Hi Sakari,
> -----Original Message-----
> From: Sakari Ailus [mailto:[email protected]]
> Sent: Thursday, May 11, 2017 12:41 AM
> To: Mani, Rajmohan <[email protected]>
> Cc: [email protected]; [email protected]; [email protected];
> [email protected]
> Subject: Re: [PATCH v4] dw9714: Initial driver for dw9714 VCM
>
> Hi Rajmohan,
>
> A few minor comments below.
>
> On Wed, May 10, 2017 at 10:00:20PM -0700, Rajmohan Mani wrote:
> > 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 <[email protected]>
> > ---
> > Changes in v4:
> > - Addressed review comments from Tomasz Changes in v3:
> > - Addressed most of the review comments from Sakari
> > on v1 of this patch
> > Changes in v2:
> > - Addressed review comments from Hans Verkuil
> > - Fixed a debug message typo
> > - Got rid of a return variable
> > ---
> > drivers/media/i2c/Kconfig | 9 ++
> > drivers/media/i2c/Makefile | 1 +
> > drivers/media/i2c/dw9714.c | 332
> > +++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 342 insertions(+)
> > create mode 100644 drivers/media/i2c/dw9714.c
> >
> > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > index fd181c9..516e2f2 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 &&
> VIDEO_V4L2_SUBDEV_API
> > + ---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..fefd5d2
> > --- /dev/null
> > +++ b/drivers/media/i2c/dw9714.c
> > @@ -0,0 +1,332 @@
> > +/*
> > + * 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
> > +/*
> > + * 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 DW9714_CTRL_STEPS 16
> > +#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;
> > +};
> > +
> > +static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl
> > +*ctrl) {
> > + return container_of(ctrl->handler, struct dw9714_device, ctrls_vcm);
> > +}
> > +
> > +static int dw9714_i2c_write(struct i2c_client *client, u16 data) {
> > + int ret;
> > + u16 val = cpu_to_be16(data);
> > + const int num_bytes = sizeof(val);
> > +
> > + ret = i2c_master_send(client, (const char *) &val, sizeof(val));
> > +
> > + /*One retry */
> > + if (ret != num_bytes)
> > + ret = i2c_master_send(client, (const char *) &val, sizeof(val));
> > +
> > + if (ret != num_bytes) {
>
> Use sizeof(val) here and three linees above and you can remove num_bytes.
>
Ack
> > + dev_err(&client->dev, "I2C write fail\n");
> > + return -EIO;
> > + }
> > + return 0;
> > +}
> > +
> > +static int dw9714_t_focus_vcm(struct dw9714_device *dw9714_dev, u16
> > +val) {
> > + struct i2c_client *client = dw9714_dev->client;
> > +
> > + dw9714_dev->current_val = val;
> > +
> > + return dw9714_i2c_write(client, DW9714_VAL(val,
> DW9714_DEFAULT_S));
> > +}
> > +
> > +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);
> > +
> > + 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,
> DW9714_CTRL_STEPS, 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_async_unregister_subdev(&dw9714_dev->sd);
> > + v4l2_device_unregister_subdev(&dw9714_dev->sd);
> > + v4l2_ctrl_handler_free(&dw9714_dev->ctrls_vcm);
> > + 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);
> > + if (rval >= 0)
> > + return 0;
> > +
> > + pm_runtime_put(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;
> > +
> > + 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;
> > +
> > + 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
> > +
> > +/*
> > + * This function sets the vcm position, so it consumes least current
> > + * The lens position is gradually moved in units of
> > +DW9714_CTRL_STEPS,
> > + * to make the movements smoothly.
> > + */
> > +static int dw9714_vcm_suspend(struct device *dev)
>
> static int __maybe_unused
>
> > +{
> > + 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);
>
> Could you add an inline function for converting v4l2_subdev to
> dw9714_device? It's done in quite a few places.
>
Ack
> > + int ret, val;
> > +
> > + 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 to the value set by the user
> > + * through v4l2_ctrl_ops s_ctrl handler
> > + * The lens position is gradually moved in units of
> > +DW9714_CTRL_STEPS,
> > + * to make the movements smoothly.
> > + */
> > +static int dw9714_vcm_resume(struct device *dev)
>
> static int __maybe_unused
>
Ack
> > +{
> > + 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;
> > +
> > + 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);
> > + return ret;
> > +}
> > +
> > +static int dw9714_runtime_suspend(struct device *dev) {
> > + return dw9714_vcm_suspend(dev);
>
> You can remove the four callbacks and use dw9714_vcm_{suspend,resume}
> directly.
>
Ack
> > +}
> > +
> > +static int dw9714_runtime_resume(struct device *dev) {
> > + return dw9714_vcm_resume(dev);
> > +}
> > +
> > +static int dw9714_suspend(struct device *dev) {
> > + return dw9714_vcm_suspend(dev);
> > +}
> > +
> > +static int dw9714_resume(struct device *dev) {
> > + return dw9714_vcm_resume(dev);
> > +}
> > +
> > +#else
>
> And please remove the #ifdefs. They're not needed here.
>
Ack
> > +
> > +#define dw9714_vcm_suspend NULL
> > +#define dw9714_vcm_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 = {
> > + SET_SYSTEM_SLEEP_PM_OPS(dw9714_suspend, dw9714_resume)
> > + SET_RUNTIME_PM_OPS(dw9714_runtime_suspend,
> dw9714_runtime_resume,
> > +NULL) };
> > +
> > +static struct i2c_driver dw9714_i2c_driver = {
> > + .driver = {
> > + .name = DW9714_NAME,
> > + .pm = &dw9714_pm_ops,
> > + .acpi_match_table = ACPI_PTR(dw9714_acpi_match),
> > + },
> > + .probe = dw9714_probe,
> > + .remove = dw9714_remove,
> > + .id_table = dw9714_id_table,
> > +};
> > +
> > +module_i2c_driver(dw9714_i2c_driver);
> > +
> > +MODULE_AUTHOR("Tianshu Qiu <[email protected]>");
> > +MODULE_AUTHOR("Jian Xu Zheng <[email protected]>");
> > +MODULE_AUTHOR("Yuning Pu <[email protected]>");
> > +MODULE_AUTHOR("Jouni Ukkonen <[email protected]>");
> > +MODULE_AUTHOR("Tommi Franttila <[email protected]>");
> > +MODULE_DESCRIPTION("DW9714 VCM driver"); MODULE_LICENSE("GPL");
>
> --
> Regards,
>
> Sakari Ailus
> e-mail: [email protected] XMPP: [email protected]
