Merge tag 'iio-for-4.20b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of IIO new device support features and cleanup for the 4.20 cycle.

One merge commit in here to bring in the SPI_CS_WORD flag patches
that are also going via the SPI tree.

There are a few more fixes than normal for a pull targetting the
next merge window.  These are all long term issues and as we are late
in the cycle, they can wait.

New device support
* ad7606
  - Add support fo the ad7605-4 driver.  This driver is still in staging
    but is heading in the right direction to graduate, motivated partly
    by the requirement for this device support.
* ST VL53L0X ToF ranging sensor
  - New minimal driver. Interrupt support to follow.

New features

* SPI_CS_WORD optimization allows long transfers with the chip select
  toggled every 16bits.   There is a software fallback as well to let
  drivers not care about whether the hardware supports it.

* bh1750
  - Device tree support and bindings.
* ti-ads7950
  - Use the SPI_CS_WORD optmization to save lots of cpu cycles (assuming
    the hardware supports it)

Fixes and cleanups

* ad5064
  - Fix some long incorrect regulator error handling that preventing
    enabling the internal regulator.
* ad7606
  - The ad7606 doesn't actually have a 2.5V range and the values provided
    for scale have always been wrong.  Fix them.
  - Drop some wrong kernel-doc (things that don't exist)
  - Add missing kernel-doc
* at91-adc
  - Fixing missing ack of dataready on sysfs channel reads to avoid spurious
    interrupts.
  - Fix a wrong channel numbers in triggered_buffer_mode
* hmc5843
  - Fix incorrect part number in a comment.
* imx25-gcq
  - Fix a device_node leak in an error path.
* meson-saradc
  - Drop an unused and pointless define.
  - Use of_device_get_match_data instead of opencoding
  - Tidy up how meson_sar_adc_param is accessed.
  - Rework prior to adding some temperature sensor support.

* tag 'iio-for-4.20b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
  iio: ad5064: Fix regulator handling
  iio: adc: meson-saradc: use the address attribute from iio_chan_spec
  iio: adc: meson-saradc: do not use meson_sar_adc_iio_channels directly
  iio: adc: at91: fix wrong channel number in triggered buffer mode
  iio: adc: at91: fix acking DRDY irq on simple conversions
  iio: adc: meson-saradc: simplify access to meson_sar_adc_param
  iio: adc: meson-saradc: use of_device_get_match_data
  iio: adc: meson-saradc: remove #define MESON_SAR_ADC_DELTA_10_TS_C_SHIFT
  iio: light: bh1750: Add device tree support
  dt-bindings: iio: light: bh1750: Add device tree binding documentation
  staging:iio:ad7606: Add support for the ad7605-4
  iio: proximity: Add driver support for ST's VL53L0X ToF ranging sensor.
  staging:iio:ad7606: update structs with doc annotations
  iio: magnetometer: hmc5843: Fixed a comment error.
  iio: adc: imx25-gcq: Fix leak of device_node in mx25_gcq_setup_cfgs()
  iio: adc: ti-ads7950: use SPI_CS_WORD to reduce CPU usage
  spi: add software implementation for SPI_CS_WORD
  spi: add new SPI_CS_WORD flag
  staging:iio:ad7606: Remove incorrect kernel doc annotations
  staging:iio:ad7606: fix voltage scales

1 files changed, 31 insertions, 22 deletions

diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c
index a5bd5944bc66..0ad63592cc3c 100644
--- a/drivers/iio/adc/ti-ads7950.c
+++ b/drivers/iio/adc/ti-ads7950.c
@@ -51,7 +51,7 @@
 
