[PATCH v2 0/2] media: video-i2c: add Melexis MLX90640 thermal camera support

[PATCH v2 0/2] media: video-i2c: add Melexis MLX90640 thermal camera support

[Matt Ranostay]

Add initial support for Melexis line of thermal cameras. This is the first part of
processing pipeline in which the real processing is done in userspace using the
V4L2 camera data.

Dependency patchset series: https://patchwork.kernel.org/cover/10650541/

Changes from v1:

* add melexis,mlx90640.txt documentation

Matt Ranostay (2):
  media: video-i2c: check if chip struct has set_power function
  media: video-i2c: add Melexis MLX90640 thermal camera support

 .../bindings/media/i2c/melexis,mlx90640.txt   |  20 +++
 drivers/media/i2c/Kconfig                     |   1 +
 drivers/media/i2c/video-i2c.c                 | 131 +++++++++++++++++-
 3 files changed, 146 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt

-- 
2.17.1

[PATCH v2 1/2] media: video-i2c: check if chip struct has set_power function

[Matt Ranostay]

Not all future supported video chips will always have power management
support, and so it is important to check before calling set_power() is
defined.

Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
---
 drivers/media/i2c/video-i2c.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
index 981166010c9b..a64e1a725a20 100644
--- a/drivers/media/i2c/video-i2c.c
+++ b/drivers/media/i2c/video-i2c.c
@@ -736,9 +736,11 @@ static int video_i2c_probe(struct i2c_client *client,
 	video_set_drvdata(&data->vdev, data);
 	i2c_set_clientdata(client, data);
 
-	ret = data->chip->set_power(data, true);
-	if (ret)
-		goto error_unregister_device;
+	if (data->chip->set_power) {
+		ret = data->chip->set_power(data, true);
+		if (ret)
+			goto error_unregister_device;
+	}
 
 	pm_runtime_get_noresume(&client->dev);
 	pm_runtime_set_active(&client->dev);
@@ -767,7 +769,8 @@ static int video_i2c_probe(struct i2c_client *client,
 	pm_runtime_disable(&client->dev);
 	pm_runtime_set_suspended(&client->dev);
 	pm_runtime_put_noidle(&client->dev);
-	data->chip->set_power(data, false);
+	if (data->chip->set_power)
+		data->chip->set_power(data, false);
 
 error_unregister_device:
 	v4l2_device_unregister(v4l2_dev);
@@ -791,7 +794,9 @@ static int video_i2c_remove(struct i2c_client *client)
 	pm_runtime_disable(&client->dev);
 	pm_runtime_set_suspended(&client->dev);
 	pm_runtime_put_noidle(&client->dev);
-	data->chip->set_power(data, false);
+
+	if (data->chip->set_power)
+		data->chip->set_power(data, false);
 
 	video_unregister_device(&data->vdev);
 
@@ -804,6 +809,9 @@ static int video_i2c_pm_runtime_suspend(struct device *dev)
 {
 	struct video_i2c_data *data = i2c_get_clientdata(to_i2c_client(dev));
 
+	if (!data->chip->set_power)
+		return 0;
+
 	return data->chip->set_power(data, false);
 }
 
@@ -811,6 +819,9 @@ static int video_i2c_pm_runtime_resume(struct device *dev)
 {
 	struct video_i2c_data *data = i2c_get_clientdata(to_i2c_client(dev));
 
+	if (!data->chip->set_power)
+		return 0;
+
 	return data->chip->set_power(data, true);
 }
 
-- 
2.17.1

[PATCH v2 2/2] media: video-i2c: add Melexis MLX90640 thermal camera support

[Matt Ranostay]

Add initial support for MLX90640 thermal cameras which output an 32x24
greyscale pixel image along with 2 rows of coefficent data.

Because of this the data outputed is really 32x26 and needs the two rows
removed after using the coefficent information to generate processed
images in userspace.

