Re: [PATCH] media: Add t4ka3 camera sensor driver

[Kate Hsuan]

Hi Christophe,

Thank you for reviewing.

On Thu, Oct 3, 2024 at 5:03 AM Christophe JAILLET
<christophe.jaillet@xxxxxxxxxx> wrote:
>
> Le 02/10/2024 à 11:30, Kate Hsuan a écrit :
> > Add the t4ka3 driver from:
> > https://github.com/kitakar5525/surface3-atomisp-cameras.git
> >
> > With many cleanups / changes (almost a full rewrite) to make it suitable
> > for upstream:
> >
> > * Remove the VCM and VCM-OTP support, the mainline kernel models VCMs and
> >    calibration data eeproms as separate v4l2-subdev-s.
> >
> > * Remove the integration-factor t4ka3_get_intg_factor() support and IOCTL,
> >    this provided info to userspace through an atomisp private IOCTL.
> >
> > * Turn atomisp specific exposure/gain IOCTL into standard v4l2 controls.
> >
> > * Use normal ACPI power-management in combination with runtime-pm support
> >    instead of atomisp specific GMIN power-management code.
> >
> > * Turn into a standard V4L2 sensor driver using
> >    v4l2_async_register_subdev_sensor().
> >
> > * Add vblank, hblank, and link-freq controls; drop get_frame_interval().
> >
> > * Use CCI register helpers.
> >
> > * Calculate values for modes instead of using fixed register-value lists,
> >    allowing arbritrary modes.
> >
> > * Add get_selection() and set_selection() support
> >
> > * Add a CSI2 bus configuration check
> >
> > This been tested on a Xiaomi Mipad2 tablet which has a T4KA3 sensor with
> > DW9761 VCM as back sensor.
> >
> > Co-developed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > Signed-off-by: Kate Hsuan <hpa@xxxxxxxxxx>
> > ---
>
> Hi,
>
> a few comments, should it help.
>
> > +static int t4ka3_s_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > +     struct t4ka3_data *sensor = to_t4ka3_sensor(sd);
> > +     int ret;
> > +
> > +     mutex_lock(&sensor->lock);
> > +
> > +     if (sensor->streaming == enable) {
> > +             dev_warn(sensor->dev, "Stream already %s\n", enable ? "started" : "stopped");
> > +             goto error_unlock;
> > +     }
> > +
> > +     if (enable) {
> > +             ret = pm_runtime_get_sync(sensor->sd.dev);
> > +             if (ret) {
> > +                     dev_err(sensor->dev, "power-up err.\n");
> > +                     goto error_unlock;
> > +             }
> > +
> > +             cci_multi_reg_write(sensor->regmap, t4ka3_init_config,
> > +                                 ARRAY_SIZE(t4ka3_init_config), &ret);
> > +             /* enable group hold */
> > +             cci_write(sensor->regmap, T4KA3_REG_PARAM_HOLD, 1, &ret);
> > +             cci_multi_reg_write(sensor->regmap, t4ka3_pre_mode_set_regs,
> > +                                 ARRAY_SIZE(t4ka3_pre_mode_set_regs), &ret);
> > +             if (ret)
> > +                     goto error_powerdown;
> > +
> > +             ret = t4ka3_set_mode(sensor);
> > +             if (ret)
> > +                     goto error_powerdown;
> > +
> > +             ret = cci_multi_reg_write(sensor->regmap, t4ka3_post_mode_set_regs,
> > +                                       ARRAY_SIZE(t4ka3_post_mode_set_regs), NULL);
> > +             if (ret)
> > +                     goto error_powerdown;
> > +
> > +             /* Restore value of all ctrls */
> > +             ret = __v4l2_ctrl_handler_setup(&sensor->ctrls.handler);
> > +             if (ret)
> > +                     goto error_powerdown;
> > +
> > +             /* disable group hold */
> > +             cci_write(sensor->regmap, T4KA3_REG_PARAM_HOLD, 0, &ret);
> > +             cci_write(sensor->regmap, T4KA3_REG_STREAM, 1, &ret);
> > +             if (ret)
> > +                     goto error_powerdown;
> > +
> > +             sensor->streaming = 1;
> > +     } else {
> > +             ret = cci_write(sensor->regmap, T4KA3_REG_STREAM, 0, NULL);
> > +             if (ret)
> > +                     goto error_powerdown;
> > +
> > +             ret = pm_runtime_put(sensor->sd.dev);
> > +             if (ret)
> > +                     goto error_unlock;
> > +
> > +             sensor->streaming = 0;
> > +     }
> > +
> > +     mutex_unlock(&sensor->lock);
> > +     return ret;
> > +
> > +error_powerdown:
> > +     ret = pm_runtime_put(sensor->sd.dev);
>
> I think that the "ret = " should be removed here.

