Linux-libre 4.8.2-gnupck-4.8.2-gnu

4 files changed, 178 insertions, 88 deletions

diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c
index f1693dbeb..d06e728ce 100644
--- a/drivers/iio/common/st_sensors/st_sensors_buffer.c
+++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c
@@ -22,34 +22,32 @@
 #include <linux/iio/common/st_sensors.h>
 
 
-int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
+static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
 {
-	int i, len;
-	int total = 0;
+	int i;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
 	unsigned int num_data_channels = sdata->num_data_channels;
 
-	for (i = 0; i < num_data_channels; i++) {
-		unsigned int bytes_to_read;
-
-		if (test_bit(i, indio_dev->active_scan_mask)) {
-			bytes_to_read = indio_dev->channels[i].scan_type.storagebits >> 3;
-			len = sdata->tf->read_multiple_byte(&sdata->tb,
-				sdata->dev, indio_dev->channels[i].address,
-				bytes_to_read,
-				buf + total, sdata->multiread_bit);
-
-			if (len < bytes_to_read)
-				return -EIO;
-
-			/* Advance the buffer pointer */
-			total += len;
-		}
+	for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
+		const struct iio_chan_spec *channel = &indio_dev->channels[i];
+		unsigned int bytes_to_read = channel->scan_type.realbits >> 3;
+		unsigned int storage_bytes =
+			channel->scan_type.storagebits >> 3;
+
+		buf = PTR_ALIGN(buf, storage_bytes);
+		if (sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
+						  channel->address,
+						  bytes_to_read, buf,
+						  sdata->multiread_bit) <
+		    bytes_to_read)
+			return -EIO;
+
+		/* Advance the buffer pointer */
+		buf += storage_bytes;
 	}
 
-	return total;
+	return 0;
 }
-EXPORT_SYMBOL(st_sensors_get_buffer_element);
 
 irqreturn_t st_sensors_trigger_handler(int irq, void *p)
 {
@@ -59,11 +57,16 @@ 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
-		timestamp = iio_get_time_ns();
+		timestamp = iio_get_time_ns(indio_dev);
 
 	len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
 	if (len < 0)
diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index 9e59c90f6..2d5282e05 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -228,7 +228,7 @@ int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable)
 }
 EXPORT_SYMBOL(st_sensors_set_axis_enable);
 
-void st_sensors_power_enable(struct iio_dev *indio_dev)
+int st_sensors_power_enable(struct iio_dev *indio_dev)
 {
 	struct st_sensor_data *pdata = iio_priv(indio_dev);
 	int err;
@@ -237,18 +237,37 @@ void st_sensors_power_enable(struct iio_dev *indio_dev)
 	pdata->vdd = devm_regulator_get_optional(indio_dev->dev.parent, "vdd");
 	if (!IS_ERR(pdata->vdd)) {
 		err = regulator_enable(pdata->vdd);
-		if (err != 0)
+		if (err != 0) {
 			dev_warn(&indio_dev->dev,
 				 "Failed to enable specified Vdd supply\n");
+			return err;
+		}
+	} else {
+		err = PTR_ERR(pdata->vdd);
+		if (err != -ENODEV)
+			return err;
 	}
 
 	pdata->vdd_io = devm_regulator_get_optional(indio_dev->dev.parent, "vddio");
 	if (!IS_ERR(pdata->vdd_io)) {
 		err = regulator_enable(pdata->vdd_io);
-		if (err != 0)
+		if (err != 0) {
 			dev_warn(&indio_dev->dev,
 				 "Failed to enable specified Vdd_IO supply\n");
+			goto st_sensors_disable_vdd;
+		}
+	} else {
+		err = PTR_ERR(pdata->vdd_io);
+		if (err != -ENODEV)
+			goto st_sensors_disable_vdd;
 	}
+
+	return 0;
+
+st_sensors_disable_vdd:
+	if (!IS_ERR_OR_NULL(pdata->vdd))
+		regulator_disable(pdata->vdd);
+	return err;
 }
 EXPORT_SYMBOL(st_sensors_power_enable);
 