Cc: devicetree@vger.kernel.org
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
---
 .../bindings/media/i2c/melexis,mlx90640.txt   |  20 ++++
 drivers/media/i2c/Kconfig                     |   1 +
 drivers/media/i2c/video-i2c.c                 | 110 +++++++++++++++++-
 3 files changed, 130 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt

diff --git a/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
new file mode 100644
index 000000000000..060d2b7a5893
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
@@ -0,0 +1,20 @@
+* Melexis MLX90640 FIR Sensor
+
+Melexis MLX90640 FIR sensor support which allows recording of thermal data
+with 32x24 resolution excluding 2 lines of coefficient data that is used by
+userspace to render processed frames.
+
+Required Properties:
+ - compatible : Must be "melexis,mlx90640"
+ - reg : i2c address of the device
+
+Example:
+
+	i2c0@1c22000 {
+		...
+		mlx90640@33 {
+			compatible = "melexis,mlx90640";
+			reg = <0x33>;
+		};
+		...
+	};
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 66bbbec487ec..24342f283f2a 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1097,6 +1097,7 @@ config VIDEO_I2C
 	  Enable the I2C transport video support which supports the
 	  following:
 	   * Panasonic AMG88xx Grid-Eye Sensors
+	   * Melexis MLX90640 Thermal Cameras
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called video-i2c
diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
index a64e1a725a20..d58f40334e8b 100644
--- a/drivers/media/i2c/video-i2c.c
+++ b/drivers/media/i2c/video-i2c.c
@@ -6,6 +6,7 @@
  *
  * Supported:
  * - Panasonic AMG88xx Grid-Eye Sensors
+ * - Melexis MLX90640 Thermal Cameras
  */
 
 #include <linux/delay.h>
@@ -18,6 +19,7 @@
 #include <linux/mutex.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/nvmem-provider.h>
 #include <linux/regmap.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -66,12 +68,26 @@ static const struct v4l2_frmsize_discrete amg88xx_size = {
 	.height = 8,
 };
 
+static const struct v4l2_fmtdesc mlx90640_format = {
+	.pixelformat = V4L2_PIX_FMT_Y16_BE,
+};
+
+static const struct v4l2_frmsize_discrete mlx90640_size = {
+	.width = 32,
+	.height = 26, /* 24 lines of pixel data + 2 lines of processing data */
+};
+
 static const struct regmap_config amg88xx_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = 0xff
 };
 
+static const struct regmap_config mlx90640_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 16,
+};
+
 struct video_i2c_chip {
 	/* video dimensions */
 	const struct v4l2_fmtdesc *format;
@@ -88,6 +104,7 @@ struct video_i2c_chip {
 	unsigned int bpp;
 
 	const struct regmap_config *regmap_config;
+	struct nvmem_config *nvmem_config;
 
 	/* setup function */
 	int (*setup)(struct video_i2c_data *data);
@@ -102,6 +119,22 @@ struct video_i2c_chip {
 	int (*hwmon_init)(struct video_i2c_data *data);
 };
 
+static int mlx90640_nvram_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	struct video_i2c_data *data = priv;
+
+	return regmap_bulk_read(data->regmap, 0x2400 + offset, val, bytes);
+}
+
+static struct nvmem_config mlx90640_nvram_config = {
+	.name = "mlx90640_nvram",
+	.word_size = 2,
+	.stride = 1,
+	.size = 1664,
+	.reg_read = mlx90640_nvram_read,
+};
+
 /* Power control register */
 #define AMG88XX_REG_PCTL	0x00
 #define AMG88XX_PCTL_NORMAL		0x00
@@ -122,12 +155,23 @@ struct video_i2c_chip {
 /* Temperature register */
 #define AMG88XX_REG_T01L	0x80
 
+/* Control register */
+#define MLX90640_REG_CTL1		0x800d
+#define MLX90640_REG_CTL1_MASK		0x0380
+#define MLX90640_REG_CTL1_MASK_SHIFT	7
+
 static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
 {
 	return regmap_bulk_read(data->regmap, AMG88XX_REG_T01L, buf,
 				data->chip->buffer_size);
 }
 
+static int mlx90640_xfer(struct video_i2c_data *data, char *buf)
+{
+	return regmap_bulk_read(data->regmap, 0x400, buf,
+				data->chip->buffer_size);
+}
+
 static int amg88xx_setup(struct video_i2c_data *data)
 {
 	unsigned int mask = AMG88XX_FPSC_1FPS;
@@ -141,6 +185,27 @@ static int amg88xx_setup(struct video_i2c_data *data)
 	return regmap_update_bits(data->regmap, AMG88XX_REG_FPSC, mask, val);
 }
 
