// SPDX-License-Identifier: GPL-2.0-only /* * AD5398 DAC driver for camera voice coil focus. * Copyright (C) 2021 Raspberry Pi (Trading) Ltd. * * Based on AD5820 DAC driver by Nokia and TI. * * This driver uses the regulator framework notification hooks on the * assumption that the VCM and sensor share a regulator. This means the VCM * position will be restored when either the sensor or VCM subdevices are opened * or powered up. The client can therefore choose to ignore the VCM subdevice, * and the lens position will be as previously requested. Without that, there * is a hard requirement to have the VCM subdevice open in order for the VCM * to be powered and at the requested position. */ #include #include #include #include #include #include #include #include #include /* Register definitions */ #define AD5398_POWER_DOWN BIT(15) #define AD5398_DAC_SHIFT 4 #define to_ad5398_device(sd) container_of(sd, struct ad5398_device, subdev) struct ad5398_device { struct v4l2_subdev subdev; struct ad5398_platform_data *platform_data; struct regulator *vana; struct notifier_block nb; struct v4l2_ctrl_handler ctrls; u32 focus_absolute; bool standby; }; static int ad5398_write(struct ad5398_device *coil, u16 data) { struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev); struct i2c_msg msg; __be16 be_data; int r; if (!client->adapter) return -ENODEV; be_data = cpu_to_be16(data); msg.addr = client->addr; msg.flags = 0; msg.len = 2; msg.buf = (u8 *)&be_data; r = i2c_transfer(client->adapter, &msg, 1); if (r < 0) { dev_err(&client->dev, "write failed, error %d\n", r); return r; } return 0; } /* * Calculate status word and write it to the device based on current * values of V4L2 controls. It is assumed that the stored V4L2 control * values are properly limited and rounded. */ static int ad5398_update_hw(struct ad5398_device *coil) { u16 status; status = coil->focus_absolute << AD5398_DAC_SHIFT; if (coil->standby) status |= AD5398_POWER_DOWN; return ad5398_write(coil, status); } /* * Power handling */ static int ad5398_power_off(struct ad5398_device *coil) { int ret = 0; coil->standby = true; ret = ad5398_update_hw(coil); return ret; } static int ad5398_power_on(struct ad5398_device *coil) { int ret; /* Restore the hardware settings. */ coil->standby = false; ret = ad5398_update_hw(coil); if (ret) goto fail; return 0; fail: coil->standby = true; return ret; } /* * V4L2 controls */ static int ad5398_set_ctrl(struct v4l2_ctrl *ctrl) { struct ad5398_device *coil = container_of(ctrl->handler, struct ad5398_device, ctrls); switch (ctrl->id) { case V4L2_CID_FOCUS_ABSOLUTE: coil->focus_absolute = ctrl->val; return ad5398_update_hw(coil); } return 0; } static const struct v4l2_ctrl_ops ad5398_ctrl_ops = { .s_ctrl = ad5398_set_ctrl, }; static int ad5398_init_controls(struct ad5398_device *coil) { v4l2_ctrl_handler_init(&coil->ctrls, 1); /* * V4L2_CID_FOCUS_ABSOLUTE * * Minimum current is 0 mA, maximum is 120 mA. Thus, 1 code is * equivalent to 120/1023 = 0.1173 mA. Nevertheless, we do not use [mA] * for focus position, because it is meaningless for user. Meaningful * would be to use focus distance or even its inverse, but since the * driver doesn't have sufficient knowledge to do the conversion, we * will just use abstract codes here. In any case, smaller value = focus * position farther from camera. The default zero value means focus at * infinity, and also least current consumption. */ v4l2_ctrl_new_std(&coil->ctrls, &ad5398_ctrl_ops, V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0); if (coil->ctrls.error) return coil->ctrls.error; coil->focus_absolute = 0; coil->subdev.ctrl_handler = &coil->ctrls; return 0; } /* * V4L2 subdev operations */ static int ad5398_registered(struct v4l2_subdev *subdev) { struct ad5398_device *coil = to_ad5398_device(subdev); return ad5398_init_controls(coil); } static int ad5398_set_power(struct