[PATCH 0/2] Pinefeat cef168 lens control board driver

[PATCH 0/2] Pinefeat cef168 lens control board driver

[Aliaksandr Smirnou]

This patch series adds support for the Pinefeat adapter, which interfaces
Canon EF and EF-S lenses to non-Canon camera bodies. The cef168 circuit
control board provides an I2C interface for electronic focus and aperture
control. The driver integrates with the V4L2 sub-device API.

For more information about the product, see:
https://github.com/pinefeat/cef168

Patches:
  dt-bindings: Pinefeat cef168 lens control board
  media/i2c: Pinefeat cef168 lens control board driver

 .../bindings/media/i2c/pinefeat,cef168.yaml   |  48 +++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 MAINTAINERS                                   |   9 +
 drivers/media/i2c/Kconfig                     |   8 +
 drivers/media/i2c/Makefile                    |   1 +
 drivers/media/i2c/cef168.c                    | 342 ++++++++++++++++++
 drivers/media/i2c/cef168.h                    |  51 +++
 7 files changed, 461 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
 create mode 100644 drivers/media/i2c/cef168.c
 create mode 100644 drivers/media/i2c/cef168.h


base-commit: 2b38afce25c4e1b8f943ff4f0a2b51d6c40f2ed2
-- 
2.34.1

[PATCH 1/2] dt-bindings: Pinefeat cef168 lens control board

[Aliaksandr Smirnou]

Add the Device Tree schema and examples for the Pinefeat cef168 lens
 control board. This board interfaces Canon EF & EF-S lenses with
 non-Canon camera bodies, enabling electronic control of focus and
 aperture via V4L2.

Signed-off-by: Aliaksandr Smirnou <support@pinefeat.co.uk>
---
 .../bindings/media/i2c/pinefeat,cef168.yaml   | 48 +++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
 MAINTAINERS                                   |  7 +++
 3 files changed, 57 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml b/Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
new file mode 100644
index 000000000000..ae0c77de5cb4
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (c) 2025 Pinefeat LLP
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/pinefeat,cef168.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Pinefeat cef168 lens driver
+
+maintainers:
+  - Aliaksandr Smirnou <support@pinefeat.co.uk>
+
+description: |
+  Pinefeat produces an adapter designed to interface between
+  Canon EF & EF-S lenses and non-Canon camera bodies, incorporating
+  features for electronic focus and aperture adjustment. The cef168
+  circuit board, included with the adapter, provides a software
+  programming interface that allows control of lens focus and
+  aperture positions. This driver enables controlling the lens
+  focus and aperture via the V4L2 (Video4Linux2) API.
+
+properties:
+  compatible:
+    enum:
+      - pinefeat,cef168
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        lens_node: cef168@d {
+            compatible = "pinefeat,cef168";
+            reg = <0x0d>;
+        };
+    };
+
+...
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 77160cd47f54..dab27f769b0a 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1195,6 +1195,8 @@ patternProperties:
     description: Picochip Ltd
   "^pine64,.*":
     description: Pine64
+  "^pinefeat,.*":
+    description: Pinefeat LLP
   "^pineriver,.*":
     description: Shenzhen PineRiver Designs Co., Ltd.
   "^pixcir,.*":
diff --git a/MAINTAINERS b/MAINTAINERS
index fe168477caa4..50dbe343ffc2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19985,6 +19985,13 @@ S:	Supported
 F:	Documentation/devicetree/bindings/input/pine64,pinephone-keyboard.yaml
 F:	drivers/input/keyboard/pinephone-keyboard.c
 
+PINEFEAT CEF168 LENS DRIVER
+M:	Aliaksandr Smirnou <support@pinefeat.co.uk>
+L:	linux-media@vger.kernel.org
+S:	Supported
+T:	git git://linuxtv.org/media.git
+F:	Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
+
 PLANTOWER PMS7003 AIR POLLUTION SENSOR DRIVER
 M:	Tomasz Duszynski <tduszyns@gmail.com>
 S:	Maintained
-- 
2.34.1

[PATCH 2/2] media/i2c: Pinefeat cef168 lens control board driver

[Aliaksandr Smirnou]

Add support for the Pinefeat cef168 lens control board that provides
electronic focus and aperture control for Canon EF & EF-S lenses on
non-Canon camera bodies.

