[PATCH v4 0/3] Add Sharp GP2AP070S Proximity Driver and enable it in Galaxy J6 (j6lte)

[PATCH v4 0/3] Add Sharp GP2AP070S Proximity Driver and enable it in Galaxy J6 (j6lte)

[Kaustabh Chakraborty]

Sharp GP2AP070S is a promixity sensor (NOT an ambient light sensor) in
mobile devices. This sensor chip is found in mobile devices, including
(but perhaps not limited to) Samsung Galaxy J6 (codename: j6lte).

To the best of my knowledge, there's no public documentation available
for this device. [1] is a downstream kernel implementation, which has
been the single source for developing this driver. Some bits have also
been stolen from existing GP2AP* drivers available in iio/light.

The last patch in this series touches the device tree sources to add the
light sensor node in j6lte. This needs to be accepted into next only
when the former patches are in next.

[1] https://github.com/Exynos7870/android_kernel_samsung_universal7870/blob/lineage-16.0/drivers/sensors/gp2ap070s.c

Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
---
Changes in v4:
- Clarify non-mandatory vled-supply commit message (Krzysztof Kozlowski)
- Simplify driver probe return paths (David Lechner)
- Rephrase fsleep() usage to use unit macros (David Lechner)
- Use regmap_reinit_cache() instead of regcache_mark_dirty() (David Lechner)
- Use regmap_assign_bits() instead on branch on regmap_{set,clear}_bits()
  (David Lechner)
- Drop redundant explicit cast to u16 (David Lechner)
- Replace (1 << 16) with macrofied BIT(16) (David Lechner)
- Add max_register to regmap config (David Lechner)
- Add upper byte register for proximity distance volatile registers (Sashiko)
- Return 0 instead of IIO_VAL_INT in iio config write calls (Sashiko)
- Add REGCACHE_FLAT to regmap (Sashiko)
- Link to v3: https://patch.msgid.link/20260731-gp2ap070s-v3-0-d1f5cecf9fe7@disroot.org

Changes in v3:
- Revoke stale patches sent erroneously, v2 changelog applies
- Link to v2: https://patch.msgid.link/20260731-gp2ap070s-v2-0-1bdfee07d5ea@disroot.org

Changes in v2:
- Reshuffle and add missing header inclusions (Joshua Crofts)
- Add missing regulators in driver and dt-schema
  (Joshua Crofts, Jonathan Cameron)
- Rename and rearrange register addresses, masks and values (Jonathan Cameron)
- Use regmap_get_device() for carrying dev pointer (Jonathan Cameron)
- Use FIELD_GET() instead of !! (Jonathan Cameron)
- Drop unused i2c_set_clientdata() (Jonathan Cameron)
- Use fsleep() instead of usleep_range() (Jonathan Cameron)
- Check if proximity-near-level is available before reading its value
  (Jonathan Cameron)
- Drop redundant dev_err_probe() from devm_request_threaded_irq()
  (Joshua Crofts)
- Use mutex guards for guarding concurrent read/write calls (Sashiko)
- Add reset chip action on removal (Sashiko)
- Ensure input value in iio_write_event_value() is 16-bit (Sashiko)
- Use regmap_bulk_*() instead of regmap_raw_*() (Jonathan Cameron)
- Hint volatile registers for regmap (Jonathan Cameron)
- Link to v1: https://patch.msgid.link/20260723-gp2ap070s-v1-0-b8ca3a4c10dd@disroot.org

---
Kaustabh Chakraborty (3):
      dt-bindings: iio: proximity: add Sharp GP2AP070S proximity sensor
      iio: proximity: add driver for Sharp GP2AP070S proximity sensor
      arm64: dts: exynos7870-j6lte: add Sharp GP2AP070S proximity sensor

 .../bindings/iio/proximity/sharp,gp2ap070s.yaml    |  60 +++
 arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts    |  55 ++-
 drivers/iio/proximity/Kconfig                      |  11 +
 drivers/iio/proximity/Makefile                     |   1 +
 drivers/iio/proximity/gp2ap070s.c                  | 491 +++++++++++++++++++++
 5 files changed, 616 insertions(+), 2 deletions(-)
---
base-commit: 290aaf24a551d5a0dce037e3fab30820f9113a10
change-id: 20260723-gp2ap070s-f7e0120970a5

Best regards,
--  
Kaustabh Chakraborty <kauschluss@disroot.org>

[PATCH v4 1/3] dt-bindings: iio: proximity: add Sharp GP2AP070S proximity sensor

[Kaustabh Chakraborty]

The GP2AP070S is a proximity sensor designed and manufactured by Sharp
Corporation. Unlike the other GP2AP* schemas, this is strictly a
proximity sensor and NOT an ambient light sensor.

For power supplies, it expects two voltage supplies, one for core and
other for driving the infrared LED which is used to measure proximity
distance. However, some variants may not explicitly require a separate
regulator for the LED as they're able to draw power from the main
supply.

