Re: [PATCH 2/2] media: i2c: dw9768: Add DW9768 VCM driver

[Dongchun Zhu <dongchun.zhu@mediatek.com>]

Hi Bingbu,

On Wed, 2019-07-24 at 11:16 +0800, Bingbu Cao wrote:
> On 7/8/19 6:06 PM, dongchun.zhu@mediatek.com wrote:
> > From: Dongchun Zhu <dongchun.zhu@mediatek.com>
> >
> > This patch adds a V4L2 sub-device driver for DW9768 lens voice coil,
> > and provides control to set the desired focus.
> >
> > The DW9807 is a 10 bit DAC from Dongwoon, designed for linear control
> > of voice coil motor.
> >
> > Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> > ---
> >  MAINTAINERS                |   1 +
> >  drivers/media/i2c/Kconfig  |  10 +
> >  drivers/media/i2c/Makefile |   1 +
> >  drivers/media/i2c/dw9768.c | 458
> > +++++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 470 insertions(+)
> >  create mode 100644 drivers/media/i2c/dw9768.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index 8f6ac93..17152d7 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -4877,6 +4877,7 @@ M:Dongchun Zhu <dongchun.zhu@mediatek.com>
> >  L:linux-media@vger.kernel.org
> >  T:git git://linuxtv.org/media_tree.git
> >  S:Maintained
> > +F:drivers/media/i2c/dw9768.c
> >  F:Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.txt
> >
> >  DONGWOON DW9807 LENS VOICE COIL DRIVER diff --git
> > a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig index
> > 7793358..8ff6c95 100644
> > --- a/drivers/media/i2c/Kconfig
> > +++ b/drivers/media/i2c/Kconfig
> > @@ -1014,6 +1014,16 @@ config VIDEO_DW9714
> >    capability. This is designed for linear control of
> >    voice coil motors, controlled via I2C serial interface.
> >
> > +config VIDEO_DW9768
> > +tristate "DW9768 lens voice coil support"
> > +depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
> > +depends on VIDEO_V4L2_SUBDEV_API
> > +help
> > +  This is a driver for the DW9768 camera lens voice coil.
> > +  DW9768 is a 10 bit DAC with 100mA output current sink
> > +  capability. This is designed for linear control of
> > +  voice coil motors, controlled via I2C serial interface.
> > +
> >  config VIDEO_DW9807_VCM
> >  tristate "DW9807 lens voice coil support"
> >  depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER diff --git
> > a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile index
> > d8ad9da..944fbf6 100644
> > --- a/drivers/media/i2c/Makefile
> > +++ b/drivers/media/i2c/Makefile
> > @@ -24,6 +24,7 @@ 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-$(CONFIG_VIDEO_DW9768)  += dw9768.o
> >  obj-$(CONFIG_VIDEO_DW9807_VCM)  += dw9807-vcm.o
> >  obj-$(CONFIG_VIDEO_ADV7170) += adv7170.o
> >  obj-$(CONFIG_VIDEO_ADV7175) += adv7175.o diff --git
> > a/drivers/media/i2c/dw9768.c b/drivers/media/i2c/dw9768.c new file
> > mode 100644 index 0000000..f5b5591
> > --- /dev/null
> > +++ b/drivers/media/i2c/dw9768.c
> > @@ -0,0 +1,458 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2018 MediaTek Inc.
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/regulator/consumer.h> #include <linux/pm_runtime.h>
> > +#include <media/v4l2-ctrls.h> #include <media/v4l2-device.h> #include
> > +<media/v4l2-subdev.h>
> > +
> > +#define DW9768_VOLTAGE_ANALOG2800000
> > +#define DW9768_NAME"dw9768"
> > +#define DW9768_MAX_FOCUS_POS1023
> > +/*
> > + * This sets the minimum granularity for the focus positions.
> > + * A value of 1 gives maximum accuracy for a desired focus position
> > +*/
> > +#define DW9768_FOCUS_STEPS1
> > +
> > +#define DW9768_CTRL_DELAY_US5000
> > +
> > +#define DW9768_REG_DAC_MSB0x03
> > +#define DW9768_REG_DAC_LSB0x04
> > +#define DW9768_REG_NULL0xff
> > +
> > +#define DW9768_DAC_SHIFT8
> > +
> > +#define DW9768_REG_VALUE_16BIT2
> > +
> > +/* dw9768 device structure */
> > +struct dw9768_device {
> > +struct v4l2_ctrl_handler ctrls;
> > +struct v4l2_subdev sd;
> > +struct regulator *analog_regulator;
> > +/*
> > + * Serialize control access, get/set format, get selection
> > + * and start streaming.
> > + */
> > +struct mutex power_lock;
> > +
> > +int power_count;
> > +bool standby;
> > +};
> > +
> > +static inline struct dw9768_device *to_dw9768_vcm(struct v4l2_ctrl
> > +*ctrl) {
> > +return container_of(ctrl->handler, struct dw9768_device, ctrls); }
> > +
> > +static inline struct dw9768_device *sd_to_dw9768_vcm(struct
> > +v4l2_subdev *subdev) {
> > +return container_of(subdev, struct dw9768_device, sd); }
> > +
> > +static int dw9768_i2c_write(struct dw9768_device *dw9768_dev, u8 *data,
> > +    int size)
> > +{
> > +struct i2c_client *client = v4l2_get_subdevdata(&dw9768_dev->sd);
> > +struct i2c_msg msg;
> > +u8 *w_buf = NULL;
> > +u8 retry_cnt = 3;
> > +int ret;
> > +
> > +if (!client->adapter)
> > +return -ENODEV;
> > +
> > +if (size != 1 && size != 2)
> > +return -EINVAL;
> > +
> > +memset(&msg, 0, sizeof(struct i2c_msg));
> > +
> > +w_buf = kzalloc(size, GFP_KERNEL);
> > +if (!w_buf)
> > +return -1;
> return -ENOMEM;

