1 files changed, 317 insertions, 0 deletions
diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
new file mode 100644
index 0000000000..463b51d463
--- /dev/null
+++ b/drivers/media/i2c/ak7375.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Intel Corporation
+
+#include <linux/acpi.h>
+#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-ctrls.h>
+#include <media/v4l2-device.h>
+
+#define AK7375_MAX_FOCUS_POS	4095
+/*
+ * This sets the minimum granularity for the focus positions.
+ * A value of 1 gives maximum accuracy for a desired focus position
+ */
+#define AK7375_FOCUS_STEPS	1
+/*
+ * This acts as the minimum granularity of lens movement.
+ * Keep this value power of 2, so the control steps can be
+ * uniformly adjusted for gradual lens movement, with desired
+ * number of control steps.
+ */
+#define AK7375_CTRL_STEPS	64
+#define AK7375_CTRL_DELAY_US	1000
+/*
+ * The vcm may take up 10 ms (tDELAY) to power on and start taking
+ * I2C messages. Based on AK7371 datasheet.
+ */
+#define AK7375_POWER_DELAY_US	10000
+
+#define AK7375_REG_POSITION	0x0
+#define AK7375_REG_CONT		0x2
+#define AK7375_MODE_ACTIVE	0x0
+#define AK7375_MODE_STANDBY	0x40
+
+static const char * const ak7375_supply_names[] = {
+	"vdd",
+	"vio",
+};
+
+/* ak7375 device structure */
+struct ak7375_device {
+	struct v4l2_ctrl_handler ctrls_vcm;
+	struct v4l2_subdev sd;
+	struct v4l2_ctrl *focus;
+	struct regulator_bulk_data supplies[ARRAY_SIZE(ak7375_supply_names)];
+
+	/* active or standby mode */
+	bool active;
+};
+
+static inline struct ak7375_device *to_ak7375_vcm(struct v4l2_ctrl *ctrl)
+{
+	return container_of(ctrl->handler, struct ak7375_device, ctrls_vcm);
+}
+
+static inline struct ak7375_device *sd_to_ak7375_vcm(struct v4l2_subdev *subdev)
+{
+	return container_of(subdev, struct ak7375_device, sd);
+}
+
+static int ak7375_i2c_write(struct ak7375_device *ak7375,
+	u8 addr, u16 data, u8 size)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ak7375->sd);
+	u8 buf[3];
+	int ret;
+
+	if (size != 1 && size != 2)
+		return -EINVAL;
+	buf[0] = addr;
+	buf[size] = data & 0xff;
+	if (size == 2)
+		buf[1] = (data >> 8) & 0xff;
+	ret = i2c_master_send(client, (const char *)buf, size + 1);
+	if (ret < 0)
+		return ret;
+	if (ret != size + 1)
+		return -EIO;
+
+	return 0;
+}
+
+static int ak7375_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct ak7375_device *dev_vcm = to_ak7375_vcm(ctrl);
+
+	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
+		return ak7375_i2c_write(dev_vcm, AK7375_REG_POSITION,
+					ctrl->val << 4, 2);
+
+	return -EINVAL;
+}
+
+static const struct v4l2_ctrl_ops ak7375_vcm_ctrl_ops = {
+	.s_ctrl = ak7375_set_ctrl,
+};
+
+static int ak7375_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	return pm_runtime_resume_and_get(sd->dev);
+}
+
+static int ak7375_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	pm_runtime_put(sd->dev);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_internal_ops ak7375_int_ops = {
+	.open = ak7375_open,
+	.close = ak7375_close,
+};
+
+static const struct v4l2_subdev_ops ak7375_ops = { };
+
+static void ak7375_subdev_cleanup(struct ak7375_device *ak7375_dev)
+{
+	v4l2_async_unregister_subdev(&ak7375_dev->sd);
+	v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
+	media_entity_cleanup(&ak7375_dev->sd.entity);
+}
+
+static int ak7375_init_controls(struct ak7375_device *dev_vcm)
+{
+	struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
+	const struct v4l2_ctrl_ops *ops = &ak7375_vcm_ctrl_ops;
+
+	v4l2_ctrl_handler_init(hdl, 1);
+
+	dev_vcm->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
+		0, AK7375_MAX_FOCUS_POS, AK7375_FOCUS_STEPS, 0);
+
+	if (hdl->error)
+		dev_err(dev_vcm->sd.dev, "%s fail error: 0x%x\n",
+			__func__, hdl->error);
+	dev_vcm->sd.ctrl_handler = hdl;
+
+	return hdl->error;
+}
+
+static int ak7375_probe(struct i2c_client *client)
+{
+	struct ak7375_device *ak7375_dev;
+	int ret;
+	unsigned int i;
+
+	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
+				  GFP_KERNEL);
+	if (!ak7375_dev)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(ak7375_supply_names); i++)
