From cd0642a55ad9cde0c1a4769afee1a454033ac374 Mon Sep 17 00:00:00 2001
From: Kieran Bingham <kieran.bingham@ideasonboard.com>
Date: Wed, 13 Sep 2023 17:53:54 +0100
Subject: [PATCH] media: i2c: Add ROHM BU64754 Camera Autofocus Actuator

Add support for the ROHM BU64754 Motor Driver for Camera Autofocus. A
V4L2 Subdevice is registered and provides a single
V4L2_CID_FOCUS_ABSOLUTE control.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
---
 drivers/media/i2c/Kconfig   |  13 ++
 drivers/media/i2c/Makefile  |   1 +
 drivers/media/i2c/bu64754.c | 315 ++++++++++++++++++++++++++++++++++++
 3 files changed, 329 insertions(+)
 create mode 100644 drivers/media/i2c/bu64754.c

--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -822,6 +822,19 @@ config VIDEO_AK7375
 	  capability. This is designed for linear control of
 	  voice coil motors, controlled via I2C serial interface.
 
+config VIDEO_BU64754
+	tristate "BU64754 Motor Driver for Camera Autofocus"
+	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 BU64754 Motor Driver for Camera
+	  Autofocus. The BU64754GWZ is an actuator driver IC which
+	  can be controlled the actuator position precisely using
+	  with internal Hall Sensor.
+
 config VIDEO_DW9714
 	tristate "DW9714 lens voice coil support"
 	depends on GPIOLIB && I2C && VIDEO_DEV
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_VIDEO_ARDUCAM_PIVARIETY) +=
 obj-$(CONFIG_VIDEO_BT819) += bt819.o
 obj-$(CONFIG_VIDEO_BT856) += bt856.o
 obj-$(CONFIG_VIDEO_BT866) += bt866.o
+obj-$(CONFIG_VIDEO_BU64754) += bu64754.o
 obj-$(CONFIG_VIDEO_CCS) += ccs/
 obj-$(CONFIG_VIDEO_CCS_PLL) += ccs-pll.o
 obj-$(CONFIG_VIDEO_CS3308) += cs3308.o
--- /dev/null
+++ b/drivers/media/i2c/bu64754.c
@@ -0,0 +1,315 @@
+// 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");
+
