[PATCH v8 0/4] iio: light: add support for veml6031x00 ALS series

[PATCH v8 0/4] iio: light: add support for veml6031x00 ALS series

[Javier Carrasco]

These ambient light sensors with I2C interface provide two light
channels (ALS and IR), high/low threshold alarms with configurable
persistence, and a data ready signal.

The devices covered by this driver have the same resolution, and they
share most of their functionality. These are the differences between
them (note that the x belongs to their names, and it is not a wildcard):

 - Device ID: accessible via two 8-bit registers, different values for
   veml6031x00/veml6031x01 and veml60311x00/veml60311x01.
 - I2C address: same grouping, 0x29 and 0x10 I2C addresses.
 - AEC qualification: AEC-Q100 for veml6031x00/veml60311x00 and
   AEC-Q101 for veml6031x01/veml60311x01.

The alarms and the data ready signals share the interrupt pin, and an
interrupt status register must be accessed to identify the source. Such
multiplexing is not new in IIO, and I have followed existing examples
for it. The persistence setting (own attribute) to trigger the alarms
uses the pattern that has already been used for the veml6030.

The device configuration is in general documented in the datasheet and
the application note. There is an exception, though: the activation of
the "active force" mode that is required for the data ready signal must
be carried out in two steps even though the affected bits are located in
the same register: first ALS_AF (active force mode enable) must be set,
and then ALS_TRIG (active force trigger setting) must be enabled. I have
added a brief commentary in the code to explain this behavior, which has
been confirmed by the manufacturer.

The datasheet specifies the scale and integration time for the ALS channel.
Although both settings also affect the measured IR value, no transfer
function, accuracy, or calibration is specified for converting the IR
output into a physical quantity. The IR channel is therefore intended only
as a qualitative indication of the infrared content of the incident light,
rather than as a precision measurement channel. Consequently, the driver
does not expose scale or integration time as IR-channel attributes.

The only functionality that has not been implemented yet is the x0.66
gain (and its x0.165 counterpart when PD_DIV=1), which makes the gts
helpers less usable due to the conversions required. It is indeed an
uncommon gain to use (there are x0.5 and x0.125 gains) with no known
use-case at the moment that justifies making adjustments to the gts
helpers or adding artificial conversions to make it work.

This driver has been tested with the four supported devices separately
as well as in pairs where the I2C addresses don't overlap.

To: Jonathan Cameron <jic23@kernel.org>
To: Lars-Peter Clausen <lars@metafoo.de>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
To: David Lechner <dlechner@baylibre.com>
To: Nuno Sá <nuno.sa@analog.com>
To: Andy Shevchenko <andy@kernel.org>
Cc: linux-iio@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>

Changes in v8:
- [2/4] declare *dev = regmap_get_device() instead of calling it in
  dev_warn().
- [4/4] split regmap writable ranges to avoid holes (reserved registers).
- [4/4] Use is_power_of_2() and ilog2() instead of hweight8() and ffs().
- [4/4] Minor modifications suggested by Andy Shevchenko (direct return
  of devm_add_action_or_reset(), unsigned where required, split regval
  assignment).

- Link to v7: https://lore.kernel.org/r/20260818-veml6031x00-v7-0-2b0de0f20edf@gmail.com

Changes in v7:
- [2..4/4] Refactor probe() (extract IIO device initialization, more
  logical initialization order).
- [2/4] Drop pm_runtime_get_noresume() and pm_runtime_put_autosuspend()
  in the probe function and let the core handle it.
- [2/4] Rephrase unknwon ID info message.
- [2/4] Rephrase Commit message to make it independent of [3..4/4]
- [2/4] Trailing comma after last channel in iio_chan_spec.
- [2/4] Return -ENODATA if i2c_get_match_data() fails.
- [2/4] Use logical splits and local variables to make lines shorter.
- [2..4/4] Use regmap_assign_bits() instead of regmap_update_bits() where
  it makes sense.
- [4/4] Use pm_runtime_put_sync()
- [4/4] Explicitly include <linux/lockdep.h> for lockdep_assert_held().
- [4/4] Use helpers to refactor code without adding goto jumps within
  scoped guards.
- [4/4] Drop own trigger assignment.
- Link to v6: https://lore.kernel.org/r/20260812-veml6031x00-v6-0-7eef6e4ce290@gmail.com

Changes in v6:
- [1/4] Fix dt-binding title.
- [2/4] Update headers as indicated by Andy and Uwe.
- [2/4] Macro to get selector from gain registers.
- [2/4] Use pm_runtime_get_noresume() (no devres).
- [2/4] Drop <linux/mod_devicetable.h>
- [2/4] Use regmap_update_bits() to set power state.
- [3/4] Add scan info for the non-irq variant.
- [3/4] Fix lock acquisition (direct mode and then scale_lock).
- [3/4] Zero-initialize scan buffer.
- [4/4] Store timestamp before calling iio_trigger_poll_nested().
- [4/4] Move mutex_init and regfield_init before setup_irq().
- [4/4] Add lockdep_assert_held() to veml6031x00_interrupt().
- [4/4] Avoid register read if a spurious interrupt arrives when the
  device is powered down.
- Link to v5: https://lore.kernel.org/r/20260807-veml6031x00-v5-0-e60876fb3640@gmail.com

Changes in v5:
- [2/4] Explicit inclusion of some missing used headers.
- [2/4] Define CONF0 as volatile to account for AF_TRIG (reset by
  hardware).
- [2/4] Drop integration time and scale for IR channel.
- [2/4] Use unsigned int instead of int where no negative values are
  possible.
- [2/4] Write a helper to update the gain and use it where needed.
- [2/4] Move i2c_get_match() closer to the data allocation.
- [2/4] Move iio dev initialization out of the runtime pm region.
- [2/4] Lower log level for unknown ID part.
- [2/4] Redefine gains as _INT_MILLI.
- [2/4] Drop pointer to the device in the private structure.
- [2/4] Fix some coding-style issues.
- [4/4] Add second iio_chan_spec to avoid exposing dead sysfs attributes if no
  irq is available.
- [4/4] Refactor goto calls in functions with guard().
- [3/4] Use IIO_DECLARE_BUFFER_WITH_TS() instead of a custom structure.
- [4/4] Use format instead of deprecated sign for the scan type.
- Link to v4: https://lore.kernel.org/r/20260531-veml6031x00-v4-0-e64f7fdce38d@gmail.com

Changes in v4:
- [1/4] Entry in alphabetical order for MAINTAINERS.
- [2/4] Fix style for device ID tables.
- [2/4] Add missing header mod_devicetable.h and move iio/sysfs.h to
  [4/4] for the persistence attribute.
- [2/4] Move IIO_DEV_ACQUIRE_DIRECT_MODE to [3/4] where buffers are
  added.
- [3/4] Use test_bit() to check the active scan mask.
- [2/4] Add mutex for operations on scattered register fields.
- [2/4] Add shutdown action after turning the device on.
- Link to v3: https://lore.kernel.org/r/20260524-veml6031x00-v3-0-29165609b2b5@gmail.com

Changes in v3:
- Move veml6030 fixes to a separate patch stack.
- Use C99 initializers for i2c_device_id.
- Split driver code into multiple patches to ease its review.
- Rework locking to get rid of atomic increment/decrement ops.
- Fix error paths in pm_runtime operations.
- Use IIO_DEV_ACQUIRE_DIRECT_MODE for single read/write ops.
- Link to v2: https://lore.kernel.org/r/20260513-veml6031x00-v2-0-4703ca661a1d@gmail.com

Changes in v2:
- Add commit to fix bug in veml6030.c (channel type when pushing
  events) and remove dead code.
- Use gts helpers to simplify operations.
- Drop unused gain_idx.
- Build INT_MASK as an OR operation of the involved bits.
- Format arrays to follow the desired standard for IIO.
- Directly return function result as the last operation within another
  function instead of 'ret = x; if (ret) return ret; return 0;'.
- Fix some spacing (double space, tab for alignemnt in info struct).
- Use sizeof() for __le16 reg instead of 2.
- Return an error if the part ID could not be read.
- Spell out sd -> shutdown.
- Use devm_mutex_init() instead of mutex_init().
- Avoid using conditional guard, use claim/release instead.
- Access integration times from the global array to get and set the
  integration time instead of using a switch.
- Simplify read of available periods (persistence).
- Drop IRQF_TRIGGER_FALLING in the threaded irq request.
- Add regmap ranges.
- Link to v1: https://lore.kernel.org/r/20241126-veml6031x00-v1-0-4affa62bfefd@gmail.com

---
Javier Carrasco (4):
      dt-bindings: iio: light: veml6030: add veml6031x00 ALS series
      iio: light: add support for veml6031x00 ALS series
      iio: light: veml6031x00: add support for triggered buffers
      iio: light: veml6031x00: add support for events and trigger

 .../bindings/iio/light/vishay,veml6030.yaml        |   13 +-
 MAINTAINERS                                        |    6 +
 drivers/iio/light/Kconfig                          |   14 +
 drivers/iio/light/Makefile                         |    1 +
 drivers/iio/light/veml6031x00.c                    | 1370 ++++++++++++++++++++
 5 files changed, 1403 insertions(+), 1 deletion(-)
---
base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
change-id: 20241109-veml6031x00-aa9463da064a

Best regards,
-- 
Javier Carrasco <javier.carrasco.cruz@gmail.com>

[PATCH v8 1/4] dt-bindings: iio: light: veml6030: add veml6031x00 ALS series

[Javier Carrasco]

These ambient light sensors share their properties with the ones
from the same manufacturer that are supported by this bindings.

Note that only two datasheets are provided as every one of them covers
two devices (veml6031x00/veml60311x00 and veml6031x01/veml60311x01).