Signed-off-by: Aliaksandr Smirnou <support@pinefeat.co.uk>
---
 MAINTAINERS                |   2 +
 drivers/media/i2c/Kconfig  |   8 +
 drivers/media/i2c/Makefile |   1 +
 drivers/media/i2c/cef168.c | 342 +++++++++++++++++++++++++++++++++++++
 drivers/media/i2c/cef168.h |  51 ++++++
 5 files changed, 404 insertions(+)
 create mode 100644 drivers/media/i2c/cef168.c
 create mode 100644 drivers/media/i2c/cef168.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 50dbe343ffc2..43c694461399 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19991,6 +19991,8 @@ L:	linux-media@vger.kernel.org
 S:	Supported
 T:	git git://linuxtv.org/media.git
 F:	Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
+F:	drivers/media/i2c/cef168.c
+F:	drivers/media/i2c/cef168.h
 
 PLANTOWER PMS7003 AIR POLLUTION SENSOR DRIVER
 M:	Tomasz Duszynski <tduszyns@gmail.com>
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 6237fe804a5c..c4c3b03a0b98 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -791,6 +791,14 @@ config VIDEO_AK7375
 	  capability. This is designed for linear control of
 	  voice coil motors, controlled via I2C serial interface.
 
+config VIDEO_CEF168
+	tristate "CEF168 lens control support"
+	help
+	  This is a driver for the CEF168 lens control board.
+	  The board provides an I2C interface for electronic focus
+	  and aperture control of EF and EF-S lenses. The driver
+	  integrates with the V4L2 sub-device API.
+
 config VIDEO_DW9714
 	tristate "DW9714 lens voice coil support"
 	depends on GPIOLIB
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 5873d29433ee..75a95f850f18 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_VIDEO_BT856) += bt856.o
 obj-$(CONFIG_VIDEO_BT866) += bt866.o
 obj-$(CONFIG_VIDEO_CCS) += ccs/
 obj-$(CONFIG_VIDEO_CCS_PLL) += ccs-pll.o
+obj-$(CONFIG_VIDEO_CEF168) += cef168.o
 obj-$(CONFIG_VIDEO_CS3308) += cs3308.o
 obj-$(CONFIG_VIDEO_CS5345) += cs5345.o
 obj-$(CONFIG_VIDEO_CS53L32A) += cs53l32a.o
diff --git a/drivers/media/i2c/cef168.c b/drivers/media/i2c/cef168.c
new file mode 100644
index 000000000000..eda5ad507c91
--- /dev/null
+++ b/drivers/media/i2c/cef168.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2025 Pinefeat LLP
+
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include "cef168.h"
+
+/*
+ * cef168 device structure
+ */
+struct cef168_device {
+	struct v4l2_ctrl_handler ctrls;
+	struct v4l2_subdev sd;
+};
+
+static inline struct cef168_device *to_cef168(struct v4l2_ctrl *ctrl)
+{
+	return container_of(ctrl->handler, struct cef168_device, ctrls);
+}
+
+static inline struct cef168_device *sd_to_cef168(struct v4l2_subdev *subdev)
+{
+	return container_of(subdev, struct cef168_device, sd);
+}
+
+static int cef168_i2c_write(struct cef168_device *cef168_dev, u8 cmd, u16 val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&cef168_dev->sd);
+	int retry, ret;
+
+	val = cpu_to_le16(val);
+	char tx_data[4] = { cmd, (val & 0xff), (val >> 8) };
+
+	tx_data[3] = crc8(cef168_crc8_table, tx_data, 3, CRC8_INIT_VALUE);
+
+	for (retry = 0; retry < 3; retry++) {
+		ret = i2c_master_send(client, tx_data, sizeof(tx_data));
+		if (ret == sizeof(tx_data))
+			return 0;
+		else if (ret != -EIO && ret != -EREMOTEIO)
