[v4,1/1] media: i2c: Add driver for DW9719 VCM

From: Daniel Scally <djrscally@gmail.com>

Add a driver for the DW9719 VCM. The driver creates a v4l2 subdevice
and registers a control to set the desired focus.

Signed-off-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v4 (Hans de Goede)
- Back to a standalone patch again (instead of being part of a series)
- Switch to using CCI helpers for register access
- Use new DEFINE_RUNTIME_DEV_PM_OPS() for pm-ops
- Make v4l2_subdev first member of dw9719_device
- Drop v4l2_ctrl_handler_init() ret value check
- Turn of VCM on dw9719_remove() if necessary

Changes in v3 (Hans de Goede)
- New patch in v3 of this series based on Dan Scally's initial
  DW9719 upstream submission:
  https://lore.kernel.org/all/20211128232115.38833-1-djrscally@gmail.com/
- Drop hack to enable "vsio" regulator, this is no longer necessary
  now that there is a device-link making the VCM a runtime-pm consumer
  of the sensor
- Add checking of device-properties for sac-mode and vcm-freq,
  as requested by Sakari, this is done similar to the dw9768:
  Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
  Note no devicetree binding doc is added since currently only
  i2c_device_id enumeration (instantiated by IPU bridge) is
  supported
---
 MAINTAINERS                |   7 +
 drivers/media/i2c/Kconfig  |  12 ++
 drivers/media/i2c/Makefile |   1 +
 drivers/media/i2c/dw9719.c | 348 +++++++++++++++++++++++++++++++++++++
 4 files changed, 368 insertions(+)
 create mode 100644 drivers/media/i2c/dw9719.c

On Thu, Jul 6, 2023 at 5:58 PM Hans de Goede <hdegoede@redhat.com> wrote:
>
> From: Daniel Scally <djrscally@gmail.com>
>
> Add a driver for the DW9719 VCM. The driver creates a v4l2 subdevice
> and registers a control to set the desired focus.