 struct ti_ads7950_state {
 	struct spi_device	*spi;
-	struct spi_transfer	ring_xfer[TI_ADS7950_MAX_CHAN + 2];
+	struct spi_transfer	ring_xfer;
 	struct spi_transfer	scan_single_xfer[3];
 	struct spi_message	ring_msg;
 	struct spi_message	scan_single_msg;
@@ -65,11 +65,11 @@ struct ti_ads7950_state {
 	 * DMA (thus cache coherency maintenance) requires the
 	 * transfer buffers to live in their own cache lines.
 	 */
-	__be16	rx_buf[TI_ADS7950_MAX_CHAN + TI_ADS7950_TIMESTAMP_SIZE]
+	u16 rx_buf[TI_ADS7950_MAX_CHAN + 2 + TI_ADS7950_TIMESTAMP_SIZE]
 							____cacheline_aligned;
-	__be16	tx_buf[TI_ADS7950_MAX_CHAN];
-	__be16			single_tx;
-	__be16			single_rx;
+	u16 tx_buf[TI_ADS7950_MAX_CHAN + 2];
+	u16 single_tx;
+	u16 single_rx;
 
 };
 
@@ -108,7 +108,7 @@ enum ti_ads7950_id {
 		.realbits = bits,				\
 		.storagebits = 16,				\
 		.shift = 12 - (bits),				\
-		.endianness = IIO_BE,				\
+		.endianness = IIO_CPU,				\
 	},							\
 }
 
@@ -249,23 +249,14 @@ static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev,
 	len = 0;
 	for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) {
 		cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings;
-		st->tx_buf[len++] = cpu_to_be16(cmd);
+		st->tx_buf[len++] = cmd;
 	}
 
 	/* Data for the 1st channel is not returned until the 3rd transfer */
-	len += 2;
-	for (i = 0; i < len; i++) {
-		if ((i + 2) < len)
-			st->ring_xfer[i].tx_buf = &st->tx_buf[i];
-		if (i >= 2)
-			st->ring_xfer[i].rx_buf = &st->rx_buf[i - 2];
-		st->ring_xfer[i].len = 2;
-		st->ring_xfer[i].cs_change = 1;
-	}
-	/* make sure last transfer's cs_change is not set */
-	st->ring_xfer[len - 1].cs_change = 0;
+	st->tx_buf[len++] = 0;
+	st->tx_buf[len++] = 0;
 
-	spi_message_init_with_transfers(&st->ring_msg, st->ring_xfer, len);
+	st->ring_xfer.len = len * 2;
 
 	return 0;
 }
@@ -281,7 +272,7 @@ static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p)
 	if (ret < 0)
 		goto out;
 
-	iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
+	iio_push_to_buffers_with_timestamp(indio_dev, &st->rx_buf[2],
 					   iio_get_time_ns(indio_dev));
 
 out:
@@ -298,13 +289,13 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
 	mutex_lock(&indio_dev->mlock);
 
 	cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings;
-	st->single_tx = cpu_to_be16(cmd);
+	st->single_tx = cmd;
 
 	ret = spi_sync(st->spi, &st->scan_single_msg);
 	if (ret)
 		goto out;
 
-	ret = be16_to_cpu(st->single_rx);
+	ret = st->single_rx;
 
 out:
 	mutex_unlock(&indio_dev->mlock);
@@ -378,6 +369,14 @@ static int ti_ads7950_probe(struct spi_device *spi)
 	const struct ti_ads7950_chip_info *info;
 	int ret;
 
+	spi->bits_per_word = 16;
+	spi->mode |= SPI_CS_WORD;
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(&spi->dev, "Error in spi setup\n");
+		return ret;
+	}
+
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;
@@ -398,6 +397,16 @@ static int ti_ads7950_probe(struct spi_device *spi)
 	indio_dev->num_channels = info->num_channels;
 	indio_dev->info = &ti_ads7950_info;
 
+	/* build spi ring message */
+	spi_message_init(&st->ring_msg);
+
+	st->ring_xfer.tx_buf = &st->tx_buf[0];
+	st->ring_xfer.rx_buf = &st->rx_buf[0];
+	/* len will be set later */
+	st->ring_xfer.cs_change = true;
+
+	spi_message_add_tail(&st->ring_xfer, &st->ring_msg);
+
 	/*
 	 * Setup default message. The sample is read at the end of the first
 	 * transfer, then it takes one full cycle to convert the sample and one