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
 .../devicetree/bindings/iio/light/vishay,veml6030.yaml      | 13 ++++++++++++-
 MAINTAINERS                                                 |  5 +++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/light/vishay,veml6030.yaml b/Documentation/devicetree/bindings/iio/light/vishay,veml6030.yaml
index 0041e1db6838..a44de649184a 100644
--- a/Documentation/devicetree/bindings/iio/light/vishay,veml6030.yaml
+++ b/Documentation/devicetree/bindings/iio/light/vishay,veml6030.yaml
@@ -4,7 +4,8 @@
 $id: http://devicetree.org/schemas/iio/light/vishay,veml6030.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: VEML3235, VEML3328, VEML6030, VEML6035 and VEML7700 Ambient Light Sensors (ALS)
+title: VEML3235, VEML3328, VEML6030, VEML6031x00 series, VEML6035
+  and VEML7700 Ambient Light Sensors (ALS)
 
 maintainers:
   - Rishi Gupta <gupt21@gmail.com>
@@ -23,6 +24,8 @@ description: |
     https://www.vishay.com/docs/80131/veml3235.pdf
     https://www.vishay.com/docs/84968/veml3328.pdf
     https://www.vishay.com/docs/84366/veml6030.pdf
+    https://www.vishay.com/docs/80007/veml6031x00.pdf
+    https://www.vishay.com/docs/80008/veml6031x01.pdf
     https://www.vishay.com/docs/84889/veml6035.pdf
     https://www.vishay.com/docs/84286/veml7700.pdf
 
@@ -32,6 +35,10 @@ properties:
       - vishay,veml3235
       - vishay,veml3328
       - vishay,veml6030
+      - vishay,veml6031x00
+      - vishay,veml6031x01
+      - vishay,veml60311x00
+      - vishay,veml60311x01
       - vishay,veml6035
       - vishay,veml7700
 
@@ -69,6 +76,8 @@ allOf:
       properties:
         compatible:
           enum:
+            - vishay,veml6031x00
+            - vishay,veml6031x01
             - vishay,veml6035
     then:
       properties:
@@ -82,6 +91,8 @@ allOf:
           enum:
             - vishay,veml3235
             - vishay,veml3328
+            - vishay,veml60311x00
+            - vishay,veml60311x01
             - vishay,veml7700
     then:
       properties:
diff --git a/MAINTAINERS b/MAINTAINERS
index 3a19da74d00c..57202b51fb66 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -29095,6 +29095,11 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/iio/light/vishay,veml6030.yaml
 F:	drivers/iio/light/veml6030.c
 
+VISHAY VEML6031X00 AMBIENT LIGHT SENSOR DRIVER
+M:	Javier Carrasco <javier.carrasco.cruz@gmail.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/iio/light/vishay,veml6030.yaml
+
 VISHAY VEML6046X00 RGBIR COLOR SENSOR DRIVER
 M:	Andreas Klinger <ak@it-klinger.de>
 S:	Maintained

-- 
2.43.0

[PATCH v8 2/4] iio: light: add support for veml6031x00 ALS series

[Javier Carrasco]

Support device identification, raw ALS and IR readings, and configuration
of the scale and integration time.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
 MAINTAINERS                     |   1 +
 drivers/iio/light/Kconfig       |  12 +
 drivers/iio/light/Makefile      |   1 +
 drivers/iio/light/veml6031x00.c | 678 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 692 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 57202b51fb66..c83f5af23d97 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -29099,6 +29099,7 @@ VISHAY VEML6031X00 AMBIENT LIGHT SENSOR DRIVER
 M:	Javier Carrasco <javier.carrasco.cruz@gmail.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/iio/light/vishay,veml6030.yaml
+F:	drivers/iio/light/veml6031x00.c
 
 VISHAY VEML6046X00 RGBIR COLOR SENSOR DRIVER
 M:	Andreas Klinger <ak@it-klinger.de>
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index f23bbce12c72..02291abeff60 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -741,6 +741,18 @@ config VEML6030
 	  To compile this driver as a module, choose M here: the
 	  module will be called veml6030.
 