This chip has been used in production mobile devices such as the Samsung
Galaxy J6.

Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
---
 .../bindings/iio/proximity/sharp,gp2ap070s.yaml    | 60 ++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/proximity/sharp,gp2ap070s.yaml b/Documentation/devicetree/bindings/iio/proximity/sharp,gp2ap070s.yaml
new file mode 100644
index 000000000000..73f0abc1f09c
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/proximity/sharp,gp2ap070s.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/proximity/sharp,gp2ap070s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sharp GP2AP070S Proximity sensor
+
+maintainers:
+  - Kaustabh Chakraborty <kauschluss@disroot.org>
+
+allOf:
+  - $ref: ../common.yaml#
+
+properties:
+  compatible:
+    const: sharp,gp2ap070s
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  vdd-supply:
+    description: Voltage supply for the internal circuitry
+
+  vled-supply:
+    description: Voltage supply for the IR LED
+
+  proximity-near-level: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - vdd-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      proximity@39 {
+        compatible = "sharp,gp2ap070s";
+        reg = <0x39>;
+        interrupt-parent = <&gpio>;
+        interrupts = <1 IRQ_TYPE_EDGE_BOTH>;
+        vdd-supply = <&vdd_supply>;
+        vled-supply = <&vled_supply>;
+        proximity-near-level = <500>;
+      };
+    };
+
+...

-- 
2.54.0

[PATCH v4 2/3] iio: proximity: add driver for Sharp GP2AP070S proximity sensor

[Kaustabh Chakraborty]

The GP2AP070S is a proximity sensor designed and manufactured by Sharp
Corporation. This sensor is used in mobile devices, including, but not
limited to - the Samsung Galaxy J6.

The driver has been adopted from Samsung's downstream kernel
implementation [1]. Due to the lack of public documentation about the
schematics of this device. The downstream driver acts as the secondary
source of information. Driver clarity has also been improved with the
help of the GP2AP* drivers in iio/light.

Link: https://github.com/Exynos7870/android_kernel_samsung_universal7870/blob/lineage-16.0/drivers/sensors/gp2ap070s.c [1]
Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
---
 drivers/iio/proximity/Kconfig     |  11 +
 drivers/iio/proximity/Makefile    |   1 +
 drivers/iio/proximity/gp2ap070s.c | 491 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 503 insertions(+)

diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
index bb77fad2a1b3..39db19e59650 100644
--- a/drivers/iio/proximity/Kconfig
+++ b/drivers/iio/proximity/Kconfig
@@ -41,6 +41,17 @@ config D3323AA
 	  To compile this driver as a module, choose M here: the module will be
 	  called d3323aa.
 
