diff options
| -rw-r--r-- | drivers/iio/common/st_sensors/st_sensors_buffer.c | 7 | ||||
| -rw-r--r-- | drivers/iio/common/st_sensors/st_sensors_trigger.c | 154 | ||||
| -rw-r--r-- | include/linux/iio/common/st_sensors.h | 2 |
3 files changed, 117 insertions, 46 deletions
diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c index 7c84e90d8ce8..2371fc875d2d 100644 --- a/drivers/iio/common/st_sensors/st_sensors_buffer.c +++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c @@ -58,7 +58,12 @@ irqreturn_t st_sensors_trigger_handler(int irq, void *p) struct st_sensor_data *sdata = iio_priv(indio_dev); s64 timestamp; - /* If we do timetamping here, do it before reading the values */ + /* + * If we do timetamping here, do it before reading the values, because + * once we've read the values, new interrupts can occur (when using + * the hardware trigger) and the hw_timestamp may get updated. + * By storing it in a local variable first, we are safe. + */ if (sdata->hw_irq_trigger) timestamp = sdata->hw_timestamp; else diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c index fab494d71951..e66f12ee8a55 100644 --- a/drivers/iio/common/st_sensors/st_sensors_trigger.c +++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c @@ -18,6 +18,50 @@ #include "st_sensors_core.h" /** + * st_sensors_new_samples_available() - check if more samples came in + * returns: + * 0 - no new samples available + * 1 - new samples available + * negative - error or unknown + */ +static int st_sensors_new_samples_available(struct iio_dev *indio_dev, + struct st_sensor_data *sdata) +{ + u8 status; + int ret; + + /* How would I know if I can't check it? */ + if (!sdata->sensor_settings->drdy_irq.addr_stat_drdy) + return -EINVAL; + + /* No scan mask, no interrupt */ + if (!indio_dev->active_scan_mask) + return 0; + + ret = sdata->tf->read_byte(&sdata->tb, sdata->dev, + sdata->sensor_settings->drdy_irq.addr_stat_drdy, + &status); + if (ret < 0) { + dev_err(sdata->dev, + "error checking samples available\n"); + return ret; + } + /* + * the lower bits of .active_scan_mask[0] is directly mapped + * to the channels on the sensor: either bit 0 for + * one-dimensional sensors, or e.g. x,y,z for accelerometers, + * gyroscopes or magnetometers. No sensor use more than 3 + * channels, so cut the other status bits here. + */ + status &= 0x07; + + if (status & (u8)indio_dev->active_scan_mask[0]) + return 1; + + return 0; +} + +/** * st_sensors_irq_handler() - top half of the IRQ-based triggers * @irq: irq number * @p: private handler data @@ -43,44 +87,43 @@ irqreturn_t st_sensors_irq_thread(int irq, void *p) struct iio_trigger *trig = p; struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); struct st_sensor_data *sdata = iio_priv(indio_dev); - int ret; /* * If this trigger is backed by a hardware interrupt and we have a - * status register, check if this IRQ came from us + * status register, check if this IRQ came from us. Notice that + * we will process also if st_sensors_new_samples_available() + * returns negative: if we can't check status, then poll + * unconditionally. */ - if (sdata->sensor_settings->drdy_irq.addr_stat_drdy) { - u8 status; - - ret = sdata->tf->read_byte(&sdata->tb, sdata->dev, - sdata->sensor_settings->drdy_irq.addr_stat_drdy, - &status); - if (ret < 0) { - dev_err(sdata->dev, "could not read channel status\n"); - goto out_poll; - } - /* - * the lower bits of .active_scan_mask[0] is directly mapped - * to the channels on the sensor: either bit 0 for - * one-dimensional sensors, or e.g. x,y,z for accelerometers, - * gyroscopes or magnetometers. No sensor use more than 3 - * channels, so cut the other status bits here. - */ - status &= 0x07; + if (sdata->hw_irq_trigger && + st_sensors_new_samples_available(indio_dev, sdata)) { + iio_trigger_poll_chained(p); + } else { + dev_dbg(sdata->dev, "spurious IRQ\n"); + return IRQ_NONE; + } - /* - * If this was not caused by any channels on this sensor, - * return IRQ_NONE - */ - if (!indio_dev->active_scan_mask) - return IRQ_NONE; - if (!