+static int mlx90640_setup(struct video_i2c_data *data)
+{
+	unsigned int n, idx;
+
+	for (n = 0; n < data->chip->num_frame_intervals - 1; n++) {
+		if (data->frame_interval.numerator
+				!= data->chip->frame_intervals[n].numerator)
+			continue;
+
+		if (data->frame_interval.denominator
+				== data->chip->frame_intervals[n].denominator)
+			break;
+	}
+
+	idx = data->chip->num_frame_intervals - n - 1;
+
+	return regmap_update_bits(data->regmap, MLX90640_REG_CTL1,
+				  MLX90640_REG_CTL1_MASK,
+				  idx << MLX90640_REG_CTL1_MASK_SHIFT);
+}
+
 static int amg88xx_set_power_on(struct video_i2c_data *data)
 {
 	int ret;
@@ -274,13 +339,27 @@ static int amg88xx_hwmon_init(struct video_i2c_data *data)
 #define	amg88xx_hwmon_init	NULL
 #endif
 
-#define AMG88XX		0
+enum {
+	AMG88XX,
+	MLX90640,
+};
 
 static const struct v4l2_fract amg88xx_frame_intervals[] = {
 	{ 1, 10 },
 	{ 1, 1 },
 };
 
+static const struct v4l2_fract mlx90640_frame_intervals[] = {
+	{ 1, 64 },
+	{ 1, 32 },
+	{ 1, 16 },
+	{ 1, 8 },
+	{ 1, 4 },
+	{ 1, 2 },
+	{ 1, 1 },
+	{ 2, 1 },
+};
+
 static const struct video_i2c_chip video_i2c_chip[] = {
 	[AMG88XX] = {
 		.size		= &amg88xx_size,
@@ -295,6 +374,18 @@ static const struct video_i2c_chip video_i2c_chip[] = {
 		.set_power	= amg88xx_set_power,
 		.hwmon_init	= amg88xx_hwmon_init,
 	},
+	[MLX90640] = {
+		.size		= &mlx90640_size,
+		.format		= &mlx90640_format,
+		.frame_intervals	= mlx90640_frame_intervals,
+		.num_frame_intervals	= ARRAY_SIZE(mlx90640_frame_intervals),
+		.buffer_size	= 1664,
+		.bpp		= 16,
+		.regmap_config	= &mlx90640_regmap_config,
+		.nvmem_config	= &mlx90640_nvram_config,
+		.setup		= mlx90640_setup,
+		.xfer		= mlx90640_xfer,
+	},
 };
 
 static const struct v4l2_file_operations video_i2c_fops = {
@@ -756,6 +847,21 @@ static int video_i2c_probe(struct i2c_client *client,
 		}
 	}
 
+	if (data->chip->nvmem_config) {
+		struct nvmem_config *config = data->chip->nvmem_config;
+		struct nvmem_device *device;
+
+		config->priv = data;
+		config->dev = &client->dev;
+
+		device = devm_nvmem_register(&client->dev, config);
+
+		if (IS_ERR(device)) {
+			dev_warn(&client->dev,
+				 "failed to register nvmem device\n");
+		}
+	}
+
 	ret = video_register_device(&data->vdev, VFL_TYPE_GRABBER, -1);
 	if (ret < 0)
 		goto error_pm_disable;
@@ -834,12 +940,14 @@ static const struct dev_pm_ops video_i2c_pm_ops = {
 
 static const struct i2c_device_id video_i2c_id_table[] = {
 	{ "amg88xx", AMG88XX },
+	{ "mlx90640", MLX90640 },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, video_i2c_id_table);
 
 static const struct of_device_id video_i2c_of_match[] = {
 	{ .compatible = "panasonic,amg88xx", .data = &video_i2c_chip[AMG88XX] },
+	{ .compatible = "melexis,mlx90640", .data = &video_i2c_chip[MLX90640] },
 	{}
 };
 MODULE_DEVICE_TABLE(of, video_i2c_of_match);
-- 
2.17.1

Re: [PATCH v2 2/2] media: video-i2c: add Melexis MLX90640 thermal camera support

[Hans Verkuil]

