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Message-ID: <CAPY8ntCKfGX_5wCSnQz3YAmQD_pyeF+q3EoMDxyXA4Dgg9osmg@mail.gmail.com>
Date: Mon, 1 Dec 2025 14:42:40 +0000
From: Dave Stevenson <dave.stevenson@...pberrypi.com>
To: Vasiliy Doylov <nekocwd@...nlining.org>
Cc: Mauro Carvalho Chehab <mchehab@...nel.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, david@...t.cz,
linux-media@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, phone-devel@...r.kernel.org,
Vitalii Skorkin <nikroks@...nlining.org>, Antonio Rische <nt8r@...tonmail.com>
Subject: Re: [PATCH v3 2/3] media: i2c: Add driver for LC898217XC VCM
Hi Vasiliy
On Mon, 1 Dec 2025 at 12:42, Vasiliy Doylov <nekocwd@...nlining.org> wrote:
>
> LC898217XC is a 11 bit DAC, designed for linear control
> of voice coil motor. This driver creates a V4L2 subdevice
> and provides control to set the desired focus.
>
> Tested on Oneplus 6 (oneplus-enchilada)
>
> Signed-off-by: Vasiliy Doylov <nekocwd@...nlining.org>
> ---
> drivers/media/i2c/Kconfig | 9 ++
> drivers/media/i2c/Makefile | 1 +
> drivers/media/i2c/lc898217xc.c | 254 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 264 insertions(+)
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 4b4db8c4f496..ee071505223f 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -866,6 +866,15 @@ config VIDEO_DW9807_VCM
> capability. This is designed for linear control of
> voice coil motors, controlled via I2C serial interface.
>
> +config VIDEO_LC898217XC
> + tristate "LC898217XC lens voice coil support"
> + select V4L2_CCI_I2C
> + help
> + This is a driver for the LC898217XC camera lens voice coil.
> + LC898217XC is a 11 bit DAC with 110mA output current sink
> + capability. This is designed for linear control of
> + voice coil motors, controlled via I2C serial interface.
> +
> endif
>
> menu "Flash devices"
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index c5f17602454f..a17774eeb43c 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -64,6 +64,7 @@ obj-$(CONFIG_VIDEO_IMX415) += imx415.o
> obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o
> obj-$(CONFIG_VIDEO_ISL7998X) += isl7998x.o
> obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
> +obj-$(CONFIG_VIDEO_LC898217XC) += lc898217xc.o
> obj-$(CONFIG_VIDEO_LM3560) += lm3560.o
> obj-$(CONFIG_VIDEO_LM3646) += lm3646.o
> obj-$(CONFIG_VIDEO_LT6911UXE) += lt6911uxe.o
> diff --git a/drivers/media/i2c/lc898217xc.c b/drivers/media/i2c/lc898217xc.c
> new file mode 100644
> index 000000000000..c2d75bd36ddb
> --- /dev/null
> +++ b/drivers/media/i2c/lc898217xc.c
> @@ -0,0 +1,254 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +// Copyright (c) 2025 Vasiliy Doylov <nekocwd@...nlining.org>
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <media/v4l2-async.h>
> +#include <media/v4l2-cci.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-subdev.h>
> +#include <media/v4l2-event.h>
> +
> +#define LC898217XC_NAME "lc898217xc"
> +/* Actuator has 11 bit resolution */
> +#define LC898217XC_MAX_FOCUS_POS (2048 - 1)
> +#define LC898217XC_MIN_FOCUS_POS 0
> +#define LC898217XC_FOCUS_STEPS 1
> +#define LC898217XC_DAC_ADDR CCI_REG16(0x84)
> +
> +static const char *const lc898217xc_supply_names[] = {
> + "vcc",
> +};
> +
> +struct lc898217xc {
> + struct regulator_bulk_data supplies[ARRAY_SIZE(lc898217xc_supply_names)];
> + struct v4l2_ctrl_handler ctrls;
> + struct v4l2_ctrl *focus;
focus is never used.