+config GP2AP070S
+	tristate "Sharp GP2AP070S proximity sensor"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say Y here to build a driver for the Sharp GP2AP070S proximity
+	  sensor.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called gp2ap070s.
+
 config HX9023S
 	tristate "TYHX HX9023S SAR sensor"
 	select IIO_BUFFER
diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
index 4352833dd8a4..627ffb04acb2 100644
--- a/drivers/iio/proximity/Makefile
+++ b/drivers/iio/proximity/Makefile
@@ -7,6 +7,7 @@
 obj-$(CONFIG_AS3935)		+= as3935.o
 obj-$(CONFIG_CROS_EC_MKBP_PROXIMITY) += cros_ec_mkbp_proximity.o
 obj-$(CONFIG_D3323AA)		+= d3323aa.o
+obj-$(CONFIG_GP2AP070S)		+= gp2ap070s.o
 obj-$(CONFIG_HX9023S)		+= hx9023s.o
 obj-$(CONFIG_IRSD200)		+= irsd200.o
 obj-$(CONFIG_ISL29501)		+= isl29501.o
diff --git a/drivers/iio/proximity/gp2ap070s.c b/drivers/iio/proximity/gp2ap070s.c
new file mode 100644
index 000000000000..49770c308ddb
--- /dev/null
+++ b/drivers/iio/proximity/gp2ap070s.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * IIO driver for Sharp GP2AP070S proximity sensor.
+ *
+ * Based on Samsung G610FXXU1CRI4 kernel driver - drivers/sensors/gp2ap070s.c
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2026 Kaustabh Chakraborty <kauschluss@disroot.org>
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/types.h>
+
+#define GP2AP070S_REG_COM1		0x80
+#define   GP2AP070S_COM1_WKUP		BIT(7)
+#define   GP2AP070S_COM1_EN		BIT(5)
+
+#define GP2AP070S_REG_COM2		0x81
+
+#define GP2AP070S_REG_COM3		0x82
+#define   GP2AP070S_COM3_INT_PULSE	BIT(1)
+
+#define GP2AP070S_REG_COM4		0x83
+#define   GP2AP070S_COM4_BLINK		GENMASK(2, 0)	/* LED Blink Interval */
+#define     GP2AP070S_COM4_BLINK_0ms	0
+#define     GP2AP070S_COM4_BLINK_2ms	1
+#define     GP2AP070S_COM4_BLINK_8ms	2
+#define     GP2AP070S_COM4_BLINK_33ms	3
+#define     GP2AP070S_COM4_BLINK_66ms	4
+#define     GP2AP070S_COM4_BLINK_131ms	5
+#define     GP2AP070S_COM4_BLINK_262ms	6
+#define     GP2AP070S_COM4_BLINK_524ms	7
+
+#define GP2AP070S_REG_PS1		0x85
+#define   GP2AP070S_PS1_RESOL		GENMASK(5, 4)	/* Resolution */
+#define     GP2AP070S_PS1_RESOL_14ms	0
+#define     GP2AP070S_PS1_RESOL_12ms	1
+#define     GP2AP070S_PS1_RESOL_10ms	2
+#define     GP2AP070S_PS1_RESOL_8ms	3
+
+#define GP2AP070S_REG_PS2		0x86
+#define   GP2AP070S_PS2_IOUT		GENMASK(6, 4)	/* Current Output */
+#define     GP2AP070S_PS2_IOUT_0mA	0
+#define     GP2AP070S_PS2_IOUT_24mA	1
+#define     GP2AP070S_PS2_IOUT_89mA	2
+#define     GP2AP070S_PS2_IOUT_130mA	3
+#define     GP2AP070S_PS2_IOUT_190mA	4
+#define   GP2AP070S_PS2_SUM32		BIT(2)
+
+#define GP2AP070S_REG_PS3		0x87
+#define   GP2AP070S_PS3_PRST		GENMASK(6, 4)	/* Repeating Measurements */
+
+#define GP2AP070S_REG_PS_THD_LO_LE16	0x88
+#define GP2AP070S_REG_PS_THD_HI_LE16	0x8a
+#define GP2AP070S_REG_D0_LE16		0x90
+
+#define GP2AP070S_REG_MAX		(GP2AP070S_REG_D0_LE16 + 1)
+
+struct gp2ap070s_drvdata {
+	struct regmap *regmap;
+	struct mutex mutex;
+	u32 near_level;
+};
+
+static bool gp2ap070s_regmap_volatile(struct device *dev, unsigned int reg)
+{
+	return reg == GP2AP070S_REG_D0_LE16 || reg == GP2AP070S_REG_D0_LE16 + 1;
+}
+
+static const struct regmap_config gp2ap070s_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.volatile_reg = gp2ap070s_regmap_volatile,
+	.max_register = GP2AP070S_REG_MAX,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const char *const gp2ap070s_regulator_names[] = {
+	"vdd",
+	"vled",
+};
+
+static ssize_t gp2ap070s_iio_read_near_level(struct iio_dev *indio_dev,
+					     uintptr_t priv,
+					     const struct iio_chan_spec *chan,
+					     char *buf)
+{
+	struct gp2ap070s_drvdata *drvdata = iio_priv(indio_dev);
+
+	return sysfs_emit(buf, "%u\n", drvdata->near_level);
+}
+
+static const struct iio_chan_spec_ext_info gp2ap070s_iio_chan_spec_ext_info[] = {
+	{
+		.name = "nearlevel",
+		.shared = IIO_SEPARATE,
+		.read = gp2ap070s_iio_read_near_level,
+	},
+	{ }
+};
+
+static const struct iio_event_spec gp2ap070s_iio_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_ENABLE),
+	},
+};
+
+static const struct iio_chan_spec gp2ap070s_iio_chan_spec[] = {
+	{
+		.type = IIO_PROXIMITY,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.ext_info = gp2ap070s_iio_chan_spec_ext_info,
+		.event_spec = gp2ap070s_iio_event_spec,
+		.num_event_specs = ARRAY_SIZE(gp2ap070s_iio_event_spec),
+	},
+};
+
+static int gp2ap070s_iio_read_raw(struct iio_dev *indio_dev,
+				  struct iio_chan_spec const *chan, int *val,