Fixed in next release.

> > +
> > +memcpy(w_buf, data, size);
> > +
> > +msg.addr  = client->addr;
> > +msg.flags = 0;
> > +msg.len   = size;
> > +msg.buf   = w_buf;
> > +
> > +do {
> > +ret = i2c_transfer(client->adapter, &msg, 1);
> > +if (ret != 1)
> > +dev_err(&client->dev, "write fail, ret:%d, retry:%d\n",
> > +ret, retry_cnt);
> > +else
> > +break;
> > +retry_cnt--;
> > +} while (retry_cnt != 0);
> > +
> > +if (retry_cnt == 0){
> > +dev_err(&client->dev, "i2c write fail(%d)\n", ret);
> > +return -EIO;
> > +}
> > +
> > +kfree(w_buf);
> > +
> > +return 0;
> > +}
> > +
> > +static int dw9768_release(struct dw9768_device *dw9768_dev) {
> > +unsigned char i;
> > +int ret;
> > +
> > +char puSendCmdArray[4][2] = {
> > +{0x02, 0x00}, {DW9768_REG_NULL, DW9768_REG_NULL},
> > +{0x01, 0x00}, {DW9768_REG_NULL, DW9768_REG_NULL},
> > +};
> > +
> > +for (i = 0; i < (sizeof(puSendCmdArray) / sizeof(char)) /
> > +     (sizeof(puSendCmdArray[0]) / sizeof(char)); i++) {> +if (puSendCmdArray[i][0] != DW9768_REG_NULL) {
> > +ret = dw9768_i2c_write(dw9768_dev, puSendCmdArray[i],
> > +       DW9768_REG_VALUE_16BIT);
> > +if (ret < 0)
> > +return ret;
> > +} else {
> > +usleep_range(DW9768_CTRL_DELAY_US,
> > +     DW9768_CTRL_DELAY_US + 100);
> > +}
> > +}
> Can we make this block more simple?  I think the loop is not necessary.

Fixed in next release.

