diff options
Diffstat (limited to 'drivers/iio/health/max30100.c')
| -rw-r--r-- | drivers/iio/health/max30100.c | 81 |
1 files changed, 75 insertions, 6 deletions
diff --git a/drivers/iio/health/max30100.c b/drivers/iio/health/max30100.c index 9d1c81f..09db893 100644 --- a/drivers/iio/health/max30100.c +++ b/drivers/iio/health/max30100.c @@ -13,7 +13,7 @@ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * - * TODO: allow LED current and pulse length controls via device tree properties + * TODO: enable pulse length controls via device tree properties */ #include <linux/module.h> @@ -24,6 +24,7 @@ #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> @@ -65,6 +66,7 @@ #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 @@ -111,6 +113,12 @@ static const struct regmap_config max30100_regmap_config = { .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[] = { @@ -243,15 +251,76 @@ static irqreturn_t max30100_interrupt_handler(int irq, void *private) 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; - /* RED IR LED = 24mA, IR LED = 50mA */ - ret = regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, - (MAX30100_REG_LED_CONFIG_24MA << - MAX30100_REG_LED_CONFIG_RED_LED_SHIFT) | - MAX30100_REG_LED_CONFIG_50MA); + /* setup LED current settings */ + ret = max30100_led_init(data); if (ret) return ret; |