A few nit-picks below, but looks fine to me
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Signed-off-by: Daniel Scally <djrscally@gmail.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v4 (Hans de Goede)
> - Back to a standalone patch again (instead of being part of a series)
> - Switch to using CCI helpers for register access
> - Use new DEFINE_RUNTIME_DEV_PM_OPS() for pm-ops
> - Make v4l2_subdev first member of dw9719_device
> - Drop v4l2_ctrl_handler_init() ret value check
> - Turn of VCM on dw9719_remove() if necessary
>
> Changes in v3 (Hans de Goede)
> - New patch in v3 of this series based on Dan Scally's initial
>   DW9719 upstream submission:
>   https://lore.kernel.org/all/20211128232115.38833-1-djrscally@gmail.com/
> - Drop hack to enable "vsio" regulator, this is no longer necessary
>   now that there iscamera a device-link making the VCM a runtime-pm consumer
>   of the sensor
> - Add checking of device-properties for sac-mode and vcm-freq,
>   as requested by Sakari, this is done similar to the dw9768:
>   Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
>   Note no devicetree binding doc is added since currently only
>   i2c_device_id enumeration (instantiated by IPU bridge) is
>   supported
> ---
>  MAINTAINERS                |   7 +
>  drivers/media/i2c/Kconfig  |  12 ++
>  drivers/media/i2c/Makefile |   1 +
>  drivers/media/i2c/dw9719.c | 348 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 368 insertions(+)
>  create mode 100644 drivers/media/i2c/dw9719.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 494682dd437f..cf8e799f6ea2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6266,6 +6266,13 @@ T:       git git://linuxtv.org/media_tree.git
>  F:     Documentation/devicetree/bindings/media/i2c/dongwoon,dw9714.yaml
>  F:     drivers/media/i2c/dw9714.c
>
> +DONGWOON DW9719 LENS VOICE COIL DRIVER
> +M:     Daniel Scally <djrscally@gmail.com>
> +L:     linux-media@vger.kernel.org
> +S:     Maintained
> +T:     git git://linuxtv.org/media_tree.git
> +F:     drivers/media/i2c/dw9719.c
> +
>  DONGWOON DW9768 LENS VOICE COIL DRIVER
>  L:     linux-media@vger.kernel.org
>  S:     Orphan
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 26dc365365d8..9f2331e9836a 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -875,6 +875,18 @@ config VIDEO_DW9714
>           capability. This is designed for linear control of
>           voice coil motors, controlled via I2C serial interface.
>
> +config VIDEO_DW9719
> +       tristate "DW9719 lens voice coil support"
> +       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 DW9719 camera lens voice coil.
> +         This is designed for linear control of voice coil motors,
> +         controlled via I2C serial interface.
> +
>  config VIDEO_DW9768
>         tristate "DW9768 lens voice coil support"
>         depends on I2C && VIDEO_DEV
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index d175a2e2fb19..745f8d07e649 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -32,6 +32,7 @@ obj-$(CONFIG_VIDEO_DS90UB913) += ds90ub913.o
>  obj-$(CONFIG_VIDEO_DS90UB953) += ds90ub953.o
>  obj-$(CONFIG_VIDEO_DS90UB960) += ds90ub960.o
>  obj-$(CONFIG_VIDEO_DW9714) += dw9714.o
> +obj-$(CONFIG_VIDEO_DW9719) += dw9719.o
>  obj-$(CONFIG_VIDEO_DW9768) += dw9768.o
>  obj-$(CONFIG_VIDEO_DW9807_VCM) += dw9807-vcm.o
>  obj-$(CONFIG_VIDEO_ET8EK8) += et8ek8/
> diff --git a/drivers/media/i2c/dw9719.c b/drivers/media/i2c/dw9719.c
> new file mode 100644
> index 000000000000..d8975b5bcfa9
> --- /dev/null
> +++ b/drivers/media/i2c/dw9719.c
> @@ -0,0 +1,348 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2012 Intel Corporation
> +
> +/*
> + * Based on linux/modules/camera/drivers/media/i2c/imx/dw9719.c in this repo:
> + * https://github.com/ZenfoneArea/android_kernel_asus_zenfone5
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/types.h>
> +
> +#include <media/v4l2-cci.h>
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-subdev.h>
> +
> +#define DW9719_MAX_FOCUS_POS   1023
> +#define DW9719_CTRL_STEPS      16
> +#define DW9719_CTRL_DELAY_US   1000
> +
> +#define DW9719_INFO                    CCI_REG8(0)
> +#define DW9719_ID                      0xF1
> +
> +#define DW9719_CONTROL                 CCI_REG8(2)
> +#define DW9719_ENABLE_RINGING          0x02
> +
> +#define DW9719_VCM_CURRENT             CCI_REG16(3)
> +
> +#define DW9719_MODE                    CCI_REG8(6)
> +#define DW9719_MODE_SAC_SHIFT          4
> +#define DW9719_MODE_SAC3               4
> +
> +#define DW9719_VCM_FREQ                        CCI_REG8(7)
> +#define DW9719_DEFAULT_VCM_FREQ                0x60
> +
> +#define to_dw9719_device(x) container_of(x, struct dw9719_device, sd)
> +
> +struct dw9719_device {
> +       struct v4l2_subdev sd;
> +       struct device *dev;
> +       struct regmap *regmap;
> +       struct regulator *regulator;
> +       u32 sac_mode;
> +       u32 vcm_freq;
> +
> +       struct dw9719_v4l2_ctrls {
> +               struct v4l2_ctrl_handler handler;
> +               struct v4l2_ctrl *focus;
> +       } ctrls;
> +};
> +
> +static int dw9719_detect(struct dw9719_device *dw9719)
> +{
> +       int ret;
> +       u64 val;
> +
> +       ret = cci_read(dw9719->regmap, DW9719_INFO, &val, NULL);
> +       if (ret < 0)
> +               return ret;
> +
> +       if (val != DW9719_ID) {
> +               dev_err(dw9719->dev, "Failed to detect correct id\n");
> +               return -ENXIO;
> +       }
> +
> +       return 0;
> +}
> +
> +static int dw9719_power_down(struct dw9719_device *dw9719)
> +{
> +       return regulator_disable(dw9719->regulator);
> +}
> +
> +static int dw9719_power_up(struct dw9719_device *dw9719)
> +{
> +       int ret;
> +
> +       ret = regulator_enable(dw9719->regulator);
> +
> +       /* Jiggle SCL pin to wake up device */
> +       cci_write(dw9719->regmap, DW9719_CONTROL, 1, &ret);
> +
> +       /* Need 100us to transit from SHUTDOWN to STANDBY*/

Still missing space before */.

