--- /dev/null
+/*
+ * drivers/media/i2c/ad5820.c
+ *
+ * AD5820 DAC driver for camera voice coil focus.
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ * Copyright (C) 2007 Texas Instruments
+ * Copyright (C) 2016 Pavel Machek <pavel@ucw.cz>
+ *
+ * Contact: Tuukka Toivonen <tuukkat76@gmail.com>
+ * Sakari Ailus <sakari.ailus@iki.fi>
+ *
+ * Based on af_d88.c by Texas Instruments.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+
+#define AD5820_NAME "ad5820"
+
+/* Register definitions */
+#define AD5820_POWER_DOWN (1 << 15)
+#define AD5820_DAC_SHIFT 4
+#define AD5820_RAMP_MODE_LINEAR (0 << 3)
+#define AD5820_RAMP_MODE_64_16 (1 << 3)
+
+#define CODE_TO_RAMP_US(s) ((s) == 0 ? 0 : (1 << ((s) - 1)) * 50)
+#define RAMP_US_TO_CODE(c) fls(((c) + ((c)>>1)) / 50)
+
+#define to_ad5820_device(sd) container_of(sd, struct ad5820_device, subdev)
+
+struct ad5820_device {
+ struct v4l2_subdev subdev;
+ struct ad5820_platform_data *platform_data;
+ struct regulator *vana;
+
+ struct v4l2_ctrl_handler ctrls;
+ u32 focus_absolute;
+ u32 focus_ramp_time;
+ u32 focus_ramp_mode;
+
+ struct mutex power_lock;
+ int power_count;
+
+ int standby : 1;
+};
+
+static int ad5820_write(struct ad5820_device *coil, u16 data)
+{
+ struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev);
+ struct i2c_msg msg;
+ int r;
+
+ if (!client->adapter)
+ return -ENODEV;
+
+ data = cpu_to_be16(data);
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = 2;
+ msg.buf = (u8 *)&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 ad5820_update_hw(struct ad5820_device *coil)
+{
+ u16 status;
+
+ status = RAMP_US_TO_CODE(coil->focus_ramp_time);
+ status |= coil->focus_ramp_mode
+ ? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR;
+ status |= coil->focus_absolute << AD5820_DAC_SHIFT;
+
+ if (coil->standby)
+ status |= AD5820_POWER_DOWN;
+
+ return ad5820_write(coil, status);
+}
+
+/*
+ * Power handling
+ */
+static int ad5820_power_off(struct ad5820_device *coil, int standby)
+{
+ int ret = 0, ret2;
+
+ /*
+ * Go to standby first as real power off my be denied by the hardware
+ * (single power line control for both coil and sensor).
+ */
+ if (standby) {
+ coil->standby = 1;
+ ret = ad5820_update_hw(coil);
+ }
+
+ ret2 = regulator_disable(coil->vana);
+ if (ret)
+ return ret;
+ return ret2;
+}
+
+static int ad5820_power_on(struct ad5820_device *coil, int restore)
+{
+ int ret;
+
+ ret = regulator_enable(coil->vana);
+ if (ret < 0)
+ return ret;
+
+ if (restore) {
+ /* Restore the hardware settings. */
+ coil->standby = 0;
+ ret = ad5820_update_hw(coil);
+ if (ret)
+ goto fail;
+ }
+ return 0;
+
+fail:
+ coil->standby = 1;
+ regulator_disable(coil->vana);
+
+ return ret;
+}
+
+/*
+ * V4L2 controls
+ */
+static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+ struct ad5820_device *coil =
+ container_of(ctrl->handler, struct ad5820_device, ctrls);
+
+ switch (ctrl->id) {
+ case V4L2_CID_FOCUS_ABSOLUTE:
+ coil->focus_absolute = ctrl->val;
+ return ad5820_update_hw(coil);
+ }
+
+ return 0;
+}
+
+static const struct v4l2_ctrl_ops ad5820_ctrl_ops = {
+ .s_ctrl = ad5820_set_ctrl,
+};
+
+
+static int ad5820_init_controls(struct ad5820_device *coil)
+{
+ v4l2_ctrl_handler_init(&coil->ctrls, 1);
+
+ /*
+ * V4L2_CID_FOCUS_ABSOLUTE
+ *
+ * Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is
+ * equivalent to 100/1023 = 0.0978 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 sufficiently 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, &ad5820_ctrl_ops,
+ V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
+
+ if (coil->ctrls.error)
+ return coil->ctrls.error;
+
+ coil->focus_absolute = 0;
+ coil->focus_ramp_time = 0;
+ coil->focus_ramp_mode = 0;
+
+ coil->subdev.ctrl_handler = &coil->ctrls;
+
+ return 0;
+}
+
+/*
+ * V4L2 subdev operations
+ */
+static int ad5820_registered(struct v4l2_subdev *subdev)
+{
+ struct ad5820_device *coil = to_ad5820_device(subdev);
+
+ return ad5820_init_controls(coil);
+}
+
+static int
+ad5820_set_power(struct v4l2_subdev *subdev, int on)
+{
+ struct ad5820_device *coil = to_ad5820_device(subdev);
+ int ret = 0;
+
+ mutex_lock(&coil->power_lock);
+
+ /*
+ * If the power count is modified from 0 to != 0 or from != 0 to 0,
+ * update the power state.
+ */
+ if (coil->power_count == !on) {
+ ret = on ? ad5820_power_on(coil, 1) : ad5820_power_off(coil, 1);
+ if (ret < 0)
+ goto done;
+ }
+
+ /* Update the power count. */
+ coil->power_count += on ? 1 : -1;
+ WARN_ON(coil->power_count < 0);
+
+done:
+ mutex_unlock(&coil->power_lock);
+ return ret;
+}
+
+static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+ return ad5820_set_power(sd, 1);
+}
+
+static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+ return ad5820_set_power(sd, 0);
+}
+
+static const struct v4l2_subdev_core_ops ad5820_core_ops = {
+ .s_power = ad5820_set_power,
+};
+
+static const struct v4l2_subdev_ops ad5820_ops = {
+ .core = &ad5820_core_ops,
+};
+
+static const struct v4l2_subdev_internal_ops ad5820_internal_ops = {
+ .registered = ad5820_registered,
+ .open = ad5820_open,
+ .close = ad5820_close,
+};
+
+/*
+ * I2C driver
+ */
+#ifdef CONFIG_PM
+
+static int ad5820_suspend(struct device *dev)
+{
+ struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+ struct v4l2_subdev *subdev = i2c_get_clientdata(client);
+ struct ad5820_device *coil = to_ad5820_device(subdev);
+
+ if (!coil->power_count)
+ return 0;
+
+ return ad5820_power_off(coil, 0);
+}
+
+static int ad5820_resume(struct device *dev)
+{
+ struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+ struct v4l2_subdev *subdev = i2c_get_clientdata(client);
+ struct ad5820_device *coil = to_ad5820_device(subdev);
+
+ if (!coil->power_count)
+ return 0;
+
+ return ad5820_power_on(coil, 1);
+}
+
+#else
+
+#define ad5820_suspend NULL
+#define ad5820_resume NULL
+
+#endif /* CONFIG_PM */
+
+static int ad5820_probe(struct i2c_client *client,
+ const struct i2c_device_id *devid)
+{
+ struct ad5820_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;
+ }
+
+ mutex_init(&coil->power_lock);
+
+ v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
+ coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+ coil->subdev.internal_ops = &ad5820_internal_ops;
+ strcpy(coil->subdev.name, "ad5820 focus");
+
+ 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;
+
+cleanup2:
+ mutex_destroy(&coil->power_lock);
+cleanup:
+ media_entity_cleanup(&coil->subdev.entity);
+ return ret;
+}
+
+static int __exit ad5820_remove(struct i2c_client *client)
+{
+ struct v4l2_subdev *subdev = i2c_get_clientdata(client);
+ struct ad5820_device *coil = to_ad5820_device(subdev);
+
+ v4l2_device_unregister_subdev(&coil->subdev);
+ v4l2_ctrl_handler_free(&coil->ctrls);
+ media_entity_cleanup(&coil->subdev.entity);
+ mutex_destroy(&coil->power_lock);
+ return 0;
+}
+
+static const struct i2c_device_id ad5820_id_table[] = {
+ { AD5820_NAME, 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ad5820_id_table);
+
+static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume);
+
+static struct i2c_driver ad5820_i2c_driver = {
+ .driver = {
+ .name = AD5820_NAME,
+ .pm = &ad5820_pm,
+ },
+ .probe = ad5820_probe,
+ .remove = __exit_p(ad5820_remove),
+ .id_table = ad5820_id_table,
+};
+
+module_i2c_driver(ad5820_i2c_driver);
+
+MODULE_AUTHOR("Tuukka Toivonen");
+MODULE_DESCRIPTION("AD5820 camera lens driver");
+MODULE_LICENSE("GPL");
projects / openwrt / staging / blogic.git / commitdiff