Re: [PATCH 2/2] media: i2c: Add ROHM BU64754 Camera Autofocus Actuator

From: Kieran Bingham
Date: Fri Sep 15 2023 - 15:20:30 EST

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In reply to: Dave Stevenson: "Re: [PATCH 2/2] media: i2c: Add ROHM BU64754 Camera Autofocus Actuator"
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Hi Dave,

Quoting Dave Stevenson (2023-09-15 18:44:02)
> Hi Kieran
>
> On Fri, 15 Sept 2023 at 18:02, Kieran Bingham
> <kieran.bingham@xxxxxxxxxxxxxxxx> wrote:
> >
> > Add support for the ROHM BU64754 Motor Driver for Camera Autofocus. A
> > V4L2 Subdevice is registered and provides a single
> > V4L2_CID_FOCUS_ABSOLUTE control.
> >
> > Signed-off-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
> > ---
> > MAINTAINERS | 1 +
> > drivers/media/i2c/Kconfig | 13 ++
> > drivers/media/i2c/Makefile | 1 +
> > drivers/media/i2c/bu64754.c | 308 ++++++++++++++++++++++++++++++++++++
> > 4 files changed, 323 insertions(+)
> > create mode 100644 drivers/media/i2c/bu64754.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index f43e0ffcaf56..fd244560c317 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -18576,6 +18576,7 @@ L: linux-media@xxxxxxxxxxxxxxx
> > S: Maintained
> > T: git git://linuxtv.org/media_tree.git
> > F: Documentation/devicetree/bindings/media/i2c/rohm,bu64754.yaml
> > +F: drivers/media/i2c/bu64754.c
> >
> > ROHM MULTIFUNCTION BD9571MWV-M PMIC DEVICE DRIVERS
> > M: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
> > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > index 74ff833ff48c..b7b8004816ed 100644
> > --- a/drivers/media/i2c/Kconfig
> > +++ b/drivers/media/i2c/Kconfig
> > @@ -641,6 +641,19 @@ config VIDEO_AK7375
> > capability. This is designed for linear control of
> > voice coil motors, controlled via I2C serial interface.
> >
> > +config VIDEO_BU64754
> > + tristate "BU64754 Motor Driver for Camera Autofocus"
> > + depends on I2C && VIDEO_DEV
> > + select MEDIA_CONTROLLER
> > + select VIDEO_V4L2_SUBDEV_API
> > + select V4L2_ASYNC
> > + select V4L2_CCI_I2C
> > + help
> > + This is a driver for the BU64754 Motor Driver for Camera
> > + Autofocus. The BU64754 is an actuator driver IC which can
> > + control the actuator position precisely using an internal
> > + Hall Sensor.
>
> I can't find any data on this driver.
> Is it still expecting a VCM and hence near instantaneous movement? I
> was noting your comment on the hall sensor and thinking you
> potentially needed to be able to report whether the target position
> had been reached or not. Michael's series at [1] was trying to address
> that.

The hall sensor is internal. The component description is just a
slightly fixed grammar of the product brief.

As I understand it, this is a VCM yes but I have so little visibility.

