From 327a0eaf19d53efc77f7073a43b2b0712bc6364d Mon Sep 17 00:00:00 2001 From: Puranjay Mohan Date: Sat, 4 Sep 2021 00:13:12 +0530 Subject: [PATCH] iio: accel: adxl355: Add triggered buffer support 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 Link: https://lore.kernel.org/r/20210903184312.21009-3-puranjay12@gmail.com Signed-off-by: Jonathan Cameron --- drivers/iio/accel/Kconfig | 4 + drivers/iio/accel/adxl355_core.c | 155 ++++++++++++++++++++++++++++++- 2 files changed, 158 insertions(+), 1 deletion(-) diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig index f1bc18f19342..49587c992a6d 100644 --- a/drivers/iio/accel/Kconfig +++ b/drivers/iio/accel/Kconfig @@ -98,6 +98,8 @@ 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. @@ -111,6 +113,8 @@ 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 d3ed7eec9485..4f485909f459 100644 --- a/drivers/iio/accel/adxl355_core.c +++ b/drivers/iio/accel/adxl355_core.c @@ -9,11 +9,16 @@ #include #include +#include #include +#include +#include +#include #include #include #include #include +#include #include #include @@ -46,6 +51,7 @@ #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 @@ -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 ? 0 : 1)); + 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); @@ -527,12 +563,74 @@ 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); + + /* + * data->buffer is used both for triggered buffer support + * and read/write_raw(), hence, it has to be zeroed here before usage. + */ + data->buffer.buf[0] = 0; + + /* + * The acceleration data is 24 bits and big endian. It has to be saved + * in 32 bits, hence, it is saved in the 2nd byte of the 4 byte buffer. + * The buf array is 14 bytes as it includes 3x4=12 bytes for + * accelaration data of x, y, and z axis. It also includes 2 bytes for + * temperature data. + */ + 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, \ @@ -546,6 +644,7 @@ 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, \ @@ -565,6 +664,7 @@ 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, @@ -572,14 +672,48 @@ 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, int irq) +{ + struct adxl355_data *data = iio_priv(indio_dev); + int ret; + + data->dready_trig = devm_iio_trigger_alloc(data->dev, "%s-dev%d", + indio_dev->name, + iio_device_id(indio_dev)); + 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, irq, + &iio_trigger_generic_data_rdy_poll, + IRQF_ONESHOT, "adxl355_irq", data->dready_trig); + if (ret) + return dev_err_probe(data->dev, ret, "request irq %d failed\n", + 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) { struct adxl355_data *data; struct iio_dev *indio_dev; int ret; + int irq; indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) @@ -596,6 +730,7 @@ int adxl355_core_probe(struct device *dev, struct regmap *regmap, 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) { @@ -603,6 +738,24 @@ int adxl355_core_probe(struct device *dev, struct regmap *regmap, return ret; } + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + &iio_pollfunc_store_time, + &adxl355_trigger_handler, NULL); + if (ret) { + dev_err(dev, "iio triggered buffer setup failed\n"); + return ret; + } + + /* + * TODO: Would be good to move it to the generic version. + */ + irq = of_irq_get_byname(dev->of_node, "DRDY"); + if (irq > 0) { + ret = adxl355_probe_trigger(indio_dev, irq); + if (ret) + return ret; + } + return devm_iio_device_register(dev, indio_dev); } EXPORT_SYMBOL_GPL(adxl355_core_probe);