// SPDX-License-Identifier: GPL-2.0
/*
 * The BU64754GWZ 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 BU64753_POSITION_STEPS	1

#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;

	position &= 0x3ff; /* BU64753_POSITION_MAX */
	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;

	ret = cci_write(bu64754->cci, BU64754_REG_ACTIVE, 0, NULL);
	if (ret < 0)
		dev_err(bu64754->dev, "Failed to enter standby 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);
	}

	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, BU64753_POSITION_STEPS,
			  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;

	bu64754->sd.entity.function = MEDIA_ENT_F_LENS;

	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 const struct dev_pm_ops bu64754_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(bu64754_vcm_suspend, bu64754_vcm_resume)
	SET_RUNTIME_PM_OPS(bu64754_vcm_suspend, bu64754_vcm_resume, NULL)
};

static struct i2c_driver bu64754_i2c_driver = {
	.driver = {
		.name = "bu64754",
		.pm = &bu64754_pm_ops,
		.of_match_table = bu64754_of_table,
	},
	.probe = bu64754_probe,
	.remove = bu64754_remove,
};

module_i2c_driver(bu64754_i2c_driver);

MODULE_AUTHOR("Kieran Bingham");
MODULE_DESCRIPTION("BU64754 VCM driver");
MODULE_LICENSE("GPL");