> > +
> > +return 0;
> > +}
> > +
> > +static int dw9768_init(struct dw9768_device *dw9768_dev) {
> > +unsigned char i;
> > +int ret;
> > +
> > +char puSendCmdArray[5][2] = {
> > +{0x02, 0x02}, {DW9768_REG_NULL, DW9768_REG_NULL},
> > +{0x06, 0x41}, {0x07, 0x39}, {DW9768_REG_NULL, DW9768_REG_NULL},
> > +};
> > +
> > +for (i = 0; i < (sizeof(puSendCmdArray) / sizeof(char)) /
> > +     (sizeof(puSendCmdArray[0]) / sizeof(char)); i++) {
> > +if (puSendCmdArray[i][0] != DW9768_REG_NULL) {
> > +ret = dw9768_i2c_write(dw9768_dev, puSendCmdArray[i],
> > +       DW9768_REG_VALUE_16BIT);
> > +if (ret < 0)
> > +return ret;
> > +} else {
> > +usleep_range(DW9768_CTRL_DELAY_US,
> > +     DW9768_CTRL_DELAY_US + 100);
> > +}
> > +}
> Ditto.

Fixed in next release.

> > +
> > +return 0;
> > +}
> > +
> > +/*
> > + * Power handling
> > + */
> > +static int dw9768_power_off(struct dw9768_device *dw9768_dev, bool
> > +standby) {
> > +struct i2c_client *client = v4l2_get_subdevdata(&dw9768_dev->sd);
> > +int ret;
> > +
> > +/*
> > + * Go to standby first as real power off my be denied by the
> > +hardware
> typo? "may be denied"

Sorry for the typo. Fixed in next release.

> > + * (single power line control for both dw9768_dev and sensor).
> > + */
> > +if (standby) {
> > +dw9768_dev->standby = true;
> > +ret = dw9768_release(dw9768_dev);
> > +if (ret)
> > +dev_err(&client->dev, "dw9768_release failed!\n");
> > +}
> > +ret = regulator_disable(dw9768_dev->analog_regulator);
> > +if (ret)
> > +return ret;
> > +
> > +return 0;
> > +}
> > +
> > +static int dw9768_power_on(struct dw9768_device *dw9768_dev, bool
> > +restore) {
> > +int ret;
> > +
> > +ret = regulator_enable(dw9768_dev->analog_regulator);
> > +if (ret < 0)
> > +return ret;
> > +
> > +if (restore) {
> > +/* Restore the hardware settings. */
> > +dw9768_dev->standby = false;
> > +ret = dw9768_init(dw9768_dev);
> > +if (ret < 0)
> > +goto fail;
> > +}
> > +
> > +return 0;
> > +
> > +fail:
> > +dw9768_dev->standby = true;
> > +regulator_disable(dw9768_dev->analog_regulator);
> > +
> > +return ret;
> > +}
> > +
> > +/*
> > + * 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 dw9768_update_hw(struct dw9768_device *dw9768_dev, u16
> > +val) {
> > +unsigned char i;
> > +int ret;
> > +
> > +char puSendCmdArray[2][2] = {
> > +{DW9768_REG_DAC_MSB, (char)(val >> DW9768_DAC_SHIFT)},
> > +{DW9768_REG_DAC_LSB, (char)(val & 0xFF)},
> > +};
> > +
> > +for (i = 0; i < (sizeof(puSendCmdArray) / sizeof(char)) /
> > +     (sizeof(puSendCmdArray[0]) / sizeof(char)); i++) {
> > +ret = dw9768_i2c_write(dw9768_dev, puSendCmdArray[i],
> > +       DW9768_REG_VALUE_16BIT);
> > +if (ret)
> > +return ret;
> > +}
> ditto.

Fixed in next release.