On 11/22/2018 04:52 AM, Matt Ranostay wrote:
> Add initial support for MLX90640 thermal cameras which output an 32x24
> greyscale pixel image along with 2 rows of coefficent data.
> 
> Because of this the data outputed is really 32x26 and needs the two rows
> removed after using the coefficent information to generate processed
> images in userspace.
> 
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
> ---
>  .../bindings/media/i2c/melexis,mlx90640.txt   |  20 ++++
>  drivers/media/i2c/Kconfig                     |   1 +
>  drivers/media/i2c/video-i2c.c                 | 110 +++++++++++++++++-
>  3 files changed, 130 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> new file mode 100644
> index 000000000000..060d2b7a5893
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> @@ -0,0 +1,20 @@
> +* Melexis MLX90640 FIR Sensor
> +
> +Melexis MLX90640 FIR sensor support which allows recording of thermal data
> +with 32x24 resolution excluding 2 lines of coefficient data that is used by
> +userspace to render processed frames.

So this means that the image doesn't conform to V4L2_PIX_FMT_Y12!

I missed that the first time around.

You have three options here:

1) Create a new V4L2_PIX_FMT define + documentation describing the format that
   this device produces.

2) Split off the image from the meta data and create a new META_CAPTURE device
   node. For the META device node you would again have to document the format

3) Split off the image from the meta data and store the meta data in a V4L2
   control, which again has to be documented.

I'm leaning towards 1 since that's easiest to implement. But the key is that
you should document those two lines. The datasheet is publicly available,
so you can refer to it for details.

Those extra two lines return addresses 0x700-0x73f, right? Is it even sufficient
to calculate the relevant data from just those lines? Looking at 11.2.2 there
is a whole calculation that should be done that is also dependent on the eeprom
values, which are not exported.

I wonder if it isn't the job of the driver to do all the calculations. It has
all the information it needs and looking at the datasheet it seems all the
calculations are integer based, so it shouldn't be too difficult. This would
be a fourth option.

BTW, did we document somewhere what the panasonic device returns? It returns
Y12 data, but what does that data mean? In order to use this in userspace you
need to be able to convert it to temperatures, so how is that done?

Regards,

	Hans

> +
> +Required Properties:
> + - compatible : Must be "melexis,mlx90640"
> + - reg : i2c address of the device
> +
> +Example:
> +
> +	i2c0@1c22000 {
> +		...
> +		mlx90640@33 {
> +			compatible = "melexis,mlx90640";
> +			reg = <0x33>;
> +		};
> +		...
> +	};

Re: [PATCH v2 2/2] media: video-i2c: add Melexis MLX90640 thermal camera support

[Matt Ranostay]

On Thu, Nov 22, 2018 at 12:57 AM Hans Verkuil <hverkuil@xs4all.nl> wrote:
>
> On 11/22/2018 04:52 AM, Matt Ranostay wrote:
> > Add initial support for MLX90640 thermal cameras which output an 32x24
> > greyscale pixel image along with 2 rows of coefficent data.
> >
> > Because of this the data outputed is really 32x26 and needs the two rows
> > removed after using the coefficent information to generate processed
> > images in userspace.
> >
> > Cc: devicetree@vger.kernel.org
> > Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
> > ---
> >  .../bindings/media/i2c/melexis,mlx90640.txt   |  20 ++++
> >  drivers/media/i2c/Kconfig                     |   1 +
> >  drivers/media/i2c/video-i2c.c                 | 110 +++++++++++++++++-
> >  3 files changed, 130 insertions(+), 1 deletion(-)
> >  create mode 100644 Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> >
> > diff --git a/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> > new file mode 100644
> > index 000000000000..060d2b7a5893
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> > @@ -0,0 +1,20 @@
> > +* Melexis MLX90640 FIR Sensor
> > +
> > +Melexis MLX90640 FIR sensor support which allows recording of thermal data
> > +with 32x24 resolution excluding 2 lines of coefficient data that is used by
> > +userspace to render processed frames.
>
> So this means that the image doesn't conform to V4L2_PIX_FMT_Y12!
>

The data for this sensor is V4L2_PIX_FMT_Y16BE not Y12

> I missed that the first time around.
>
> You have three options here:
>
> 1) Create a new V4L2_PIX_FMT define + documentation describing the format that
>    this device produces.
>
> 2) Split off the image from the meta data and create a new META_CAPTURE device
>    node. For the META device node you would again have to document the format
>
> 3) Split off the image from the meta data and store the meta data in a V4L2
>    control, which again has to be documented.
>
> I'm leaning towards 1 since that's easiest to implement. But the key is that
> you should document those two lines. The datasheet is publicly available,
> so you can refer to it for details.
>

1 is mostly what I have now, excluding the documentation and new pixel format.