> + struct v4l2_subdev sd;
> + struct regmap *regmap;
> +};
> +
> +static inline struct lc898217xc *sd_to_lc898217xc(struct v4l2_subdev *subdev)
> +{
> + return container_of(subdev, struct lc898217xc, sd);
> +}
> +
> +static int lc898217xc_set_dac(struct lc898217xc *lc898217xc, u16 val)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&lc898217xc->sd);
> + int ret;
> +
> + ret = cci_write(lc898217xc->regmap, LC898217XC_DAC_ADDR, val, NULL);
> + if (ret)
> + dev_err(&client->dev, "failed to set DAC: %d\n", ret);
> +
> + return ret;
> +}
> +
> +static int __maybe_unused lc898217xc_runtime_suspend(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct lc898217xc *lc898217xc = sd_to_lc898217xc(sd);
> +
> + regulator_bulk_disable(ARRAY_SIZE(lc898217xc_supply_names),
> + lc898217xc->supplies);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused lc898217xc_runtime_resume(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct lc898217xc *lc898217xc = sd_to_lc898217xc(sd);
> + int ret;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(lc898217xc_supply_names),
> + lc898217xc->supplies);
> +
> + if (ret < 0) {
> + dev_err(dev, "failed to enable regulators\n");
> + return ret;
> + }
> +
> + usleep_range(8000, 10000);
Do you not want to restore the current position after resuming power?
Potentially use __v4l2_ctrl_handler_setup() to reset all controls
should any extra ones get added.
> +
> + return ret;
> +}
> +
> +static int lc898217xc_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct lc898217xc *lc898217xc = container_of(ctrl->handler,
> + struct lc898217xc, ctrls);
> +
> + if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
> + return lc898217xc_set_dac(lc898217xc, ctrl->val);
> +
> + return 0;
> +}
> +
> +static const struct v4l2_ctrl_ops lc898217xc_ctrl_ops = {
> + .s_ctrl = lc898217xc_set_ctrl,
> +};
> +
> +static int lc898217xc_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> + return pm_runtime_resume_and_get(sd->dev);
> +}
> +
> +static int lc898217xc_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> + pm_runtime_mark_last_busy(sd->dev);
> + pm_runtime_put_autosuspend(sd->dev);
> +
> + return 0;
> +}
> +
> +static const struct v4l2_subdev_internal_ops lc898217xc_int_ops = {
> + .open = lc898217xc_open,
> + .close = lc898217xc_close,
> +};
> +
> +static const struct v4l2_subdev_core_ops lc898217xc_core_ops = {
> + .log_status = v4l2_ctrl_subdev_log_status,
> + .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> + .unsubscribe_event = v4l2_event_subdev_unsubscribe,
subscribe and unsubscribe_event hooks shouldn't be needed if it's only
for controls since e7724e23196a ("media: v4l2-subdev: Refactor
events"). That may not have been merged when you added this in v2.
