From 099c31b8568b7e8c11e57ffced2da1cbccbfbcad Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Wed, 29 Sep 2021 14:04:28 +0100 Subject: [PATCH] media: i2c: Add driver for AD5398 VCM lens driver Adds a driver for the Analog Devices AD5398 10 bit I2C DAC which is commonly used for driving VCM lens mechanisms. Signed-off-by: Dave Stevenson --- drivers/media/i2c/Kconfig | 7 + drivers/media/i2c/Makefile | 1 + drivers/media/i2c/ad5398.c | 341 +++++++++++++++++++++++++++++++++++++ 3 files changed, 349 insertions(+) create mode 100644 drivers/media/i2c/ad5398.c --- a/drivers/media/i2c/Kconfig +++ b/drivers/media/i2c/Kconfig @@ -817,6 +817,13 @@ endif menu "Lens drivers" visible if MEDIA_CAMERA_SUPPORT +config VIDEO_AD5398 + tristate "AD5398 lens voice coil support" + depends on GPIOLIB && I2C && VIDEO_DEV + select MEDIA_CONTROLLER + help + This is a driver for the AD5398 camera lens voice coil. + config VIDEO_AD5820 tristate "AD5820 lens voice coil support" depends on GPIOLIB && I2C && VIDEO_DEV --- a/drivers/media/i2c/Makefile +++ b/drivers/media/i2c/Makefile @@ -3,6 +3,7 @@ msp3400-objs := msp3400-driver.o msp3400-kthreads.o obj-$(CONFIG_SDR_MAX2175) += max2175.o +obj-$(CONFIG_VIDEO_AD5398) += ad5398.o obj-$(CONFIG_VIDEO_AD5820) += ad5820.o obj-$(CONFIG_VIDEO_AD9389B) += ad9389b.o obj-$(CONFIG_VIDEO_ADP1653) += adp1653.o --- /dev/null +++ b/drivers/media/i2c/ad5398.c @@ -0,0 +1,341 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AD5398 DAC driver for camera voice coil focus. + * Copyright (C) 2021 Raspberry Pi (Trading) Ltd. + * + * Based on AD5820 DAC driver by Nokia and TI. + * + * This driver uses the regulator framework notification hooks on the + * assumption that the VCM and sensor share a regulator. This means the VCM + * position will be restored when either the sensor or VCM subdevices are opened + * or powered up. The client can therefore choose to ignore the VCM subdevice, + * and the lens position will be as previously requested. Without that, there + * is a hard requirement to have the VCM subdevice open in order for the VCM + * to be powered and at the requested position. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* Register definitions */ +#define AD5398_POWER_DOWN BIT(15) +#define AD5398_DAC_SHIFT 4 + +#define to_ad5398_device(sd) container_of(sd, struct ad5398_device, subdev) + +struct ad5398_device { + struct v4l2_subdev subdev; + struct ad5398_platform_data *platform_data; + struct regulator *vana; + struct notifier_block nb; + + struct v4l2_ctrl_handler ctrls; + u32 focus_absolute; + + bool standby; +}; + +static int ad5398_write(struct ad5398_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 ad5398_update_hw(struct ad5398_device *coil) +{ + u16 status; + + status = coil->focus_absolute << AD5398_DAC_SHIFT; + + if (coil->standby) + status |= AD5398_POWER_DOWN; + + return ad5398_write(coil, status); +} + +/* + * Power handling + */ +static int ad5398_power_off(struct ad5398_device *coil) +{ + int ret = 0; + + coil->standby = true; + ret = ad5398_update_hw(coil); + + return ret; +} + +static int ad5398_power_on(struct ad5398_device *coil) +{ + int ret; + + /* Restore the hardware settings. */ + coil->standby = false; + ret = ad5398_update_hw(coil); + if (ret) + goto fail; + + return 0; + +fail: + coil->standby = true; + + return ret; +} + +/* + * V4L2 controls + */ +static int ad5398_set_ctrl(struct v4l2_ctrl *ctrl) +{ + struct ad5398_device *coil = + container_of(ctrl->handler, struct ad5398_device, ctrls); + + switch (ctrl->id) { + case V4L2_CID_FOCUS_ABSOLUTE: + coil->focus_absolute = ctrl->val; + return ad5398_update_hw(coil); + } + + return 0; +} + +static const struct v4l2_ctrl_ops ad5398_ctrl_ops = { + .s_ctrl = ad5398_set_ctrl, +}; + +static int ad5398_init_controls(struct ad5398_device *coil) +{ + v4l2_ctrl_handler_init(&coil->ctrls, 1); + + /* + * V4L2_CID_FOCUS_ABSOLUTE + * + * Minimum current is 0 mA, maximum is 120 mA. Thus, 1 code is + * equivalent to 120/1023 = 0.1173 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 sufficient 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, &ad5398_ctrl_ops, + V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0); + + if (coil->ctrls.error) + return coil->ctrls.error; + + coil->focus_absolute = 0; + + coil->subdev.ctrl_handler = &coil->ctrls; + + return 0; +} + +/* + * V4L2 subdev operations + */ +static int ad5398_registered(struct v4l2_subdev *subdev) +{ + struct ad5398_device *coil = to_ad5398_device(subdev); + + return ad5398_init_controls(coil); +} + +static int +ad5398_set_power(struct v4l2_subdev *subdev, int on) +{ + struct ad5398_device *coil = to_ad5398_device(subdev); + int ret; + + if (on) + ret = regulator_enable(coil->vana); + else + ret = regulator_disable(coil->vana); + + return ret; +} + +static int ad5398_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) +{ + struct ad5398_device *coil = to_ad5398_device(sd); + + return regulator_enable(coil->vana); +} + +static int ad5398_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) +{ + struct ad5398_device *coil = to_ad5398_device(sd); + + return regulator_disable(coil->vana); +} + +static const struct v4l2_subdev_core_ops ad5398_core_ops = { + .s_power = ad5398_set_power, +}; + +static const struct v4l2_subdev_ops ad5398_ops = { + .core = &ad5398_core_ops, +}; + +static const struct v4l2_subdev_internal_ops ad5398_internal_ops = { + .registered = ad5398_registered, + .open = ad5398_open, + .close = ad5398_close, +}; + +/* + * I2C driver + */ +static int __maybe_unused ad5398_suspend(struct device *dev) +{ + struct i2c_client *client = container_of(dev, struct i2c_client, dev); + struct v4l2_subdev *subdev = i2c_get_clientdata(client); + struct ad5398_device *coil = to_ad5398_device(subdev); + + return regulator_enable(coil->vana); +} + +static int __maybe_unused ad5398_resume(struct device *dev) +{ + struct i2c_client *client = container_of(dev, struct i2c_client, dev); + struct v4l2_subdev *subdev = i2c_get_clientdata(client); + struct ad5398_device *coil = to_ad5398_device(subdev); + + return regulator_disable(coil->vana); +} + +static int ad5398_regulator_notifier(struct notifier_block *nb, + unsigned long event, + void *ignored) +{ + struct ad5398_device *coil = container_of(nb, struct ad5398_device, nb); + + if (event == REGULATOR_EVENT_ENABLE) + ad5398_power_on(coil); + else if (event == REGULATOR_EVENT_PRE_DISABLE) + ad5398_power_off(coil); + + return NOTIFY_OK; +} + +static int ad5398_probe(struct i2c_client *client, + const struct i2c_device_id *devid) +{ + struct ad5398_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; + } + + v4l2_i2c_subdev_init(&coil->subdev, client, &ad5398_ops); + coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; + coil->subdev.internal_ops = &ad5398_internal_ops; + coil->subdev.entity.function = MEDIA_ENT_F_LENS; + strscpy(coil->subdev.name, "ad5398 focus", sizeof(coil->subdev.name)); + + coil->nb.notifier_call = &ad5398_regulator_notifier; + ret = regulator_register_notifier(coil->vana, &coil->nb); + if (ret < 0) + return ret; + + 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; + +cleanup: + media_entity_cleanup(&coil->subdev.entity); +cleanup2: + regulator_unregister_notifier(coil->vana, &coil->nb); + return ret; +} + +static void ad5398_remove(struct i2c_client *client) +{ + struct v4l2_subdev *subdev = i2c_get_clientdata(client); + struct ad5398_device *coil = to_ad5398_device(subdev); + + v4l2_async_unregister_subdev(&coil->subdev); + v4l2_ctrl_handler_free(&coil->ctrls); + media_entity_cleanup(&coil->subdev.entity); +} + +static const struct i2c_device_id ad5398_id_table[] = { + { "ad5398", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ad5398_id_table); + +static const struct of_device_id ad5398_of_table[] = { + { .compatible = "adi,ad5398" }, + { } +}; +MODULE_DEVICE_TABLE(of, ad5398_of_table); + +static SIMPLE_DEV_PM_OPS(ad5398_pm, ad5398_suspend, ad5398_resume); + +static struct i2c_driver ad5398_i2c_driver = { + .driver = { + .name = "ad5398", + .pm = &ad5398_pm, + .of_match_table = ad5398_of_table, + }, + .probe = ad5398_probe, + .remove = ad5398_remove, + .id_table = ad5398_id_table, +}; + +module_i2c_driver(ad5398_i2c_driver); + +MODULE_AUTHOR("Dave Stevenson "); +MODULE_DESCRIPTION("AD5398 camera lens driver"); +MODULE_LICENSE("GPL");