diff options
Diffstat (limited to 'drivers/iio/health/max30100.c')
| -rw-r--r-- | drivers/iio/health/max30100.c | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/drivers/iio/health/max30100.c b/drivers/iio/health/max30100.c index 814f521e47ae..3d441013893c 100644 --- a/drivers/iio/health/max30100.c +++ b/drivers/iio/health/max30100.c @@ -5,7 +5,6 @@ * Copyright (C) 2015, 2018 * Author: Matt Ranostay <matt.ranostay@konsulko.com> * - * TODO: enable pulse length controls via device tree properties */ #include <linux/module.h> @@ -18,6 +17,7 @@ #include <linux/mutex.h> #include <linux/property.h> #include <linux/regmap.h> +#include <linux/bitfield.h> #include <linux/iio/iio.h> #include <linux/iio/buffer.h> #include <linux/iio/kfifo_buf.h> @@ -52,9 +52,13 @@ #define MAX30100_REG_MODE_CONFIG_PWR BIT(7) #define MAX30100_REG_SPO2_CONFIG 0x07 +#define MAX30100_REG_SPO2_CONFIG_PW_MASK GENMASK(1, 0) +#define MAX30100_REG_SPO2_CONFIG_200US 0x0 +#define MAX30100_REG_SPO2_CONFIG_400US 0x1 +#define MAX30100_REG_SPO2_CONFIG_800US 0x2 +#define MAX30100_REG_SPO2_CONFIG_1600US 0x3 #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 @@ -306,19 +310,47 @@ static int max30100_led_init(struct max30100_data *data) MAX30100_REG_LED_CONFIG_LED_MASK, reg); } +static int max30100_get_pulse_width(unsigned int pwidth_us) +{ + switch (pwidth_us) { + case 200: + return MAX30100_REG_SPO2_CONFIG_200US; + case 400: + return MAX30100_REG_SPO2_CONFIG_400US; + case 800: + return MAX30100_REG_SPO2_CONFIG_800US; + case 1600: + return MAX30100_REG_SPO2_CONFIG_1600US; + default: + return -EINVAL; + } +} + static int max30100_chip_init(struct max30100_data *data) { int ret; + int pulse_width; + /* set default LED pulse-width to 1600 us */ + unsigned int pulse_us = 1600; + struct device *dev = &data->client->dev; /* setup LED current settings */ ret = max30100_led_init(data); if (ret) return ret; + /* Read LED pulse-width-us from DT */ + device_property_read_u32(dev, "maxim,pulse-width-us", &pulse_us); + + pulse_width = max30100_get_pulse_width(pulse_us); + if (pulse_width < 0) + return dev_err_probe(dev, pulse_width, "invalid LED pulse-width %uus\n", pulse_us); + /* 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); + MAX30100_REG_SPO2_CONFIG_100HZ | + FIELD_PREP(MAX30100_REG_SPO2_CONFIG_PW_MASK, pulse_width)); if (ret) return ret; |