5 files changed, 154 insertions, 75 deletions

diff --git a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
index 595511022..5b41f9d0d 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
@@ -115,7 +115,7 @@ int hid_sensor_power_state(struct hid_sensor_common *st, bool state)
 		return ret;
 	}
 
- 	return 0;
+	return 0;
 #else
 	atomic_set(&st->user_requested_state, state);
 	return _hid_sensor_power_state(st, state);
diff --git a/drivers/iio/common/ms_sensors/ms_sensors_i2c.c b/drivers/iio/common/ms_sensors/ms_sensors_i2c.c
index 669dc7c27..ecf7721ec 100644
--- a/drivers/iio/common/ms_sensors/ms_sensors_i2c.c
+++ b/drivers/iio/common/ms_sensors/ms_sensors_i2c.c
@@ -106,7 +106,7 @@ int ms_sensors_convert_and_read(void *cli, u8 conv, u8 rd,
 				unsigned int delay, u32 *adc)
 {
 	int ret;
-        __be32 buf = 0;
+	__be32 buf = 0;
 	struct i2c_client *client = (struct i2c_client *)cli;
 
 	/* Trigger conversion */
diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c
index e18bc6782..f1693dbeb 100644
--- a/drivers/iio/common/st_sensors/st_sensors_buffer.c
+++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c
@@ -24,81 +24,30 @@
 
 int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
 {
-	u8 *addr;
-	int i, n = 0, len;
+	int i, len;
+	int total = 0;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
 	unsigned int num_data_channels = sdata->num_data_channels;
-	unsigned int byte_for_channel =
-			indio_dev->channels[0].scan_type.storagebits >> 3;
-
-	addr = kmalloc(num_data_channels, GFP_KERNEL);
-	if (!addr) {
-		len = -ENOMEM;
-		goto st_sensors_get_buffer_element_error;
-	}
 
 	for (i = 0; i < num_data_channels; i++) {
+		unsigned int bytes_to_read;
+
 		if (test_bit(i, indio_dev->active_scan_mask)) {
-			addr[n] = indio_dev->channels[i].address;
-			n++;
-		}
-	}
-	switch (n) {
-	case 1:
-		len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
-			addr[0], byte_for_channel, buf, sdata->multiread_bit);
-		break;
-	case 2:
-		if ((addr[1] - addr[0]) == byte_for_channel) {
+			bytes_to_read = indio_dev->channels[i].scan_type.storagebits >> 3;
 			len = sdata->tf->read_multiple_byte(&sdata->tb,
-				sdata->dev, addr[0], byte_for_channel * n,
-				buf, sdata->multiread_bit);
-		} else {
-			u8 *rx_array;
-			rx_array = kmalloc(byte_for_channel * num_data_channels,
-					   GFP_KERNEL);
-			if (!rx_array) {
-				len = -ENOMEM;
-				goto st_sensors_free_memory;
-			}
+				sdata->dev, indio_dev->channels[i].address,
+				bytes_to_read,
+				buf + total, sdata->multiread_bit);
 
-			len = sdata->tf->read_multiple_byte(&sdata->tb,
-				sdata->dev, addr[0],
-				byte_for_channel * num_data_channels,
-				rx_array, sdata->multiread_bit);
-			if (len < 0) {
-				kfree(rx_array);
-				goto st_sensors_free_memory;
-			}
-
-			for (i = 0; i < n * byte_for_channel; i++) {
-				if (i < n)
-					buf[i] = rx_array[i];
-				else
-					buf[i] = rx_array[n + i];
-			}
-			kfree(rx_array);
-			len = byte_for_channel * n;
+			if (len < bytes_to_read)
+				return -EIO;
+
+			/* Advance the buffer pointer */
+			total += len;
 		}
-		break;
-	case 3:
-		len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
-			addr[0], byte_for_channel * num_data_channels,
-			buf, sdata->multiread_bit);
-		break;
-	default:
-		len = -EINVAL;
-		goto st_sensors_free_memory;
-	}
-	if (len != byte_for_channel * n) {
-		len = -EIO;
-		goto st_sensors_free_memory;
 	}
 
-st_sensors_free_memory:
-	kfree(addr);
-st_sensors_get_buffer_element_error:
-	return len;
+	return total;
 }
 EXPORT_SYMBOL(st_sensors_get_buffer_element);
 
@@ -108,13 +57,20 @@ irqreturn_t st_sensors_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
+	s64 timestamp;
+
+	/* If we do timetamping here, do it before reading the values */
+	if (sdata->hw_irq_trigger)
+		timestamp = sdata->hw_timestamp;
+	else
+		timestamp = iio_get_time_ns();
 
 	len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
 	if (len < 0)
 		goto st_sensors_get_buffer_element_error;
 
 	iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data,
-		pf->timestamp);
+					   timestamp);
 
 st_sensors_get_buffer_element_error:
 	iio_trigger_notify_done(indio_dev->trig);
diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index f5a2d445d..9e59c90f6 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -301,6 +301,14 @@ static int st_sensors_set_drdy_int_pin(struct iio_dev *indio_dev,
 		return -EINVAL;
 	}
 