+				  int *val2, long mask)
+{
+	struct gp2ap070s_drvdata *drvdata = iio_priv(indio_dev);
+	__le16 value;
+	int ret;
+
+	ret = regmap_bulk_read(drvdata->regmap, GP2AP070S_REG_D0_LE16, &value,
+			       sizeof(value));
+	if (ret)
+		return ret;
+
+	*val = le16_to_cpu(value);
+	return IIO_VAL_INT;
+}
+
+static int gp2ap070s_iio_read_event_value(struct iio_dev *indio_dev,
+					  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)
+{
+	struct gp2ap070s_drvdata *drvdata = iio_priv(indio_dev);
+	__le16 value;
+	int ret;
+
+	if (type != IIO_EV_TYPE_THRESH || info != IIO_EV_INFO_VALUE)
+		return -EINVAL;
+
+	guard(mutex)(&drvdata->mutex);
+
+	switch (dir) {
+	case IIO_EV_DIR_RISING:
+		ret = regmap_bulk_read(drvdata->regmap,
+				       GP2AP070S_REG_PS_THD_HI_LE16, &value,
+				       sizeof(value));
+		if (ret)
+			return ret;
+
+		*val = le16_to_cpu(value);
+		return IIO_VAL_INT;
+	case IIO_EV_DIR_FALLING:
+		ret = regmap_bulk_read(drvdata->regmap,
+				       GP2AP070S_REG_PS_THD_LO_LE16, &value,
+				       sizeof(value));
+		if (ret)
+			return ret;
+
+		*val = le16_to_cpu(value);
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int gp2ap070s_iio_write_event_value(struct iio_dev *indio_dev,
+					   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)
+{
+	struct gp2ap070s_drvdata *drvdata = iio_priv(indio_dev);
+	__le16 value;
+	u16 threshold_other;
+	int ret;
+
+	if (type != IIO_EV_TYPE_THRESH || info != IIO_EV_INFO_VALUE)
+		return -EINVAL;
+
+	/* Ensure val is a 16-bit value */
+	if (val < 0 || val >= BIT(16))
+		return -EINVAL;
+
+	guard(mutex)(&drvdata->mutex);
+
+	switch (dir) {
+	case IIO_EV_DIR_RISING:
+		ret = regmap_bulk_read(drvdata->regmap,
+				       GP2AP070S_REG_PS_THD_LO_LE16, &value,
+				       sizeof(value));
+		if (ret)
+			return ret;
+
+		/* Ensure lo_threshold < hi_threshold */
+		threshold_other = le16_to_cpu(value);
+		if (threshold_other >= val)
+			return -EINVAL;
+
+		value = cpu_to_le16(val);
+		ret = regmap_bulk_write(drvdata->regmap,
+					GP2AP070S_REG_PS_THD_HI_LE16, &value,
+					sizeof(value));
+		if (ret)
+			return ret;
+
+		return 0;
+	case IIO_EV_DIR_FALLING:
+		ret = regmap_bulk_read(drvdata->regmap,
+				       GP2AP070S_REG_PS_THD_HI_LE16, &value,
+				       sizeof(value));
+		if (ret)
+			return ret;
+
+		/* Ensure hi_threshold > lo_threshold */
+		threshold_other = le16_to_cpu(value);
+		if (threshold_other <= val)
+			return -EINVAL;
+
+		value = cpu_to_le16(val);
+		ret = regmap_bulk_write(drvdata->regmap,
+					GP2AP070S_REG_PS_THD_LO_LE16, &value,
+					sizeof(value));
+		if (ret)
+			return ret;
+
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int gp2ap070s_read_event_config(struct iio_dev *indio_dev,
+				       const struct iio_chan_spec *chan,
+				       enum iio_event_type type,
+				       enum iio_event_direction dir)
+{
+	struct gp2ap070s_drvdata *drvdata = iio_priv(indio_dev);
+	unsigned int value;
+	int ret;
+
+	if (type != IIO_EV_TYPE_THRESH)
+		return -EINVAL;
+
+	guard(mutex)(&drvdata->mutex);
+
+	switch (dir) {
+	case IIO_EV_DIR_EITHER:
+		ret = regmap_read(drvdata->regmap, GP2AP070S_REG_COM3, &value);
+		if (ret)
+			return ret;
+
+		return FIELD_GET(GP2AP070S_COM3_INT_PULSE, value);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int gp2ap070s_write_event_config(struct iio_dev *indio_dev,
+					const struct iio_chan_spec *chan,
+					enum iio_event_type type,
+					enum iio_event_direction dir,
+					bool state)
+{
+	struct gp2ap070s_drvdata *drvdata = iio_priv(indio_dev);
+
+	if (type != IIO_EV_TYPE_THRESH)
+		return -EINVAL;
+
+	guard(mutex)(&drvdata->mutex);
+
+	switch (dir) {
+	case IIO_EV_DIR_EITHER:
+		return regmap_assign_bits(drvdata->regmap, GP2AP070S_REG_COM3,
+					  GP2AP070S_COM3_INT_PULSE, state);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info gp2ap070s_iio_info = {
+	.read_raw = gp2ap070s_iio_read_raw,
+	.read_event_value = gp2ap070s_iio_read_event_value,
+	.write_event_value = gp2ap070s_iio_write_event_value,
+	.read_event_config = gp2ap070s_read_event_config,
+	.write_event_config = gp2ap070s_write_event_config,
+};
+
+static irqreturn_t gp2ap070s_irq_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	s64 timestamp = iio_get_time_ns(indio_dev);
+
+	iio_push_event(indio_dev,
+		       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0, IIO_EV_TYPE_THRESH,
+					    IIO_EV_DIR_EITHER),
+		       timestamp);
+
+	return IRQ_HANDLED;
+}
+
+static int gp2ap070s_reset(struct gp2ap070s_drvdata *drvdata)