>
> [1] https://patchwork.linuxtv.org/project/linux-media/cover/20230406-feature-controls-lens-v2-0-faa8ad2bc404@xxxxxxxxxxxxxx/
>
> > +
> > config VIDEO_DW9714
> > tristate "DW9714 lens voice coil support"
> > depends on I2C && VIDEO_DEV
> > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > index 80b00d39b48f..e62aa0df7b1a 100644
> > --- a/drivers/media/i2c/Makefile
> > +++ b/drivers/media/i2c/Makefile
> > @@ -22,6 +22,7 @@ obj-$(CONFIG_VIDEO_AR0521) += ar0521.o
> > obj-$(CONFIG_VIDEO_BT819) += bt819.o
> > obj-$(CONFIG_VIDEO_BT856) += bt856.o
> > obj-$(CONFIG_VIDEO_BT866) += bt866.o
> > +obj-$(CONFIG_VIDEO_BU64754) += bu64754.o
> > obj-$(CONFIG_VIDEO_CCS) += ccs/
> > obj-$(CONFIG_VIDEO_CCS_PLL) += ccs-pll.o
> > obj-$(CONFIG_VIDEO_CS3308) += cs3308.o
> > diff --git a/drivers/media/i2c/bu64754.c b/drivers/media/i2c/bu64754.c
> > new file mode 100644
> > index 000000000000..3367b6f17660
> > --- /dev/null
> > +++ b/drivers/media/i2c/bu64754.c
> > @@ -0,0 +1,308 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * The BU64754 is an actuator driver IC which can control the
> > + * actuator position precisely using an internal Hall Sensor.
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/regulator/consumer.h>
> > +
> > +#include <media/v4l2-cci.h>
> > +#include <media/v4l2-ctrls.h>
> > +#include <media/v4l2-device.h>
> > +
> > +#define BU64754_REG_ACTIVE CCI_REG16(0x07)
> > +#define BU64754_ACTIVE_MODE 0x8080
> > +
> > +#define BU64754_REG_SERVE CCI_REG16(0xd9)
> > +#define BU64754_SERVE_ON 0x0404
> > +
> > +#define BU64754_REG_POSITION CCI_REG16(0x45)
> > +#define BU64753_POSITION_MAX 1023 /* 0x3ff */
> > +
> > +#define BU64754_POWER_ON_DELAY 800 /* uS : t1, t3 */
> > +
> > +struct bu64754 {
> > + struct device *dev;
> > +
> > + struct v4l2_ctrl_handler ctrls_vcm;
> > + struct v4l2_subdev sd;
> > + struct regmap *cci;
> > +
> > + u16 current_val;
> > + struct regulator *vdd;
> > + struct notifier_block notifier;
> > +};
> > +
> > +static inline struct bu64754 *sd_to_bu64754(struct v4l2_subdev *subdev)
> > +{
> > + return container_of(subdev, struct bu64754, sd);
> > +}
> > +
> > +static int bu64754_set(struct bu64754 *bu64754, u16 position)
> > +{
> > + int ret;
> > +
> > + ret = cci_write(bu64754->cci, BU64754_REG_POSITION, position, NULL);
> > + if (ret) {
> > + dev_err(bu64754->dev, "Set position failed ret=%d\n", ret);
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int bu64754_active(struct bu64754 *bu64754)
> > +{
> > + int ret;
> > +
> > + /* Power on */
> > + ret = cci_write(bu64754->cci, BU64754_REG_ACTIVE, BU64754_ACTIVE_MODE,
> > + NULL);
> > + if (ret < 0) {
> > + dev_err(bu64754->dev, "Failed to set active mode ret = %d\n",
> > + ret);
> > + return ret;
> > + }
> > +
> > + /* Serve on */
> > + ret = cci_write(bu64754->cci, BU64754_REG_SERVE, BU64754_SERVE_ON,
> > + NULL);
> > + if (ret < 0) {
> > + dev_err(bu64754->dev, "Failed to enable serve ret = %d\n",
> > + ret);
> > + return ret;
> > + }
> > +
> > + return bu64754_set(bu64754, bu64754->current_val);
> > +}
> > +
> > +static int bu64754_standby(struct bu64754 *bu64754)
> > +{
> > + int ret;
> > +
> > + cci_write(bu64754->cci, BU64754_REG_ACTIVE, 0, &ret);
> > + if (ret < 0)
> > + dev_err(bu64754->dev, "Failed to set active mode ret = %d\n",
> > + ret);
> > +
> > + return ret;
> > +}
> > +
> > +static int bu64754_regulator_event(struct notifier_block *nb,
> > + unsigned long action, void *data)
> > +{
> > + struct bu64754 *bu64754 = container_of(nb, struct bu64754, notifier);
> > +
> > + if (action & REGULATOR_EVENT_ENABLE) {
> > + /*
> > + * Initialisation delay between VDD low->high and availability
> > + * i2c operation.
> > + */
> > + usleep_range(BU64754_POWER_ON_DELAY,
> > + BU64754_POWER_ON_DELAY + 100);
> > +
> > + bu64754_active(bu64754);
> > + } else if (action & REGULATOR_EVENT_PRE_DISABLE) {
> > + bu64754_standby(bu64754);
> > + }
>
> Presumably this is based on the assumption that the same regulator
> controls sensor and lens, so when the sensor is powered up the lens
> position gets restored.
> I'm sure when I suggested doing the same previously it was shot down
> in flames ... found it [2]
>
> Personally I think it makes sense that the lens powers up
> automagically, and have almost exactly the same code as this in a
> couple of our VCM drivers, but others disagree.