(status & (u8)indio_dev->active_scan_mask[0])) - return IRQ_NONE; + /* + * If we have proper level IRQs the handler will be re-entered if + * the line is still active, so return here and come back in through + * the top half if need be. + */ + if (!sdata->edge_irq) + return IRQ_HANDLED; + + /* + * If we are using egde IRQs, new samples arrived while processing + * the IRQ and those may be missed unless we pick them here, so poll + * again. If the sensor delivery frequency is very high, this thread + * turns into a polled loop handler. + */ + while (sdata->hw_irq_trigger && + st_sensors_new_samples_available(indio_dev, sdata)) { + dev_dbg(sdata->dev, "more samples came in during polling\n"); + sdata->hw_timestamp = iio_get_time_ns(indio_dev); + iio_trigger_poll_chained(p); } -out_poll: - /* It's our IRQ: proceed to handle the register polling */ - iio_trigger_poll_chained(p); return IRQ_HANDLED; } @@ -107,13 +150,18 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev, * If the IRQ is triggered on falling edge, we need to mark the * interrupt as active low, if the hardware supports this. */ - if (irq_trig == IRQF_TRIGGER_FALLING) { + switch(irq_trig) { + case IRQF_TRIGGER_FALLING: + case IRQF_TRIGGER_LOW: if (!sdata->sensor_settings->drdy_irq.addr_ihl) { dev_err(&indio_dev->dev, - "falling edge specified for IRQ but hardware " - "only support rising edge, will request " - "rising edge\n"); - irq_trig = IRQF_TRIGGER_RISING; + "falling/low specified for IRQ " + "but hardware only support rising/high: " + "will request rising/high\n"); + if (irq_trig == IRQF_TRIGGER_FALLING) + irq_trig = IRQF_TRIGGER_RISING; + if (irq_trig == IRQF_TRIGGER_LOW) + irq_trig = IRQF_TRIGGER_HIGH; } else { /* Set up INT active low i.e. falling edge */ err = st_sensors_write_data_with_mask(indio_dev, @@ -122,20 +170,39 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev, if (err < 0) goto iio_trigger_free; dev_info(&indio_dev->dev, - "interrupts on the falling edge\n"); + "interrupts on the falling edge or " + "active low level\n"); } - } else if (irq_trig == IRQF_TRIGGER_RISING) { + break; + case IRQF_TRIGGER_RISING: dev_info(&indio_dev->dev, "interrupts on the rising edge\n"); - - } else { + break; + case IRQF_TRIGGER_HIGH: + dev_info(&indio_dev->dev, + "interrupts active high level\n"); + break; + default: + /* This is the most preferred mode, if possible */ dev_err(&indio_dev->dev, - "unsupported IRQ trigger specified (%lx), only " - "rising and falling edges supported, enforce " + "unsupported IRQ trigger specified (%lx), enforce " "rising edge\n", irq_trig); irq_trig = IRQF_TRIGGER_RISING; } + /* Tell the interrupt handler that we're dealing with edges */ + if (irq_trig == IRQF_TRIGGER_FALLING || + irq_trig == IRQF_TRIGGER_RISING) + sdata->edge_irq = true; + else + /* + * If we're not using edges (i.e. level interrupts) we + * just mask off the IRQ, handle one interrupt, then + * if the line is still low, we return to the + * interrupt handler top half again and start over. + */ + irq_trig |= IRQF_ONESHOT; + /* * If the interrupt pin is Open Drain, by definition this * means that the interrupt line may be shared with other @@ -148,9 +215,6 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev, sdata->sensor_settings->drdy_irq.addr_stat_drdy) irq_trig |= IRQF_SHARED; - /* Let's create an interrupt thread masking the hard IRQ here */ - irq_trig |= IRQF_ONESHOT; - err = request_threaded_irq(sdata->get_irq_data_ready(indio_dev), st_sensors_irq_handler, st_sensors_irq_thread, diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h index 28052cddaa03..228bd44efa4c 100644 --- a/include/linux/iio/common/st_sensors.h +++ b/include/linux/iio/common/st_sensors.h @@ -223,6 +223,7 @@ struct st_sensor_settings { * @get_irq_data_ready: Function to get the IRQ used for data ready signal. * @tf: Transfer function structure used by I/O operations. * @tb: Transfer buffers and mutex used by I/O operations. + * @edge_irq: the IRQ triggers on edges and need special handling. * @hw_irq_trigger: if we're using the hardware interrupt on the sensor. * @hw_timestamp: Latest timestamp from the interrupt handler, when in use. */ @@ -250,6 +251,7 @@ struct st_sensor_data { const struct st_sensor_transfer_function *tf; struct st_sensor_transfer_buffer tb; + bool edge_irq; bool hw_irq_trigger; s64 hw_timestamp; }; |
