Second set of IIO fixes for the 5.4 cycle.

* adis16480
   - Prevent negative numbers being accepted for sampling frequency.
 * inv_mpu6050
   - Fix an issue where fifo overflow bits don't actually work as expected,
     by checking the fifo count instead.
 * srf04
   - Allow more time for echo to signal as some sensors supported have
     a higher range.
 * stm32-adc
   - Fix a potential race in dma disable by ensuring all transfers are done.
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Merge tag 'iio-fixes-for-5.4b' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus

Second set of IIO fixes for the 5.4 cycle.

* adis16480
  - Prevent negative numbers being accepted for sampling frequency.
* inv_mpu6050
  - Fix an issue where fifo overflow bits don't actually work as expected,
    by checking the fifo count instead.
* srf04
  - Allow more time for echo to signal as some sensors supported have
    a higher range.
* stm32-adc
  - Fix a potential race in dma disable by ensuring all transfers are done.

* tag 'iio-fixes-for-5.4b' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
  iio: adc: stm32-adc: fix stopping dma
  iio: imu: inv_mpu6050: fix no data on MPU6050
  iio: srf04: fix wrong limitation in distance measuring
  iio: imu: adis16480: make sure provided frequency is positive

drivers/iio/adc/stm32-adc.c

@@ -1399,7 +1399,7 @@ static int stm32_adc_dma_start(struct iio_dev *indio_dev)
 	cookie = dmaengine_submit(desc);
 	ret = dma_submit_error(cookie);
 	if (ret) {
-		dmaengine_terminate_all(adc->dma_chan);
+		dmaengine_terminate_sync(adc->dma_chan);
 		return ret;
 	}
 
@@ -1477,7 +1477,7 @@ static void __stm32_adc_buffer_predisable(struct iio_dev *indio_dev)
 		stm32_adc_conv_irq_disable(adc);
 
 	if (adc->dma_chan)
-		dmaengine_terminate_all(adc->dma_chan);
+		dmaengine_terminate_sync(adc->dma_chan);
 
 	if (stm32_adc_set_trig(indio_dev, NULL))
 		dev_err(&indio_dev->dev, "Can't clear trigger\n");

drivers/iio/imu/adis16480.c

@@ -317,8 +317,11 @@ static int adis16480_set_freq(struct iio_dev *indio_dev, int val, int val2)
 	struct adis16480 *st = iio_priv(indio_dev);
 	unsigned int t, reg;
 
+	if (val < 0 || val2 < 0)
+		return -EINVAL;
+
 	t =  val * 1000 + val2 / 1000;
-	if (t <= 0)
+	if (t == 0)
 		return -EINVAL;
 
 	/*

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c

@@ -114,54 +114,63 @@ static const struct inv_mpu6050_hw hw_info[] = {
 		.name = "MPU6050",
 		.reg = &reg_set_6050,
 		.config = &chip_config_6050,
+		.fifo_size = 1024,
 	},
 	{
 		.whoami = INV_MPU6500_WHOAMI_VALUE,
 		.name = "MPU6500",
 		.reg = &reg_set_6500,
 		.config = &chip_config_6050,
+		.fifo_size = 512,
 	},
 	{
 		.whoami = INV_MPU6515_WHOAMI_VALUE,
 		.name = "MPU6515",
 		.reg = &reg_set_6500,
 		.config = &chip_config_6050,
+		.fifo_size = 512,
 	},
 	{
 		.whoami = INV_MPU6000_WHOAMI_VALUE,
 		.name = "MPU6000",
 		.reg = &reg_set_6050,
 		.config = &chip_config_6050,
+		.fifo_size = 1024,
 	},
 	{
 		.whoami = INV_MPU9150_WHOAMI_VALUE,
 		.name = "MPU9150",
 		.reg = &reg_set_6050,
 		.config = &chip_config_6050,
+		.fifo_size = 1024,
 	},
 	{
 		.whoami = INV_MPU9250_WHOAMI_VALUE,
 		.name = "MPU9250",
 		.reg = &reg_set_6500,
 		.config = &chip_config_6050,
+		.fifo_size = 512,
 	},
 	{
 		.whoami = INV_MPU9255_WHOAMI_VALUE,
 		.name = "MPU9255",
 		.reg = &reg_set_6500,
 		.config = &chip_config_6050,
+		.fifo_size = 512,
 	},
 	{
 		.whoami = INV_ICM20608_WHOAMI_VALUE,
 		.name = "ICM20608",
 		.reg = &reg_set_6500,
 		.config = &chip_config_6050,
+		.fifo_size = 512,
 	},
 	{
 		.whoami = INV_ICM20602_WHOAMI_VALUE,
 		.name = "ICM20602",
 		.reg = &reg_set_icm20602,
 		.config = &chip_config_6050,
+		.fifo_size = 1008,
 	},
 };
 

drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h

@@ -100,12 +100,14 @@ struct inv_mpu6050_chip_config {
  *  @name:      name of the chip.
  *  @reg:   register map of the chip.
  *  @config:    configuration of the chip.
+ *  @fifo_size:	size of the FIFO in bytes.
  */
 struct inv_mpu6050_hw {
 	u8 whoami;
 	u8 *name;
 	const struct inv_mpu6050_reg_map *reg;
 	const struct inv_mpu6050_chip_config *config;
+	size_t fifo_size;
 };
 
