Merge tag 'iio-fixes-for-5.9a' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus

Jonathan writes:

First set of IIO fixes for the 5.9 cycle

Most of the fixes this time are for a long term issue that Lars-Peter
Clausen identified recently.

IIO assumes that any data pushed to the buffer interface (either kfifo
or another in kernel consumer) are naturally aligned.  Unfortunately
this isn't true in a number of drivers, mostly by failing to ensure
the buffer used is aligned suitably for an s64 timestamp.

For the ones covered this time we use a structure to enforce this
alignment, with the added need for __aligned(8) to ensure 8 byte
alignment of the timestamp on x86_32 and similar platforms where
it would be 4 byte aligned giving different padded from some other
architectures.

Patches to make this requirement clearer and potentially cause an
error print will follow once we've cleaned up existing cases.
Note that it is a very hard to hit problem and as a result of this
as we only have one bug report despite the problem being present
for many years.

Other fixes:
* cros_ec:
  - set gyroscope default frequency. For some older boards not having
    this set can lead to a choice that doesn't work.
* counter,microchip-tcb-capture:
  - Fix a wrong value check in error check.
* mcp3422
  - Fix locking to protect against race condition.
* meson-adc
  - Use right device when looking up fuse values for calibration.
* rockchip-adc
  - Fix missing Kconfig dependency.
* ti-ads1015:
  - Fix reading when CONFIG_PM not set.

* tag 'iio-fixes-for-5.9a' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
  iio: adc: mcp3422: fix locking scope
  iio: adc: meson-saradc: Use the parent device to look up the calib data
  iio:adc:max1118 Fix alignment of timestamp and data leak issues
  iio:adc:ina2xx Fix timestamp alignment issue.
  iio:adc:ti-adc084s021 Fix alignment and data leak issues.
  iio:adc:ti-adc081c Fix alignment and data leak issues
  iio:magnetometer:ak8975 Fix alignment and data leak issues.
  iio:light:ltr501 Fix timestamp alignment issue.
  iio:light:max44000 Fix timestamp alignment and prevent data leak.
  iio:chemical:ccs811: Fix timestamp alignment and prevent data leak.
  iio:proximity:mb1232: Fix timestamp alignment and prevent data leak.
  iio:accel:mma7455: Fix timestamp alignment and prevent data leak.
  iio:accel:bmc150-accel: Fix timestamp alignment and prevent data leak.
  iio:accel:mma8452: Fix timestamp alignment and prevent data leak.
  iio: accel: kxsd9: Fix alignment of local buffer.
  iio: adc: rockchip_saradc: select IIO_TRIGGERED_BUFFER
  iio: adc: ti-ads1015: fix conversion when CONFIG_PM is not set
  counter: microchip-tcb-capture: check the correct variable
  iio: cros_ec: Set Gyroscope default frequency to 25Hz

Author: gregkh

drivers/counter/microchip-tcb-capture.c

@@ -320,8 +320,8 @@ static int mchp_tc_probe(struct platform_device *pdev)
 	}
 
 	regmap = syscon_node_to_regmap(np->parent);
-	if (IS_ERR(priv->regmap))
-		return PTR_ERR(priv->regmap);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
 
 	/* max. channels number is 2 when in QDEC mode */
 	priv->num_channels = of_property_count_u32_elems(np, "reg");

drivers/iio/accel/bmc150-accel-core.c

@@ -189,6 +189,14 @@ struct bmc150_accel_data {
 	struct mutex mutex;
 	u8 fifo_mode, watermark;
 	s16 buffer[8];
+	/*
+	 * Ensure there is sufficient space and correct alignment for
+	 * the timestamp if enabled
+	 */
+	struct {
+		__le16 channels[3];
+		s64 ts __aligned(8);
+	} scan;
 	u8 bw_bits;
 	u32 slope_dur;
 	u32 slope_thres;
@@ -922,15 +930,16 @@ static int __bmc150_accel_fifo_flush(struct iio_dev *indio_dev,
 	 * now.
 	 */
 	for (i = 0; i < count; i++) {
-		u16 sample[8];
 		int j, bit;
 
 		j = 0;
 		for_each_set_bit(bit, indio_dev->active_scan_mask,
 				 indio_dev->masklength)
-			memcpy(&sample[j++], &buffer[i * 3 + bit], 2);
+			memcpy(&data->scan.channels[j++], &buffer[i * 3 + bit],
+			       sizeof(data->scan.channels[0]));
 