> > +
> > +return 0;
> > +}
> > +
> > +static int dw9768_set_ctrl(struct v4l2_ctrl *ctrl) {
> > +struct dw9768_device *dw9768_dev = to_dw9768_vcm(ctrl);
> > +
> > +if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
> > +return dw9768_update_hw(dw9768_dev, ctrl->val);
> > +
> > +return 0;
> > +}
> > +
> > +static const struct v4l2_ctrl_ops dw9768_vcm_ctrl_ops = {
> > +.s_ctrl = dw9768_set_ctrl,
> > +};
> > +
> > +static int
> > +dw9768_set_power(struct v4l2_subdev *subdev, int on) {
> > +struct dw9768_device *dw9768_dev = sd_to_dw9768_vcm(subdev);
> > +int ret = 0;
> > +
> > +mutex_lock(&dw9768_dev->power_lock);
> > +
> > +/*
> > + * If the power count is modified from 0 to != 0 or from != 0 to 0,
> > + * update the power state.
> > + */
> > +if (dw9768_dev->power_count == !on) {
> > +ret = on ? dw9768_power_on(dw9768_dev, true) :
> > +dw9768_power_off(dw9768_dev, true);
> > +if (ret < 0)
> > +goto done;
> > +}
> > +
> > +/* Update the power count. */
> > +dw9768_dev->power_count += on ? 1 : -1;
> > +WARN_ON(dw9768_dev->power_count < 0);
> > +
> > +done:
> > +mutex_unlock(&dw9768_dev->power_lock);
> > +return ret;
> > +}
> > +
> > +static int dw9768_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh
> > +*fh) {
> > +return dw9768_set_power(sd, 1);
> > +}
> > +
> > +static int dw9768_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh
> > +*fh) {
> > +return dw9768_set_power(sd, 0);
> > +}
> I am a little confused about the pm control here.
> Could we use the pm generic APIs to help do this?

Fixed in next release.