+config VEML6031X00
+	tristate "VEML6031X00 ambient light sensor series"
+	select REGMAP_I2C
+	select IIO_GTS_HELPER
+	depends on I2C
+	help
+	  Say Y here if you want to build a driver for the Vishay VEML6031X00
+	  ambient light sensor series.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called veml6031x00.
+
 config VEML6040
 	tristate "VEML6040 RGBW light sensor"
 	select REGMAP_I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 64e354c49ed8..6672ed01a819 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_VCNL4035)		+= vcnl4035.o
 obj-$(CONFIG_VEML3235)		+= veml3235.o
 obj-$(CONFIG_VEML3328)		+= veml3328.o
 obj-$(CONFIG_VEML6030)		+= veml6030.o
+obj-$(CONFIG_VEML6031X00)	+= veml6031x00.o
 obj-$(CONFIG_VEML6040)		+= veml6040.o
 obj-$(CONFIG_VEML6046X00)	+= veml6046x00.o
 obj-$(CONFIG_VEML6070)		+= veml6070.o
diff --git a/drivers/iio/light/veml6031x00.c b/drivers/iio/light/veml6031x00.c
new file mode 100644
index 000000000000..f3772577a05d
--- /dev/null
+++ b/drivers/iio/light/veml6031x00.c
@@ -0,0 +1,678 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VEML6031X00 Ambient Light Sensor
+ *
+ * Copyright (c) 2026, Javier Carrasco <javier.carrasco.cruz@gmail.com>
+ */
+
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+
+#include <asm/byteorder.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/iio-gts-helper.h>
+
+/* Device registers */
+#define VEML6031X00_REG_CONF0       0x00
+#define VEML6031X00_REG_CONF1       0x01
+#define VEML6031X00_REG_ALS_L       0x10
+#define VEML6031X00_REG_ALS_H       0x11
+#define VEML6031X00_REG_IR_L        0x12
+#define VEML6031X00_REG_IR_H        0x13
+#define VEML6031X00_REG_ID_L        0x14
+#define VEML6031X00_REG_ID_H        0x15
+
+/* Bit masks for specific functionality */
+#define VEML6031X00_CONF0_SD        BIT(0)
+#define VEML6031X00_CONF1_IR_SD     BIT(7)
+
+#define VEML6031X00_GAIN_SEL(pd_div4, gain) (((pd_div4) << 2) | (gain))
+
+struct veml6031x00_rf {
+	struct regmap_field *gain;
+	struct regmap_field *it;
+	struct regmap_field *pd_div4;
+};
+
+struct veml6031x00_chip {
+	const char *name;
+	const unsigned int part_id;
+};
+
+struct veml6031x00_data {
+	struct iio_gts gts;
+	struct regmap *regmap;
+	struct veml6031x00_rf rf;
+	const struct veml6031x00_chip *chip;
+	/*
+	 * Serialize access to scale register fields scattered across multiple
+	 * registers (rf.gain, rf.pd_div4, rf.it) to read and write them as a
+	 * consistent set.
+	 */
+	struct mutex scale_lock;
+};
+
+static const struct iio_itime_sel_mul veml6031x00_it_sel[] = {
+	GAIN_SCALE_ITIME_US(3125, 0, 1),
+	GAIN_SCALE_ITIME_US(6250, 1, 2),
+	GAIN_SCALE_ITIME_US(12500, 2, 4),
+	GAIN_SCALE_ITIME_US(25000, 3, 8),
+	GAIN_SCALE_ITIME_US(50000, 4, 16),
+	GAIN_SCALE_ITIME_US(100000, 5, 32),
+	GAIN_SCALE_ITIME_US(200000, 6, 64),
+	GAIN_SCALE_ITIME_US(400000, 7, 128),
+};
+
+/*
+ * The gain selector encodes (PD_D4 << 2) | GAIN to identify each gain setting.
+ * Gains are multiplied by 8 to work with integers. The values in the iio-gts
+ * tables don't need corrections because the maximum value of the scale refers
+ * to GAIN = x1, and the rest of the values are obtained from the resulting
+ * linear function.
+ * TODO: add support for GAIN_0_165 and GAIN_0_660
+ */
+#define VEML6031X00_SEL_GAIN_0_125 0x07
+#define VEML6031X00_SEL_GAIN_0_250 0x04
+#define VEML6031X00_SEL_GAIN_0_500 0x03
+#define VEML6031X00_SEL_GAIN_1_000 0x00
+#define VEML6031X00_SEL_GAIN_2_000 0x01
+static const struct iio_gain_sel_pair veml6031x00_gain_sel[] = {
+	GAIN_SCALE_GAIN(1, VEML6031X00_SEL_GAIN_0_125),
+	GAIN_SCALE_GAIN(2, VEML6031X00_SEL_GAIN_0_250),
+	GAIN_SCALE_GAIN(4, VEML6031X00_SEL_GAIN_0_500),
+	GAIN_SCALE_GAIN(8, VEML6031X00_SEL_GAIN_1_000),
+	GAIN_SCALE_GAIN(16, VEML6031X00_SEL_GAIN_2_000),
+};
+
+/*
+ * The shutdown bits (SD and ALS_IR_SD) are in different registers, and both
+ * must be updated when changing the device power state.
+ */
+static int veml6031x00_set_power(struct veml6031x00_data *data, bool state)
+{
+	int ret;
+
+	ret = regmap_assign_bits(data->regmap, VEML6031X00_REG_CONF0,
+				 VEML6031X00_CONF0_SD, !state);
+	if (ret)
+		return ret;
+
+	return regmap_assign_bits(data->regmap, VEML6031X00_REG_CONF1,
+				  VEML6031X00_CONF1_IR_SD, !state);
+}
+
+static void veml6031x00_als_shutdown_action(void *data)
+{
+	struct veml6031x00_data *priv = data;
+	struct device *dev = regmap_get_device(priv->regmap);
+	int ret;
+
+	ret = veml6031x00_set_power(priv, false);
+	if (ret)
+		dev_warn(dev, "Failed to shut down device: %d\n", ret);
+}
+
+static const struct iio_chan_spec veml6031x00_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.address = VEML6031X00_REG_ALS_L,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_INT_TIME) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_INT_TIME) |
+						BIT(IIO_CHAN_INFO_SCALE),
+	},
+	{
+		.type = IIO_INTENSITY,
+		.address = VEML6031X00_REG_IR_L,
+		.modified = 1,
+		.channel2 = IIO_MOD_LIGHT_IR,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+	},
+};
+
+static const struct regmap_range veml6031x00_readable_ranges[] = {
+	regmap_reg_range(VEML6031X00_REG_CONF0, VEML6031X00_REG_CONF1),
+	regmap_reg_range(VEML6031X00_REG_ALS_L, VEML6031X00_REG_ID_H),
+};
+
+static const struct regmap_access_table veml6031x00_readable_table = {
+	.yes_ranges = veml6031x00_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(veml6031x00_readable_ranges),
+};
+
+static const struct regmap_range veml6031x00_writable_ranges[] = {
+	regmap_reg_range(VEML6031X00_REG_CONF0, VEML6031X00_REG_CONF1),
+};
+
+static const struct regmap_access_table veml6031x00_writable_table = {
+	.yes_ranges = veml6031x00_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(veml6031x00_writable_ranges),
+};
+
+static const struct regmap_range veml6031x00_volatile_ranges[] = {
+	/* AF_TRIG in CONF0 is volatile */
+	regmap_reg_range(VEML6031X00_REG_CONF0, VEML6031X00_REG_CONF0),
+	regmap_reg_range(VEML6031X00_REG_ALS_L, VEML6031X00_REG_IR_H),
+};
+
+static const struct regmap_access_table veml6031x00_volatile_table = {
+	.yes_ranges = veml6031x00_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(veml6031x00_volatile_ranges),
+};
+
+static const struct regmap_config veml6031x00_regmap_config = {
+	.name = "veml6031x00_regmap",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.rd_table = &veml6031x00_readable_table,
+	.wr_table = &veml6031x00_writable_table,
+	.volatile_table = &veml6031x00_volatile_table,
+	.max_register = VEML6031X00_REG_ID_H,
+	.cache_type = REGCACHE_MAPLE,
+};
+
+static const struct reg_field veml6031x00_rf_it =
+	REG_FIELD(VEML6031X00_REG_CONF0, 4, 6);
+
+static const struct reg_field veml6031x00_rf_gain =
+	REG_FIELD(VEML6031X00_REG_CONF1, 3, 4);
+
+static const struct reg_field veml6031x00_rf_pd_div4 =
+	REG_FIELD(VEML6031X00_REG_CONF1, 6, 6);
+
+static int veml6031x00_regfield_init(struct veml6031x00_data *data)
+{
+	struct regmap *map = data->regmap;
+	struct device *dev = regmap_get_device(map);
+	struct regmap_field *rm_field;
+	struct veml6031x00_rf *rf = &data->rf;
+
+	rm_field = devm_regmap_field_alloc(dev, map, veml6031x00_rf_gain);
+	if (IS_ERR(rm_field))
+		return PTR_ERR(rm_field);
+	rf->gain = rm_field;
+
+	rm_field = devm_regmap_field_alloc(dev, map, veml6031x00_rf_it);
+	if (IS_ERR(rm_field))
+		return PTR_ERR(rm_field);
+	rf->it = rm_field;
+
+	rm_field = devm_regmap_field_alloc(dev, map, veml6031x00_rf_pd_div4);
+	if (IS_ERR(rm_field))
+		return PTR_ERR(rm_field);
+	rf->pd_div4 = rm_field;
+
+	return 0;
+}
+
+static int __veml6031x00_get_it(struct veml6031x00_data *data, int *val2)
+{
+	unsigned int it_idx;
+	int ret;
+
+	ret = regmap_field_read(data->rf.it, &it_idx);
+	if (ret)
+		return ret;
+
+	ret = iio_gts_find_int_time_by_sel(&data->gts, it_idx);
+	if (ret < 0)
+		return ret;
+
+	*val2 = ret;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int veml6031x00_get_it(struct veml6031x00_data *data, int *val2)
+{
+	guard(mutex)(&data->scale_lock);
+
+	return __veml6031x00_get_it(data, val2);
+}
+
+static int veml6031x00_write_gain(struct veml6031x00_data *data, unsigned int gain)
+{
+	int ret;
+
+	ret = regmap_field_write(data->rf.pd_div4, gain >> 2);
+	if (ret)
+		return ret;
+
+	return regmap_field_write(data->rf.gain, gain & 0x03);
+}
+
+static int veml6031x00_set_it(struct iio_dev *iio, int val, int val2)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret, gain_sel, new_gain, prev_gain, prev_it;
+	unsigned int gain_reg, it_idx, pd_div4;
+	struct iio_gts *gts = &data->gts;
+	bool gain_in_range;
+
+	if (val || !iio_gts_valid_time(gts, val2))
+		return -EINVAL;
+
+	guard(mutex)(&data->scale_lock);
+
+	ret = regmap_field_read(data->rf.it, &it_idx);
+	if (ret)
+		return ret;
+
+	ret = regmap_field_read(data->rf.gain, &gain_reg);
+	if (ret)
+		return ret;
+
+	ret = regmap_field_read(data->rf.pd_div4, &pd_div4);
+	if (ret)
+		return ret;
+
+	prev_it = iio_gts_find_int_time_by_sel(gts, it_idx);
+	if (prev_it < 0)
+		return prev_it;
+
+	if (prev_it == val2)
+		return 0;
+
+	gain_sel = VEML6031X00_GAIN_SEL(pd_div4, gain_reg);
+	prev_gain = iio_gts_find_gain_by_sel(gts, gain_sel);
+	if (prev_gain < 0)
+		return prev_gain;
+
+	ret = iio_gts_find_new_gain_by_gain_time_min(gts, prev_gain, prev_it, val2,
+						     &new_gain, &gain_in_range);
+	if (ret)
+		return ret;
+
+	if (!gain_in_range)
+		dev_dbg(dev, "Optimal gain out of range\n");
+
+	ret = iio_gts_find_sel_by_int_time(gts, val2);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_field_write(data->rf.it, ret);
+	if (ret)
+		return ret;
+
+	gain_sel = iio_gts_find_sel_by_gain(gts, new_gain);
+	if (gain_sel < 0)
+		return gain_sel;
+
+	return veml6031x00_write_gain(data, gain_sel);
+}
+
+static int veml6031x00_set_scale(struct iio_dev *iio, int val, int val2)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct iio_gts *gts = &data->gts;
+	int gain_sel, it_sel, ret;
+
+	ret = iio_gts_find_gain_time_sel_for_scale(gts, val, val2, &gain_sel, &it_sel);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&data->scale_lock);
+
+	ret = regmap_field_write(data->rf.it, it_sel);
+	if (ret)
+		return ret;
+
+	return veml6031x00_write_gain(data, gain_sel);
+}
+
+static int veml6031x00_get_scale(struct veml6031x00_data *data, int *val, int *val2)
+{
+	unsigned int gain_reg, pd_div4, it_reg;
+	int gain, it, ret, sel;
+
+	scoped_guard(mutex, &data->scale_lock) {
+		ret = regmap_field_read(data->rf.gain, &gain_reg);
+		if (ret)
+			return ret;
+
+		ret = regmap_field_read(data->rf.pd_div4, &pd_div4);
+		if (ret)
+			return ret;
+
+		sel = VEML6031X00_GAIN_SEL(pd_div4, gain_reg);
+		gain = iio_gts_find_gain_by_sel(&data->gts, sel);
+		if (gain < 0)
+			return gain;
+
+		ret = regmap_field_read(data->rf.it, &it_reg);
+		if (ret)
+			return ret;
+	}
+
+	it = iio_gts_find_int_time_by_sel(&data->gts, it_reg);
+	if (it < 0)
+		return it;
+
+	ret = iio_gts_get_scale(&data->gts, gain, it, val, val2);
+	if (ret)
+		return ret;
+
+	return IIO_VAL_INT_PLUS_NANO;
+}
+
+static int veml6031x00_single_read(struct iio_dev *iio, enum iio_chan_type type,
+				   int *val)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	unsigned int addr;
+	int it_usec, ret;
+	__le16 regval;
+
+	switch (type) {
+	case IIO_LIGHT:
+		addr = VEML6031X00_REG_ALS_L;
+		break;
+	case IIO_INTENSITY:
+		addr = VEML6031X00_REG_IR_L;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	guard(mutex)(&data->scale_lock);
+
+	PM_RUNTIME_ACQUIRE_AUTOSUSPEND(regmap_get_device(data->regmap), pm);
+	ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+	if (ret)
+		return ret;
+
+	ret = __veml6031x00_get_it(data, &it_usec);
+	if (ret < 0)
+		return ret;
+
+	/* integration time + 10% to ensure completion */
+	fsleep(it_usec + (it_usec / 10));
+
+	ret = regmap_bulk_read(data->regmap, addr, &regval, sizeof(regval));
+	if (ret)
+		return ret;
+
+	*val = le16_to_cpu(regval);
+
+	return IIO_VAL_INT;
+}
+
+static int veml6031x00_read_raw(struct iio_dev *iio,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		return veml6031x00_single_read(iio, chan->type, val);
+	case IIO_CHAN_INFO_INT_TIME:
+		*val = 0;
+		return veml6031x00_get_it(data, val2);
+	case IIO_CHAN_INFO_SCALE:
+		return veml6031x00_get_scale(data, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6031x00_read_avail(struct iio_dev *iio,
+				  struct iio_chan_spec const *chan,
+				  const int **vals, int *type, int *length,
+				  long mask)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_INT_TIME:
+		return iio_gts_avail_times(&data->gts, vals, type, length);
+	case IIO_CHAN_INFO_SCALE:
+		return iio_gts_all_avail_scales(&data->gts, vals, type, length);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6031x00_write_raw(struct iio_dev *iio,
+				 struct iio_chan_spec const *chan,
+				 int val, int val2, long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_INT_TIME:
+		return veml6031x00_set_it(iio, val, val2);
+	case IIO_CHAN_INFO_SCALE:
+		return veml6031x00_set_scale(iio, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6031x00_write_raw_get_fmt(struct iio_dev *indio_dev,
+					 struct iio_chan_spec const *chan,
+					 long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_INT_TIME:
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info veml6031x00_info = {
+	.read_raw = veml6031x00_read_raw,
+	.read_avail = veml6031x00_read_avail,
+	.write_raw = veml6031x00_write_raw,
+	.write_raw_get_fmt = veml6031x00_write_raw_get_fmt,
+};
+
+static int veml6031x00_validate_part_id(struct veml6031x00_data *data)
+{
+	struct regmap *map = data->regmap;
+	struct device *dev = regmap_get_device(map);
+	unsigned int part_id;
+	int ret;
+	__le16 regval;
+
+	ret = regmap_bulk_read(map, VEML6031X00_REG_ID_L, &regval, sizeof(regval));
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to read ID\n");
+
+	part_id = le16_to_cpu(regval);
+	if (part_id != data->chip->part_id)
+		dev_info(dev, "Unknown or unexpected ID %04x\n", part_id);
+
+	return 0;
+}
+
+static int veml6031x00_probe(struct i2c_client *i2c)
+{
+	struct device *dev = &i2c->dev;
+	struct veml6031x00_data *data;
+	struct iio_dev *iio;
+	int ret;
+
+	iio = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!iio)
+		return -ENOMEM;
+
+	data = iio_priv(iio);
+	i2c_set_clientdata(i2c, iio);
+
+	data->chip = i2c_get_match_data(i2c);
+	if (!data->chip)
+		return dev_err_probe(dev, -ENODATA, "Failed to get chip data\n");
+
+	ret = devm_mutex_init(dev, &data->scale_lock);
+	if (ret)
+		return ret;
+
+	data->regmap = devm_regmap_init_i2c(i2c, &veml6031x00_regmap_config);
+	if (IS_ERR(data->regmap))
+		return dev_err_probe(dev, PTR_ERR(data->regmap),
+				     "Failed to set regmap\n");
+
+	iio->name = data->chip->name;
+	iio->channels = veml6031x00_channels;
+	iio->num_channels = ARRAY_SIZE(veml6031x00_channels);
+	iio->modes = INDIO_DIRECT_MODE;
+	iio->info = &veml6031x00_info;
+
+	ret = veml6031x00_regfield_init(data);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to init regfield\n");
+
+	ret = devm_regulator_get_enable(dev, "vdd");
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable regulator\n");
+
+	/* The device starts in power down mode by default */
+	ret = veml6031x00_set_power(data, true);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to power on the device\n");
+
+	ret = devm_add_action_or_reset(dev, veml6031x00_als_shutdown_action, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to add shutdown action\n");
+
+	pm_runtime_set_autosuspend_delay(dev, 2000);
+	pm_runtime_use_autosuspend(dev);
+	ret = devm_pm_runtime_set_active_enabled(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable runtime PM\n");
+
+	ret = veml6031x00_validate_part_id(data);
+	if (ret)
+		return ret;
+
+	/* Max resolution = 6.9632 lx/cnt for gain = 0.125 and IT = 3.125ms */
+	ret = devm_iio_init_iio_gts(dev, 6, 963200000,
+				    veml6031x00_gain_sel,
+				    ARRAY_SIZE(veml6031x00_gain_sel),
+				    veml6031x00_it_sel,
+				    ARRAY_SIZE(veml6031x00_it_sel),
+				    &data->gts);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to init IIO GTS\n");
+
+	ret = devm_iio_device_register(dev, iio);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register IIO device\n");
+
+	return 0;
+}
+
+static int veml6031x00_runtime_suspend(struct device *dev)
+{
+	struct veml6031x00_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return veml6031x00_set_power(data, false);
+}
+
+static int veml6031x00_runtime_resume(struct device *dev)
+{
+	struct veml6031x00_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return veml6031x00_set_power(data, true);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(veml6031x00_pm_ops,
+				 veml6031x00_runtime_suspend,
+				 veml6031x00_runtime_resume,
+				 NULL);
+
+static const struct veml6031x00_chip veml6031x00_chip = {
+	.name = "veml6031x00",
+	.part_id = 0x0001,
+};
+
+static const struct veml6031x00_chip veml6031x01_chip = {
+	.name = "veml6031x01",
+	.part_id = 0x0001,
+};
+
+static const struct veml6031x00_chip veml60311x00_chip = {
+	.name = "veml60311x00",
+	.part_id = 0x1001,
+};
+
+static const struct veml6031x00_chip veml60311x01_chip = {
+	.name = "veml60311x01",
+	.part_id = 0x1001,
+};
+
+static const struct of_device_id veml6031x00_of_match[] = {
+	{
+		.compatible = "vishay,veml6031x00",
+		.data = &veml6031x00_chip,
+	},
+	{
+		.compatible = "vishay,veml6031x01",
+		.data = &veml6031x01_chip,
+	},
+	{
+		.compatible = "vishay,veml60311x00",
+		.data = &veml60311x00_chip,
+	},
+	{
+		.compatible = "vishay,veml60311x01",
+		.data = &veml60311x01_chip,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, veml6031x00_of_match);
+
+static const struct i2c_device_id veml6031x00_id[] = {
+	{
+		.name = "veml6031x00",
+		.driver_data = (kernel_ulong_t)&veml6031x00_chip,
+	},
+	{
+		.name = "veml6031x01",
+		.driver_data = (kernel_ulong_t)&veml6031x01_chip,
+	},
+	{
+		.name = "veml60311x00",
+		.driver_data = (kernel_ulong_t)&veml60311x00_chip,
+	},
+	{
+		.name = "veml60311x01",
+		.driver_data = (kernel_ulong_t)&veml60311x01_chip,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, veml6031x00_id);
+
+static struct i2c_driver veml6031x00_driver = {
+	.driver = {
+		.name = "veml6031x00",
+		.of_match_table = veml6031x00_of_match,
+		.pm = pm_ptr(&veml6031x00_pm_ops),
+	},
+	.probe = veml6031x00_probe,
+	.id_table = veml6031x00_id,
+};
+module_i2c_driver(veml6031x00_driver);
+
+MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");
+MODULE_DESCRIPTION("VEML6031X00 Ambient Light Sensor");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("IIO_GTS_HELPER");