v4l2_subdev *subdev, int on) { struct ad5398_device *coil = to_ad5398_device(subdev); int ret; if (on) ret = regulator_enable(coil->vana); else ret = regulator_disable(coil->vana); return ret; } static int ad5398_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) { struct ad5398_device *coil = to_ad5398_device(sd); return regulator_enable(coil->vana); } static int ad5398_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) { struct ad5398_device *coil = to_ad5398_device(sd); return regulator_disable(coil->vana); } static const struct v4l2_subdev_core_ops ad5398_core_ops = { .s_power = ad5398_set_power, }; static const struct v4l2_subdev_ops ad5398_ops = { .core = &ad5398_core_ops, }; static const struct v4l2_subdev_internal_ops ad5398_internal_ops = { .registered = ad5398_registered, .open = ad5398_open, .close = ad5398_close, }; /* * I2C driver */ static int __maybe_unused ad5398_suspend(struct device *dev) { struct i2c_client *client = container_of(dev, struct i2c_client, dev); struct v4l2_subdev *subdev = i2c_get_clientdata(client); struct ad5398_device *coil = to_ad5398_device(subdev); return regulator_enable(coil->vana); } static int __maybe_unused ad5398_resume(struct device *dev) { struct i2c_client *client = container_of(dev, struct i2c_client, dev); struct v4l2_subdev *subdev = i2c_get_clientdata(client); struct ad5398_device *coil = to_ad5398_device(subdev); return regulator_disable(coil->vana); } static int ad5398_regulator_notifier(struct notifier_block *nb, unsigned long event, void *ignored) { struct ad5398_device *coil = container_of(nb, struct ad5398_device, nb); if (event == REGULATOR_EVENT_ENABLE) ad5398_power_on(coil); else if (event == REGULATOR_EVENT_PRE_DISABLE) ad5398_power_off(coil); return NOTIFY_OK; } static int ad5398_probe(struct i2c_client *client) { struct ad5398_device *coil; int ret; coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL); if (!coil) return -ENOMEM; coil->vana = devm_regulator_get(&client->dev, "VANA"); if (IS_ERR(coil->vana)) { ret = PTR_ERR(coil->vana); if (ret != -EPROBE_DEFER) dev_err(&client->dev, "could not get regulator for vana\n"); return ret; } v4l2_i2c_subdev_init(&coil->subdev, client, &ad5398_ops); coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; coil->subdev.internal_ops = &ad5398_internal_ops; coil->subdev.entity.function = MEDIA_ENT_F_LENS; strscpy(coil->subdev.name, "ad5398 focus", sizeof(coil->subdev.name)); coil->nb.notifier_call = &ad5398_regulator_notifier; ret = regulator_register_notifier(coil->vana, &coil->nb); if (ret < 0) return ret; ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL); if (ret < 0) goto cleanup2; ret = v4l2_async_register_subdev(&coil->subdev); if (ret < 0) goto cleanup; return ret; cleanup: media_entity_cleanup(&coil->subdev.entity); cleanup2: regulator_unregister_notifier(coil->vana, &coil->nb); return ret; } static void ad5398_remove(struct i2c_client *client) { struct v4l2_subdev *subdev = i2c_get_clientdata(client); struct ad5398_device *coil = to_ad5398_device(subdev); v4l2_async_unregister_subdev(&coil->subdev); v4l2_ctrl_handler_free(&coil->ctrls); media_entity_cleanup(&coil->subdev.entity); } static const struct i2c_device_id ad5398_id_table[] = { { "ad5398", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, ad5398_id_table); static const struct of_device_id ad5398_of_table[] = { { .compatible = "adi,ad5398" }, { } }; MODULE_DEVICE_TABLE(of, ad5398_of_table); static SIMPLE_DEV_PM_OPS(ad5398_pm, ad5398_suspend, ad5398_resume); static struct i2c_driver ad5398_i2c_driver = { .driver = { .name = "ad5398", .pm = &ad5398_pm, .of_match_table = ad5398_of_table, }, .probe = ad5398_probe, .remove = ad5398_remove, .id_table = ad5398_id_table, }; module_i2c_driver(ad5398_i2c_driver); MODULE_AUTHOR("Dave Stevenson "); MODULE_DESCRIPTION("AD5398 camera lens driver"); MODULE_LICENSE("GPL");