+		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
+
+	ret = devm_regulator_bulk_get(&client->dev,
+				      ARRAY_SIZE(ak7375_supply_names),
+				      ak7375_dev->supplies);
+	if (ret) {
+		dev_err_probe(&client->dev, ret, "Failed to get regulators\n");
+		return ret;
+	}
+
+	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
+	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
+	ak7375_dev->sd.entity.function = MEDIA_ENT_F_LENS;
+
+	ret = ak7375_init_controls(ak7375_dev);
+	if (ret)
+		goto err_cleanup;
+
+	ret = media_entity_pads_init(&ak7375_dev->sd.entity, 0, NULL);
+	if (ret < 0)
+		goto err_cleanup;
+
+	ret = v4l2_async_register_subdev(&ak7375_dev->sd);
+	if (ret < 0)
+		goto err_cleanup;
+
+	pm_runtime_set_active(&client->dev);
+	pm_runtime_enable(&client->dev);
+	pm_runtime_idle(&client->dev);
+
+	return 0;
+
+err_cleanup:
+	v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
+	media_entity_cleanup(&ak7375_dev->sd.entity);
+
+	return ret;
+}
+
+static void ak7375_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
+
+	ak7375_subdev_cleanup(ak7375_dev);
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+}
+
+/*
+ * This function sets the vcm position, so it consumes least current
+ * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
+ * to make the movements smoothly.
+ */
+static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
+	int ret, val;
+
+	if (!ak7375_dev->active)
+		return 0;
+
+	for (val = ak7375_dev->focus->val & ~(AK7375_CTRL_STEPS - 1);
+	     val >= 0; val -= AK7375_CTRL_STEPS) {
+		ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
+				       val << 4, 2);
+		if (ret)
+			dev_err_once(dev, "%s I2C failure: %d\n",
+				     __func__, ret);
+		usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
+	}
+
+	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
+			       AK7375_MODE_STANDBY, 1);
+	if (ret)
+		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(ak7375_supply_names),
+				     ak7375_dev->supplies);
+	if (ret)
+		return ret;
+
+	ak7375_dev->active = false;
+
+	return 0;
+}
+
+/*
+ * This function sets the vcm position to the value set by the user
+ * through v4l2_ctrl_ops s_ctrl handler
+ * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
+ * to make the movements smoothly.
+ */
+static int __maybe_unused ak7375_vcm_resume(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
+	int ret, val;
+
+	if (ak7375_dev->active)
+		return 0;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ak7375_supply_names),
+				    ak7375_dev->supplies);
+	if (ret)
+		return ret;
+
+	/* Wait for vcm to become ready */
+	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
+
+	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
+		AK7375_MODE_ACTIVE, 1);
+	if (ret) {
+		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
+		return ret;
+	}
+
+	for (val = ak7375_dev->focus->val % AK7375_CTRL_STEPS;
+	     val <= ak7375_dev->focus->val;
+	     val += AK7375_CTRL_STEPS) {
+		ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
+				       val << 4, 2);
+		if (ret)
+			dev_err_ratelimited(dev, "%s I2C failure: %d\n",
+						__func__, ret);
+		usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
+	}
+
+	ak7375_dev->active = true;
+
+	return 0;
+}
+
+static const struct of_device_id ak7375_of_table[] = {
+	{ .compatible = "asahi-kasei,ak7375" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ak7375_of_table);
+
+static const struct dev_pm_ops ak7375_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume)
+	SET_RUNTIME_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume, NULL)
+};
+
+static struct i2c_driver ak7375_i2c_driver = {
+	.driver = {
+		.name = "ak7375",
+		.pm = &ak7375_pm_ops,
+		.of_match_table = ak7375_of_table,
+	},
+	.probe = ak7375_probe,
+	.remove = ak7375_remove,
+};
+module_i2c_driver(ak7375_i2c_driver);
+
+MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
+MODULE_AUTHOR("Bingbu Cao <bingbu.cao@intel.com>");
+MODULE_DESCRIPTION("AK7375 VCM driver");
+MODULE_LICENSE("GPL v2");