Provide a way for continuous data capture by setting up buffer support. The data ready signal exposed at the SYNC pin of the ADXRS290 is exploited as a hardware interrupt which triggers to fill the buffer.
Triggered buffer setup was tested with both hardware trigger (DATA_RDY) and software triggers (sysfs-trig & hrtimer). Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com> Signed-off-by: Nishant Malpani <nish.malpan...@gmail.com> --- Changes in v3: - issue a separate precursor patch for the devm resource unwinding hook - rename labels in the error-path - use dev_err_probe() (which handles deferred probing) only for calls which request h/w resources Changes in v2: - In adxrs290_set_mode(), move 'if' block outside the locked section - use break statement for error handling instead of goto labels in switch-case blocks - remove outer parentheses when conditional ternary operator is used - use dev_err_probe() saving a few lines of code - re-align 'buffer' variable name in 'struct adxrs290_state' - don't return errors in 'try_reenable' callback - use 'st->spi' inline in 'adxrs290_trigger_handler' - unnecessary to mention default 'shift' (= 0) in iio_chan_spec.scan_type - bring in consistent wrapping of parameters while staying under the advised 80 chars line limit --- drivers/iio/gyro/Kconfig | 2 + drivers/iio/gyro/adxrs290.c | 211 +++++++++++++++++++++++++++++++++--- 2 files changed, 199 insertions(+), 14 deletions(-) diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig index 024a34139875..5824f2edf975 100644 --- a/drivers/iio/gyro/Kconfig +++ b/drivers/iio/gyro/Kconfig @@ -44,6 +44,8 @@ config ADIS16260 config ADXRS290 tristate "Analog Devices ADXRS290 Dual-Axis MEMS Gyroscope SPI driver" depends on SPI + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER help Say yes here to build support for Analog Devices ADXRS290 programmable digital output gyroscope. diff --git a/drivers/iio/gyro/adxrs290.c b/drivers/iio/gyro/adxrs290.c index 2864eb443957..41b1f995a143 100644 --- a/drivers/iio/gyro/adxrs290.c +++ b/drivers/iio/gyro/adxrs290.c @@ -13,8 +13,12 @@ #include <linux/module.h> #include <linux/spi/spi.h> +#include <linux/iio/buffer.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> #define ADXRS290_ADI_ID 0xAD #define ADXRS290_MEMS_ID 0x1D @@ -35,7 +39,9 @@ #define ADXRS290_READ BIT(7) #define ADXRS290_TSM BIT(0) #define ADXRS290_MEASUREMENT BIT(1) -#define ADXRS290_SYNC GENMASK(1, 0) +#define ADXRS290_DATA_RDY_OUT BIT(0) +#define ADXRS290_SYNC_MASK GENMASK(1, 0) +#define ADXRS290_SYNC(x) FIELD_PREP(ADXRS290_SYNC_MASK, x) #define ADXRS290_LPF_MASK GENMASK(2, 0) #define ADXRS290_LPF(x) FIELD_PREP(ADXRS290_LPF_MASK, x) #define ADXRS290_HPF_MASK GENMASK(7, 4) @@ -50,6 +56,13 @@ enum adxrs290_mode { ADXRS290_MODE_MEASUREMENT, }; +enum adxrs290_scan_index { + ADXRS290_IDX_X, + ADXRS290_IDX_Y, + ADXRS290_IDX_TEMP, + ADXRS290_IDX_TS, +}; + struct adxrs290_state { struct spi_device *spi; /* Serialize reads and their subsequent processing */ @@ -57,6 +70,12 @@ struct adxrs290_state { enum adxrs290_mode mode; unsigned int lpf_3db_freq_idx; unsigned int hpf_3db_freq_idx; + struct iio_trigger *dready_trig; + /* Ensure correct alignment of timestamp when present */ + struct { + s16 channels[3]; + s64 ts __aligned(8); + } buffer; }; /* @@ -270,24 +289,34 @@ static int adxrs290_read_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_RAW: + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + switch (chan->type) { case IIO_ANGL_VEL: ret = adxrs290_get_rate_data(indio_dev, ADXRS290_READ_REG(chan->address), val); if (ret < 0) - return ret; + break; - return IIO_VAL_INT; + ret = IIO_VAL_INT; + break; case IIO_TEMP: ret = adxrs290_get_temp_data(indio_dev, val); if (ret < 0) - return ret; + break; - return IIO_VAL_INT; + ret = IIO_VAL_INT; + break; default: - return -EINVAL; + ret = -EINVAL; + break; } + + iio_device_release_direct_mode(indio_dev); + return ret; case IIO_CHAN_INFO_SCALE: switch (chan->type) { case IIO_ANGL_VEL: @@ -334,34 +363,52 @@ static int adxrs290_write_raw(struct iio_dev *indio_dev, long mask) { struct adxrs290_state *st = iio_priv(indio_dev); - int lpf_idx, hpf_idx; + int ret, lpf_idx, hpf_idx; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; switch (mask) { case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table, ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table), val, val2); - if (lpf_idx < 0) - return -EINVAL; + if (lpf_idx < 0) { + ret = -EINVAL; + break; + } + /* caching the updated state of the low-pass filter */ st->lpf_3db_freq_idx = lpf_idx; /* retrieving the current state of the high-pass filter */ hpf_idx = st->hpf_3db_freq_idx; - return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx); + ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx); + break; + case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY: hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table, ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table), val, val2); - if (hpf_idx < 0) - return -EINVAL; + if (hpf_idx < 0) { + ret = -EINVAL; + break; + } + /* caching the updated state of the high-pass filter */ st->hpf_3db_freq_idx = hpf_idx; /* retrieving