-- 
2.43.0

[PATCH v8 3/4] iio: light: veml6031x00: add support for triggered buffers

[Javier Carrasco]

Add triggered buffer functionality for the two channels the device
provides (ALS and IR).

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
 drivers/iio/light/Kconfig       |   2 +
 drivers/iio/light/veml6031x00.c | 113 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+)

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 02291abeff60..462fff1ddef2 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -745,6 +745,8 @@ config VEML6031X00
 	tristate "VEML6031X00 ambient light sensor series"
 	select REGMAP_I2C
 	select IIO_GTS_HELPER
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	depends on I2C
 	help
 	  Say Y here if you want to build a driver for the Vishay VEML6031X00
diff --git a/drivers/iio/light/veml6031x00.c b/drivers/iio/light/veml6031x00.c
index f3772577a05d..3d5a27a0baae 100644
--- a/drivers/iio/light/veml6031x00.c
+++ b/drivers/iio/light/veml6031x00.c
@@ -13,6 +13,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
+#include <linux/interrupt.h>
 #include <linux/limits.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -25,6 +26,8 @@
 
 #include <linux/iio/iio.h>
 #include <linux/iio/iio-gts-helper.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
 
 /* Device registers */
 #define VEML6031X00_REG_CONF0       0x00
@@ -42,6 +45,12 @@
 
 #define VEML6031X00_GAIN_SEL(pd_div4, gain) (((pd_div4) << 2) | (gain))
 
+enum veml6031x00_scan {
+	VEML6031X00_SCAN_ALS,
+	VEML6031X00_SCAN_IR,
+	VEML6031X00_SCAN_TIMESTAMP,
+};
+
 struct veml6031x00_rf {
 	struct regmap_field *gain;
 	struct regmap_field *it;
@@ -135,6 +144,13 @@ static const struct iio_chan_spec veml6031x00_channels[] = {
 				      BIT(IIO_CHAN_INFO_SCALE),
 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_INT_TIME) |
 						BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = VEML6031X00_SCAN_ALS,
+		.scan_type = {
+			.format = IIO_SCAN_FORMAT_UNSIGNED_INT,
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
 	},
 	{
 		.type = IIO_INTENSITY,
@@ -142,7 +158,15 @@ static const struct iio_chan_spec veml6031x00_channels[] = {
 		.modified = 1,
 		.channel2 = IIO_MOD_LIGHT_IR,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index = VEML6031X00_SCAN_IR,
+		.scan_type = {
+			.format = IIO_SCAN_FORMAT_UNSIGNED_INT,
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(VEML6031X00_SCAN_TIMESTAMP),
 };
 
 static const struct regmap_range veml6031x00_readable_ranges[] = {
@@ -390,6 +414,10 @@ static int veml6031x00_single_read(struct iio_dev *iio, enum iio_chan_type type,
 		return -EINVAL;
 	}
 
