/* * 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 * * Contact: Tuukka Toivonen * Sakari Ailus * * 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 #include #include #include #include #include #include #include #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; bool standby; }; static int ad5820_write(struct ad5820_device *coil, u16 data) { struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev); struct i2c_msg msg; __be16 be_data; int r; if (!client->adapter) return -ENODEV; be_data = cpu_to_be16(data); msg.addr = client->addr; msg.flags = 0; msg.len = 2; msg.buf = (u8 *)&be_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, bool 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 = true; 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, bool restore) { int ret; ret = regulator_enable(coil->vana); if (ret < 0) return ret; if (restore) { /* Restore the hardware settings. */ coil->standby = false; ret = ad5820_update_hw(coil); if (ret) goto fail; } return 0; fail: coil->standby = true; 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, true) : ad5820_power_off(coil, true); 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 */ static int __maybe_unused 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, false); } static int __maybe_unused 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, true); } 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; strscpy(coil->subdev.name, "ad5820 focus", sizeof(coil->subdev.name)); 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 ad5820_remove(struct i2c_client *client) { struct v4l2_subdev *subdev = i2c_get_clientdata(client); struct ad5820_device *coil = to_ad5820_device(subdev); v4l2_async_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 = 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");