-		iio_push_to_buffers_with_timestamp(indio_dev, sample, tstamp);
+		iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
+						   tstamp);
 
 		tstamp += sample_period;
 	}

drivers/iio/accel/kxsd9.c

@@ -209,22 +209,28 @@ static irqreturn_t kxsd9_trigger_handler(int irq, void *p)
 	const struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct kxsd9_state *st = iio_priv(indio_dev);
+	/*
+	 * Ensure correct positioning and alignment of timestamp.
+	 * No need to zero initialize as all elements written.
+	 */
+	struct {
+		__be16 chan[4];
+		s64 ts __aligned(8);
+	} hw_values;
 	int ret;
-	/* 4 * 16bit values AND timestamp */
-	__be16 hw_values[8];
 
 	ret = regmap_bulk_read(st->map,
 			       KXSD9_REG_X,
-			       &hw_values,
-			       8);
+			       hw_values.chan,
+			       sizeof(hw_values.chan));
 	if (ret) {
 		dev_err(st->dev,
 			"error reading data\n");
 		return ret;
 	}
 
 	iio_push_to_buffers_with_timestamp(indio_dev,
-					   hw_values,
+					   &hw_values,
 					   iio_get_time_ns(indio_dev));
 	iio_trigger_notify_done(indio_dev->trig);
 

drivers/iio/accel/mma7455_core.c

@@ -52,6 +52,14 @@
 
 struct mma7455_data {
 	struct regmap *regmap;
+	/*
+	 * Used to reorganize data.  Will ensure correct alignment of
+	 * the timestamp if present
+	 */
+	struct {
+		__le16 channels[3];
+		s64 ts __aligned(8);
+	} scan;
 };
 
 static int mma7455_drdy(struct mma7455_data *mma7455)
@@ -82,19 +90,19 @@ static irqreturn_t mma7455_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct mma7455_data *mma7455 = iio_priv(indio_dev);
-	u8 buf[16]; /* 3 x 16-bit channels + padding + ts */
 	int ret;
 
 	ret = mma7455_drdy(mma7455);
 	if (ret)
 		goto done;
 
-	ret = regmap_bulk_read(mma7455->regmap, MMA7455_REG_XOUTL, buf,
-			       sizeof(__le16) * 3);
+	ret = regmap_bulk_read(mma7455->regmap, MMA7455_REG_XOUTL,
+			       mma7455->scan.channels,
+			       sizeof(mma7455->scan.channels));
 	if (ret)
 		goto done;
 
-	iio_push_to_buffers_with_timestamp(indio_dev, buf,
+	iio_push_to_buffers_with_timestamp(indio_dev, &mma7455->scan,
 					   iio_get_time_ns(indio_dev));
 
 done:

drivers/iio/accel/mma8452.c

@@ -110,6 +110,12 @@ struct mma8452_data {
 	int sleep_val;
 	struct regulator *vdd_reg;
 	struct regulator *vddio_reg;
+
+	/* Ensure correct alignment of time stamp when present */
+	struct {
+		__be16 channels[3];
+		s64 ts __aligned(8);
+	} buffer;
 };
 
  /**
@@ -1091,14 +1097,13 @@ static irqreturn_t mma8452_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct mma8452_data *data = iio_priv(indio_dev);
-	u8 buffer[16]; /* 3 16-bit channels + padding + ts */
 	int ret;
 
-	ret = mma8452_read(data, (__be16 *)buffer);
+	ret = mma8452_read(data, data->buffer.channels);
 	if (ret < 0)
 		goto done;
 
-	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
 					   iio_get_time_ns(indio_dev));
 
 done:

drivers/iio/adc/Kconfig

@@ -865,6 +865,8 @@ config ROCKCHIP_SARADC
 	tristate "Rockchip SARADC driver"
 	depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST)
 	depends on RESET_CONTROLLER
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for the SARADC found in SoCs from
 	  Rockchip.

