--- /dev/null
+// 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");
+