Although I have to say the META_CAPTURE options seems a bit more
clean, but doesn't seem
to be documented well.  So would it basically mux the pixel data, and
metadata with the same
timestamp?  Originally I looked at the VBI/closed caption to show the
metadata/frame-only data but that
was a way too low of a bandwidth (43-bytes a second IIRC).

> Those extra two lines return addresses 0x700-0x73f, right? Is it even sufficient
> to calculate the relevant data from just those lines?

Yep that is the last 2 lines so 32x26 of reported data, but only 32x24
is pixel data.

> Looking at 11.2.2 there
> is a whole calculation that should be done that is also dependent on the eeprom
> values, which are not exported.
>

You must have missed the nvmem part of the patchset.. :) The
respective eeprom values are exported to userspace using that.

> I wonder if it isn't the job of the driver to do all the calculations. It has
> all the information it needs and looking at the datasheet it seems all the
> calculations are integer based, so it shouldn't be too difficult. This would
> be a fourth option.

Well it isn't really all integer based.. sure the value from the frame
and eeprom are integers but the
coefficients you generate ( frame value divided by eeprom value )
usually produces a floating point value.

>
> BTW, did we document somewhere what the panasonic device returns? It returns
> Y12 data, but what does that data mean? In order to use this in userspace you
> need to be able to convert it to temperatures, so how is that done?

It is a signed 12-bit value with 0.25C resolution per LSB but doesn't
need any processing.

>
> Regards,
>
>         Hans
>
> > +
> > +Required Properties:
> > + - compatible : Must be "melexis,mlx90640"
> > + - reg : i2c address of the device
> > +
> > +Example:
> > +
> > +     i2c0@1c22000 {
> > +             ...
> > +             mlx90640@33 {
> > +                     compatible = "melexis,mlx90640";
> > +                     reg = <0x33>;
> > +             };
> > +             ...
> > +     };

Re: [PATCH v2 2/2] media: video-i2c: add Melexis MLX90640 thermal camera support

[Hans Verkuil]

On 11/22/2018 04:52 AM, Matt Ranostay wrote:
> Add initial support for MLX90640 thermal cameras which output an 32x24
> greyscale pixel image along with 2 rows of coefficent data.
> 
> Because of this the data outputed is really 32x26 and needs the two rows
> removed after using the coefficent information to generate processed
> images in userspace.
> 
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
> ---
>  .../bindings/media/i2c/melexis,mlx90640.txt   |  20 ++++
>  drivers/media/i2c/Kconfig                     |   1 +
>  drivers/media/i2c/video-i2c.c                 | 110 +++++++++++++++++-
>  3 files changed, 130 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt

This patch needs to be split up in two: one for the bindings, one for
the driver changes.

Once the bindings for the v3 of this patch are accepted, I can merge this.

Note that I am in the process of merging '[PATCH v3] media: video-i2c: check if chip
struct has set_power function', so it shouldn't be necessary to repost that patch.