> +       fsleep(100);
> +
> +       cci_write(dw9719->regmap, DW9719_CONTROL, DW9719_ENABLE_RINGING, &ret);
> +       cci_write(dw9719->regmap, DW9719_MODE,
> +                 dw9719->sac_mode << DW9719_MODE_SAC_SHIFT, &ret);
> +       cci_write(dw9719->regmap, DW9719_VCM_FREQ, dw9719->vcm_freq, &ret);
> +
> +       if (ret)
> +               dw9719_power_down(dw9719);
> +
> +       return ret;
> +}
> +
> +static int dw9719_t_focus_abs(struct dw9719_device *dw9719, s32 value)
> +{
> +       return cci_write(dw9719->regmap, DW9719_VCM_CURRENT, value, NULL);
> +}
> +
> +static int dw9719_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +       struct dw9719_device *dw9719 = container_of(ctrl->handler,
> +                                                   struct dw9719_device,
> +                                                   ctrls.handler);
> +       int ret;
> +
> +       /* Only apply changes to the controls if the device is powered up */
> +       if (!pm_runtime_get_if_in_use(dw9719->dev))
> +               return 0;
> +
> +       switch (ctrl->id) {
> +       case V4L2_CID_FOCUS_ABSOLUTE:
> +               ret = dw9719_t_focus_abs(dw9719, ctrl->val);
> +               break;
> +       default:
> +               ret = -EINVAL;
> +       }
> +
> +       pm_runtime_put(dw9719->dev);
> +
> +       return ret;
> +}
> +
> +static const struct v4l2_ctrl_ops dw9719_ctrl_ops = {
> +       .s_ctrl = dw9719_set_ctrl,
> +};
> +
> +static int dw9719_suspend(struct device *dev)
> +{
> +       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +       struct dw9719_device *dw9719 = to_dw9719_device(sd);
> +       int ret;
> +       int val;
> +
> +       for (val = dw9719->ctrls.focus->val; val >= 0;
> +            val -= DW9719_CTRL_STEPS) {
> +               ret = dw9719_t_focus_abs(dw9719, val);
> +               if (ret)
> +                       return ret;

Maybe have a separate definition for the upper limit and put a comment
why we need it this way.

