Hi Hans, Thanks for the quick review. Please see my comments inline... I will post the new v2 patch soon. > -----Original Message----- > From: Hans Verkuil [mailto:hverkuil@xxxxxxxxx] > Sent: Monday, May 08, 2017 6:59 PM > To: Mani, Rajmohan <rajmohan.mani@xxxxxxxxx>; linux- > media@xxxxxxxxxxxxxxx; mchehab@xxxxxxxxxx > Subject: Re: [PATCH] dw9714: Initial driver for dw9714 VCM > > Hi Rajmohan, > > Thanks for the patch! > > A quick code review: > > On 05/07/2017 01:33 PM, rajmohan.mani@xxxxxxxxx wrote: > > From: Rajmohan Mani <rajmohan.mani@xxxxxxxxx> > > > > DW9714 is a 10 bit DAC, designed for linear control of voice coil > > motor. > > > > This driver creates a V4L2 subdevice and provides control to set the > > desired focus. > > > > Signed-off-by: Rajmohan Mani <rajmohan.mani@xxxxxxxxx> > > --- > > drivers/media/i2c/Kconfig | 9 ++ > > drivers/media/i2c/Makefile | 1 + > > drivers/media/i2c/dw9714.c | 333 > > +++++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 343 insertions(+) > > create mode 100644 drivers/media/i2c/dw9714.c > > > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig > > index fd181c9..4f0a7ad 100644 > > --- a/drivers/media/i2c/Kconfig > > +++ b/drivers/media/i2c/Kconfig > > @@ -300,6 +300,15 @@ 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_DW9714 > > + tristate "DW9714 lens voice coil support" > > + depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER > > + ---help--- > > + This is a driver for the DW9714 camera lens voice coil. > > + DW9714 is a 10 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_SAA7110 > > tristate "Philips SAA7110 video decoder" > > depends on VIDEO_V4L2 && I2C > > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile > > index 62323ec..987bd1f 100644 > > --- a/drivers/media/i2c/Makefile > > +++ b/drivers/media/i2c/Makefile > > @@ -21,6 +21,7 @@ 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-$(CONFIG_VIDEO_DW9714) += dw9714.o > > obj-$(CONFIG_VIDEO_ADV7170) += adv7170.o > > obj-$(CONFIG_VIDEO_ADV7175) += adv7175.o > > obj-$(CONFIG_VIDEO_ADV7180) += adv7180.o diff --git > > a/drivers/media/i2c/dw9714.c b/drivers/media/i2c/dw9714.c new file > > mode 100644 index 0000000..276d3f2 > > --- /dev/null > > +++ b/drivers/media/i2c/dw9714.c > > @@ -0,0 +1,333 @@ > > +/* > > + * Copyright (c) 2015--2017 Intel Corporation. > > + * > > + * 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/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 DW9714_NAME "dw9714" > > +#define DW9714_MAX_FOCUS_POS 1023 > > +#define DW9714_CTRL_STEPS 16 /* Keep this value power of 2 > */ > > +#define DW9714_CTRL_DELAY_US 1000 > > +/* > > + * S[3:2] = 0x00, codes per step for "Linear Slope Control" > > + * S[1:0] = 0x00, step period > > + */ > > +#define DW9714_DEFAULT_S 0x0 > > +#define DW9714_VAL(data, s) (u16)((data) << 4 | (s)) > > + > > +/* dw9714 device structure */ > > +struct dw9714_device { > > + struct i2c_client *client; > > + struct v4l2_ctrl_handler ctrls_vcm; > > + struct v4l2_subdev sd; > > + u16 current_val; > > +}; > > + > > +#define to_dw9714_vcm(_ctrl) \ > > + container_of(_ctrl->handler, struct dw9714_device, ctrls_vcm) > > + > > +static int dw9714_i2c_write(struct i2c_client *client, u16 data) { > > + const int num_msg = 1; > > + int ret; > > + u16 val = cpu_to_be16(data); > > + struct i2c_msg msg = { > > + .addr = client->addr, > > + .flags = 0, > > + .len = sizeof(val), > > + .buf = (u8 *) &val, > > + }; > > + > > + ret = i2c_transfer(client->adapter, &msg, num_msg); > > + > > + /*One retry */ > > + if (ret != num_msg) > > + ret = i2c_transfer(client->adapter, &msg, num_msg); > > + > > + if (ret != num_msg) { > > + dev_err(&client->dev, "I2C write fail fail\n"); > > + return -EIO; > > + } else { > > No need for the 'else' here, since the 'if' already returns. Ack I also removed the redundant " fail" in the dev_err() message. > > > + return 0; > > + } > > +} > > + > > +static int dw9714_t_focus_vcm(struct dw9714_device *dw9714_dev, u16 > > +val) { > > + struct i2c_client *client = dw9714_dev->client; > > + int ret = -EINVAL; > > + > > + dev_dbg(&client->dev, "Setting new value VCM: %d\n", val); > > + dw9714_dev->current_val = val; > > + > > + ret = dw9714_i2c_write(client, DW9714_VAL(val, > DW9714_DEFAULT_S)); > > + return ret; > > Just do return dw9714_i2c_write(client, DW9714_VAL(val, > DW9714_DEFAULT_S)); > > Thus dropping the 'ret' variable. Ack > > > +} > > + > > +static int dw9714_set_ctrl(struct v4l2_ctrl *ctrl) { > > + struct dw9714_device *dev_vcm = to_dw9714_vcm(ctrl); > > + > > + if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE) > > + return dw9714_t_focus_vcm(dev_vcm, ctrl->val); > > Personally I would merge the dw9714_t_focus_vcm in here. And probably use a > switch instead of an if. Up to you, though. With just one ctrl->id, dw9714_set_ctrl() looks to be more readable with the if and dw9714_t_focus_vcm() call. When more ids are added, merging of dw9714_t_focus_vcm() and switch statement becomes more apt. So, for now, I am leaving it as such. > > > + else > > No need for 'else' Ack > > > + return -EINVAL; > > +} > > + > > +static const struct v4l2_ctrl_ops dw9714_vcm_ctrl_ops = { > > + .s_ctrl = dw9714_set_ctrl, > > +}; > > + > > +static int dw9714_init_controls(struct dw9714_device *dev_vcm) { > > + struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm; > > + const struct v4l2_ctrl_ops *ops = &dw9714_vcm_ctrl_ops; > > + struct i2c_client *client = dev_vcm->client; > > + > > + v4l2_ctrl_handler_init(hdl, 1); > > + > > + v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE, > > + 0, DW9714_MAX_FOCUS_POS, 1, 0); > > + > > + if (hdl->error) > > + dev_err(&client->dev, "dw9714_init_controls fail\n"); > > + dev_vcm->sd.ctrl_handler = hdl; > > + return hdl->error; > > +} > > + > > +static void dw9714_subdev_cleanup(struct dw9714_device *dw9714_dev) { > > + v4l2_ctrl_handler_free(&dw9714_dev->ctrls_vcm); > > + v4l2_async_unregister_subdev(&dw9714_dev->sd); > > + v4l2_device_unregister_subdev(&dw9714_dev->sd); > > + media_entity_cleanup(&dw9714_dev->sd.entity); > > +} > > + > > +static int dw9714_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh > > +*fh) { > > + struct dw9714_device *dw9714_dev = container_of(sd, > > + struct > dw9714_device, > > + sd); > > + struct device *dev = &dw9714_dev->client->dev; > > + int rval; > > + > > + rval = pm_runtime_get_sync(dev); > > + dev_dbg(dev, "%s rval = %d\n", __func__, rval); > > The error is propagated to userspace anyway as errno, so do you really need a > dev_dbg here? Ack I removed the dev_dbg message. I also got rid of rval, by just doing ret pm_runtime_get_sync(dev) > > > + > > + return rval; > > +} > > + > > +static int dw9714_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh > > +*fh) { > > + struct dw9714_device *dw9714_dev = container_of(sd, > > + struct > dw9714_device, > > + sd); > > + struct device *dev = &dw9714_dev->client->dev; > > + > > + dev_dbg(dev, "%s\n", __func__); > > Seems useless here as well. Ack > > > + pm_runtime_put(dev); > > + > > + return 0; > > +} > > + > > +static const struct v4l2_subdev_internal_ops dw9714_int_ops = { > > + .open = dw9714_open, > > + .close = dw9714_close, > > +}; > > + > > +static const struct v4l2_subdev_ops dw9714_ops = { }; > > + > > +static int dw9714_probe(struct i2c_client *client, > > + const struct i2c_device_id *devid) { > > + struct dw9714_device *dw9714_dev; > > + int rval; > > + > > + dw9714_dev = devm_kzalloc(&client->dev, sizeof(*dw9714_dev), > > + GFP_KERNEL); > > + > > + if (dw9714_dev == NULL) > > + return -ENOMEM; > > + > > + dw9714_dev->client = client; > > + > > + v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops); > > + dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; > > + dw9714_dev->sd.internal_ops = &dw9714_int_ops; > > + > > + snprintf(dw9714_dev->sd.name, > > + sizeof(dw9714_dev->sd.name), > > + DW9714_NAME " %d-%4.4x", i2c_adapter_id(client- > >adapter), > > + client->addr); > > v4l2_i2c_subdev_init() already fills in the sd.name, so this can be dropped. Ack > > > + > > + rval = dw9714_init_controls(dw9714_dev); > > + if (rval) > > + goto err_cleanup; > > + > > + rval = media_entity_pads_init(&dw9714_dev->sd.entity, 0, NULL); > > + if (rval < 0) > > + goto err_cleanup; > > + > > + dw9714_dev->sd.entity.function = MEDIA_ENT_F_LENS; > > + > > + rval = v4l2_async_register_subdev(&dw9714_dev->sd); > > + if (rval < 