+			break;
+	}
+
+	dev_err(&client->dev, "I2C write fail after %d retries, ret=%d\n",
+		retry, ret);
+	return -EIO;
+}
+
+static int cef168_i2c_read(struct cef168_device *cef168_dev,
+			   struct cef168_data *rx_data)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&cef168_dev->sd);
+
+	int ret = i2c_master_recv(client, (char *)rx_data,
+				  sizeof(struct cef168_data));
+	if (ret != sizeof(struct cef168_data)) {
+		dev_err(&client->dev, "I2C read fail, ret=%d\n", ret);
+		return -EIO;
+	}
+
+	u8 computed_crc = crc8(cef168_crc8_table, (const u8 *)rx_data,
+			       sizeof(struct cef168_data) - 1, CRC8_INIT_VALUE);
+	if (computed_crc != rx_data->crc8) {
+		dev_err(&client->dev,
+			"CRC mismatch calculated=0x%02X read=0x%02X\n",
+			computed_crc, rx_data->crc8);
+		return -EIO;
+	}
+
+	rx_data->moving_time = le16_to_cpu(rx_data->moving_time);
+	rx_data->focus_position_min = le16_to_cpu(rx_data->focus_position_min);
+	rx_data->focus_position_max = le16_to_cpu(rx_data->focus_position_max);
+	rx_data->focus_position_cur = le16_to_cpu(rx_data->focus_position_cur);
+	rx_data->focus_distance_min = le16_to_cpu(rx_data->focus_distance_min);
+	rx_data->focus_distance_max = le16_to_cpu(rx_data->focus_distance_max);
+
+	return 0;
+}
+
+static int cef168_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct cef168_device *dev = to_cef168(ctrl);
+	u8 cmd;
+
+	switch (ctrl->id) {
+	case V4L2_CID_FOCUS_ABSOLUTE:
+		return cef168_i2c_write(dev, INP_SET_FOCUS, ctrl->val);
+	case V4L2_CID_FOCUS_RELATIVE:
+		cmd = ctrl->val < 0 ? INP_SET_FOCUS_N : INP_SET_FOCUS_P;
+		return cef168_i2c_write(dev, cmd, abs(ctrl->val));
+	case V4L2_CID_IRIS_ABSOLUTE:
+		return cef168_i2c_write(dev, INP_SET_APERTURE, ctrl->val);
+	case V4L2_CID_IRIS_RELATIVE:
+		cmd = ctrl->val < 0 ? INP_SET_APERTURE_N : INP_SET_APERTURE_P;
+		return cef168_i2c_write(dev, cmd, abs(ctrl->val));
+	case CEF168_V4L2_CID_CUSTOM(calibrate):
+		return cef168_i2c_write(dev, INP_CALIBRATE, 0);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int cef168_get_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct cef168_device *dev = to_cef168(ctrl);
+	int rval;
+
+	if (ctrl->id != V4L2_CID_FOCUS_ABSOLUTE &&
+	    ctrl->id != CEF168_V4L2_CID_CUSTOM(data) &&
+	    ctrl->id != CEF168_V4L2_CID_CUSTOM(focus_range) &&
+	    ctrl->id != CEF168_V4L2_CID_CUSTOM(lens_id))
+		return -EINVAL;
+
+	struct cef168_data data;
+
+	rval = cef168_i2c_read(dev, &data);
+	if (rval < 0)
+		return rval;
+
+	switch (ctrl->id) {
+	case V4L2_CID_FOCUS_ABSOLUTE:
+		ctrl->val = data.focus_position_cur;
+		return 0;
+	case CEF168_V4L2_CID_CUSTOM(focus_range):
+		ctrl->p_new.p_u32[0] =
+			(u32)le32_to_cpu(((u32)data.focus_position_min << 16) |
+					 data.focus_position_max);
+		return 0;
+	case CEF168_V4L2_CID_CUSTOM(lens_id):
+		ctrl->p_new.p_u8[0] = data.lens_id;
+		return 0;
+	case CEF168_V4L2_CID_CUSTOM(data):
+		memcpy(ctrl->p_new.p_u8, &data, sizeof(data));
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static const struct v4l2_ctrl_ops cef168_ctrl_ops = {
+	.g_volatile_ctrl = cef168_get_ctrl,
+	.s_ctrl = cef168_set_ctrl,
+};
+
+static const struct v4l2_ctrl_config cef168_lens_id_ctrl = {
+	.ops = &cef168_ctrl_ops,