Regards,

	Hans

> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> new file mode 100644
> index 000000000000..060d2b7a5893
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt
> @@ -0,0 +1,20 @@
> +* Melexis MLX90640 FIR Sensor
> +
> +Melexis MLX90640 FIR sensor support which allows recording of thermal data
> +with 32x24 resolution excluding 2 lines of coefficient data that is used by
> +userspace to render processed frames.
> +
> +Required Properties:
> + - compatible : Must be "melexis,mlx90640"
> + - reg : i2c address of the device
> +
> +Example:
> +
> +	i2c0@1c22000 {
> +		...
> +		mlx90640@33 {
> +			compatible = "melexis,mlx90640";
> +			reg = <0x33>;
> +		};
> +		...
> +	};
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 66bbbec487ec..24342f283f2a 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -1097,6 +1097,7 @@ config VIDEO_I2C
>  	  Enable the I2C transport video support which supports the
>  	  following:
>  	   * Panasonic AMG88xx Grid-Eye Sensors
> +	   * Melexis MLX90640 Thermal Cameras
>  
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called video-i2c
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index a64e1a725a20..d58f40334e8b 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -6,6 +6,7 @@
>   *
>   * Supported:
>   * - Panasonic AMG88xx Grid-Eye Sensors
> + * - Melexis MLX90640 Thermal Cameras
>   */
>  
>  #include <linux/delay.h>
> @@ -18,6 +19,7 @@
>  #include <linux/mutex.h>
>  #include <linux/of_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/nvmem-provider.h>
>  #include <linux/regmap.h>
>  #include <linux/sched.h>
>  #include <linux/slab.h>
> @@ -66,12 +68,26 @@ static const struct v4l2_frmsize_discrete amg88xx_size = {
>  	.height = 8,
>  };
>  
> +static const struct v4l2_fmtdesc mlx90640_format = {
> +	.pixelformat = V4L2_PIX_FMT_Y16_BE,
> +};
> +
> +static const struct v4l2_frmsize_discrete mlx90640_size = {
> +	.width = 32,
> +	.height = 26, /* 24 lines of pixel data + 2 lines of processing data */
> +};
> +
>  static const struct regmap_config amg88xx_regmap_config = {
>  	.reg_bits = 8,
>  	.val_bits = 8,
>  	.max_register = 0xff
>  };
>  
> +static const struct regmap_config mlx90640_regmap_config = {
> +	.reg_bits = 16,
> +	.val_bits = 16,
> +};
> +
>  struct video_i2c_chip {
>  	/* video dimensions */
>  	const struct v4l2_fmtdesc *format;
> @@ -88,6 +104,7 @@ struct video_i2c_chip {
>  	unsigned int bpp;
>  
>  	const struct regmap_config *regmap_config;
> +	struct nvmem_config *nvmem_config;
>  
>  	/* setup function */
>  	int (*setup)(struct video_i2c_data *data);
> @@ -102,6 +119,22 @@ struct video_i2c_chip {
>  	int (*hwmon_init)(struct video_i2c_data *data);
>  };
>  
> +static int mlx90640_nvram_read(void *priv, unsigned int offset, void *val,
> +			     size_t bytes)
> +{
> +	struct video_i2c_data *data = priv;
> +
> +	return regmap_bulk_read(data->regmap, 0x2400 + offset, val, bytes);
> +}
> +
> +static struct nvmem_config mlx90640_nvram_config = {
> +	.name = "mlx90640_nvram",
> +	.word_size = 2,
> +	.stride = 1,
> +	.size = 1664,
> +	.reg_read = mlx90640_nvram_read,
> +};
> +
>  /* Power control register */
>  #define AMG88XX_REG_PCTL	0x00
>  #define AMG88XX_PCTL_NORMAL		0x00
> @@ -122,12 +155,23 @@ struct video_i2c_chip {
>  /* Temperature register */
>  #define AMG88XX_REG_T01L	0x80
>  
> +/* Control register */
> +#define MLX90640_REG_CTL1		0x800d
> +#define MLX90640_REG_CTL1_MASK		0x0380
> +#define MLX90640_REG_CTL1_MASK_SHIFT	7
> +
>  static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
>  {