 /*

drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c

@@ -180,9 +180,6 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 			"failed to ack interrupt\n");
 		goto flush_fifo;
 	}
-	/* handle fifo overflow by reseting fifo */
-	if (int_status & INV_MPU6050_BIT_FIFO_OVERFLOW_INT)
-		goto flush_fifo;
 	if (!(int_status & INV_MPU6050_BIT_RAW_DATA_RDY_INT)) {
 		dev_warn(regmap_get_device(st->map),
 			"spurious interrupt with status 0x%x\n", int_status);
@@ -211,6 +208,18 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 	if (result)
 		goto end_session;
 	fifo_count = get_unaligned_be16(&data[0]);
+
+	/*
+	 * Handle fifo overflow by resetting fifo.
+	 * Reset if there is only 3 data set free remaining to mitigate
+	 * possible delay between reading fifo count and fifo data.
+	 */
+	nb = 3 * bytes_per_datum;
+	if (fifo_count >= st->hw->fifo_size - nb) {
+		dev_warn(regmap_get_device(st->map), "fifo overflow reset\n");
+		goto flush_fifo;
+	}
+
 	/* compute and process all complete datum */
 	nb = fifo_count / bytes_per_datum;
 	inv_mpu6050_update_period(st, pf->timestamp, nb);

drivers/iio/proximity/srf04.c

@@ -110,7 +110,7 @@ static int srf04_read(struct srf04_data *data)
 	udelay(data->cfg->trigger_pulse_us);
 	gpiod_set_value(data->gpiod_trig, 0);
 
-	/* it cannot take more than 20 ms */
+	/* it should not take more than 20 ms until echo is rising */
 	ret = wait_for_completion_killable_timeout(&data->rising, HZ/50);
 	if (ret < 0) {
 		mutex_unlock(&data->lock);
@@ -120,7 +120,8 @@ static int srf04_read(struct srf04_data *data)
 		return -ETIMEDOUT;
 	}
 
-	ret = wait_for_completion_killable_timeout(&data->falling, HZ/50);
+	/* it cannot take more than 50 ms until echo is falling */
+	ret = wait_for_completion_killable_timeout(&data->falling, HZ/20);
 	if (ret < 0) {
 		mutex_unlock(&data->lock);
 		return ret;
@@ -135,19 +136,19 @@ static int srf04_read(struct srf04_data *data)
 
 	dt_ns = ktime_to_ns(ktime_dt);
 	/*
-	 * measuring more than 3 meters is beyond the capabilities of
-	 * the sensor
+	 * measuring more than 6,45 meters is beyond the capabilities of
+	 * the supported sensors
 	 * ==> filter out invalid results for not measuring echos of
 	 *     another us sensor
 	 *
 	 * formula:
-	 *         distance       3 m
-	 * time = ---------- = --------- = 9404389 ns
-	 *          speed       319 m/s
+	 *         distance     6,45 * 2 m
+	 * time = ---------- = ------------ = 40438871 ns
+	 *          speed         319 m/s
 	 *
 	 * using a minimum speed at -20 °C of 319 m/s
 	 */
-	if (dt_ns > 9404389)
+	if (dt_ns > 40438871)
 		return -EIO;
 
 	time_ns = dt_ns;
@@ -159,20 +160,20 @@ static int srf04_read(struct srf04_data *data)
 	 *   with Temp in °C
 	 *   and speed in m/s
 	 *
-	 * use 343 m/s as ultrasonic speed at 20 °C here in absence of the
+	 * use 343,5 m/s as ultrasonic speed at 20 °C here in absence of the
 	 * temperature
 	 *
 	 * therefore:
-	 *             time     343
-	 * distance = ------ * -----
-	 *             10^6       2
+	 *             time     343,5     time * 106
+	 * distance = ------ * ------- = ------------
+	 *             10^6         2         617176
 	 *   with time in ns
 	 *   and distance in mm (one way)
 	 *
-	 * because we limit to 3 meters the multiplication with 343 just
+	 * because we limit to 6,45 meters the multiplication with 106 just
 	 * fits into 32 bit
 	 */
-	distance_mm = time_ns * 343 / 2000000;
+	distance_mm = time_ns * 106 / 617176;
 
 	return distance_mm;
 }