+{
+	int ret;
+
+	ret = regmap_write(drvdata->regmap, GP2AP070S_REG_COM1, 0);
+	if (ret)
+		return ret;
+
+	return regmap_reinit_cache(drvdata->regmap, &gp2ap070s_regmap_config);
+}
+
+static void gp2ap070s_reset_action(void *private)
+{
+	struct gp2ap070s_drvdata *drvdata = private;
+
+	gp2ap070s_reset(drvdata);
+}
+
+static int gp2ap070s_probe_hw_register(struct gp2ap070s_drvdata *drvdata)
+{
+	struct device *dev = regmap_get_device(drvdata->regmap);
+	int ret;
+
+	ret = gp2ap070s_reset(drvdata);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to reset sensor\n");
+
+	ret = regmap_write(drvdata->regmap, GP2AP070S_REG_COM2, 0);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable interrupts\n");
+
+	ret = regmap_set_bits(drvdata->regmap, GP2AP070S_REG_COM3,
+			      GP2AP070S_COM3_INT_PULSE);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to unmask interrupts\n");
+
+	ret = regmap_write_bits(drvdata->regmap, GP2AP070S_REG_COM4,
+				GP2AP070S_COM4_BLINK,
+				FIELD_PREP_CONST(GP2AP070S_COM4_BLINK,
+						 GP2AP070S_COM4_BLINK_33ms));
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to set LED blink timing\n");
+
+	ret = regmap_write_bits(drvdata->regmap, GP2AP070S_REG_PS1,
+				GP2AP070S_PS1_RESOL,
+				FIELD_PREP_CONST(GP2AP070S_PS1_RESOL,
+						 GP2AP070S_PS1_RESOL_10ms));
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to set resolution\n");
+
+	ret = regmap_write_bits(drvdata->regmap, GP2AP070S_REG_PS2,
+				GP2AP070S_PS2_IOUT | GP2AP070S_PS2_SUM32,
+				FIELD_PREP_CONST(GP2AP070S_PS2_IOUT,
+						 GP2AP070S_PS2_IOUT_89mA) |
+				GP2AP070S_PS2_SUM32);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to set current output\n");
+
+	ret = regmap_write_bits(drvdata->regmap, GP2AP070S_REG_PS3,
+				GP2AP070S_PS3_PRST,
+				FIELD_PREP_CONST(GP2AP070S_PS3_PRST, 3));
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to set measurement repetitions\n");
+
+	ret = regmap_set_bits(drvdata->regmap, GP2AP070S_REG_COM1,
+			      GP2AP070S_COM1_WKUP | GP2AP070S_COM1_EN);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable sensor\n");
+
+	return 0;
+}
+
+static int gp2ap070s_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct iio_dev *indio_dev;
+	struct gp2ap070s_drvdata *drvdata;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*drvdata));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	drvdata = iio_priv(indio_dev);
+	drvdata->regmap = devm_regmap_init_i2c(client, &gp2ap070s_regmap_config);
+	if (IS_ERR(drvdata->regmap))
+		return dev_err_probe(dev, PTR_ERR(drvdata->regmap), "Failed to create regmap\n");
+
+	ret = devm_mutex_init(dev, &drvdata->mutex);
+	if (ret)
+		return ret;
+
+	ret = devm_regulator_bulk_get_enable(dev,
+					     ARRAY_SIZE(gp2ap070s_regulator_names),
+					     gp2ap070s_regulator_names);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get and enable regulators\n");
+
+	fsleep(10 * (MICRO / MILLI));
+
+	indio_dev->name = "gp2ap070s";
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = gp2ap070s_iio_chan_spec;
+	indio_dev->num_channels = ARRAY_SIZE(gp2ap070s_iio_chan_spec);
+	indio_dev->info = &gp2ap070s_iio_info;
+
+	if (device_property_present(dev, "proximity-near-level")) {
+		ret = device_property_read_u32(dev, "proximity-near-level",
+					       &drvdata->near_level);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to get value for proximity-near-level\n");
+	}
+
+	ret = gp2ap070s_probe_hw_register(drvdata);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, gp2ap070s_reset_action, drvdata);
+	if (ret)
+		return ret;
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+					gp2ap070s_irq_handler, IRQF_ONESHOT,
+					"gp2ap070s-irq", indio_dev);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id gp2ap070s_of_device_id[] = {
+	{ .compatible = "sharp,gp2ap070s" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, gp2ap070s_of_device_id);
+
+static const struct i2c_device_id gp2ap070s_i2c_device_id[] = {
+	{ .name = "gp2ap070s" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, gp2ap070s_i2c_device_id);
+
+static struct i2c_driver gp2ap070s_i2c_driver = {
+	.driver = {
+		.name = "gp2ap070s",
+		.of_match_table = gp2ap070s_of_device_id,
+	},
+	.probe = gp2ap070s_probe,
+	.id_table = gp2ap070s_i2c_device_id,
+};
+module_i2c_driver(gp2ap070s_i2c_driver);
+
+MODULE_AUTHOR("Kaustabh Chakraborty <kauschluss@disroot.org>");
+MODULE_DESCRIPTION("Sharp GP2AP070S Proximity Sensor");
+MODULE_LICENSE("GPL");