I've tested this on the Raspberry Pi, and I expect this design model
comes from you originally then. I thought it was a good way to handle
things, but I wasn't aware that others had already disagreed.

Being a module that will connect over the RPi interface, with a single
POWER_EN, indeed - the regulators are shared with the camera, and
synchronising how it is handled seemed reasonable. I guess I have some
more reading to do now then.

I'm already thinking about making a 'simple-vcm' module or parent-driver
that can reduce the boilerplate for the vcms though. There's very little
difference between them all ... and I think they could be abstracted out
substantially to simplify adding new devices.

--
Kieran

>
> Dave
>
> [2] https://lore.kernel.org/all/CAPY8ntBZpZjecHNCMf-eMefcp2EgmbqkXMt4p=UeOe0n-o8WrA@xxxxxxxxxxxxxx/
>
> > +
> > + return 0;
> > +}
> > +
> > +static int bu64754_set_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > + struct bu64754 *bu64754 = container_of(ctrl->handler,
> > + struct bu64754, ctrls_vcm);
> > +
> > + if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE) {
> > + bu64754->current_val = ctrl->val;
> > + return bu64754_set(bu64754, ctrl->val);
> > + }
> > +
> > + return -EINVAL;
> > +}
> > +
> > +static const struct v4l2_ctrl_ops bu64754_vcm_ctrl_ops = {
> > + .s_ctrl = bu64754_set_ctrl,
> > +};
> > +
> > +static int bu64754_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> > +{
> > + return pm_runtime_resume_and_get(sd->dev);
> > +}
> > +
> > +static int bu64754_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> > +{
> > + pm_runtime_put(sd->dev);
> > + return 0;
> > +}
> > +
> > +static const struct v4l2_subdev_internal_ops bu64754_int_ops = {
> > + .open = bu64754_open,
> > + .close = bu64754_close,
> > +};
> > +
> > +static const struct v4l2_subdev_ops bu64754_ops = { };
> > +
> > +static void bu64754_subdev_cleanup(struct bu64754 *bu64754)
> > +{
> > + v4l2_async_unregister_subdev(&bu64754->sd);
> > + v4l2_ctrl_handler_free(&bu64754->ctrls_vcm);
> > + media_entity_cleanup(&bu64754->sd.entity);
> > +}
> > +
> > +static int bu64754_init_controls(struct bu64754 *bu64754)
> > +{
> > + struct v4l2_ctrl_handler *hdl = &bu64754->ctrls_vcm;
> > + const struct v4l2_ctrl_ops *ops = &bu64754_vcm_ctrl_ops;
> > +
> > + v4l2_ctrl_handler_init(hdl, 1);
> > +
> > + v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
> > + 0, BU64753_POSITION_MAX, 1, 0);
> > +
> > + bu64754->current_val = 0;
> > +
> > + bu64754->sd.ctrl_handler = hdl;
> > + if (hdl->error) {
> > + dev_err(bu64754->dev, "%s fail error: 0x%x\n",
> > + __func__, hdl->error);
> > + return hdl->error;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int bu64754_probe(struct i2c_client *client)
> > +{
> > + struct bu64754 *bu64754;
> > + int ret;
> > +
> > + bu64754 = devm_kzalloc(&client->dev, sizeof(*bu64754), GFP_KERNEL);
> > + if (!bu64754)
> > + return -ENOMEM;
> > +
> > + bu64754->dev = &client->dev;
> > +
> > + bu64754->cci = devm_cci_regmap_init_i2c(client, 8);
> > + if (IS_ERR(bu64754->cci)) {
> > + dev_err(bu64754->dev, "Failed to initialize CCI\n");
> > + return PTR_ERR(bu64754->cci);
> > + }
> > +
> > + bu64754->vdd = devm_regulator_get_optional(&client->dev, "vdd");
> > + if (IS_ERR(bu64754->vdd)) {
> > + if (PTR_ERR(bu64754->vdd) != -ENODEV)
> > + return PTR_ERR(bu64754->vdd);
