[PATCH v5] dw9714: Initial driver for dw9714 VCM

[PATCH v5] dw9714: Initial driver for dw9714 VCM

[Rajmohan Mani]

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@intel.com>
---
Changes in v5:
	- Addressed review comments from Tomasz, Sakari and Sylwester on v4
	of this patch
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 | 292 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 302 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..22c84de
--- /dev/null
+++ b/drivers/media/i2c/dw9714.c
@@ -0,0 +1,292 @@
+/*
+ * 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) ((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 inline struct dw9714_device *sd_to_dw9714_vcm(struct v4l2_subdev *subdev)
+{
+	return container_of(subdev, struct dw9714_device, sd);
+}
+
+static int dw9714_i2c_write(struct i2c_client *client, u16 data)
+{
+	int ret;
+	u16 val = cpu_to_be16(data);
+
+	ret = i2c_master_send(client, (const char *)&val, sizeof(val));
+	if (ret != sizeof(val)) {
+		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 = sd_to_dw9714_vcm(sd);
+	struct device *dev = &dw9714_dev->client->dev;
+	int rval;
+
+	rval = pm_runtime_get_sync(dev);
+	if (rval < 0) {
+		pm_runtime_put_noidle(dev);
+		return rval;
+	}
+
+	return 0;
+}
+
+static int dw9714_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(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 = sd_to_dw9714_vcm(sd);
+
+	pm_runtime_disable(&client->dev);
+	dw9714_subdev_cleanup(dw9714_dev);
+
+	return 0;
+}
+
+/*
+ * 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 __maybe_unused dw9714_vcm_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 = sd_to_dw9714_vcm(sd);
+	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(val, DW9714_DEFAULT_S));
+		if (ret)
+			dev_err_once(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  __maybe_unused dw9714_vcm_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 = sd_to_dw9714_vcm(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(val, DW9714_DEFAULT_S));
+		if (ret)
+			dev_err_ratelimited(dev, "%s I2C failure: %d",
+						__func__, ret);
+		usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
+	}
+
+	return 0;
+}
+
+#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_vcm_suspend, dw9714_vcm_resume)
+	SET_RUNTIME_PM_OPS(dw9714_vcm_suspend, dw9714_vcm_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 <tian.shu.qiu@intel.com>");
+MODULE_AUTHOR("Jian Xu Zheng <jian.xu.zheng@intel.com>");
+MODULE_AUTHOR("Yuning Pu <yuning.pu@intel.com>");
+MODULE_AUTHOR("Jouni Ukkonen <jouni.ukkonen@intel.com>");
+MODULE_AUTHOR("Tommi Franttila <tommi.franttila@intel.com>");
+MODULE_DESCRIPTION("DW9714 VCM driver");
+MODULE_LICENSE("GPL");
-- 
1.9.1

Re: [PATCH v5] dw9714: Initial driver for dw9714 VCM

[Sakari Ailus]

Hi Rajmohan,

Thankd for the update. A few more comments I missed earlier.

On Thu, May 25, 2017 at 06:50:35PM -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 <rajmohan.mani@intel.com>
> ---
> Changes in v5:
> 	- Addressed review comments from Tomasz, Sakari and Sylwester on v4
> 	of this patch
> 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 | 292 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 302 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

This would be better split on two lines.

> +	---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..22c84de
> --- /dev/null
> +++ b/drivers/media/i2c/dw9714.c
> @@ -0,0 +1,292 @@
> +/*
> + * 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) ((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 inline struct dw9714_device *sd_to_dw9714_vcm(struct v4l2_subdev *subdev)
> +{
> +	return container_of(subdev, struct dw9714_device, sd);
> +}
> +
> +static int dw9714_i2c_write(struct i2c_client *client, u16 data)
> +{
> +	int ret;
> +	u16 val = cpu_to_be16(data);
> +
> +	ret = i2c_master_send(client, (const char *)&val, sizeof(val));
> +	if (ret != sizeof(val)) {
> +		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)

It'd be nicer to arrange dw9714_init_controls() and dw9714_subdev_cleanup()
that are both related to probe() and remove() closer to the functions that
call them.

> +{
> +	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_device_unregister_subdev() is extra; v4l2_async_unregiste_subdev()
already calls it.

> +	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 = sd_to_dw9714_vcm(sd);
> +	struct device *dev = &dw9714_dev->client->dev;
> +	int rval;
> +
> +	rval = pm_runtime_get_sync(dev);
> +	if (rval < 0) {
> +		pm_runtime_put_noidle(dev);
> +		return rval;
> +	}
> +
> +	return 0;
> +}
> +
> +static int dw9714_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> +	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(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);
> +

No need for a newline here.