-- 
2.54.0

[PATCH v4 3/3] arm64: dts: exynos7870-j6lte: add Sharp GP2AP070S proximity sensor

[Kaustabh Chakraborty]

The Sharp GP2AP070S is a proximity sensor, which is connected to a
GPIO-driven I2C line. Define the devicetree node for the sensor.

The sensor requires two voltage supplies, one of which is from the
primary regulator bank of the device, while the other one is controlled
by the GPIO. Add a regulator wrapping over the concerned GPIO so as to
feed it to the sensor node.

Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
---
 arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts | 55 ++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts b/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts
index de30d0970336..dd493138fed6 100644
--- a/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts
+++ b/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts
@@ -73,6 +73,35 @@ key-volup {
 		};
 	};
 
+	i2c-proximity {
+		compatible = "i2c-gpio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&i2c_proxm_bus>;
+
+		sda-gpios = <&gpf4 3 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+		scl-gpios = <&gpf4 2 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+
+		i2c-gpio,delay-us = <2>;
+
+		proximity@39 {
+			compatible = "sharp,gp2ap070s";
+			reg = <0x39>;
+			interrupt-parent = <&gpa0>;
+			interrupts = <5 IRQ_TYPE_EDGE_BOTH>;
+
+			pinctrl-names = "default";
+			pinctrl-0 = <&proxm_irq>;
+
+			vdd-supply = <&vdd_fixed_proxm>;
+			vled-supply = <&vdd_ldo33>;
+
+			proximity-near-level = <500>;
+		};
+	};
+
 	memory@40000000 {
 		device_type = "memory";
 		reg = <0x0 0x40000000 0x3d800000>,
@@ -94,6 +123,16 @@ vdd_fixed_mmc2: regulator-fixed-mmc2 {
 		enable-active-high;
 	};
 
+	/* proximity: vdd */
+	vdd_fixed_proxm: regulator-fixed-proxm {
+		compatible = "regulator-fixed";
+		regulator-name = "vdd_fixed_proxm";
+		regulator-max-microvolt = <3300000>;
+		regulator-min-microvolt = <3300000>;
+		gpio = <&gpd2 3 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+	};
+
 	reserved-memory {
 		#address-cells = <2>;
 		#size-cells = <1>;
@@ -354,13 +393,12 @@ vdd_ldo32: ldo32 {
 				regulator-ramp-delay = <12000>;
 			};
 
+			/* proximity: vled */
 			vdd_ldo33: ldo33 {
 				regulator-name = "vdd_ldo33";
 				regulator-min-microvolt = <3300000>;
 				regulator-max-microvolt = <3300000>;
 				regulator-ramp-delay = <12000>;
-				regulator-boot-on;
-				regulator-always-on;
 			};
 
 			/* touchscreen: vdd */
@@ -556,6 +594,13 @@ pmic_irq: pmic-irq-pins {
 		samsung,pin-drv = <EXYNOS5433_PIN_DRV_FAST_SR4>;
 	};
 
+	proxm_irq: proxm-irq-pins {
+		samsung,pins = "gpa0-5";
+		samsung,pin-function = <EXYNOS_PIN_FUNC_EINT>;
+		samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
+		samsung,pin-drv = <EXYNOS5433_PIN_DRV_FAST_SR1>;
+	};
+
 	touch_irq: touch-irq-pins {
 		samsung,pins = "gpa0-6";
 		samsung,pin-function = <EXYNOS_PIN_FUNC_EINT>;
@@ -579,6 +624,12 @@ bt_enable: bt-enable-pins {
 		samsung,pin-pud = <EXYNOS_PIN_PULL_DOWN>;
 	};
 
+	i2c_proxm_bus: i2c-proxm-bus-pins {
+		samsung,pins = "gpf4-3", "gpf4-2";
+		samsung,pin-function = <EXYNOS_PIN_FUNC_3>;
+		samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
+	};
+
 	wlan_enable: wlan-enable-pins {
 		samsung,pins = "gpd3-6";
 		samsung,pin-function = <EXYNOS_PIN_FUNC_OUTPUT>;

