30100_read_temp(struct max30100_data *data, int *val) |
| { |
| int ret; |
| unsigned int reg; |
| |
| ret = regmap_read(data->regmap, MAX30100_REG_TEMP_INTEGER, ®); |
| if (ret < 0) |
| return ret; |
| *val = reg << 4; |
| |
| ret = regmap_read(data->regmap, MAX30100_REG_TEMP_FRACTION, ®); |
| if (ret < 0) |
| return ret; |
| |
| *val |= reg & 0xf; |
| *val = sign_extend32(*val, 11); |
| |
| return 0; |
| } |
| |
| static int max30100_get_temp(struct max30100_data *data, int *val) |
| { |
| int ret; |
| |
| /* start acquisition */ |
| ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, |
| MAX30100_REG_MODE_CONFIG_TEMP_EN, |
| MAX30100_REG_MODE_CONFIG_TEMP_EN); |
| if (ret) |
| return ret; |
| |
| usleep_range(35000, 50000); |
| |
| return max30100_read_temp(data, val); |
| } |
| |
| static int max30100_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| struct max30100_data *data = iio_priv(indio_dev); |
| int ret = -EINVAL; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| /* |
| * Temperature reading can only be acquired while engine |
| * is running |
| */ |
| mutex_lock(&indio_dev->mlock); |
| |
| if (!iio_buffer_enabled(indio_dev)) |
| ret = -EAGAIN; |
| else { |
| ret = max30100_get_temp(data, val); |
| if (!ret) |
| ret = IIO_VAL_INT; |
| |
| } |
| |
| mutex_unlock(&indio_dev->mlock); |
| break; |
| case IIO_CHAN_INFO_SCALE: |
| *val = 1; /* 0.0625 */ |
| *val2 = 16; |
| ret = IIO_VAL_FRACTIONAL; |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static const struct iio_info max30100_info = { |
| .driver_module = THIS_MODULE, |
| .read_raw = max30100_read_raw, |
| }; |
| |
| static int max30100_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct max30100_data *data; |
| struct iio_buffer *buffer; |
| struct iio_dev *indio_dev; |
| int ret; |
| |
| indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| buffer = devm_iio_kfifo_allocate(&client->dev); |
| if (!buffer) |
| return -ENOMEM; |
| |
| iio_device_attach_buffer(indio_dev, buffer); |
| |
| indio_dev->name = MAX30100_DRV_NAME; |
| indio_dev->channels = max30100_channels; |
| indio_dev->info = &max30100_info; |
| indio_dev->num_channels = ARRAY_SIZE(max30100_channels); |
| indio_dev->available_scan_masks = max30100_scan_masks; |
| indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE); |
| indio_dev->setup_ops = &max30100_buffer_setup_ops; |
| |
| data = iio_priv(indio_dev); |
| data->indio_dev = indio_dev; |
| data->client = client; |
| |
| mutex_init(&data->lock); |
| i2c_set_clientdata(client, indio_dev); |
| |
| data->regmap = devm_regmap_init_i2c(client, &max30100_regmap_config); |
| if (IS_ERR(data->regmap)) { |
| dev_err(&client->dev, "regmap initialization failed.\n"); |
| return PTR_ERR(data->regmap); |
| } |
| max30100_set_powermode(data, false); |
| |
| ret = max30100_chip_init(data); |
| if (ret) |
| return ret; |
| |
| if (client->irq <= 0) { |
| dev_err(&client->dev, "no valid irq defined\n"); |
| return -EINVAL; |
| } |
| ret = devm_request_threaded_irq(&client->dev, client->irq, |
| NULL, max30100_interrupt_handler, |
| IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
| "max30100_irq", indio_dev); |
| if (ret) { |
| dev_err(&client->dev, "request irq (%d) failed\n", client->irq); |
| return ret; |
| } |
| |
| return iio_device_register(indio_dev); |
| } |
| |
| static int max30100_remove(struct i2c_client *client) |
| { |
| struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| struct max30100_data *data = iio_priv(indio_dev); |
| |
| iio_device_unregister(indio_dev); |
| max30100_set_powermode(data, false); |
| |
| return 0; |
| } |
| |
| static const struct i2c_device_id max30100_id[] = { |
| { "max30100", 0 }, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(i2c, max30100_id); |
| |
| static const struct of_device_id max30100_dt_ids[] = { |
| { .compatible = "maxim,max30100" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, max30100_dt_ids); |
| |
| static struct i2c_driver max30100_driver = { |
| .driver = { |
| .name = MAX30100_DRV_NAME, |
| .of_match_table = of_match_ptr(max30100_dt_ids), |
| }, |
| .probe = max30100_probe, |
| .remove = max30100_remove, |
| .id_table = max30100_id, |
| }; |
| module_i2c_driver(max30100_driver); |
| |
| MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>"); |
| MODULE_DESCRIPTION("MAX30100 heart rate and pulse oximeter sensor"); |
| MODULE_LICENSE("GPL"); |