VL53L0X can be configured to use interrupt pin (GPIO1) to notify host about readiness of new measurement. If interrupt pin is not specified, driver still uses polling. Signed-off-by: Ivan Drobyshevskyi <drobyshevskyi@xxxxxxxxx> --- changes since v1: - remove explicit DT parsing for IRQ number, reuse i2c_client's irq - add checking of i2c_smbus_write_byte_data return value - fix checking of i2c_smbus_read_byte_data return value - other styling/cosmetic changes as suggested by Jonathan drivers/iio/proximity/vl53l0x-i2c.c | 104 +++++++++++++++++++++++++--- 1 file changed, 93 insertions(+), 11 deletions(-) diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c index b48216cc1..e92a0bf79 100644 --- a/drivers/iio/proximity/vl53l0x-i2c.c +++ b/drivers/iio/proximity/vl53l0x-i2c.c @@ -4,18 +4,19 @@ * * Copyright (C) 2016 STMicroelectronics Imaging Division. * Copyright (C) 2018 Song Qiang <songqiang1304521@xxxxxxxxx> + * Copyright (C) 2020 Ivan Drobyshevskyi <drobyshevskyi@xxxxxxxxx> * * Datasheet available at * <https://www.st.com/resource/en/datasheet/vl53l0x.pdf> * * Default 7-bit i2c slave address 0x29. * - * TODO: FIFO buffer, continuous mode, interrupts, range selection, - * sensor ID check. + * TODO: FIFO buffer, continuous mode, range selection, sensor ID check. */ #include <linux/delay.h> #include <linux/i2c.h> +#include <linux/interrupt.h> #include <linux/module.h> #include <linux/iio/iio.h> @@ -29,14 +30,72 @@ #define VL_REG_SYSRANGE_MODE_TIMED BIT(2) #define VL_REG_SYSRANGE_MODE_HISTOGRAM BIT(3) +#define VL_REG_SYSTEM_INTERRUPT_CONFIG_GPIO 0x0A +#define VL_REG_SYSTEM_INTERRUPT_GPIO_NEW_SAMPLE_READY BIT(2) + +#define VL_REG_SYSTEM_INTERRUPT_CLEAR 0x0B + #define VL_REG_RESULT_INT_STATUS 0x13 #define VL_REG_RESULT_RANGE_STATUS 0x14 #define VL_REG_RESULT_RANGE_STATUS_COMPLETE BIT(0) struct vl53l0x_data { struct i2c_client *client; + struct completion completion; }; +static irqreturn_t vl53l0x_handle_irq(int irq, void *priv) +{ + struct iio_dev *indio_dev = priv; + struct vl53l0x_data *data = iio_priv(indio_dev); + + complete(&data->completion); + + return IRQ_HANDLED; +} + +static int vl53l0x_configure_irq(struct i2c_client *client, + struct iio_dev *indio_dev) +{ + struct vl53l0x_data *data = iio_priv(indio_dev); + int ret; + + ret = devm_request_irq(&client->dev, client->irq, vl53l0x_handle_irq, + IRQF_TRIGGER_FALLING, indio_dev->name, indio_dev); + if (ret) { + dev_err(&client->dev, "devm_request_irq error: %d\n", ret); + return ret; + } + + ret = i2c_smbus_write_byte_data(data->client, + VL_REG_SYSTEM_INTERRUPT_CONFIG_GPIO, + VL_REG_SYSTEM_INTERRUPT_GPIO_NEW_SAMPLE_READY); + if (ret < 0) + dev_err(&client->dev, "failed to configure IRQ: %d\n", ret); + + return ret; +} + +static void vl53l0x_clear_irq(struct vl53l0x_data *data) +{ + struct device *dev = &data->client->dev; + int ret; + + ret = i2c_smbus_write_byte_data(data->client, + VL_REG_SYSTEM_INTERRUPT_CLEAR, 1); + if (ret < 0) + dev_err(dev, "failed to clear error irq: %d\n", ret); + + ret = i2c_smbus_write_byte_data(data->client, + VL_REG_SYSTEM_INTERRUPT_CLEAR, 0); + if (ret < 0) + dev_err(dev, "failed to clear range irq: %d\n", ret); + + ret = i2c_smbus_read_byte_data(data->client, VL_REG_RESULT_INT_STATUS); + if (ret < 0 || ret & 0x07) + dev_err(dev, "failed to clear irq: %d\n", ret); +} + static int vl53l0x_read_proximity(struct vl53l0x_data *data, const struct iio_chan_spec *chan, int *val) @@ -50,19 +109,31 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data, if (ret < 0) return ret; - do { - ret = i2c_smbus_read_byte_data(client, - VL_REG_RESULT_RANGE_STATUS); + if (data->client->irq) { + reinit_completion(&data->completion); + + ret = wait_for_completion_timeout(&data->completion, HZ/10); if (ret < 0) return ret; + else if (ret == 0) + return -ETIMEDOUT; - if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE) - break; + vl53l0x_clear_irq(data); + } else { + do { + ret = i2c_smbus_read_byte_data(client, + VL_REG_RESULT_RANGE_STATUS); + if (ret < 0) + return ret; - usleep_range(1000, 5000); - } while (--tries); - if (!tries) - return -ETIMEDOUT; + if (ret & VL_REG_RESULT_RANGE_STATUS_COMPLETE) + break; + + usleep_range(1000, 5000); + } while (--tries); + if (!tries) + return -ETIMEDOUT; + } ret = i2c_smbus_read_i2c_block_data(client, VL_REG_RESULT_RANGE_STATUS, 12, buffer); @@ -141,6 +212,17 @@ static int vl53l0x_probe(struct i2c_client *client) indio_dev->num_channels = ARRAY_SIZE(vl53l0x_channels); indio_dev->modes = INDIO_DIRECT_MODE; + /* usage of interrupt is optional */ + if (client->irq) { + int ret; + + init_completion(&data->completion); + + ret = vl53l0x_configure_irq(client, indio_dev); + if (ret) + return ret; + } + return devm_iio_device_register(&client->dev, indio_dev); } -- 2.26.0