-- 
2.54.0

Re: [PATCH v4 2/3] iio: proximity: add driver for Sharp GP2AP070S proximity sensor

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 4 potential issue(s) to consider:
- [High] Calling `regmap_reinit_cache` in device teardown path allocates memory and debugfs nodes improperly.
- [High] Using `REGCACHE_FLAT` without `reg_defaults` breaks threshold bounds checking logic.
- [High] Race condition between IRQ handler and IIO device unregistration leads to Use-After-Free.
- [Medium] Inaccurate timestamping due to unnecessary use of threaded IRQ.
--

--- Patch [2]: [PATCH v4 2/3] iio: proximity: add driver for Sharp GP2AP070S proximity sensor ---
commit cd2088367308936b58996051286de0d57904dcfc
Author: Kaustabh Chakraborty <kauschluss@disroot.org>

iio: proximity: add driver for Sharp GP2AP070S proximity sensor
    
The GP2AP070S is a proximity sensor designed and manufactured by Sharp
Corporation. This sensor is used in mobile devices, including, but not
limited to - the Samsung Galaxy J6.
    
Link: https://github.com/Exynos7870/android_kernel_samsung_universal7870/blob/lineage-16.0/drivers/sensors/gp2ap070s.c [1]

diff --git a/drivers/iio/proximity/gp2ap070s.c b/drivers/iio/proximity/gp2ap070s.c
new file mode 100644
index 0000000000000..49770c308ddbb
--- /dev/null
+++ b/drivers/iio/proximity/gp2ap070s.c
@@ -0,0 +1,491 @@
[ ... ]
> +static const struct regmap_config gp2ap070s_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.volatile_reg = gp2ap070s_regmap_volatile,
> +	.max_register = GP2AP070S_REG_MAX,
> +	.cache_type = REGCACHE_FLAT,
> +};

[Severity: High]
Does using REGCACHE_FLAT without providing initial hardware defaults break
the threshold bounds checking logic?

Because PS_THD_LO_LE16 and PS_THD_HI_LE16 are not written during probe, the
flat regmap cache implementation satisfies reads from its 0-initialized array
and does not fall back to hardware. This causes unwritten registers to be
cached as 0, which breaks the bounds check in
gp2ap070s_iio_write_event_value().

[ ... ]
> +static int gp2ap070s_iio_write_event_value(struct iio_dev *indio_dev,
[ ... ]
> +	case IIO_EV_DIR_RISING:
> +		ret = regmap_bulk_read(drvdata->regmap,
> +				       GP2AP070S_REG_PS_THD_LO_LE16, &value,
> +				       sizeof(value));
> +		if (ret)
> +			return ret;
> +
> +		/* Ensure lo_threshold < hi_threshold */
> +		threshold_other = le16_to_cpu(value);
> +		if (threshold_other >= val)
> +			return -EINVAL;
> +
> +		value = cpu_to_le16(val);
> +		ret = regmap_bulk_write(drvdata->regmap,
> +					GP2AP070S_REG_PS_THD_HI_LE16, &value,
> +					sizeof(value));
> +		if (ret)
> +			return ret;
> +
> +		return 0;
> +	case IIO_EV_DIR_FALLING:
> +		ret = regmap_bulk_read(drvdata->regmap,
> +				       GP2AP070S_REG_PS_THD_HI_LE16, &value,
> +				       sizeof(value));
> +		if (ret)
> +			return ret;
> +
> +		/* Ensure hi_threshold > lo_threshold */
> +		threshold_other = le16_to_cpu(value);
> +		if (threshold_other <= val)
> +			return -EINVAL;

[Severity: High]
Could this reject valid writes to the falling threshold?

If a user writes the falling threshold before the rising threshold,
threshold_other will be incorrectly read as 0 from the uninitialized cache.
The check (0 <= val) will always evaluate to true for positive values,
returning -EINVAL.

[ ... ]
> +static irqreturn_t gp2ap070s_irq_handler(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	s64 timestamp = iio_get_time_ns(indio_dev);

[Severity: Medium]
Will this timestamp suffer from thread scheduling latency?

Since the IRQ is requested with a NULL primary handler, this entire routine
executes in a kernel thread. Capturing the timestamp in threaded context
rather than hard IRQ context can introduce jitter to the IIO event
timestamps.

> +
> +	iio_push_event(indio_dev,
> +		       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0, IIO_EV_TYPE_THRESH,
> +					    IIO_EV_DIR_EITHER),
> +		       timestamp);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int gp2ap070s_reset(struct gp2ap070s_drvdata *drvdata)
> +{
> +	int ret;
> +
> +	ret = regmap_write(drvdata->regmap, GP2AP070S_REG_COM1, 0);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_reinit_cache(drvdata->regmap, &gp2ap070s_regmap_config);
> +}
> +
> +static void gp2ap070s_reset_action(void *private)
> +{
> +	struct gp2ap070s_drvdata *drvdata = private;
> +
> +	gp2ap070s_reset(drvdata);
> +}

[Severity: High]
Is it safe to call regmap_reinit_cache() during device teardown?