+	IIO_DEV_ACQUIRE_DIRECT_MODE(iio, claim);
+	if (IIO_DEV_ACQUIRE_FAILED(claim))
+		return -EBUSY;
+
 	guard(mutex)(&data->scale_lock);
 
 	PM_RUNTIME_ACQUIRE_AUTOSUSPEND(regmap_get_device(data->regmap), pm);
@@ -453,6 +481,10 @@ static int veml6031x00_write_raw(struct iio_dev *iio,
 				 struct iio_chan_spec const *chan,
 				 int val, int val2, long mask)
 {
+	IIO_DEV_ACQUIRE_DIRECT_MODE(iio, claim);
+	if (IIO_DEV_ACQUIRE_FAILED(claim))
+		return -EBUSY;
+
 	switch (mask) {
 	case IIO_CHAN_INFO_INT_TIME:
 		return veml6031x00_set_it(iio, val, val2);
@@ -484,6 +516,80 @@ static const struct iio_info veml6031x00_info = {
 	.write_raw_get_fmt = veml6031x00_write_raw_get_fmt,
 };
 
+static int veml6031x00_buffer_preenable(struct iio_dev *iio)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret, it_usec;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	ret = veml6031x00_get_it(data, &it_usec);
+	if (ret < 0) {
+		pm_runtime_put_autosuspend(dev);
+		return ret;
+	}
+
+	/*
+	 * Wait one integration period + 10% margin so the first triggered
+	 * read does not race with the sensor completing its first conversion
+	 * after power-on.
+	 */
+	fsleep(it_usec + (it_usec / 10));
+
+	return 0;
+}
+
+static int veml6031x00_buffer_postdisable(struct iio_dev *iio)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	pm_runtime_put_autosuspend(regmap_get_device(data->regmap));
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops veml6031x00_buffer_setup_ops = {
+	.preenable = veml6031x00_buffer_preenable,
+	.postdisable = veml6031x00_buffer_postdisable,
+};
+
+static irqreturn_t veml6031x00_trig_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *iio = pf->indio_dev;
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct regmap *map = data->regmap;
+	IIO_DECLARE_BUFFER_WITH_TS(__le16, scan, 2) = { };
+	unsigned int i;
+	int ch, ret;
+
+	if (test_bit(VEML6031X00_SCAN_ALS, iio->active_scan_mask) &&
+	    test_bit(VEML6031X00_SCAN_IR, iio->active_scan_mask)) {
+		ret = regmap_bulk_read(map, VEML6031X00_REG_ALS_L,
+				       scan, 2 * sizeof(*scan));
+		if (ret)
+			goto done;
+	} else {
+		i = 0;
+		iio_for_each_active_channel(iio, ch) {
+			ret = regmap_bulk_read(map, iio->channels[ch].address,
+					       &scan[i++], sizeof(*scan));
+			if (ret)
+				goto done;
+		}
+	}
+
+	iio_push_to_buffers_with_ts(iio, scan, sizeof(scan), pf->timestamp);
+
+done:
+	iio_trigger_notify_done(iio->trig);
+
+	return IRQ_HANDLED;
+}
+
 static int veml6031x00_validate_part_id(struct veml6031x00_data *data)
 {
 	struct regmap *map = data->regmap;
@@ -573,6 +679,13 @@ static int veml6031x00_probe(struct i2c_client *i2c)
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to init IIO GTS\n");
 
+	ret = devm_iio_triggered_buffer_setup(dev, iio,
+					      iio_pollfunc_store_time,
+					      veml6031x00_trig_handler,
+					      &veml6031x00_buffer_setup_ops);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register triggered buffer\n");
+
 	ret = devm_iio_device_register(dev, iio);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to register IIO device\n");

-- 
2.43.0

[PATCH v8 4/4] iio: light: veml6031x00: add support for events and trigger

[Javier Carrasco]

The device provides a shared interrupt line to notify events and
data ready.

Add support for configurations with and without an interrupt line,
providing events and trigger support when an interrupt line is available.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
 drivers/iio/light/veml6031x00.c | 593 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 586 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/light/veml6031x00.c b/drivers/iio/light/veml6031x00.c
index 3d5a27a0baae..7bd7975eb1a7 100644
--- a/drivers/iio/light/veml6031x00.c
+++ b/drivers/iio/light/veml6031x00.c
@@ -15,6 +15,7 @@
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/limits.h>
+#include <linux/lockdep.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/pm_runtime.h>
@@ -25,6 +26,9 @@
 #include <asm/byteorder.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/events.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
 #include <linux/iio/iio-gts-helper.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>
@@ -32,16 +36,28 @@
 /* Device registers */
 #define VEML6031X00_REG_CONF0       0x00
 #define VEML6031X00_REG_CONF1       0x01
+#define VEML6031X00_REG_WH_L        0x04
+#define VEML6031X00_REG_WH_H        0x05
+#define VEML6031X00_REG_WL_L        0x06
+#define VEML6031X00_REG_WL_H        0x07
 #define VEML6031X00_REG_ALS_L       0x10
 #define VEML6031X00_REG_ALS_H       0x11
 #define VEML6031X00_REG_IR_L        0x12
 #define VEML6031X00_REG_IR_H        0x13
 #define VEML6031X00_REG_ID_L        0x14
 #define VEML6031X00_REG_ID_H        0x15
+#define VEML6031X00_REG_INT         0x17
 
 /* Bit masks for specific functionality */
 #define VEML6031X00_CONF0_SD        BIT(0)
+#define VEML6031X00_CONF0_AF_TRIG   BIT(2)
+#define VEML6031X00_CONF0_AF        BIT(3)
 #define VEML6031X00_CONF1_IR_SD     BIT(7)
+#define VEML6031X00_INT_TH_H        BIT(1)
+#define VEML6031X00_INT_TH_L        BIT(2)
+#define VEML6031X00_INT_DRDY        BIT(3)
+#define VEML6031X00_INT_MASK \
+	(VEML6031X00_INT_TH_L | VEML6031X00_INT_TH_H | VEML6031X00_INT_DRDY)
 
 #define VEML6031X00_GAIN_SEL(pd_div4, gain) (((pd_div4) << 2) | (gain))
 
@@ -53,8 +69,10 @@ enum veml6031x00_scan {
 
 struct veml6031x00_rf {
 	struct regmap_field *gain;
+	struct regmap_field *int_en;
 	struct regmap_field *it;
 	struct regmap_field *pd_div4;
+	struct regmap_field *pers;
 };
 
 struct veml6031x00_chip {
@@ -65,6 +83,7 @@ struct veml6031x00_chip {
 struct veml6031x00_data {
 	struct iio_gts gts;
 	struct regmap *regmap;
+	struct iio_trigger *trig;
 	struct veml6031x00_rf rf;
 	const struct veml6031x00_chip *chip;
 	/*
@@ -73,6 +92,14 @@ struct veml6031x00_data {
 	 * consistent set.
 	 */
 	struct mutex scale_lock;
+	/*
+	 * Serialize access to irq enable/disable by events and trigger
+	 * (shared line).
+	 */
+	struct mutex irq_lock;
+	unsigned int interrupt_users;
+	bool ev_en;
+	bool trig_en;
 };
 
 static const struct iio_itime_sel_mul veml6031x00_it_sel[] = {
@@ -107,6 +134,17 @@ static const struct iio_gain_sel_pair veml6031x00_gain_sel[] = {
 	GAIN_SCALE_GAIN(16, VEML6031X00_SEL_GAIN_2_000),
 };
 
+static IIO_CONST_ATTR(in_illuminance_thresh_either_period_available, "1 2 4 8");
+
+static struct attribute *veml6031x00_event_attributes[] = {
+	&iio_const_attr_in_illuminance_thresh_either_period_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group veml6031x00_event_attr_group = {
+	.attrs = veml6031x00_event_attributes,
+};
+
 /*
  * The shutdown bits (SD and ALS_IR_SD) are in different registers, and both
  * must be updated when changing the device power state.
@@ -135,6 +173,23 @@ static void veml6031x00_als_shutdown_action(void *data)
 		dev_warn(dev, "Failed to shut down device: %d\n", ret);
 }
 
+static const struct iio_event_spec veml6031x00_event_spec[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_PERIOD) |
+				 BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
 static const struct iio_chan_spec veml6031x00_channels[] = {
 	{
 		.type = IIO_LIGHT,
@@ -169,9 +224,47 @@ static const struct iio_chan_spec veml6031x00_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(VEML6031X00_SCAN_TIMESTAMP),
 };
 