> > +
> > + bu64754->vdd = NULL;
> > + } else {
> > + bu64754->notifier.notifier_call = bu64754_regulator_event;
> > +
> > + ret = regulator_register_notifier(bu64754->vdd,
> > + &bu64754->notifier);
> > + if (ret) {
> > + dev_err(bu64754->dev,
> > + "could not register regulator notifier\n");
> > + return ret;
> > + }
> > + }
> > +
> > + v4l2_i2c_subdev_init(&bu64754->sd, client, &bu64754_ops);
> > + bu64754->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > + bu64754->sd.internal_ops = &bu64754_int_ops;
> > + bu64754->sd.entity.function = MEDIA_ENT_F_LENS;
> > +
> > + ret = bu64754_init_controls(bu64754);
> > + if (ret)
> > + goto err_cleanup;
> > +
> > + ret = media_entity_pads_init(&bu64754->sd.entity, 0, NULL);
> > + if (ret < 0)
> > + goto err_cleanup;
> > +
> > + ret = v4l2_async_register_subdev(&bu64754->sd);
> > + if (ret < 0)
> > + goto err_cleanup;
> > +
> > + if (!bu64754->vdd)
> > + pm_runtime_set_active(&client->dev);
> > +
> > + pm_runtime_enable(&client->dev);
> > + pm_runtime_idle(&client->dev);
> > +
> > + return 0;
> > +
> > +err_cleanup:
> > + v4l2_ctrl_handler_free(&bu64754->ctrls_vcm);
> > + media_entity_cleanup(&bu64754->sd.entity);
> > +
> > + return ret;
> > +}
> > +
> > +static void bu64754_remove(struct i2c_client *client)
> > +{
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct bu64754 *bu64754 = sd_to_bu64754(sd);
> > +
> > + if (bu64754->vdd)
> > + regulator_unregister_notifier(bu64754->vdd,
> > + &bu64754->notifier);
> > +
> > + pm_runtime_disable(&client->dev);
> > +
> > + bu64754_subdev_cleanup(bu64754);
> > +}
> > +
> > +static int __maybe_unused bu64754_vcm_suspend(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct bu64754 *bu64754 = sd_to_bu64754(sd);
> > +
> > + if (bu64754->vdd)
> > + return regulator_disable(bu64754->vdd);
> > +
> > + return bu64754_standby(bu64754);
> > +}
> > +
> > +static int __maybe_unused bu64754_vcm_resume(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct bu64754 *bu64754 = sd_to_bu64754(sd);
> > +
> > + if (bu64754->vdd)
> > + return regulator_enable(bu64754->vdd);
> > +
> > + return bu64754_active(bu64754);
> > +}
> > +
> > +static const struct of_device_id bu64754_of_table[] = {
> > + { .compatible = "rohm,bu64754", },
> > + { /* sentinel */ }
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, bu64754_of_table);
> > +
> > +static SIMPLE_DEV_PM_OPS(bu64754_pm, bu64754_vcm_suspend, bu64754_vcm_resume);
> > +
> > +static struct i2c_driver bu64754_i2c_driver = {
> > + .driver = {
> > + .name = "bu64754",
> > + .pm = &bu64754_pm,
> > + .of_match_table = bu64754_of_table,
> > + },
> > + .probe = bu64754_probe,
> > + .remove = bu64754_remove,
> > +};
> > +
> > +module_i2c_driver(bu64754_i2c_driver);
> > +
> > +MODULE_AUTHOR("Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>");
> > +MODULE_DESCRIPTION("ROHM BU64754 VCM driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.34.1
> >

Next message: patchwork-bot+netdevbpf: "Re: [PATCH bpf v3 0/2] link to v1: https://lore.kernel.org/bpf/20230915103228.1196234-1-jolsa@xxxxxxxxxx/"
Previous message: tip-bot2 for Olaf Hering: "[tip: smp/core] cpu/hotplug: Remove unused cpuhp_state CPUHP_AP_X86_VDSO_VMA_ONLINE"
In reply to: Dave Stevenson: "Re: [PATCH 2/2] media: i2c: Add ROHM BU64754 Camera Autofocus Actuator"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]