+	if (pdata->open_drain) {
+		if (!sdata->sensor_settings->drdy_irq.addr_od)
+			dev_err(&indio_dev->dev,
+				"open drain requested but unsupported.\n");
+		else
+			sdata->int_pin_open_drain = true;
+	}
+
 	return 0;
 }
 
@@ -321,6 +329,8 @@ static struct st_sensors_platform_data *st_sensors_of_probe(struct device *dev,
 	else
 		pdata->drdy_int_pin = defdata ? defdata->drdy_int_pin : 0;
 
+	pdata->open_drain = of_property_read_bool(np, "drive-open-drain");
+
 	return pdata;
 }
 #else
@@ -353,6 +363,11 @@ int st_sensors_init_sensor(struct iio_dev *indio_dev,
 	if (err < 0)
 		return err;
 
+	/* Disable DRDY, this might be still be enabled after reboot. */
+	err = st_sensors_set_dataready_irq(indio_dev, false);
+	if (err < 0)
+		return err;
+
 	if (sdata->current_fullscale) {
 		err = st_sensors_set_fullscale(indio_dev,
 						sdata->current_fullscale->num);
@@ -374,6 +389,16 @@ int st_sensors_init_sensor(struct iio_dev *indio_dev,
 			return err;
 	}
 
+	if (sdata->int_pin_open_drain) {
+		dev_info(&indio_dev->dev,
+			 "set interrupt line to open drain mode\n");
+		err = st_sensors_write_data_with_mask(indio_dev,
+				sdata->sensor_settings->drdy_irq.addr_od,
+				sdata->sensor_settings->drdy_irq.mask_od, 1);
+		if (err < 0)
+			return err;
+	}
+
 	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
 
 	return err;
@@ -404,6 +429,9 @@ int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable)
 	else
 		drdy_mask = sdata->sensor_settings->drdy_irq.mask_int2;
 
+	/* Flag to the poll function that the hardware trigger is in use */
+	sdata->hw_irq_trigger = enable;
+
 	/* Enable/Disable the interrupt generator for data ready. */
 	err = st_sensors_write_data_with_mask(indio_dev,
 					sdata->sensor_settings->drdy_irq.addr,
diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c
index 6a8c98327..296e4ff19 100644
--- a/drivers/iio/common/st_sensors/st_sensors_trigger.c
+++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c
@@ -17,6 +17,73 @@
 #include <linux/iio/common/st_sensors.h>
 #include "st_sensors_core.h"
 
+/**
+ * st_sensors_irq_handler() - top half of the IRQ-based triggers
+ * @irq: irq number
+ * @p: private handler data
+ */
+irqreturn_t st_sensors_irq_handler(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);
+
+	/* Get the time stamp as close in time as possible */
+	sdata->hw_timestamp = iio_get_time_ns();
+	return IRQ_WAKE_THREAD;
+}
+
+/**
+ * st_sensors_irq_thread() - bottom half of the IRQ-based triggers
+ * @irq: irq number
+ * @p: private handler data
+ */
+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
+	 */
+	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 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;
+	}
+
+out_poll:
+	/* It's our IRQ: proceed to handle the register polling */
+	iio_trigger_poll_chained(p);
+	return IRQ_HANDLED;
+}
+
 int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
 				const struct iio_trigger_ops *trigger_ops)
 {
@@ -30,6 +97,10 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
 		return -ENOMEM;
 	}
 
+	iio_trigger_set_drvdata(sdata->trig, indio_dev);
+	sdata->trig->ops = trigger_ops;
+	sdata->trig->dev.parent = sdata->dev;
+
 	irq = sdata->get_irq_data_ready(indio_dev);
 	irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
 	/*
@@ -64,9 +135,25 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
 			"rising edge\n", irq_trig);
 		irq_trig = IRQF_TRIGGER_RISING;
 	}
-	err = request_threaded_irq(irq,
-			iio_trigger_generic_data_rdy_poll,
-			NULL,
+
+	/*
+	 * If the interrupt pin is Open Drain, by definition this
+	 * means that the interrupt line may be shared with other
+	 * peripherals. But to do this we also need to have a status
+	 * register and mask to figure out if this sensor was firing
+	 * the IRQ or not, so we can tell the interrupt handle that
+	 * it was "our" interrupt.
+	 */
+	if (sdata->int_pin_open_drain &&
+	    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,
 			irq_trig,
 			sdata->trig->name,
 			sdata->trig);
@@ -75,10 +162,6 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
 		goto iio_trigger_free;
 	}
 
-	iio_trigger_set_drvdata(sdata->trig, indio_dev);
-	sdata->trig->ops = trigger_ops;
-	sdata->trig->dev.parent = sdata->dev;
-
 	err = iio_trigger_register(sdata->trig);
 	if (err < 0) {
 		dev_err(&indio_dev->dev, "failed to register iio trigger.\n");
@@ -106,6 +189,18 @@ void st_sensors_deallocate_trigger(struct iio_dev *indio_dev)
 }
 EXPORT_SYMBOL(st_sensors_deallocate_trigger);
 
+int st_sensors_validate_device(struct iio_trigger *trig,
+			       struct iio_dev *indio_dev)
+{
+	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
+
+	if (indio != indio_dev)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(st_sensors_validate_device);
+
 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
 MODULE_DESCRIPTION("STMicroelectronics ST-sensors trigger");
 MODULE_LICENSE("GPL v2");