+	.id = CEF168_V4L2_CID_CUSTOM(lens_id),
+	.type = V4L2_CTRL_TYPE_U8,
+	.name = "Lens ID",
+	.min = 0,
+	.max = U8_MAX,
+	.step = 1,
+	.def = 0,
+	.flags = V4L2_CTRL_FLAG_VOLATILE | V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static const struct v4l2_ctrl_config cef168_focus_range_ctrl = {
+	.ops = &cef168_ctrl_ops,
+	.id = CEF168_V4L2_CID_CUSTOM(focus_range),
+	.type = V4L2_CTRL_TYPE_U32,
+	.name = "Focus Range",
+	.min = 0,
+	.max = U32_MAX,
+	.step = 1,
+	.def = 0,
+	.flags = V4L2_CTRL_FLAG_VOLATILE | V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static const struct v4l2_ctrl_config cef168_data_ctrl = {
+	.ops = &cef168_ctrl_ops,
+	.id = CEF168_V4L2_CID_CUSTOM(data),
+	.type = V4L2_CTRL_TYPE_U8,
+	.name = "Data",
+	.min = 0,
+	.max = U8_MAX,
+	.step = 1,
+	.def = 0,
+	.dims = { sizeof(struct cef168_data) / sizeof(u8) },
+	.elem_size = sizeof(u8),
+	.flags = V4L2_CTRL_FLAG_VOLATILE | V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static const struct v4l2_ctrl_config cef168_calibrate_ctrl = {
+	.ops = &cef168_ctrl_ops,
+	.id = CEF168_V4L2_CID_CUSTOM(calibrate),
+	.type = V4L2_CTRL_TYPE_BUTTON,
+	.name = "Calibrate",
+};
+
+static int cef168_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	return pm_runtime_resume_and_get(sd->dev);
+}
+
+static int cef168_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	pm_runtime_put(sd->dev);
+	return 0;
+}
+
+static const struct v4l2_subdev_internal_ops cef168_int_ops = {
+	.open = cef168_open,
+	.close = cef168_close,
+};
+
+static const struct v4l2_subdev_core_ops cef168_core_ops = {
+	.log_status = v4l2_ctrl_subdev_log_status,
+	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
+	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
+static const struct v4l2_subdev_ops cef168_ops = {
+	.core = &cef168_core_ops,
+};
+
+static void cef168_subdev_cleanup(struct cef168_device *cef168_dev)
+{
+	v4l2_async_unregister_subdev(&cef168_dev->sd);
+	v4l2_ctrl_handler_free(&cef168_dev->ctrls);
+	media_entity_cleanup(&cef168_dev->sd.entity);
+}
+
+static int cef168_init_controls(struct cef168_device *dev)
+{
+	struct v4l2_ctrl *ctrl;
+	struct v4l2_ctrl_handler *hdl = &dev->ctrls;
+	const struct v4l2_ctrl_ops *ops = &cef168_ctrl_ops;
+
+	v4l2_ctrl_handler_init(hdl, 8);
+
+	ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE, 0, S16_MAX,
+				 1, 0);
+	if (ctrl)
+		ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE |
+			       V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_RELATIVE, S16_MIN, S16_MAX,
+			  1, 0);
+	ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_IRIS_ABSOLUTE, 0, S16_MAX,
+				 1, 0);
+	if (ctrl)
+		ctrl->flags |= V4L2_CTRL_FLAG_WRITE_ONLY |
+			       V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_IRIS_RELATIVE, S16_MIN, S16_MAX, 1,
+			  0);
+	v4l2_ctrl_new_custom(hdl, &cef168_calibrate_ctrl, NULL);
+	v4l2_ctrl_new_custom(hdl, &cef168_focus_range_ctrl, NULL);
+	v4l2_ctrl_new_custom(hdl, &cef168_data_ctrl, NULL);
+	v4l2_ctrl_new_custom(hdl, &cef168_lens_id_ctrl, NULL);
+
+	if (hdl->error)
+		dev_err(dev->sd.dev, "%s fail error: 0x%x\n", __func__,
+			hdl->error);
+	dev->sd.ctrl_handler = hdl;
+	return hdl->error;
+}
+
+static int cef168_probe(struct i2c_client *client)