> +               usleep_range(DW9719_CTRL_DELAY_US, DW9719_CTRL_DELAY_US + 10);
> +       }
> +
> +       return dw9719_power_down(dw9719);
> +}
> +
> +static int dw9719_resume(struct device *dev)
> +{
> +       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +       struct dw9719_device *dw9719 = to_dw9719_device(sd);
> +       int current_focus = dw9719->ctrls.focus->val;
> +       int ret;
> +       int val;
> +
> +       ret = dw9719_power_up(dw9719);
> +       if (ret)
> +               return ret;
> +
> +       for (val = current_focus % DW9719_CTRL_STEPS; val < current_focus;
> +            val += DW9719_CTRL_STEPS) {
> +               ret = dw9719_t_focus_abs(dw9719, val);
> +               if (ret)
> +                       goto err_power_down;
> +
> +               usleep_range(DW9719_CTRL_DELAY_US, DW9719_CTRL_DELAY_US + 10);
> +       }
> +
> +       return 0;
> +
> +err_power_down:
> +       dw9719_power_down(dw9719);
> +       return ret;
> +}
> +
> +static int dw9719_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> +       return pm_runtime_resume_and_get(sd->dev);
> +}
> +
> +static int dw9719_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> +       pm_runtime_put(sd->dev);
> +
> +       return 0;
> +}
> +
> +static const struct v4l2_subdev_internal_ops dw9719_internal_ops = {
> +       .open = dw9719_open,
> +       .close = dw9719_close,
> +};
> +
> +static int dw9719_init_controls(struct dw9719_device *dw9719)
> +{
> +       const struct v4l2_ctrl_ops *ops = &dw9719_ctrl_ops;
> +       int ret;
> +
> +       v4l2_ctrl_handler_init(&dw9719->ctrls.handler, 1);
> +
> +       dw9719->ctrls.focus = v4l2_ctrl_new_std(&dw9719->ctrls.handler, ops,
> +                                               V4L2_CID_FOCUS_ABSOLUTE, 0,
> +                                               DW9719_MAX_FOCUS_POS, 1, 0);
> +
> +       if (dw9719->ctrls.handler.error) {
> +               dev_err(dw9719->dev, "Error initialising v4l2 ctrls\n");
> +               ret = dw9719->ctrls.handler.error;
> +               goto err_free_handler;
> +       }
> +
> +       dw9719->sd.ctrl_handler = &dw9719->ctrls.handler;
> +       return 0;
> +
> +err_free_handler:
> +       v4l2_ctrl_handler_free(&dw9719->ctrls.handler);
> +       return ret;
> +}
> +
> +static const struct v4l2_subdev_ops dw9719_ops = { };
> +
> +static int dw9719_probe(struct i2c_client *client)
> +{
> +       struct dw9719_device *dw9719;
> +       int ret;
> +
> +       dw9719 = devm_kzalloc(&client->dev, sizeof(*dw9719), GFP_KERNEL);
> +       if (!dw9719)
> +               return -ENOMEM;
> +
> +       dw9719->regmap = devm_cci_regmap_init_i2c(client, 8);
> +       if (IS_ERR(dw9719->regmap))
> +               return PTR_ERR(dw9719->regmap);
> +
> +       dw9719->dev = &client->dev;
> +       dw9719->sac_mode = DW9719_MODE_SAC3;
> +       dw9719->vcm_freq = DW9719_DEFAULT_VCM_FREQ;
> +
> +       /* Optional indication of SAC mode select */
> +       device_property_read_u32(&client->dev, "dongwoon,sac-mode",
> +                                &dw9719->sac_mode);
> +
> +       /* Optional indication of VCM frequency */
> +       device_property_read_u32(&client->dev, "dongwoon,vcm-freq",
> +                                &dw9719->vcm_freq);
> +
> +       dw9719->regulator = devm_regulator_get(&client->dev, "vdd");
> +       if (IS_ERR(dw9719->regulator))
> +               return dev_err_probe(&client->dev, PTR_ERR(dw9719->regulator),
> +                                    "getting regulator\n");
> +
> +       v4l2_i2c_subdev_init(&dw9719->sd, client, &dw9719_ops);
> +       dw9719->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +       dw9719->sd.internal_ops = &dw9719_internal_ops;
> +
> +       ret = dw9719_init_controls(dw9719);
> +       if (ret)
> +               return ret;
> +
> +       ret = media_entity_pads_init(&dw9719->sd.entity, 0, NULL);
> +       if (ret < 0)
> +               goto err_free_ctrl_handler;
> +
> +       dw9719->sd.entity.function = MEDIA_ENT_F_LENS;
> +
> +       /*
> +        * We need the driver to work in the event that pm runtime is disable in
> +        * the kernel, so power up and verify the chip now. In the event that
> +        * runtime pm is disabled this will leave the chip on, so that the lens
> +        * will work.
> +        */
> +
> +       ret = dw9719_power_up(dw9719);
> +       if (ret)
> +               goto err_cleanup_media;
> +
> +       ret = dw9719_detect(dw9719);
> +       if (ret)
> +               goto err_powerdown;
> +
> +       pm_runtime_set_active(&client->dev);
> +       pm_runtime_get_noresume(&client->dev);
> +       pm_runtime_enable(&client->dev);
> +
> +       ret = v4l2_async_register_subdev(&dw9719->sd);
> +       if (ret < 0)
> +               goto err_pm_runtime;
> +
> +       pm_runtime_set_autosuspend_delay(&client->dev, 1000);
> +       pm_runtime_use_autosuspend(&client->dev);
> +       pm_runtime_put_autosuspend(&client->dev);
> +
> +       return ret;
> +
> +err_pm_runtime:
> +       pm_runtime_disable(&client->dev);
> +       pm_runtime_put_noidle(&client->dev);
> +err_powerdown:
> +       dw9719_power_down(dw9719);
> +err_cleanup_media:
> +       media_entity_cleanup(&dw9719->sd.entity);
> +err_free_ctrl_handler:
> +       v4l2_ctrl_handler_free(&dw9719->ctrls.handler);
> +
> +       return ret;
> +}
> +
> +static void dw9719_remove(struct i2c_client *client)
> +{
> +       struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +       struct dw9719_device *dw9719 =
> +               container_of(sd, struct dw9719_device, sd);
> +
> +       v4l2_async_unregister_subdev(sd);
> +       v4l2_ctrl_handler_free(&dw9719->ctrls.handler);
> +       media_entity_cleanup(&dw9719->sd.entity);
> +
> +       pm_runtime_disable(&client->dev);
> +       if (!pm_runtime_status_suspended(&client->dev))
> +               dw9719_power_down(dw9719);
> +       pm_runtime_set_suspended(&client->dev);
> +}
> +
> +static const struct i2c_device_id dw9719_id_table[] = {
> +       { "dw9719" },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(i2c, dw9719_id_table);
> +
> +static DEFINE_RUNTIME_DEV_PM_OPS(dw9719_pm_ops, dw9719_suspend, dw9719_resume,
> +                                NULL);

I would logically split this, i.e.

static DEFINE_RUNTIME_DEV_PM_OPS(dw9719_pm_ops,
                                 dw9719_suspend, dw9719_resume,
                                 NULL);

Or

static DEFINE_RUNTIME_DEV_PM_OPS(dw9719_pm_ops,
                                 dw9719_suspend, dw9719_resume, NULL);

> +static struct i2c_driver dw9719_i2c_driver = {
> +       .driver = {
> +               .name = "dw9719",
> +               .pm = pm_sleep_ptr(&dw9719_pm_ops),
> +       },
> +       .probe = dw9719_probe,
> +       .remove = dw9719_remove,
> +       .id_table = dw9719_id_table,
> +};
> +module_i2c_driver(dw9719_i2c_driver);
> +
> +MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
> +MODULE_DESCRIPTION("DW9719 VCM Driver");
> +MODULE_LICENSE("GPL");
> --
> 2.41.0
>