When the module is unloaded or unbound, the devres group executes
gp2ap070s_reset_action(), which calls gp2ap070s_reset(). Calling
regmap_reinit_cache() allocates memory and attempts to re-create debugfs
nodes.

The I2C subsystem cleans up the client's debugfs directory before devres
actions run, so attempting to create files in a destroyed parent directory
can lead to kernel warnings or memory corruption.

[ ... ]
> +static int gp2ap070s_probe(struct i2c_client *client)
> +{
[ ... ]
> +	ret = devm_request_threaded_irq(dev, client->irq, NULL,
> +					gp2ap070s_irq_handler, IRQF_ONESHOT,
> +					"gp2ap070s-irq", indio_dev);

[Severity: Medium]
Is it necessary to use a threaded IRQ here?

Since the interrupt handler only captures a timestamp and pushes an event
without performing blocking operations like I2C reads, could this run as a
primary hard IRQ handler to improve timestamp accuracy?

> +	if (ret)
> +		return ret;
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}

[Severity: High]
Does registering the IRQ before the IIO device introduce a use-after-free
race during module unload?

Due to devres LIFO ordering, devm_iio_device_register() cleanup runs first
on removal, calling iio_device_unregister() and destroying the event
interface.

If an interrupt fires in the window before the IRQ is freed,
gp2ap070s_irq_handler() will execute and call iio_push_event(), which races
with the teardown thread and can dereference the freed event interface.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260807-gp2ap070s-v4-0-74f6a67b6272@disroot.org?part=2

Re: [PATCH v4 3/3] arm64: dts: exynos7870-j6lte: add Sharp GP2AP070S proximity sensor

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The devicetree node `i2c-proximity` uses the software bit-banged `i2c-gpio` driver, but its pinctrl node `i2c_proxm_bus` explicitly configures the pins to the hardware I2C controller's alternate function instead of GPIO mode.
--

--- Patch [3]: [PATCH v4 3/3] arm64: dts: exynos7870-j6lte: add Sharp GP2AP070S proximity sensor ---
commit c0b785824301e0a2b3734b066c904e45cdad7f77
Author: Kaustabh Chakraborty <kauschluss@disroot.org>

arm64: dts: exynos7870-j6lte: add Sharp GP2AP070S proximity sensor

The commit adds a Sharp GP2AP070S proximity sensor to the exynos7870-j6lte
device tree. It connects the sensor via a GPIO-driven I2C bus and provides
necessary regulator supplies.

> diff --git a/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts b/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts
> index de30d0970336f..dd493138fed6e 100644
> --- a/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts
> +++ b/arch/arm64/boot/dts/exynos/exynos7870-j6lte.dts
> @@ -73,6 +73,35 @@ key-volup {
>  		};
>  	};
>  
> +	i2c-proximity {
> +		compatible = "i2c-gpio";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&i2c_proxm_bus>;
> +
> +		sda-gpios = <&gpf4 3 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
> +		scl-gpios = <&gpf4 2 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;

[ ... ]

> @@ -579,6 +624,12 @@ bt_enable: bt-enable-pins {
>  		samsung,pin-pud = <EXYNOS_PIN_PULL_DOWN>;
>  	};
>  
> +	i2c_proxm_bus: i2c-proxm-bus-pins {
> +		samsung,pins = "gpf4-3", "gpf4-2";
> +		samsung,pin-function = <EXYNOS_PIN_FUNC_3>;

[Severity: Medium]
Is it intentional to configure these pins to the hardware I2C controller
alternate function (EXYNOS_PIN_FUNC_3) while using the software bit-banged
i2c-gpio driver?

During device probe, the pinctrl framework will route the pins to the hardware
I2C controller.

This contradicts the bit-banged I2C design and creates a window where the pins
are driven by the hardware controller before the GPIO framework eventually
overrides the pin multiplexing.

If the hardware controller isn't powered or properly initialized, could this
cause the pins to float or drive the bus incorrectly, leading to I2C bus
glitches?

> +		samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
> +	};
> +

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260807-gp2ap070s-v4-0-74f6a67b6272@disroot.org?part=3

Re: [PATCH v4 1/3] dt-bindings: iio: proximity: add Sharp GP2AP070S proximity sensor

[Krzysztof Kozlowski]

On Fri, Aug 07, 2026 at 01:18:41AM +0530, Kaustabh Chakraborty wrote:
> +  interrupts:
> +    maxItems: 1
> +
> +  vdd-supply:
> +    description: Voltage supply for the internal circuitry
> +
> +  vled-supply:
> +    description: Voltage supply for the IR LED
> +
> +  proximity-near-level: true

Same comment.

Best regards,
Krzysztof