> +	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 = sd_to_dw9714_vcm(sd);
> +
> +	pm_runtime_disable(&client->dev);
> +	dw9714_subdev_cleanup(dw9714_dev);
> +
> +	return 0;
> +}
> +
> +/*
> + * 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 __maybe_unused dw9714_vcm_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 = sd_to_dw9714_vcm(sd);
> +	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(val, DW9714_DEFAULT_S));
> +		if (ret)
> +			dev_err_once(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  __maybe_unused dw9714_vcm_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 = sd_to_dw9714_vcm(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(val, DW9714_DEFAULT_S));
> +		if (ret)
> +			dev_err_ratelimited(dev, "%s I2C failure: %d",
> +						__func__, ret);
> +		usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
> +	}
> +
> +	return 0;
> +}
> +
> +#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_vcm_suspend, dw9714_vcm_resume)
> +	SET_RUNTIME_PM_OPS(dw9714_vcm_suspend, dw9714_vcm_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 <tian.shu.qiu@intel.com>");
> +MODULE_AUTHOR("Jian Xu Zheng <jian.xu.zheng@intel.com>");
> +MODULE_AUTHOR("Yuning Pu <yuning.pu@intel.com>");
> +MODULE_AUTHOR("Jouni Ukkonen <jouni.ukkonen@intel.com>");
> +MODULE_AUTHOR("Tommi Franttila <tommi.franttila@intel.com>");
> +MODULE_DESCRIPTION("DW9714 VCM driver");
> +MODULE_LICENSE("GPL");

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk

RE: [PATCH v5] dw9714: Initial driver for dw9714 VCM

[Mani, Rajmohan]

Hi Sakari,

> -----Original Message-----
> From: Sakari Ailus [mailto:sakari.ailus@iki.fi]
> Sent: Friday, May 26, 2017 1:20 AM
> To: Mani, Rajmohan <rajmohan.mani@intel.com>
> Cc: linux-media@vger.kernel.org; mchehab@kernel.org; hverkuil@xs4all.nl;
> tfiga@chromium.org; s.nawrocki@samsung.com; Toivonen, Tuukka
> <tuukka.toivonen@intel.com>
> Subject: Re: [PATCH v5] dw9714: Initial driver for dw9714 VCM
> 
> Hi Rajmohan,
> 
> Thankd for the update. A few more comments I missed earlier.
> 
> On Thu, May 25, 2017 at 06:50:35PM -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 <rajmohan.mani@intel.com>
> > ---
> > Changes in v5:
> > 	- Addressed review comments from Tomasz, Sakari and Sylwester on v4
> > 	of this patch
> > 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 | 292
> > +++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 302 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
> 
> This would be better split on two lines.
> 

Ack

> > +	---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..22c84de
> > --- /dev/null
> > +++ b/drivers/media/i2c/dw9714.c
> > @@ -0,0 +1,292 @@
> > +/*
> > + * 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) ((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 inline struct dw9714_device *sd_to_dw9714_vcm(struct
> > +v4l2_subdev *subdev) {
> > +	return container_of(subdev, struct dw9714_device, sd); }
> > +
> > +static int dw9714_i2c_write(struct i2c_client *client, u16 data) {
> > +	int ret;
> > +	u16 val = cpu_to_be16(data);
> > +
> > +	ret = i2c_master_send(client, (const char *)&val, sizeof(val));
> > +	if (ret != sizeof(val)) {
> > +		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)
> 
> It'd be nicer to arrange dw9714_init_controls() and dw9714_subdev_cleanup()
> that are both related to probe() and remove() closer to the functions that call
> them.
> 

Ack

> > +{
> > +	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_device_unregister_subdev() is extra; v4l2_async_unregiste_subdev()
> already calls it.
> 

Ack

> > +	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 = sd_to_dw9714_vcm(sd);
> > +	struct device *dev = &dw9714_dev->client->dev;
> > +	int rval;
> > +
> > +	rval = pm_runtime_get_sync(dev);
> > +	if (rval < 0) {
> > +		pm_runtime_put_noidle(dev);
> > +		return rval;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int dw9714_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh
> > +*fh) {
> > +	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(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);
> > +
> 
> No need for a newline here.
> 

Ack

> > +	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 = sd_to_dw9714_vcm(sd);
> > +
> > +	pm_runtime_disable(&client->dev);
> > +	dw9714_subdev_cleanup(dw9714_dev);
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * 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 __maybe_unused dw9714_vcm_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 = sd_to_dw9714_vcm(sd);
> > +	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(val, DW9714_DEFAULT_S));
> > +		if (ret)
> > +			dev_err_once(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  __maybe_unused dw9714_vcm_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 = sd_to_dw9714_vcm(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(val, DW9714_DEFAULT_S));
> > +		if (ret)
> > +			dev_err_ratelimited(dev, "%s I2C failure: %d",
> > +						__func__, ret);
> > +		usleep_range(DW9714_CTRL_DELAY_US,
> DW9714_CTRL_DELAY_US + 10);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +#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_vcm_suspend,
> dw9714_vcm_resume)
> > +	SET_RUNTIME_PM_OPS(dw9714_vcm_suspend,
> dw9714_vcm_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 <tian.shu.qiu@intel.com>");
> > +MODULE_AUTHOR("Jian Xu Zheng <jian.xu.zheng@intel.com>");
> > +MODULE_AUTHOR("Yuning Pu <yuning.pu@intel.com>");
> > +MODULE_AUTHOR("Jouni Ukkonen <jouni.ukkonen@intel.com>");
> > +MODULE_AUTHOR("Tommi Franttila <tommi.franttila@intel.com>");
> > +MODULE_DESCRIPTION("DW9714 VCM driver"); MODULE_LICENSE("GPL");
> 
> --
> Kind regards,
> 
> Sakari Ailus
> e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk