Hi Bingbu, On Tue, Jun 19, 2018 at 02:01:47PM +0800, bingbu.cao@xxxxxxxxx wrote: > From: Bingbu Cao <bingbu.cao@xxxxxxxxx> > > Add a v4l2 sub-device driver for the ak7375 lens voice coil. > This is a voice coil module using the i2c bus to control the > focus position. > > ak7375 can write multiple bytes of data at a time. If more > data is received instead of the stop condition after receiving > one byte of data, the address inside the chip is automatically > incremented and the data is written into the next address. > > The ak7375 can control the position with 12 bits value and > consists of two 8 bit registers show as below: > register 0x00(AK7375_REG_POSITION): > +---+---+---+---+---+---+---+---+ > |D11|D10|D09|D08|D07|D06|D05|D04| > +---+---+---+---+---+---+---+---+ > register 0x01: > +---+---+---+---+---+---+---+---+ > |D03|D02|D01|D00|---|---|---|---| > +---+---+---+---+---+---+---+---+ > > This driver support : > - set ak7375 to standby mode once suspend and > turn it back to active if resume > - set the position via V4L2_CID_FOCUS_ABSOLUTE ctrl > > Signed-off-by: Tianshu Qiu <tian.shu.qiu@xxxxxxxxx> > Signed-off-by: Bingbu Cao <bingbu.cao@xxxxxxxxx> > Reviewed-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> > > --- > Changes from v1 -> v3: > - correct i2c write > - add media_entity_pads_init() into probe > - move the MAINTAINERs change into dt-binding change > - correct the compatible stringa > Changes since v3: > - add active flag to indicate the mode > - refine some coding style > > This patch is based on Sakari's media-tree git: > https://git.linuxtv.org/sailus/media_tree.git/log/?h=for-4.18-5 > --- > --- > drivers/media/i2c/Kconfig | 10 ++ > drivers/media/i2c/Makefile | 1 + > drivers/media/i2c/ak7375.c | 293 +++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 304 insertions(+) > create mode 100644 drivers/media/i2c/ak7375.c > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig > index 341452fe98df..ff3cb5afb0e1 100644 > --- a/drivers/media/i2c/Kconfig > +++ b/drivers/media/i2c/Kconfig > @@ -326,6 +326,16 @@ config VIDEO_AD5820 > This is a driver for the AD5820 camera lens voice coil. > It is used for example in Nokia N900 (RX-51). > > +config VIDEO_AK7375 > + tristate "AK7375 lens voice coil support" > + depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER > + depends on VIDEO_V4L2_SUBDEV_API > + help > + This is a driver for the AK7375 camera lens voice coil. > + AK7375 is a 12 bit DAC with 120mA output current sink > + capability. This is designed for linear control of > + voice coil motors, controlled via I2C serial interface. > + > config VIDEO_DW9714 > tristate "DW9714 lens voice coil support" > depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile > index d679d57cd3b3..05b97e319ea9 100644 > --- a/drivers/media/i2c/Makefile > +++ b/drivers/media/i2c/Makefile > @@ -23,6 +23,7 @@ obj-$(CONFIG_VIDEO_SAA7127) += saa7127.o > obj-$(CONFIG_VIDEO_SAA7185) += saa7185.o > obj-$(CONFIG_VIDEO_SAA6752HS) += saa6752hs.o > obj-$(CONFIG_VIDEO_AD5820) += ad5820.o > +obj-$(CONFIG_VIDEO_AK7375) += ak7375.o > obj-$(CONFIG_VIDEO_DW9714) += dw9714.o > obj-$(CONFIG_VIDEO_ADV7170) += adv7170.o > obj-$(CONFIG_VIDEO_ADV7175) += adv7175.o > diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c > new file mode 100644 > index 000000000000..9f039513d57f > --- /dev/null > +++ b/drivers/media/i2c/ak7375.c > @@ -0,0 +1,293 @@ > +// 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 <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 > + > +#define AK7375_REG_POSITION 0x0 > +#define AK7375_REG_CONT 0x2 > +#define AK7375_MODE_ACTIVE 0x0 > +#define AK7375_MODE_STANDBY 0x40 > + > +/* ak7375 device structure */ > +struct ak7375_device { > + struct v4l2_ctrl_handler ctrls_vcm; > + struct v4l2_subdev sd; > + struct v4l2_ctrl *focus; > + /* 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) > +{ > + int ret; > + > + ret = pm_runtime_get_sync(sd->dev); > + if (ret < 0) { > + pm_runtime_put_noidle(sd->dev); > + return ret; > + } > + > + return 0; > +} > + > +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 val; "ret" would seem to be a more appropriate name for this. I'll apply the patch with this change if you're fine with that. > + > + ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev), > + GFP_KERNEL); > + if (!ak7375_dev) > + return -ENOMEM; > + > + 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; > + > + val = ak7375_init_controls(ak7375_dev); > + if (val) > + goto err_cleanup; > + > + val = media_entity_pads_init(&ak7375_dev->sd.entity, 0, NULL); > + if (val < 0) > + goto err_cleanup; > + > + val = v4l2_async_register_subdev(&ak7375_dev->sd); > + if (val < 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); > + dev_err(&client->dev, "Probe failed: %d\n", val); > + > + return val; > +} > + > +static int 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); > + > + return 0; > +} > + > +/* > + * 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 i2c_client *client = to_i2c_client(dev); > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > + 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); > + > + 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 i2c_client *client = to_i2c_client(dev); > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > + struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd); > + int ret, val; > + > + if (ak7375_dev->active) > + return 0; > + > + 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_new = ak7375_probe, > + .remove = ak7375_remove, > +}; > +module_i2c_driver(ak7375_i2c_driver); > + > +MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@xxxxxxxxx>"); > +MODULE_AUTHOR("Bingbu Cao <bingbu.cao@xxxxxxxxx>"); > +MODULE_DESCRIPTION("AK7375 VCM driver"); > +MODULE_LICENSE("GPL v2"); > -- > 1.9.1 > -- Sakari Ailus sakari.ailus@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
