Provide a way for continuous data capture by setting up buffer support. The data ready signal exposed at the DRDY pin of the ADXL355 is exploited as a hardware interrupt which triggers to fill the buffer. Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx> --- drivers/iio/accel/Kconfig | 4 + drivers/iio/accel/adxl355_core.c | 154 ++++++++++++++++++++++++++++++- 2 files changed, 155 insertions(+), 3 deletions(-) diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig index d0c45c809..9c16c1841 100644 --- a/drivers/iio/accel/Kconfig +++ b/drivers/iio/accel/Kconfig @@ -69,6 +69,8 @@ config ADXL355_I2C depends on I2C select ADXL355 select REGMAP_I2C + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER help Say Y here if you want to build i2c support for the Analog Devices ADXL355 3-axis digital accelerometer. @@ -82,6 +84,8 @@ config ADXL355_SPI depends on SPI select ADXL355 select REGMAP_SPI + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER help Say Y here if you want to build spi support for the Analog Devices ADXL355 3-axis digital accelerometer. diff --git a/drivers/iio/accel/adxl355_core.c b/drivers/iio/accel/adxl355_core.c index c91d2254c..bd5304bcf 100644 --- a/drivers/iio/accel/adxl355_core.c +++ b/drivers/iio/accel/adxl355_core.c @@ -6,14 +6,18 @@ * * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/adxl354_adxl355.pdf */ - #include <linux/bits.h> #include <linux/bitfield.h> +#include <linux/iio/buffer.h> #include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> #include <linux/limits.h> #include <linux/math64.h> #include <linux/module.h> #include <linux/mod_devicetable.h> +#include <linux/of_irq.h> #include <linux/regmap.h> #include <asm/unaligned.h> @@ -46,6 +50,7 @@ #define ADXL355_RANGE_REG 0x2C #define ADXL355_POWER_CTL_REG 0x2D #define ADXL355_POWER_CTL_MODE_MSK GENMASK(1, 0) +#define ADXL355_POWER_CTL_DRDY_MSK BIT(2) #define ADXL355_SELF_TEST_REG 0x2E #define ADXL355_RESET_REG 0x2F @@ -157,6 +162,7 @@ static const struct adxl355_chan_info adxl355_chans[] = { }; struct adxl355_data { + int irq; struct regmap *regmap; struct device *dev; struct mutex lock; /* lock to protect op_mode */ @@ -165,7 +171,14 @@ struct adxl355_data { enum adxl355_hpf_3db hpf_3db; int calibbias[3]; int adxl355_hpf_3db_table[7][2]; - u8 transf_buf[3] ____cacheline_aligned; + struct iio_trigger *dready_trig; + union { + u8 transf_buf[3]; + struct { + u8 buf[14]; + s64 ts; + } buffer; + } ____cacheline_aligned; }; static int adxl355_set_op_mode(struct adxl355_data *data, @@ -186,6 +199,23 @@ static int adxl355_set_op_mode(struct adxl355_data *data, return ret; } +static int adxl355_data_rdy_trigger_set_state(struct iio_trigger *trig, + bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct adxl355_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->lock); + ret = regmap_update_bits(data->regmap, ADXL355_POWER_CTL_REG, + ADXL355_POWER_CTL_DRDY_MSK, + FIELD_PREP(ADXL355_POWER_CTL_DRDY_MSK, + !state)); + mutex_unlock(&data->lock); + + return ret; +} + static void adxl355_fill_3db_frequency_table(struct adxl355_data *data) { u32 multiplier; @@ -246,6 +276,12 @@ static int adxl355_setup(struct adxl355_data *data) if (ret) return ret; + ret = regmap_update_bits(data->regmap, ADXL355_POWER_CTL_REG, + ADXL355_POWER_CTL_DRDY_MSK, + FIELD_PREP(ADXL355_POWER_CTL_DRDY_MSK, 1)); + if (ret) + return ret; + adxl355_fill_3db_frequency_table(data); return adxl355_set_op_mode(data, ADXL355_MEASUREMENT); @@ -499,12 +535,65 @@ static int adxl355_read_avail(struct iio_dev *indio_dev, } } +static const unsigned long adxl355_avail_scan_masks[] = { + GENMASK(3, 0), + 0 +}; + static const struct iio_info adxl355_info = { .read_raw = adxl355_read_raw, .write_raw = adxl355_write_raw, .read_avail = &adxl355_read_avail, }; +static const struct iio_trigger_ops adxl355_trigger_ops = { + .set_trigger_state = &adxl355_data_rdy_trigger_set_state, + .validate_device = &iio_trigger_validate_own_device, +}; + +static irqreturn_t adxl355_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct adxl355_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->lock); + + ret = regmap_bulk_read(data->regmap, ADXL355_XDATA3_REG, + &data->buffer.buf[1], + 3); + if (ret) + goto out_unlock_notify; + + ret = regmap_bulk_read(data->regmap, ADXL355_YDATA3_REG, + &data->buffer.buf[5], + 3); + if (ret) + goto out_unlock_notify; + + ret = regmap_bulk_read(data->regmap, ADXL355_ZDATA3_REG, + &data->buffer.buf[9], + 3); + if (ret) + goto out_unlock_notify; + + ret = regmap_bulk_read(data->regmap, ADXL355_TEMP2_REG, + &data->buffer.buf[12], + 2); + if (ret) + goto out_unlock_notify; + + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, + pf->timestamp); + +out_unlock_notify: + mutex_unlock(&data->lock); + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + #define ADXL355_ACCEL_CHANNEL(index, reg, axis) { \ .type = IIO_ACCEL, \ .address = reg, \ @@ -518,6 +607,7 @@ static const struct iio_info adxl355_info = { .info_mask_shared_by_type_available = \ BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \ + .scan_index = index, \ .scan_type = { \ .sign = 's', \ .realbits = 20, \ @@ -537,6 +627,7 @@ static const struct iio_chan_spec adxl355_channels[] = { .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), + .scan_index = 3, .scan_type = { .sign = 's', .realbits = 12, @@ -544,8 +635,46 @@ static const struct iio_chan_spec adxl355_channels[] = { .endianness = IIO_BE, }, }, + IIO_CHAN_SOFT_TIMESTAMP(4), }; +static int adxl355_probe_trigger(struct iio_dev *indio_dev) +{ + struct adxl355_data *data = iio_priv(indio_dev); + int ret; + + if (!data->irq) { + dev_info(data->dev, "no irq, using polling\n"); + return 0; + } + + data->dready_trig = devm_iio_trigger_alloc(data->dev, "%s-dev%d", + indio_dev->name, + indio_dev->id); + if (!data->dready_trig) + return -ENOMEM; + + data->dready_trig->ops = &adxl355_trigger_ops; + iio_trigger_set_drvdata(data->dready_trig, indio_dev); + + ret = devm_request_irq(data->dev, data->irq, + &iio_trigger_generic_data_rdy_poll, + IRQF_ONESHOT, "adxl355_irq", data->dready_trig); + if (ret < 0) + return dev_err_probe(data->dev, ret, "request irq %d failed\n", + data->irq); + + ret = devm_iio_trigger_register(data->dev, data->dready_trig); + if (ret) { + dev_err(data->dev, "iio trigger register failed\n"); + return ret; + } + + indio_dev->trig = iio_trigger_get(data->dready_trig); + + return 0; +} + int adxl355_core_probe(struct device *dev, struct regmap *regmap, const char *name) { @@ -563,18 +692,37 @@ int adxl355_core_probe(struct device *dev, struct regmap *regmap, data->op_mode = ADXL355_STANDBY; mutex_init(&data->lock); + /* + * Would be good to move it to the generic version. + */ + ret = of_irq_get_byname(dev->of_node, "DRDY"); + if (ret > 0) + data->irq = ret; + indio_dev->name = name; indio_dev->info = &adxl355_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = adxl355_channels; indio_dev->num_channels = ARRAY_SIZE(adxl355_channels); + indio_dev->available_scan_masks = adxl355_avail_scan_masks; ret = adxl355_setup(data); - if (ret < 0) { + if (ret) { dev_err(dev, "ADXL355 setup failed\n"); return ret; } + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + &iio_pollfunc_store_time, + &adxl355_trigger_handler, NULL); + if (ret) + return dev_err_probe(dev, ret, + "iio triggered buffer setup failed\n"); + + ret = adxl355_probe_trigger(indio_dev); + if (ret) + return ret; + return devm_iio_device_register(dev, indio_dev); } EXPORT_SYMBOL_GPL(adxl355_core_probe); -- 2.30.1