>  	return regmap_bulk_read(data->regmap, AMG88XX_REG_T01L, buf,
>  				data->chip->buffer_size);
>  }
>  
> +static int mlx90640_xfer(struct video_i2c_data *data, char *buf)
> +{
> +	return regmap_bulk_read(data->regmap, 0x400, buf,
> +				data->chip->buffer_size);
> +}
> +
>  static int amg88xx_setup(struct video_i2c_data *data)
>  {
>  	unsigned int mask = AMG88XX_FPSC_1FPS;
> @@ -141,6 +185,27 @@ static int amg88xx_setup(struct video_i2c_data *data)
>  	return regmap_update_bits(data->regmap, AMG88XX_REG_FPSC, mask, val);
>  }
>  
> +static int mlx90640_setup(struct video_i2c_data *data)
> +{
> +	unsigned int n, idx;
> +
> +	for (n = 0; n < data->chip->num_frame_intervals - 1; n++) {
> +		if (data->frame_interval.numerator
> +				!= data->chip->frame_intervals[n].numerator)
> +			continue;
> +
> +		if (data->frame_interval.denominator
> +				== data->chip->frame_intervals[n].denominator)
> +			break;
> +	}
> +
> +	idx = data->chip->num_frame_intervals - n - 1;
> +
> +	return regmap_update_bits(data->regmap, MLX90640_REG_CTL1,
> +				  MLX90640_REG_CTL1_MASK,
> +				  idx << MLX90640_REG_CTL1_MASK_SHIFT);
> +}
> +
>  static int amg88xx_set_power_on(struct video_i2c_data *data)
>  {
>  	int ret;
> @@ -274,13 +339,27 @@ static int amg88xx_hwmon_init(struct video_i2c_data *data)
>  #define	amg88xx_hwmon_init	NULL
>  #endif
>  
> -#define AMG88XX		0
> +enum {
> +	AMG88XX,
> +	MLX90640,
> +};
>  
>  static const struct v4l2_fract amg88xx_frame_intervals[] = {
>  	{ 1, 10 },
>  	{ 1, 1 },
>  };
>  
> +static const struct v4l2_fract mlx90640_frame_intervals[] = {
> +	{ 1, 64 },
> +	{ 1, 32 },
> +	{ 1, 16 },
> +	{ 1, 8 },
> +	{ 1, 4 },
> +	{ 1, 2 },
> +	{ 1, 1 },
> +	{ 2, 1 },
> +};
> +
>  static const struct video_i2c_chip video_i2c_chip[] = {
>  	[AMG88XX] = {
>  		.size		= &amg88xx_size,
> @@ -295,6 +374,18 @@ static const struct video_i2c_chip video_i2c_chip[] = {
>  		.set_power	= amg88xx_set_power,
>  		.hwmon_init	= amg88xx_hwmon_init,
>  	},
> +	[MLX90640] = {
> +		.size		= &mlx90640_size,
> +		.format		= &mlx90640_format,
> +		.frame_intervals	= mlx90640_frame_intervals,
> +		.num_frame_intervals	= ARRAY_SIZE(mlx90640_frame_intervals),
> +		.buffer_size	= 1664,
> +		.bpp		= 16,
> +		.regmap_config	= &mlx90640_regmap_config,
> +		.nvmem_config	= &mlx90640_nvram_config,
> +		.setup		= mlx90640_setup,
> +		.xfer		= mlx90640_xfer,
> +	},
>  };
>  
>  static const struct v4l2_file_operations video_i2c_fops = {
> @@ -756,6 +847,21 @@ static int video_i2c_probe(struct i2c_client *client,
>  		}
>  	}
>  
> +	if (data->chip->nvmem_config) {
> +		struct nvmem_config *config = data->chip->nvmem_config;
> +		struct nvmem_device *device;
> +
> +		config->priv = data;
> +		config->dev = &client->dev;
> +
> +		device = devm_nvmem_register(&client->dev, config);
> +
> +		if (IS_ERR(device)) {
> +			dev_warn(&client->dev,
> +				 "failed to register nvmem device\n");
> +		}
> +	}
> +
>  	ret = video_register_device(&data->vdev, VFL_TYPE_GRABBER, -1);
>  	if (ret < 0)
>  		goto error_pm_disable;
> @@ -834,12 +940,14 @@ static const struct dev_pm_ops video_i2c_pm_ops = {
>  
>  static const struct i2c_device_id video_i2c_id_table[] = {
>  	{ "amg88xx", AMG88XX },
> +	{ "mlx90640", MLX90640 },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(i2c, video_i2c_id_table);
>  
>  static const struct of_device_id video_i2c_of_match[] = {
>  	{ .compatible = "panasonic,amg88xx", .data = &video_i2c_chip[AMG88XX] },
> +	{ .compatible = "melexis,mlx90640", .data = &video_i2c_chip[MLX90640] },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, video_i2c_of_match);
>