+static const struct iio_chan_spec veml6031x00_channels_irq[] = {
+	{
+		.type = IIO_LIGHT,
+		.address = VEML6031X00_REG_ALS_L,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_INT_TIME) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_INT_TIME) |
+						BIT(IIO_CHAN_INFO_SCALE),
+		.event_spec = veml6031x00_event_spec,
+		.num_event_specs = ARRAY_SIZE(veml6031x00_event_spec),
+		.scan_index = VEML6031X00_SCAN_ALS,
+		.scan_type = {
+			.format = IIO_SCAN_FORMAT_UNSIGNED_INT,
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
+	},
+	{
+		.type = IIO_INTENSITY,
+		.address = VEML6031X00_REG_IR_L,
+		.modified = 1,
+		.channel2 = IIO_MOD_LIGHT_IR,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index = VEML6031X00_SCAN_IR,
+		.scan_type = {
+			.format = IIO_SCAN_FORMAT_UNSIGNED_INT,
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(VEML6031X00_SCAN_TIMESTAMP),
+};
+
 static const struct regmap_range veml6031x00_readable_ranges[] = {
 	regmap_reg_range(VEML6031X00_REG_CONF0, VEML6031X00_REG_CONF1),
+	regmap_reg_range(VEML6031X00_REG_WH_L, VEML6031X00_REG_WL_H),
 	regmap_reg_range(VEML6031X00_REG_ALS_L, VEML6031X00_REG_ID_H),
+	regmap_reg_range(VEML6031X00_REG_INT, VEML6031X00_REG_INT),
 };
 
 static const struct regmap_access_table veml6031x00_readable_table = {
@@ -181,6 +274,7 @@ static const struct regmap_access_table veml6031x00_readable_table = {
 
 static const struct regmap_range veml6031x00_writable_ranges[] = {
 	regmap_reg_range(VEML6031X00_REG_CONF0, VEML6031X00_REG_CONF1),
+	regmap_reg_range(VEML6031X00_REG_WH_L, VEML6031X00_REG_WL_H),
 };
 
 static const struct regmap_access_table veml6031x00_writable_table = {
@@ -192,6 +286,7 @@ static const struct regmap_range veml6031x00_volatile_ranges[] = {
 	/* AF_TRIG in CONF0 is volatile */
 	regmap_reg_range(VEML6031X00_REG_CONF0, VEML6031X00_REG_CONF0),
 	regmap_reg_range(VEML6031X00_REG_ALS_L, VEML6031X00_REG_IR_H),
+	regmap_reg_range(VEML6031X00_REG_INT, VEML6031X00_REG_INT),
 };
 
 static const struct regmap_access_table veml6031x00_volatile_table = {
@@ -199,6 +294,15 @@ static const struct regmap_access_table veml6031x00_volatile_table = {
 	.n_yes_ranges = ARRAY_SIZE(veml6031x00_volatile_ranges),
 };
 
+static const struct regmap_range veml6031x00_precious_ranges[] = {
+	regmap_reg_range(VEML6031X00_REG_INT, VEML6031X00_REG_INT),
+};
+
+static const struct regmap_access_table veml6031x00_precious_table = {
+	.yes_ranges = veml6031x00_precious_ranges,
+	.n_yes_ranges = ARRAY_SIZE(veml6031x00_precious_ranges),
+};
+
 static const struct regmap_config veml6031x00_regmap_config = {
 	.name = "veml6031x00_regmap",
 	.reg_bits = 8,
@@ -206,13 +310,20 @@ static const struct regmap_config veml6031x00_regmap_config = {
 	.rd_table = &veml6031x00_readable_table,
 	.wr_table = &veml6031x00_writable_table,
 	.volatile_table = &veml6031x00_volatile_table,
-	.max_register = VEML6031X00_REG_ID_H,
+	.precious_table = &veml6031x00_precious_table,
+	.max_register = VEML6031X00_REG_INT,
 	.cache_type = REGCACHE_MAPLE,
 };
 
+static const struct reg_field veml6031x00_rf_int_en =
+	REG_FIELD(VEML6031X00_REG_CONF0, 1, 1);
+
 static const struct reg_field veml6031x00_rf_it =
 	REG_FIELD(VEML6031X00_REG_CONF0, 4, 6);
 
+static const struct reg_field veml6031x00_rf_pers =
+	REG_FIELD(VEML6031X00_REG_CONF1, 1, 2);
+
 static const struct reg_field veml6031x00_rf_gain =
 	REG_FIELD(VEML6031X00_REG_CONF1, 3, 4);
 
@@ -236,11 +347,21 @@ static int veml6031x00_regfield_init(struct veml6031x00_data *data)
 		return PTR_ERR(rm_field);
 	rf->it = rm_field;
 
+	rm_field = devm_regmap_field_alloc(dev, map, veml6031x00_rf_int_en);
+	if (IS_ERR(rm_field))
+		return PTR_ERR(rm_field);
+	rf->int_en = rm_field;
+
 	rm_field = devm_regmap_field_alloc(dev, map, veml6031x00_rf_pd_div4);
 	if (IS_ERR(rm_field))
 		return PTR_ERR(rm_field);
 	rf->pd_div4 = rm_field;
 
+	rm_field = devm_regmap_field_alloc(dev, map, veml6031x00_rf_pers);
+	if (IS_ERR(rm_field))
+		return PTR_ERR(rm_field);
+	rf->pers = rm_field;
+
 	return 0;
 }
 
@@ -341,6 +462,31 @@ static int veml6031x00_set_it(struct iio_dev *iio, int val, int val2)
 	return veml6031x00_write_gain(data, gain_sel);
 }
 
+static int veml6031x00_read_period(struct iio_dev *iio, int *val)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_field_read(data->rf.pers, &regval);
+	if (ret)
+		return ret;
+
+	*val = BIT(regval);
+
+	return IIO_VAL_INT;
+}
+
+static int veml6031x00_write_period(struct iio_dev *iio, int val)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	if (val < 0 || val > 8 || !is_power_of_2(val))
+		return -EINVAL;
+
+	return regmap_field_write(data->rf.pers, ilog2(val));
+}
+
 static int veml6031x00_set_scale(struct iio_dev *iio, int val, int val2)
 {
 	struct veml6031x00_data *data = iio_priv(iio);
@@ -395,6 +541,55 @@ static int veml6031x00_get_scale(struct veml6031x00_data *data, int *val, int *v
 	return IIO_VAL_INT_PLUS_NANO;
 }
 
+static int veml6031x00_read_th(struct iio_dev *iio, enum iio_event_direction dir,
+			       int *val, int *val2)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	__le16 regval;
+	int ret;
+
+	if (dir == IIO_EV_DIR_RISING)
+		ret = regmap_bulk_read(data->regmap, VEML6031X00_REG_WH_L,
+				       &regval, sizeof(regval));
+	else
+		ret = regmap_bulk_read(data->regmap, VEML6031X00_REG_WL_L,
+				       &regval, sizeof(regval));
+	if (ret)
+		return ret;
+
+	*val = le16_to_cpu(regval);
+
+	return IIO_VAL_INT;
+}
+
+static int veml6031x00_write_th(struct iio_dev *iio, enum iio_event_direction dir,
+				int val, int val2)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct device *dev = regmap_get_device(data->regmap);
+	__le16 regval;
+	int ret;
+
+	if (val < 0 || val > U16_MAX || val2)
+		return -EINVAL;
+
+	regval = cpu_to_le16(val);
+
+	if (dir == IIO_EV_DIR_RISING) {
+		ret = regmap_bulk_write(data->regmap, VEML6031X00_REG_WH_L,
+					&regval, sizeof(regval));
+		if (ret)
+			dev_dbg(dev, "Failed to set high threshold %d\n", ret);
+	} else {
+		ret = regmap_bulk_write(data->regmap, VEML6031X00_REG_WL_L,
+					&regval, sizeof(regval));
+		if (ret)
+			dev_dbg(dev, "Failed to set low threshold %d\n", ret);
+	}
+
+	return ret;
+}
+
 static int veml6031x00_single_read(struct iio_dev *iio, enum iio_chan_type type,
 				   int *val)
 {
@@ -509,13 +704,240 @@ static int veml6031x00_write_raw_get_fmt(struct iio_dev *indio_dev,
 	}
 }
 
+static int veml6031x00_set_interrupt(struct veml6031x00_data *data, bool state)
+	__must_hold(&data->irq_lock)
+{
+	int ret;
+
+	lockdep_assert_held(&data->irq_lock);
+
+	if (state) {
+		data->interrupt_users++;
+		if (data->interrupt_users > 1)
+			return 0;
+	} else {
+		data->interrupt_users--;
+		if (data->interrupt_users > 0)
+			return 0;
+	}
+
+	ret = regmap_field_write(data->rf.int_en, state);
+	if (ret) {
+		if (state)
+			data->interrupt_users--;
+		else
+			data->interrupt_users++;
+	}
+
+	return ret;
+}
+
+static int veml6031x00_read_event_val(struct iio_dev *iio,
+				      const struct iio_chan_spec *chan,
+				      enum iio_event_type type,
+				      enum iio_event_direction dir,
+				      enum iio_event_info info,
+				      int *val, int *val2)
+{
+	switch (type) {
+	case IIO_EV_TYPE_THRESH:
+		if (dir == IIO_EV_DIR_EITHER && info == IIO_EV_INFO_PERIOD)
+			return veml6031x00_read_period(iio, val);
+
+		return veml6031x00_read_th(iio, dir, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6031x00_write_event_val(struct iio_dev *iio,
+				       const struct iio_chan_spec *chan,
+				       enum iio_event_type type,
+				       enum iio_event_direction dir,
+				       enum iio_event_info info,
+				       int val, int val2)
+{
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		return veml6031x00_write_th(iio, dir, val, val2);
+	case IIO_EV_INFO_PERIOD:
+		return veml6031x00_write_period(iio, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6031x00_read_event_config(struct iio_dev *iio,
+					 const struct iio_chan_spec *chan,
+					 enum iio_event_type type,
+					 enum iio_event_direction dir)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	guard(mutex)(&data->irq_lock);
+
+	return data->ev_en;
+}
+
+static int veml6031x00_event_enable(struct veml6031x00_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	ret = veml6031x00_set_interrupt(data, true);
+	if (ret) {
+		pm_runtime_put_autosuspend(dev);
+		return ret;
+	}
+
+	data->ev_en = true;
+
+	return 0;
+}
+
+static int veml6031x00_event_disable(struct veml6031x00_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = veml6031x00_set_interrupt(data, false);
+	if (ret)
+		return ret;
+
+	data->ev_en = false;
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
+}
+
+static int veml6031x00_write_event_config(struct iio_dev *iio,
+					  const struct iio_chan_spec *chan,
+					  enum iio_event_type type,
+					  enum iio_event_direction dir,
+					  bool state)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	guard(mutex)(&data->irq_lock);
+
+	/* avoid multiple increments/decrements from one source */
+	if (state == data->ev_en)
+		return 0;
+
+	if (state)
+		return veml6031x00_event_enable(data);
+
+	return veml6031x00_event_disable(data);
+}
+
+static void veml6031x00_disable_event_action(void *arg)
+{
+	struct veml6031x00_data *data = arg;
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	guard(mutex)(&data->irq_lock);
+
+	if (!data->ev_en)
+		return;
+
+	ret = veml6031x00_set_interrupt(data, false);
+	if (ret)
+		dev_err(dev, "Failed to disable events: %d\n", ret);
+	else
+		data->ev_en = false;
+
+	pm_runtime_put_sync(dev);
+}
+
 static const struct iio_info veml6031x00_info = {
 	.read_raw = veml6031x00_read_raw,
 	.read_avail = veml6031x00_read_avail,
 	.write_raw = veml6031x00_write_raw,
 	.write_raw_get_fmt = veml6031x00_write_raw_get_fmt,
+	.read_event_value = veml6031x00_read_event_val,
+	.write_event_value = veml6031x00_write_event_val,
+	.read_event_config = veml6031x00_read_event_config,
+	.write_event_config = veml6031x00_write_event_config,
+	.event_attrs = &veml6031x00_event_attr_group,
 };
 