drivers/iio/adc/ina2xx-adc.c

@@ -146,6 +146,11 @@ struct ina2xx_chip_info {
 	int range_vbus; /* Bus voltage maximum in V */
 	int pga_gain_vshunt; /* Shunt voltage PGA gain */
 	bool allow_async_readout;
+	/* data buffer needs space for channel data and timestamp */
+	struct {
+		u16 chan[4];
+		u64 ts __aligned(8);
+	} scan;
 };
 
 static const struct ina2xx_config ina2xx_config[] = {
@@ -738,8 +743,6 @@ static int ina2xx_conversion_ready(struct iio_dev *indio_dev)
 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
 {
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
-	/* data buffer needs space for channel data and timestap */
-	unsigned short data[4 + sizeof(s64)/sizeof(short)];
 	int bit, ret, i = 0;
 	s64 time;
 
@@ -758,10 +761,10 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev)
 		if (ret < 0)
 			return ret;
 
-		data[i++] = val;
+		chip->scan.chan[i++] = val;
 	}
 
-	iio_push_to_buffers_with_timestamp(indio_dev, data, time);
+	iio_push_to_buffers_with_timestamp(indio_dev, &chip->scan, time);
 
 	return 0;
 };

drivers/iio/adc/max1118.c

@@ -36,6 +36,11 @@ struct max1118 {
 	struct spi_device *spi;
 	struct mutex lock;
 	struct regulator *reg;
+	/* Ensure natural alignment of buffer elements */
+	struct {
+		u8 channels[2];
+		s64 ts __aligned(8);
+	} scan;
 
 	u8 data ____cacheline_aligned;
 };
@@ -166,7 +171,6 @@ static irqreturn_t max1118_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct max1118 *adc = iio_priv(indio_dev);
-	u8 data[16] = { }; /* 2x 8-bit ADC data + padding + 8 bytes timestamp */
 	int scan_index;
 	int i = 0;
 
@@ -184,10 +188,10 @@ static irqreturn_t max1118_trigger_handler(int irq, void *p)
 			goto out;
 		}
 
-		data[i] = ret;
+		adc->scan.channels[i] = ret;
 		i++;
 	}
-	iio_push_to_buffers_with_timestamp(indio_dev, data,
+	iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan,
 					   iio_get_time_ns(indio_dev));
 out:
 	mutex_unlock(&adc->lock);

drivers/iio/adc/mcp3422.c

@@ -96,16 +96,12 @@ static int mcp3422_update_config(struct mcp3422 *adc, u8 newconfig)
 {
 	int ret;
 
-	mutex_lock(&adc->lock);
-
 	ret = i2c_master_send(adc->i2c, &newconfig, 1);
 	if (ret > 0) {
 		adc->config = newconfig;
 		ret = 0;
 	}
 
-	mutex_unlock(&adc->lock);
-
 	return ret;
 }
 
@@ -138,6 +134,8 @@ static int mcp3422_read_channel(struct mcp3422 *adc,
 	u8 config;
 	u8 req_channel = channel->channel;
 
+	mutex_lock(&adc->lock);
+
 	if (req_channel != MCP3422_CHANNEL(adc->config)) {
 		config = adc->config;
 		config &= ~MCP3422_CHANNEL_MASK;
@@ -150,7 +148,11 @@ static int mcp3422_read_channel(struct mcp3422 *adc,
 		msleep(mcp3422_read_times[MCP3422_SAMPLE_RATE(adc->config)]);
 	}
 
-	return mcp3422_read(adc, value, &config);
+	ret = mcp3422_read(adc, value, &config);
+
+	mutex_unlock(&adc->lock);
+
+	return ret;
 }
 
 static int mcp3422_read_raw(struct iio_dev *iio,

drivers/iio/adc/meson_saradc.c

@@ -707,7 +707,7 @@ static int meson_sar_adc_temp_sensor_init(struct iio_dev *indio_dev)
 	size_t read_len;
 	int ret;
 
-	temperature_calib = devm_nvmem_cell_get(&indio_dev->dev,
+	temperature_calib = devm_nvmem_cell_get(indio_dev->dev.parent,
 						"temperature_calib");
 	if (IS_ERR(temperature_calib)) {
 		ret = PTR_ERR(temperature_calib);