Okay, make sense.

>
> > +error_unlock:
> > +     mutex_unlock(&sensor->lock);
> > +     return ret;
> > +}
>
> ...
>
> > +static int t4ka3_probe(struct i2c_client *client)
> > +{
> > +     struct t4ka3_data *sensor;
> > +     int ret;
> > +
> > +     /* allocate sensor device & init sub device */
> > +     sensor = devm_kzalloc(&client->dev, sizeof(*sensor), GFP_KERNEL);
> > +     if (!sensor)
> > +             return -ENOMEM;
> > +
> > +     sensor->dev = &client->dev;
> > +
> > +     ret = t4ka3_check_hwcfg(sensor);
> > +     if (ret)
> > +             return ret;
> > +
> > +     mutex_init(&sensor->lock);
> > +
> > +     sensor->link_freq[0] = T4KA3_LINK_FREQ;
> > +     sensor->mode.crop = t4ka3_default_crop;
> > +     t4ka3_fill_format(sensor, &sensor->mode.fmt, T4KA3_ACTIVE_WIDTH, T4KA3_ACTIVE_HEIGHT);
> > +     t4ka3_calc_mode(sensor);
> > +
> > +     v4l2_i2c_subdev_init(&(sensor->sd), client, &t4ka3_ops);
> > +     sensor->sd.internal_ops = &t4ka3_internal_ops;
> > +
> > +     sensor->powerdown_gpio = devm_gpiod_get(&client->dev, "powerdown",
> > +                                             GPIOD_OUT_HIGH);
> > +     if (IS_ERR(sensor->powerdown_gpio))
> > +             return dev_err_probe(&client->dev, PTR_ERR(sensor->powerdown_gpio),
> > +                                  "getting powerdown GPIO\n");
> > +
> > +     sensor->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
> > +                                                  GPIOD_OUT_HIGH);
> > +     if (IS_ERR(sensor->reset_gpio))
> > +             return dev_err_probe(&client->dev, PTR_ERR(sensor->reset_gpio),
> > +                                  "getting reset GPIO\n");
> > +
> > +     pm_runtime_set_suspended(&client->dev);
> > +     pm_runtime_enable(&client->dev);
> > +     pm_runtime_set_autosuspend_delay(&client->dev, 1000);
> > +     pm_runtime_use_autosuspend(&client->dev);
> > +
> > +     sensor->regmap = devm_cci_regmap_init_i2c(client, 16);
> > +     if (IS_ERR(sensor->regmap))
> > +             return PTR_ERR(sensor->regmap);
>
> I thing this should goto err_pm_runtime;

Okay, I'll get the regmap information before setting up runtime pm.
So, probe() can return without diable the pm.

>
> > +
> > +     ret = t4ka3_s_config(&sensor->sd);
> > +     if (ret)
> > +             goto err_pm_runtime;
> > +
> > +     sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +     sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
> > +     sensor->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > +
> > +     ret = t4ka3_init_controls(sensor);
> > +     if (ret)
> > +             goto err_controls;
> > +
> > +     ret = media_entity_pads_init(&sensor->sd.entity, 1, &sensor->pad);
> > +     if (ret)
> > +             goto err_controls;
> > +
> > +     ret = v4l2_async_register_subdev_sensor(&sensor->sd);
> > +     if (ret)
> > +             goto err_media_entity;
> > +
> > +     return 0;
> > +
> > +err_media_entity:
> > +     media_entity_cleanup(&sensor->sd.entity);
> > +err_controls:
> > +     v4l2_ctrl_handler_free(&sensor->ctrls.handler);
> > +err_pm_runtime:
> > +     pm_runtime_disable(&client->dev);
> > +     return ret;
> > +}
> > +
> > +static struct acpi_device_id t4ka3_acpi_match[] = {
> > +     { "XMCC0003" },
> > +     {},
>
> No need for ending comma after terminator.
Okay.

>
> > +};
>
> ...
>
> CJ
>

I'll propose a v2 patch to include the improvements.

-- 
BR,
Kate