0) > > + goto err_cleanup; > > + > > + pm_runtime_enable(&client->dev); > > + > > + return 0; > > + > > +err_cleanup: > > + dw9714_subdev_cleanup(dw9714_dev); > > + dev_err(&client->dev, "Probe failed: %d\n", rval); > > + return rval; > > +} > > + > > +static int dw9714_remove(struct i2c_client *client) { > > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > > + struct dw9714_device *dw9714_dev = container_of(sd, > > + struct > dw9714_device, > > + sd); > > + > > + pm_runtime_disable(&client->dev); > > + dw9714_subdev_cleanup(dw9714_dev); > > + > > + return 0; > > +} > > + > > +#ifdef CONFIG_PM > > + > > +static int dw9714_runtime_suspend(struct device *dev) { > > + return 0; > > +} > > + > > +static int dw9714_runtime_resume(struct device *dev) { > > + return 0; > > +} > > + > > +/* This function sets the vcm position, so it consumes least current > > +*/ static int dw9714_suspend(struct device *dev) { > > + struct i2c_client *client = to_i2c_client(dev); > > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > > + struct dw9714_device *dw9714_dev = container_of(sd, > > + struct > dw9714_device, > > + sd); > > + int ret, val; > > + > > + dev_dbg(dev, "%s\n", __func__); > > + > > + for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS - 1); > > + val >= 0; val -= DW9714_CTRL_STEPS) { > > + ret = dw9714_i2c_write(client, > > + DW9714_VAL((u16) val, > DW9714_DEFAULT_S)); > > + if (ret) > > + dev_err(dev, "%s I2C failure: %d", __func__, ret); > > + usleep_range(DW9714_CTRL_DELAY_US, > DW9714_CTRL_DELAY_US + 10); > > + } > > + return 0; > > +} > > + > > +/* > > + * This function sets the vcm position, so the focus position is set > > + * closer to the camera > > + */ > > +static int dw9714_resume(struct device *dev) { > > + struct i2c_client *client = to_i2c_client(dev); > > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > > + struct dw9714_device *dw9714_dev = container_of(sd, > > + struct > dw9714_device, > > + sd); > > + int ret, val; > > + > > + dev_dbg(dev, "%s\n", __func__); > > + > > + for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS; > > + val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1; > > + val += DW9714_CTRL_STEPS) { > > + ret = dw9714_i2c_write(client, > > + DW9714_VAL((u16) val, > DW9714_DEFAULT_S)); > > + if (ret) > > + dev_err(dev, "%s I2C failure: %d", __func__, ret); > > + usleep_range(DW9714_CTRL_DELAY_US, > DW9714_CTRL_DELAY_US + 10); > > + } > > + > > + /* restore v4l2 control values */ > > + ret = v4l2_ctrl_handler_setup(&dw9714_dev->ctrls_vcm); > > + dev_dbg(dev, "%s ret = %d\n", __func__, ret); > > + return ret; > > +} > > + > > +#else > > + > > +#define dw9714_suspend NULL > > +#define dw9714_resume NULL > > +#define dw9714_runtime_suspend NULL > > +#define dw9714_runtime_resume NULL > > + > > +#endif /* CONFIG_PM */ > > + > > +#ifdef CONFIG_ACPI > > +static const struct acpi_device_id dw9714_acpi_match[] = { > > + {"DW9714", 0}, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(acpi, dw9714_acpi_match); #endif > > + > > +static const struct i2c_device_id dw9714_id_table[] = { > > + {DW9714_NAME, 0}, > > + {} > > +}; > > + > > +MODULE_DEVICE_TABLE(i2c, dw9714_id_table); > > + > > +static const struct dev_pm_ops dw9714_pm_ops = { > > + .suspend = dw9714_suspend, > > + .resume = dw9714_resume, > > + .runtime_suspend = dw9714_runtime_suspend, > > + .runtime_resume = dw9714_runtime_resume, }; > > + > > +static struct i2c_driver dw9714_i2c_driver = { > > + .driver = { > > + .name = DW9714_NAME, > > + .pm = &dw9714_pm_ops, > > +#ifdef CONFIG_ACPI > > + .acpi_match_table = ACPI_PTR(dw9714_acpi_match), #endif > > + }, > > + .probe = dw9714_probe, > > + .remove = dw9714_remove, > > + .id_table = dw9714_id_table, > > +}; > > + > > +module_i2c_driver(dw9714_i2c_driver); > > + > > +MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@xxxxxxxxx>"); > > +MODULE_AUTHOR("Jian Xu Zheng <jian.xu.zheng@xxxxxxxxx>"); > > +MODULE_AUTHOR("Yuning Pu <yuning.pu@xxxxxxxxx>"); > > +MODULE_AUTHOR("Jouni Ukkonen <jouni.ukkonen@xxxxxxxxx>"); > > +MODULE_AUTHOR("Tommi Franttila <tommi.franttila@xxxxxxxxx>"); > > +MODULE_DESCRIPTION("DW9714 VCM driver"); MODULE_LICENSE("GPL"); > > > > Regards, > > Hans