+static const struct iio_info veml6031x00_info_no_irq = {
+	.read_raw = veml6031x00_read_raw,
+	.read_avail = veml6031x00_read_avail,
+	.write_raw = veml6031x00_write_raw,
+	.write_raw_get_fmt = veml6031x00_write_raw_get_fmt,
+};
+
+static irqreturn_t veml6031x00_irq(int irq, void *private)
+{
+	struct iio_dev *iio = private;
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct device *dev = regmap_get_device(data->regmap);
+	s64 timestamp;
+	unsigned int regval;
+	int ret;
+	bool trigger_poll;
+
+	ret = pm_runtime_get_if_active(dev);
+	if (ret <= 0)
+		return IRQ_NONE;
+
+	scoped_guard(mutex, &data->irq_lock) {
+		ret = regmap_read(data->regmap, VEML6031X00_REG_INT, &regval);
+		if (ret) {
+			dev_dbg(dev, "Failed to read interrupt register %d\n", ret);
+			pm_runtime_put(dev);
+			return IRQ_NONE;
+		}
+
+		if (!(regval & VEML6031X00_INT_MASK)) {
+			pm_runtime_put(dev);
+			return IRQ_NONE;
+		}
+
+		timestamp = iio_get_time_ns(iio);
+
+		if (data->ev_en &&
+		    (regval & (VEML6031X00_INT_TH_H | VEML6031X00_INT_TH_L))) {
+			if (regval & VEML6031X00_INT_TH_H)
+				iio_push_event(iio,
+					       IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
+								    IIO_EV_TYPE_THRESH,
+								    IIO_EV_DIR_RISING),
+					       timestamp);
+			if (regval & VEML6031X00_INT_TH_L)
+				iio_push_event(iio,
+					       IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
+								    IIO_EV_TYPE_THRESH,
+								    IIO_EV_DIR_FALLING),
+					       timestamp);
+		}
+
+		trigger_poll = data->trig_en && (regval & VEML6031X00_INT_DRDY);
+	}
+
+	/*
+	 * iio_trigger_poll_nested() must be called with irq_lock released:
+	 * it runs trig_handler() synchronously in this thread, which calls
+	 * reenable() on completion, and that callback also takes irq_lock.
+	 * iio_pollfunc_store_time() is not called for our own trigger, so the
+	 * timestamp is stored here.
+	 */
+	if (trigger_poll) {
+		iio->pollfunc->timestamp = timestamp;
+		iio_trigger_poll_nested(data->trig);
+	}
+
+	pm_runtime_put(dev);
+
+	return IRQ_HANDLED;
+}
+
 static int veml6031x00_buffer_preenable(struct iio_dev *iio)
 {
 	struct veml6031x00_data *data = iio_priv(iio);
@@ -551,11 +973,83 @@ static int veml6031x00_buffer_postdisable(struct iio_dev *iio)
 	return 0;
 }
 
+static int __veml6031x00_set_trigger_state(struct veml6031x00_data *data, bool state)
+	__must_hold(&data->irq_lock)
+{
+	int ret;
+
+	lockdep_assert_held(&data->irq_lock);
+
+	ret = veml6031x00_set_interrupt(data, state);
+	if (ret)
+		return ret;
+
+	/* The AF bit must be updated before updating AF_TRIG */
+	ret = regmap_assign_bits(data->regmap, VEML6031X00_REG_CONF0,
+				 VEML6031X00_CONF0_AF, state);
+	if (ret)
+		goto clear_interrupt;
+
+	ret = regmap_assign_bits(data->regmap, VEML6031X00_REG_CONF0,
+				 VEML6031X00_CONF0_AF_TRIG, state);
+	if (ret) {
+		regmap_assign_bits(data->regmap, VEML6031X00_REG_CONF0,
+				   VEML6031X00_CONF0_AF, !state);
+		goto clear_interrupt;
+	}
+
+	data->trig_en = state;
+
+	return 0;
+
+clear_interrupt:
+	veml6031x00_set_interrupt(data, !state);
+
+	return ret;
+}
+
+static int veml6031x00_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *iio = iio_trigger_get_drvdata(trig);
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	guard(mutex)(&data->irq_lock);
+
+	if (state == data->trig_en)
+		return 0;
+
+	return __veml6031x00_set_trigger_state(data, state);
+}
+
 static const struct iio_buffer_setup_ops veml6031x00_buffer_setup_ops = {
 	.preenable = veml6031x00_buffer_preenable,
 	.postdisable = veml6031x00_buffer_postdisable,
 };
 
+static void veml6031x00_trigger_reenable(struct iio_trigger *trig)
+{
+	struct iio_dev *iio = iio_trigger_get_drvdata(trig);
+	struct veml6031x00_data *data = iio_priv(iio);
+	int ret;
+
+	guard(mutex)(&data->irq_lock);
+
+	if (!data->trig_en)
+		return;
+
+	ret = regmap_assign_bits(data->regmap, VEML6031X00_REG_CONF0,
+				 VEML6031X00_CONF0_AF_TRIG, true);
+	if (ret)
+		dev_err(regmap_get_device(data->regmap),
+			"Failed to reenable trigger: %d\n", ret);
+}
+
+static const struct iio_trigger_ops veml6031x00_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+	.set_trigger_state = veml6031x00_set_trigger_state,
+	.reenable = veml6031x00_trigger_reenable,
+};
+
 static irqreturn_t veml6031x00_trig_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
@@ -609,6 +1103,85 @@ static int veml6031x00_validate_part_id(struct veml6031x00_data *data)
 	return 0;
 }
 
+static int veml6031x00_hw_init(struct veml6031x00_data *data)
+{
+	struct regmap *map = data->regmap;
+	struct device *dev = regmap_get_device(map);
+	unsigned int val;
+	__le16 regval;
+	int ret;
+
+	regval = 0;
+	ret = regmap_bulk_write(map, VEML6031X00_REG_WL_L, &regval, sizeof(regval));
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to set low threshold\n");
+
+	regval = cpu_to_le16(U16_MAX);
+	ret = regmap_bulk_write(map, VEML6031X00_REG_WH_L, &regval, sizeof(regval));
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to set high threshold\n");
+
+	ret = regmap_field_write(data->rf.int_en, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(map, VEML6031X00_REG_INT, &val);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to clear interrupts\n");
+
+	return 0;
+}
+
+static int veml6031x00_setup_irq(struct i2c_client *i2c, struct iio_dev *iio)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	data->trig = devm_iio_trigger_alloc(dev, "%s-drdy%d",
+					    iio->name, iio_device_id(iio));
+	if (!data->trig)
+		return -ENOMEM;
+
+	data->trig->ops = &veml6031x00_trigger_ops;
+	iio_trigger_set_drvdata(data->trig, iio);
+
+	ret = devm_iio_trigger_register(dev, data->trig);
+	if (ret)
+		return ret;
+
+	return devm_request_threaded_irq(dev, i2c->irq, NULL, veml6031x00_irq,
+					 IRQF_ONESHOT, iio->name, iio);
+}
+
+static int veml6031x00_init_iiodev(struct i2c_client *i2c, struct iio_dev *iio)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	iio->name = data->chip->name;
+	iio->modes = INDIO_DIRECT_MODE;
+
+	if (!i2c->irq) {
+		iio->channels = veml6031x00_channels;
+		iio->num_channels = ARRAY_SIZE(veml6031x00_channels);
+		iio->info = &veml6031x00_info_no_irq;
+
+		return 0;
+	}
+
+	iio->channels = veml6031x00_channels_irq;
+	iio->num_channels = ARRAY_SIZE(veml6031x00_channels_irq);
+	iio->info = &veml6031x00_info;
+
+	ret = veml6031x00_setup_irq(i2c, iio);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, veml6031x00_disable_event_action, data);
+}
+
 static int veml6031x00_probe(struct i2c_client *i2c)
 {
 	struct device *dev = &i2c->dev;
@@ -631,17 +1204,15 @@ static int veml6031x00_probe(struct i2c_client *i2c)
 	if (ret)
 		return ret;
 
+	ret = devm_mutex_init(dev, &data->irq_lock);
+	if (ret)
+		return ret;
+
 	data->regmap = devm_regmap_init_i2c(i2c, &veml6031x00_regmap_config);
 	if (IS_ERR(data->regmap))
 		return dev_err_probe(dev, PTR_ERR(data->regmap),
 				     "Failed to set regmap\n");
 