+{
+	struct cef168_device *cef168_dev;
+	int rval;
+
+	cef168_dev =
+		devm_kzalloc(&client->dev, sizeof(*cef168_dev), GFP_KERNEL);
+	if (cef168_dev == NULL)
+		return -ENOMEM;
+
+	v4l2_i2c_subdev_init(&cef168_dev->sd, client, &cef168_ops);
+	cef168_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
+				V4L2_SUBDEV_FL_HAS_EVENTS;
+	cef168_dev->sd.internal_ops = &cef168_int_ops;
+
+	rval = cef168_init_controls(cef168_dev);
+	if (rval)
+		goto err_cleanup;
+
+	rval = media_entity_pads_init(&cef168_dev->sd.entity, 0, NULL);
+	if (rval < 0)
+		goto err_cleanup;
+
+	cef168_dev->sd.entity.function = MEDIA_ENT_F_LENS;
+
+	rval = v4l2_async_register_subdev(&cef168_dev->sd);
+	if (rval < 0)
+		goto err_cleanup;
+
+	crc8_populate_msb(cef168_crc8_table, CEF_CRC8_POLYNOMIAL);
+
+	pm_runtime_set_active(&client->dev);
+	pm_runtime_enable(&client->dev);
+	pm_runtime_idle(&client->dev);
+
+	return 0;
+
+err_cleanup:
+	v4l2_ctrl_handler_free(&cef168_dev->ctrls);
+	media_entity_cleanup(&cef168_dev->sd.entity);
+
+	return rval;
+}
+
+static void cef168_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct cef168_device *cef168_dev = sd_to_cef168(sd);
+
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+	cef168_subdev_cleanup(cef168_dev);
+}
+
+static const struct i2c_device_id cef168_id_table[] = { { CEF168_NAME, 0 },
+							{ { 0 } } };
+MODULE_DEVICE_TABLE(i2c, cef168_id_table);
+
+static const struct of_device_id cef168_of_table[] = {
+	{ .compatible = "pinefeat,cef168" },
+	{ { 0 } }
+};
+MODULE_DEVICE_TABLE(of, cef168_of_table);
+
+static struct i2c_driver cef168_i2c_driver = {
+		.driver = {
+				.name = CEF168_NAME,
+				.of_match_table = cef168_of_table,
+		},
+		.probe = cef168_probe,
+		.remove = cef168_remove,
+		.id_table = cef168_id_table,
+};
+
+module_i2c_driver(cef168_i2c_driver);
+
+MODULE_AUTHOR("support@pinefeat.co.uk>");
+MODULE_DESCRIPTION("CEF168 lens driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/i2c/cef168.h b/drivers/media/i2c/cef168.h
new file mode 100644
index 000000000000..cdce1a19bda0
--- /dev/null
+++ b/drivers/media/i2c/cef168.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Pinefeat cef168 lens driver
+ *
+ * Copyright (c) 2025 Pinefeat LLP
+ */
+
+#ifndef CEF168_CEF168_H
+#define CEF168_CEF168_H
+
+#define CEF168_NAME "cef168"
+
+#define CEF168_V4L2_CID_CUSTOM(ctrl) \
+	((V4L2_CID_USER_BASE | 168) + custom_##ctrl)
+
+enum { custom_lens_id, custom_data, custom_focus_range, custom_calibrate };
+
+/**
+ * cef168 data structure
+ */
+struct cef168_data {
+	__u8 lens_id;
+	__u8 moving : 1;
+	__u8 calibrating : 2;
+	__u16 moving_time;
+	__u16 focus_position_min;
+	__u16 focus_position_max;
+	__u16 focus_position_cur;
+	__u16 focus_distance_min;
+	__u16 focus_distance_max;
+	__u8 crc8;
+} __packed;
+
+/*
+ * cef168 I2C protocol commands
+ */
+#define INP_CALIBRATE 0x22
+#define INP_SET_FOCUS 0x80
+#define INP_SET_FOCUS_P 0x81
+#define INP_SET_FOCUS_N 0x82
+#define INP_SET_APERTURE 0x7A
+#define INP_SET_APERTURE_P 0x7B
+#define INP_SET_APERTURE_N 0x7C
+
+#define CEF_CRC8_POLYNOMIAL 168
+
+#ifdef DECLARE_CRC8_TABLE
+DECLARE_CRC8_TABLE(cef168_crc8_table);
+#endif
+
+#endif //CEF168_CEF168_H
-- 
2.34.1