the current state of the low-pass filter */ lpf_idx = st->lpf_3db_freq_idx; - return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx); + ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx); + break; + + default: + ret = -EINVAL; + break; } - return -EINVAL; + iio_device_release_direct_mode(indio_dev); + return ret; } static int adxrs290_read_avail(struct iio_dev *indio_dev, @@ -389,6 +436,72 @@ static int adxrs290_read_avail(struct iio_dev *indio_dev, } } +static int adxrs290_data_rdy_trigger_set_state(struct iio_trigger *trig, + bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct adxrs290_state *st = iio_priv(indio_dev); + int ret; + u8 val; + + val = state ? ADXRS290_SYNC(ADXRS290_DATA_RDY_OUT) : 0; + + ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_DATA_RDY, val); + if (ret < 0) + dev_err(&st->spi->dev, "failed to start data rdy interrupt\n"); + + return ret; +} + +static int adxrs290_reset_trig(struct iio_trigger *trig) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + int val; + + /* + * Data ready interrupt is reset after a read of the data registers. + * Here, we only read the 16b DATAY registers as that marks the end of + * a read of the data registers and initiates a reset for the interrupt + * line. + */ + adxrs290_get_rate_data(indio_dev, + ADXRS290_READ_REG(ADXRS290_REG_DATAY0), &val); + + return 0; +} + +static const struct iio_trigger_ops adxrs290_trigger_ops = { + .set_trigger_state = &adxrs290_data_rdy_trigger_set_state, + .validate_device = &iio_trigger_validate_own_device, + .try_reenable = &adxrs290_reset_trig, +}; + +static irqreturn_t adxrs290_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct adxrs290_state *st = iio_priv(indio_dev); + u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0); + int ret; + + mutex_lock(&st->lock); + + /* exercise a bulk data capture starting from reg DATAX0... */ + ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels, + sizeof(st->buffer.channels)); + if (ret < 0) + goto out_unlock_notify; + + iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer, + pf->timestamp); + +out_unlock_notify: + mutex_unlock(&st->lock); + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + #define ADXRS290_ANGL_VEL_CHANNEL(reg, axis) { \ .type = IIO_ANGL_VEL, \ .address = reg, \ @@ -401,6 +514,13 @@ static int adxrs290_read_avail(struct iio_dev *indio_dev, .info_mask_shared_by_type_available = \ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \ BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \ + .scan_index = ADXRS290_IDX_##axis, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_LE, \ + }, \ } static const struct iio_chan_spec adxrs290_channels[] = { @@ -411,7 +531,20 @@ static const struct iio_chan_spec adxrs290_channels[] = { .address = ADXRS290_REG_TEMP0, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), + .scan_index = ADXRS290_IDX_TEMP, + .scan_type = { + .sign = 's', + .realbits = 12, + .storagebits = 16, + .endianness = IIO_LE, + }, }, + IIO_CHAN_SOFT_TIMESTAMP(ADXRS290_IDX_TS), +}; + +static const unsigned long adxrs290_avail_scan_masks[] = { + BIT(ADXRS290_IDX_X) | BIT(ADXRS290_IDX_Y) | BIT(ADXRS290_IDX_TEMP), + 0 }; static const struct iio_info adxrs290_info = { @@ -420,6 +553,44 @@ static const struct iio_info adxrs290_info = { .read_avail = &adxrs290_read_avail, }; +static int adxrs290_probe_trigger(struct iio_dev *indio_dev) +{ + struct adxrs290_state *st = iio_priv(indio_dev); + int ret; + + if (!st->spi->irq) { + dev_info(&st->spi->dev, "no irq, using polling\n"); + return 0; + } + + st->dready_trig = devm_iio_trigger_alloc(&st->spi->dev, "%s-dev%d", + indio_dev->name, + indio_dev->id); + if (!st->dready_trig) + return -ENOMEM; + + st->dready_trig->dev.parent = &st->spi->dev; + st->dready_trig->ops = &adxrs290_trigger_ops; + iio_trigger_set_drvdata(st->dready_trig, indio_dev); + + ret = devm_request_irq(&st->spi->dev, st->spi->irq, + &iio_trigger_generic_data_rdy_poll, + IRQF_ONESHOT, "adxrs290_irq", st->dready_trig); + if (ret < 0) + return dev_err_probe(&st->spi->dev, ret, + "request irq %d failed\n", st->spi->irq); + + ret = devm_iio_trigger_register(&st->spi->dev, st->dready_trig); + if (ret) { + dev_err(&st->spi->dev, "iio trigger register failed\n"); + return ret; + } + + indio_dev->trig = iio_trigger_get(st->dready_trig); + + return 0; +} + static int adxrs290_probe(struct spi_device *spi) { struct iio_dev *indio_dev; @@ -439,6 +610,7 @@ static int adxrs290_probe(struct spi_device *spi) indio_dev->channels = adxrs290_channels; indio_dev->num_channels = ARRAY_SIZE(adxrs290_channels); indio_dev->info = &adxrs290_info; + indio_dev->available_scan_masks = adxrs290_avail_scan_masks; mutex_init(&st->lock); @@ -478,6 +650,17 @@ static int adxrs290_probe(struct spi_device *spi) st->lpf_3db_freq_idx = val; st->hpf_3db_freq_idx = val2; + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, + &iio_pollfunc_store_time, + &adxrs290_trigger_handler, NULL); + if (ret < 0) + return dev_err_probe(&spi->dev, ret, + "iio triggered buffer setup failed\n"); + + ret = adxrs290_probe_trigger(indio_dev); + if (ret < 0) + return ret; + return devm_iio_device_register(&spi->dev, indio_dev); } -- 2.20.1