> > +
> > +static const struct v4l2_subdev_internal_ops dw9768_int_ops = {
> > +.open = dw9768_open,
> > +.close = dw9768_close,
> > +};
> > +
> > +static const struct v4l2_subdev_ops dw9768_ops = { };
> > +
> > +static void dw9768_subdev_cleanup(struct dw9768_device *dw9768_dev) {
> > +v4l2_async_unregister_subdev(&dw9768_dev->sd);
> > +v4l2_ctrl_handler_free(&dw9768_dev->ctrls);
> > +media_entity_cleanup(&dw9768_dev->sd.entity);
> > +}
> > +
> > +static int dw9768_init_controls(struct dw9768_device *dw9768_dev) {
> > +struct v4l2_ctrl_handler *hdl = &dw9768_dev->ctrls;
> > +const struct v4l2_ctrl_ops *ops = &dw9768_vcm_ctrl_ops;
> > +
> > +v4l2_ctrl_handler_init(hdl, 1);
> > +
> > +v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
> > +  0, DW9768_MAX_FOCUS_POS, DW9768_FOCUS_STEPS, 0);
> > +
> > +if (hdl->error) {
> > +dev_err(dw9768_dev->sd.dev, "%s fail error: 0x%x\n",
> > +__func__, hdl->error);
> > +return hdl->error;
> > +}
> > +
> > +dw9768_dev->sd.ctrl_handler = hdl;
> > +
> > +return 0;
> > +}
> > +
> > +static int dw9768_probe(struct i2c_client *client) {
> > +struct device *dev = &client->dev;
> > +struct dw9768_device *dw9768_dev;
> > +int rval;
> > +
> > +dw9768_dev = devm_kzalloc(&client->dev, sizeof(*dw9768_dev),
> > +  GFP_KERNEL);
> > +if (!dw9768_dev)
> > +return -ENOMEM;
> > +
> > +dw9768_dev->analog_regulator = devm_regulator_get(dev, "afvdd");
> > +if (IS_ERR(dw9768_dev->analog_regulator)) {
> > +dev_err(dev, "cannot get analog regulator\n");
> > +return PTR_ERR(dw9768_dev->analog_regulator);
> > +}
> > +
> > +rval = regulator_set_voltage(dw9768_dev->analog_regulator,
> > +     DW9768_VOLTAGE_ANALOG,
> > +     DW9768_VOLTAGE_ANALOG);
> > +if (rval < 0) {
> > +dev_err(dev, "cannot set analog voltage\n");
> > +return rval;
> > +}
> > +
> > +mutex_init(&dw9768_dev->power_lock);
> > +
> > +v4l2_i2c_subdev_init(&dw9768_dev->sd, client, &dw9768_ops);
> > +dw9768_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +dw9768_dev->sd.internal_ops = &dw9768_int_ops;
> > +
> > +rval = dw9768_init_controls(dw9768_dev);
> > +if (rval)
> > +goto err_cleanup;
> > +
> > +rval = media_entity_pads_init(&dw9768_dev->sd.entity, 0, NULL);
> > +if (rval < 0)
> > +goto err_cleanup;
> > +
> > +dw9768_dev->sd.entity.function = MEDIA_ENT_F_LENS;
> > +
> > +rval = v4l2_async_register_subdev(&dw9768_dev->sd);
> > +if (rval < 0)
> > +goto err_cleanup;
> > +
> > +pm_runtime_set_active(dev);
> > +pm_runtime_enable(dev);
> > +pm_runtime_idle(dev);
> > +
> > +return 0;
> > +
> > +err_cleanup:
> > +mutex_destroy(&dw9768_dev->power_lock);
> > +dw9768_subdev_cleanup(dw9768_dev);
> > +dev_err(dev, "Probe failed: %d\n", rval);
> > +return rval;
> > +}
> > +
> > +static int dw9768_remove(struct i2c_client *client) {
> > +struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +struct dw9768_device *dw9768_dev = sd_to_dw9768_vcm(sd);
> > +
> > +pm_runtime_disable(&client->dev);
> > +dw9768_subdev_cleanup(dw9768_dev);
> > +
> > +return 0;
> > +}
> > +
> > +/*
> > + * This function sets the vcm position, so it consumes least current
> > + * The lens position is gradually moved in units of
> > +DW9768_CTRL_STEPS,
> > + * to make the movements smoothly.
> > + */
> > +static int __maybe_unused dw9768_vcm_suspend(struct device *dev) {
> > +struct i2c_client *client = to_i2c_client(dev);
> > +struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +struct dw9768_device *dw9768_dev = sd_to_dw9768_vcm(sd);
> > +
> > +if (!dw9768_dev->power_count)
> > +return 0;
> > +
> > +return dw9768_power_off(dw9768_dev, false); }
> > +
> > +/*
> > + * 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
> > +DW9768_CTRL_STEPS,
> > + * to make the movements smoothly.
> > + */
> > +static int __maybe_unused dw9768_vcm_resume(struct device *dev) {
> > +struct i2c_client *client = to_i2c_client(dev);
> > +struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +struct dw9768_device *dw9768_dev = sd_to_dw9768_vcm(sd);
> > +
> > +if (!dw9768_dev->power_count)
> > +return 0;
> > +
> > +return dw9768_power_on(dw9768_dev, true); }
> > +
> > +static const struct i2c_device_id dw9768_id_table[] = {
> > +{ DW9768_NAME, 0 },
> > +{ { 0 } }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, dw9768_id_table);
> > +
> > +static const struct of_device_id dw9768_of_table[] = {
> > +{ .compatible = "dongwoon,dw9768" },
> > +{ { 0 } }
> > +};
> > +MODULE_DEVICE_TABLE(of, dw9768_of_table);
> > +
> > +static const struct dev_pm_ops dw9768_pm_ops = {
> > +SET_SYSTEM_SLEEP_PM_OPS(dw9768_vcm_suspend, dw9768_vcm_resume)
> > +SET_RUNTIME_PM_OPS(dw9768_vcm_suspend, dw9768_vcm_resume, NULL) };
> > +
> > +static struct i2c_driver dw9768_i2c_driver = {
> > +.driver = {
> > +.name = DW9768_NAME,
> > +.pm = &dw9768_pm_ops,
> > +.of_match_table = dw9768_of_table,
> > +},
> > +.probe_new  = dw9768_probe,
> > +.remove = dw9768_remove,
> > +.id_table = dw9768_id_table,
> > +};
> > +
> > +module_i2c_driver(dw9768_i2c_driver);
> > +
> > +MODULE_AUTHOR("Dongchun Zhu <dongchun.zhu@mediatek.com>");
> > +MODULE_DESCRIPTION("DW9768 VCM driver"); MODULE_LICENSE("GPL v2");
> >
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