Re: [PATCH 1/2] dt-bindings: Pinefeat cef168 lens control board

[Krzysztof Kozlowski]

On 10/08/2025 21:26, Aliaksandr Smirnou wrote:
> Add the Device Tree schema and examples for the Pinefeat cef168 lens
>  control board. This board interfaces Canon EF & EF-S lenses with
>  non-Canon camera bodies, enabling electronic control of focus and
>  aperture via V4L2.
> 
> Signed-off-by: Aliaksandr Smirnou <support@pinefeat.co.uk>

<form letter>
Please use scripts/get_maintainers.pl to get a list of necessary people
and lists to CC (and consider --no-git-fallback argument, so you will
not CC people just because they made one commit years ago). It might
happen, that command when run on an older kernel, gives you outdated
entries. Therefore please be sure you base your patches on recent Linux
kernel.

Tools like b4 or scripts/get_maintainer.pl provide you proper list of
people, so fix your workflow. Tools might also fail if you work on some
ancient tree (don't, instead use mainline) or work on fork of kernel
(don't, instead use mainline). Just use b4 and everything should be
fine, although remember about `b4 prep --auto-to-cc` if you added new
patches to the patchset.
</form letter>

> ---
>  .../bindings/media/i2c/pinefeat,cef168.yaml   | 48 +++++++++++++++++++
>  .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
>  MAINTAINERS                                   |  7 +++
>  3 files changed, 57 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml b/Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
> new file mode 100644
> index 000000000000..ae0c77de5cb4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/pinefeat,cef168.yaml
> @@ -0,0 +1,48 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (c) 2025 Pinefeat LLP
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/i2c/pinefeat,cef168.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Pinefeat cef168 lens driver
> +
> +maintainers:
> +  - Aliaksandr Smirnou <support@pinefeat.co.uk>
> +
> +description: |
> +  Pinefeat produces an adapter designed to interface between
> +  Canon EF & EF-S lenses and non-Canon camera bodies, incorporating
> +  features for electronic focus and aperture adjustment. The cef168
> +  circuit board, included with the adapter, provides a software
> +  programming interface that allows control of lens focus and
> +  aperture positions. This driver enables controlling the lens
> +  focus and aperture via the V4L2 (Video4Linux2) API.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - pinefeat,cef168
> +
> +  reg:
> +    maxItems: 1

Missing supply

> +
> +required:
> +  - compatible
> +  - reg

Also here

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        lens_node: cef168@d {

Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation


> +            compatible = "pinefeat,cef168";
> +            reg = <0x0d>;
> +        };
> +    };
> +
> +...
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> index 77160cd47f54..dab27f769b0a 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> @@ -1195,6 +1195,8 @@ patternProperties:
>      description: Picochip Ltd
>    "^pine64,.*":
>      description: Pine64
> +  "^pinefeat,.*":
> +    description: Pinefeat LLP
>    "^pineriver,.*":
>      description: Shenzhen PineRiver Designs Co., Ltd.
>    "^pixcir,.*":
> diff --git a/MAINTAINERS b/MAINTAINERS
> index fe168477caa4..50dbe343ffc2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19985,6 +19985,13 @@ S:	Supported
>  F:	Documentation/devicetree/bindings/input/pine64,pinephone-keyboard.yaml
>  F:	drivers/input/keyboard/pinephone-keyboard.c
>  
> +PINEFEAT CEF168 LENS DRIVER
> +M:	Aliaksandr Smirnou <support@pinefeat.co.uk>
> +L:	linux-media@vger.kernel.org
> +S:	Supported
> +T:	git git://linuxtv.org/media.git

Drop, unless you have commit rights there.


Best regards,
Krzysztof

Re: [PATCH 2/2] media/i2c: Pinefeat cef168 lens control board driver

[Krzysztof Kozlowski]

On 10/08/2025 21:26, Aliaksandr Smirnou wrote:
> +static int cef168_probe(struct i2c_client *client)
> +{
> +	struct cef168_device *cef168_dev;
> +	int rval;
> +
> +	cef168_dev =
> +		devm_kzalloc(&client->dev, sizeof(*cef168_dev), GFP_KERNEL);

Wrap according to Linux coding style. Not clang.

> +	if (cef168_dev == NULL)
> +		return -ENOMEM;
> +
> +	v4l2_i2c_subdev_init(&cef168_dev->sd, client, &cef168_ops);
> +	cef168_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
> +				V4L2_SUBDEV_FL_HAS_EVENTS;
> +	cef168_dev->sd.internal_ops = &cef168_int_ops;
> +
> +	rval = cef168_init_controls(cef168_dev);
> +	if (rval)
> +		goto err_cleanup;
> +
> +	rval = media_entity_pads_init(&cef168_dev->sd.entity, 0, NULL);
> +	if (rval < 0)
> +		goto err_cleanup;
> +
> +	cef168_dev->sd.entity.function = MEDIA_ENT_F_LENS;
> +
> +	rval = v4l2_async_register_subdev(&cef168_dev->sd);
> +	if (rval < 0)
> +		goto err_cleanup;
> +
> +	crc8_populate_msb(cef168_crc8_table, CEF_CRC8_POLYNOMIAL);
> +
> +	pm_runtime_set_active(&client->dev);
> +	pm_runtime_enable(&client->dev);
> +	pm_runtime_idle(&client->dev);
> +
> +	return 0;
> +
> +err_cleanup:
> +	v4l2_ctrl_handler_free(&cef168_dev->ctrls);
> +	media_entity_cleanup(&cef168_dev->sd.entity);
> +
> +	return rval;
> +}
> +
> +static void cef168_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct cef168_device *cef168_dev = sd_to_cef168(sd);
> +
> +	pm_runtime_disable(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);
> +	cef168_subdev_cleanup(cef168_dev);
> +}
> +
> +static const struct i2c_device_id cef168_id_table[] = { { CEF168_NAME, 0 },
> +							{ { 0 } } };

This is some oddly formed style. You need to use Linux coding style.

> +MODULE_DEVICE_TABLE(i2c, cef168_id_table);
> +
> +static const struct of_device_id cef168_of_table[] = {
> +	{ .compatible = "pinefeat,cef168" },
> +	{ { 0 } }

Also here, there is no such style in the kernel. It's just {}


Best regards,
Krzysztof