-	iio->name = data->chip->name;
-	iio->channels = veml6031x00_channels;
-	iio->num_channels = ARRAY_SIZE(veml6031x00_channels);
-	iio->modes = INDIO_DIRECT_MODE;
-	iio->info = &veml6031x00_info;
-
 	ret = veml6031x00_regfield_init(data);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to init regfield\n");
@@ -669,6 +1240,10 @@ static int veml6031x00_probe(struct i2c_client *i2c)
 	if (ret)
 		return ret;
 
+	ret = veml6031x00_hw_init(data);
+	if (ret)
+		return ret;
+
 	/* Max resolution = 6.9632 lx/cnt for gain = 0.125 and IT = 3.125ms */
 	ret = devm_iio_init_iio_gts(dev, 6, 963200000,
 				    veml6031x00_gain_sel,
@@ -679,6 +1254,10 @@ static int veml6031x00_probe(struct i2c_client *i2c)
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to init IIO GTS\n");
 
+	ret = veml6031x00_init_iiodev(i2c, iio);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to initialize IIO device\n");
+
 	ret = devm_iio_triggered_buffer_setup(dev, iio,
 					      iio_pollfunc_store_time,
 					      veml6031x00_trig_handler,

-- 
2.43.0

Re: [PATCH v8 4/4] iio: light: veml6031x00: add support for events and trigger

[Javier Carrasco]

On Tue Sep 1, 2026 at 3:22 PM CEST, sashiko-bot wrote:
> Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
> - [High] Use-After-Free of iio->pollfunc in IRQ handler during device unbind or probe failure.
> - [Medium] Unintended I2C read of configuration register when pushing timestamp to buffer
> - [Medium] The interrupt_users counter can permanently underflow during error recovery, breaking hardware interrupt control.
> --
>
> commit c87f3d48e1ee614fc184995b816c8f8679a6b774
> Author: Javier Carrasco <javier.carrasco.cruz@gmail.com>
>
> iio: light: veml6031x00: add support for events and trigger
>
> The device provides a shared interrupt line to notify events and data ready.
> Add support for configurations with and without an interrupt line, providing
> events and trigger support when an interrupt line is available.
>
>> diff --git a/drivers/iio/light/veml6031x00.c b/drivers/iio/light/veml6031x00.c
>> index 3d5a27a0baaed..7bd7975eb1a76 100644
>> --- a/drivers/iio/light/veml6031x00.c
>> +++ b/drivers/iio/light/veml6031x00.c
> [ ... ]
>> +static irqreturn_t veml6031x00_irq(int irq, void *private)
>> +{
> [ ... ]
>> +	if (trigger_poll) {
>> +		iio->pollfunc->timestamp = timestamp;
>> +		iio_trigger_poll_nested(data->trig);
>> +	}
>> +
>> +	pm_runtime_put(dev);
>> +
>> +	return IRQ_HANDLED;
>> +}
>
> [Severity: High]
> Could this lead to a use-after-free of the pollfunc during device unbind or
> if probe fails?
>
> Because the IRQ is requested via devres inside veml6031x00_init_iiodev()
> before the triggered buffer is set up in veml6031x00_probe(), devres will
> tear down the buffer (and free iio->pollfunc) before freeing the IRQ. If an
> interrupt fires during this teardown window, the IRQ thread could be
> preempted and then dereference the freed iio->pollfunc here.
>
> Would it be safer to ensure devm_iio_triggered_buffer_setup() is called
> before the IRQ is requested?
>

I will register the IRQ right after calling
devm_iio_triggered_buffer_setup(), removing it from
veml6031x00_init_iiodev(). It was there not to check i2c->irq twice,
because that is also necessary to properly initialize the IIO device
with the right data, but it is true that the tear down is not clean at
the moment.

> [ ... ]
>> +static int __veml6031x00_set_trigger_state(struct veml6031x00_data *data, bool state)
>> +	__must_hold(&data->irq_lock)
>> +{
> [ ... ]
>> +	data->trig_en = state;
>> +
>> +	return 0;
>> +
>> +clear_interrupt:
>> +	veml6031x00_set_interrupt(data, !state);
>> +
>> +	return ret;
>> +}
>
> [Severity: Medium]
> Can data->interrupt_users permanently underflow here during error recovery?
>
> If an I2C error occurs in __veml6031x00_set_trigger_state() while disabling
> the trigger, this error recovery path calls veml6031x00_set_interrupt() to
> revert the counter, but fails to update the software state (data->trig_en).
>
> If a subsequent successful disable happens later, the counter will be
> decremented again, potentially underflowing to UINT_MAX and silently skipping
> all future hardware writes.
>
> [ ... ]

That is not true because the error path will *increment* the counter to
re-enable the IRQ and keept it consistent with data->trig_en. If an I2C
operation fails, the trigger will stay enabled in the device registers,
and therefore data-trig_en should stay enabled.

I tested it by adding some hacks to force that situation, and what may
actually happen is that if *on top* of that failure, the I2C operation
in veml6031x00_set_interrupt() also fails, interrupt_users will be
decremented (as it should, because the interrupt could not be
re-enabled), and *then* a second call to disable the trigger will set
interrupt_users to UINT_MAX.

Although this is very unlikely, the fix seems to be trivial:

 if (state) {
 	data->interrupt_users++;
 	if (data->interrupt_users > 1)
 		return 0;
 } else {
 	+	if (!data->interrupt_users)
 	+		return 0;

 	data->interrupt_users--;
 	if (data->interrupt_users > 0)
 		return 0;
 }

Note that this fix is not a hack to just get rid of reaching UINT_MAX, it
reflects the fact that the previous failed operations lead to a disabled
interrupt and an enabled trigger in the hardware, and there is no need
to act on the interrupt again when trying to disable the trigger a
second time.

I will add it for V9 after testing it with some hacks to force that
scenario.

Best regards,
Javier

Re: [PATCH v8 4/4] iio: light: veml6031x00: add support for events and trigger

[Javier Carrasco]

On Tue Sep 1, 2026 at 10:19 PM CEST, Javier Carrasco wrote:
> On Tue Sep 1, 2026 at 3:22 PM CEST, sashiko-bot wrote:
>> Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
>> - [High] Use-After-Free of iio->pollfunc in IRQ handler during device unbind or probe failure.
>> - [Medium] Unintended I2C read of configuration register when pushing timestamp to buffer
>> - [Medium] The interrupt_users counter can permanently underflow during error recovery, breaking hardware interrupt control.
>> --
>>
>> commit c87f3d48e1ee614fc184995b816c8f8679a6b774
>> Author: Javier Carrasco <javier.carrasco.cruz@gmail.com>
>>
>> iio: light: veml6031x00: add support for events and trigger
>>
>> The device provides a shared interrupt line to notify events and data ready.
>> Add support for configurations with and without an interrupt line, providing
>> events and trigger support when an interrupt line is available.
>>
>>> diff --git a/drivers/iio/light/veml6031x00.c b/drivers/iio/light/veml6031x00.c
>>> index 3d5a27a0baaed..7bd7975eb1a76 100644
>>> --- a/drivers/iio/light/veml6031x00.c
>>> +++ b/drivers/iio/light/veml6031x00.c
>> [ ... ]
>>> +static int __veml6031x00_set_trigger_state(struct veml6031x00_data *data, bool state)
>>> +	__must_hold(&data->irq_lock)
>>> +{
>> [ ... ]
>>> +	data->trig_en = state;
>>> +
>>> +	return 0;
>>> +
>>> +clear_interrupt:
>>> +	veml6031x00_set_interrupt(data, !state);
>>> +
>>> +	return ret;
>>> +}
>>
>> [Severity: Medium]
>> Can data->interrupt_users permanently underflow here during error recovery?
>>
>> If an I2C error occurs in __veml6031x00_set_trigger_state() while disabling
>> the trigger, this error recovery path calls veml6031x00_set_interrupt() to
>> revert the counter, but fails to update the software state (data->trig_en).
>>
>> If a subsequent successful disable happens later, the counter will be
>> decremented again, potentially underflowing to UINT_MAX and silently skipping
>> all future hardware writes.
>>
>> [ ... ]
>
> That is not true because the error path will *increment* the counter to
> re-enable the IRQ and keept it consistent with data->trig_en. If an I2C
> operation fails, the trigger will stay enabled in the device registers,
> and therefore data-trig_en should stay enabled.
>
> I tested it by adding some hacks to force that situation, and what may
> actually happen is that if *on top* of that failure, the I2C operation
> in veml6031x00_set_interrupt() also fails, interrupt_users will be
> decremented (as it should, because the interrupt could not be
> re-enabled), and *then* a second call to disable the trigger will set
> interrupt_users to UINT_MAX.
>
> Although this is very unlikely, the fix seems to be trivial:
>
>  if (state) {
>  	data->interrupt_users++;
>  	if (data->interrupt_users > 1)
>  		return 0;
>  } else {
>  	+	if (!data->interrupt_users)
>  	+		return 0;
>
>  	data->interrupt_users--;
>  	if (data->interrupt_users > 0)
>  		return 0;
>  }
>
> Note that this fix is not a hack to just get rid of reaching UINT_MAX, it
> reflects the fact that the previous failed operations lead to a disabled
> interrupt and an enabled trigger in the hardware, and there is no need
> to act on the interrupt again when trying to disable the trigger a
> second time.
>
> I will add it for V9 after testing it with some hacks to force that
> scenario.
>

I am trying to reproduce that scenario with forced errors, and even if
those two errors happen during the first attempt to disable the trigger,
it's not really possible to reach interrupt_users = UINT_MAX.
The 'buffer/enable' attribute is set to 0 by the core even if
set_trigger_state() returns an error code, and the next time
'buffer/enable' is set to 0, nothing really happens because
set_trigger_state() is not even called.

I could still add the check I suggested in V9 and avoid future issues,
but I don't see how to reproduce this in the current state of the core
and driver, even forcing those failed I2C operations.

Best regards,
Javier