@@ -256,10 +275,10 @@ void st_sensors_power_disable(struct iio_dev *indio_dev)
 {
 	struct st_sensor_data *pdata = iio_priv(indio_dev);
 
-	if (!IS_ERR(pdata->vdd))
+	if (!IS_ERR_OR_NULL(pdata->vdd))
 		regulator_disable(pdata->vdd);
 
-	if (!IS_ERR(pdata->vdd_io))
+	if (!IS_ERR_OR_NULL(pdata->vdd_io))
 		regulator_disable(pdata->vdd_io);
 }
 EXPORT_SYMBOL(st_sensors_power_disable);
@@ -471,7 +490,7 @@ static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
 	int err;
 	u8 *outdata;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
-	unsigned int byte_for_channel = ch->scan_type.storagebits >> 3;
+	unsigned int byte_for_channel = ch->scan_type.realbits >> 3;
 
 	outdata = kmalloc(byte_for_channel, GFP_KERNEL);
 	if (!outdata)
@@ -531,7 +550,7 @@ int st_sensors_check_device_support(struct iio_dev *indio_dev,
 			int num_sensors_list,
 			const struct st_sensor_settings *sensor_settings)
 {
-	int i, n, err;
+	int i, n, err = 0;
 	u8 wai;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
 
@@ -551,17 +570,21 @@ int st_sensors_check_device_support(struct iio_dev *indio_dev,
 		return -ENODEV;
 	}
 
-	err = sdata->tf->read_byte(&sdata->tb, sdata->dev,
-					sensor_settings[i].wai_addr, &wai);
-	if (err < 0) {
-		dev_err(&indio_dev->dev, "failed to read Who-Am-I register.\n");
-		return err;
-	}
+	if (sensor_settings[i].wai_addr) {
+		err = sdata->tf->read_byte(&sdata->tb, sdata->dev,
+					   sensor_settings[i].wai_addr, &wai);
+		if (err < 0) {
+			dev_err(&indio_dev->dev,
+				"failed to read Who-Am-I register.\n");
+			return err;
+		}
 
-	if (sensor_settings[i].wai != wai) {
-		dev_err(&indio_dev->dev, "%s: WhoAmI mismatch (0x%x).\n",
-						indio_dev->name, wai);
-		return -EINVAL;
+		if (sensor_settings[i].wai != wai) {
+			dev_err(&indio_dev->dev,
+				"%s: WhoAmI mismatch (0x%x).\n",
+				indio_dev->name, wai);
+			return -EINVAL;
+		}
 	}
 
 	sdata->sensor_settings =
diff --git a/drivers/iio/common/st_sensors/st_sensors_i2c.c b/drivers/iio/common/st_sensors/st_sensors_i2c.c
index 98cfee296..b43aa3603 100644
--- a/drivers/iio/common/st_sensors/st_sensors_i2c.c
+++ b/drivers/iio/common/st_sensors/st_sensors_i2c.c
@@ -48,8 +48,8 @@ static int st_sensors_i2c_read_multiple_byte(
 	if (multiread_bit)
 		reg_addr |= ST_SENSORS_I2C_MULTIREAD;
 
-	return i2c_smbus_read_i2c_block_data(to_i2c_client(dev),
-							reg_addr, len, data);
+	return i2c_smbus_read_i2c_block_data_or_emulated(to_i2c_client(dev),
+							 reg_addr, len, data);
 }
 
 static int st_sensors_i2c_write_byte(struct st_sensor_transfer_buffer *tb,
diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c
index 296e4ff19..e66f12ee8 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
@@ -29,7 +73,7 @@ irqreturn_t st_sensors_irq_handler(int irq, void *p)
 	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();
+	sdata->hw_timestamp = iio_get_time_ns(indio_dev);
 	return IRQ_WAKE_THREAD;
 }
 
@@ -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,