> +};
> +
> +static const struct v4l2_subdev_ops lc898217xc_ops = {
> + .core = &lc898217xc_core_ops,
> +};
> +
> +static int lc898217xc_init_controls(struct lc898217xc *lc898217xc)
> +{
> + struct v4l2_ctrl_handler *hdl = &lc898217xc->ctrls;
> + const struct v4l2_ctrl_ops *ops = &lc898217xc_ctrl_ops;
> +
> + v4l2_ctrl_handler_init(hdl, 1);
> +
> + lc898217xc->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
> + LC898217XC_MIN_FOCUS_POS,
> + LC898217XC_MAX_FOCUS_POS,
> + LC898217XC_FOCUS_STEPS, 0);
> +
> + if (hdl->error)
> + return hdl->error;
> +
> + lc898217xc->sd.ctrl_handler = hdl;
> +
> + return 0;
> +}
> +
> +static int lc898217xc_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct lc898217xc *lc898217xc;
> + unsigned int i;
> + int ret;
> +
> + lc898217xc = devm_kzalloc(dev, sizeof(*lc898217xc), GFP_KERNEL);
> + if (!lc898217xc)
> + return -ENOMEM;
> +
> + lc898217xc->regmap = devm_cci_regmap_init_i2c(client, 8);
> + if (IS_ERR(lc898217xc->regmap))
> + return dev_err_probe(dev, PTR_ERR(lc898217xc->regmap),
> + "failed to initialize CCI\n");
> +
> + /* Initialize subdev */
> + v4l2_i2c_subdev_init(&lc898217xc->sd, client, &lc898217xc_ops);
> +
> + for (i = 0; i < ARRAY_SIZE(lc898217xc_supply_names); i++)
> + lc898217xc->supplies[i].supply = lc898217xc_supply_names[i];
> +
> + ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(lc898217xc_supply_names),
> + lc898217xc->supplies);
> +
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to get regulators\n");
> +
> + /* Initialize controls */
> + ret = lc898217xc_init_controls(lc898217xc);
> + if (ret) {
> + dev_err_probe(dev, ret, "failed to init v4l2 controls\n");
> + goto err_free_handler;
> + }
> +
> + /* Initialize subdev */
> + lc898217xc->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
> + V4L2_SUBDEV_FL_HAS_EVENTS;
e7724e23196a also removes the need for you to set
V4L2_SUBDEV_FL_HAS_EVENTS if you have a ctrl_handler.
Dave
> + lc898217xc->sd.internal_ops = &lc898217xc_int_ops;
> +
> + ret = media_entity_pads_init(&lc898217xc->sd.entity, 0, NULL);
> + if (ret < 0) {
> + dev_err_probe(dev, ret, "failed to init media entity pads");
> + goto err_free_handler;
> + }
> +
> + lc898217xc->sd.entity.function = MEDIA_ENT_F_LENS;
> +
> + pm_runtime_enable(dev);
> + ret = v4l2_async_register_subdev(&lc898217xc->sd);
> +
> + if (ret < 0) {
> + dev_err_probe(dev, ret, "failed to register V4L2 subdev\n");
> + goto err_power_off;
> + }
> +
> + pm_runtime_set_autosuspend_delay(dev, 1000);
> + pm_runtime_use_autosuspend(dev);
> + pm_runtime_idle(dev);
> +
> + return 0;
> +
> +err_power_off:
> + pm_runtime_disable(dev);
> + media_entity_cleanup(&lc898217xc->sd.entity);
> +err_free_handler:
> + v4l2_ctrl_handler_free(&lc898217xc->ctrls);
> +
> + return ret;
> +}
> +
> +static void lc898217xc_remove(struct i2c_client *client)
> +{
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct lc898217xc *lc898217xc = sd_to_lc898217xc(sd);
> + struct device *dev = &client->dev;
> +
> + v4l2_async_unregister_subdev(&lc898217xc->sd);
> + v4l2_ctrl_handler_free(&lc898217xc->ctrls);
> + media_entity_cleanup(&lc898217xc->sd.entity);
> + pm_runtime_disable(dev);
> +}
> +
> +static const struct of_device_id lc898217xc_of_table[] = {
> + { .compatible = "onnn,lc898217xc" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, lc898217xc_of_table);
> +
> +static const struct dev_pm_ops lc898217xc_pm_ops = {
> + SET_RUNTIME_PM_OPS(lc898217xc_runtime_suspend,
> + lc898217xc_runtime_resume, NULL)
> +};
> +
> +static struct i2c_driver lc898217xc_i2c_driver = {
> + .driver = {
> + .name = LC898217XC_NAME,
> + .pm = &lc898217xc_pm_ops,
> + .of_match_table = lc898217xc_of_table,
> + },
> + .probe = lc898217xc_probe,
> + .remove = lc898217xc_remove,
> +};
> +module_i2c_driver(lc898217xc_i2c_driver);
> +
> +MODULE_AUTHOR("Vasiliy Doylov <nekocwd@...nlining.org>");
> +MODULE_DESCRIPTION("Onsemi LC898217XC VCM driver");
> +MODULE_LICENSE("GPL");
>
> --
> 2.52.0
>
>
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