[PATCH v2 0/8] Input: atmel_mxt_ts - output raw touch diagnostic data via V4L

[PATCH v2 0/8] Input: atmel_mxt_ts - output raw touch diagnostic data via V4L

[Nick Dyer]

This is a series of patches to add diagnostic data support to the Atmel
maXTouch driver. It's a rewrite of the previous implementation which output via
debugfs: it now uses a V4L2 device in a similar way to the sur40 driver.

There are significant performance advantages to putting this code into the
driver.  The algorithm for retrieving the data has been fairly consistent
across a range of chips, with the exception of the mXT1386 series (see patch).

We have a utility which can read the data and display it in a useful format:
    https://github.com/ndyer/heatmap/commits/heatmap-v4l

These patches are also available from
    https://github.com/ndyer/linux/commits/diagnostic-v4l

Changes in v2:
- Split pixfmt changes into separate commit and add DocBook
- Introduce VFL_TYPE_TOUCH_SENSOR and /dev/v4l-touch
- Remove "single node" support for now, it may be better to treat it as metadata later
- Explicitly set VFL_DIR_RX
- Fix Kconfig

[PATCH v2 1/8] Input: atmel_mxt_ts - add support for T37 diagnostic data

[Nick Dyer]

Atmel maXTouch devices have a T37 object which can be used to read raw
touch deltas from the device. This consists of an array of 16-bit
integers, one for each node on the touchscreen matrix.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 152 +++++++++++++++++++++++++++++++
 1 file changed, 152 insertions(+)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 2160512..cd97713 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -124,6 +124,17 @@ struct t9_range {
 #define MXT_COMMS_CTRL		0
 #define MXT_COMMS_CMD		1
 
+/* MXT_DEBUG_DIAGNOSTIC_T37 */
+#define MXT_DIAGNOSTIC_PAGEUP	0x01
+#define MXT_DIAGNOSTIC_DELTAS	0x10
+#define MXT_DIAGNOSTIC_SIZE	128
+
+struct t37_debug {
+	u8 mode;
+	u8 page;
+	u8 data[MXT_DIAGNOSTIC_SIZE];
+};
+
 /* Define for MXT_GEN_COMMAND_T6 */
 #define MXT_BOOT_VALUE		0xa5
 #define MXT_RESET_VALUE		0x01
@@ -205,6 +216,14 @@ struct mxt_object {
 	u8 num_report_ids;
 } __packed;
 
+struct mxt_dbg {
+	u16 t37_address;
+	u16 diag_cmd_address;
+	struct t37_debug *t37_buf;
+	unsigned int t37_pages;
+	unsigned int t37_nodes;
+};
+
 /* Each client has this additional data */
 struct mxt_data {
 	struct i2c_client *client;
@@ -233,6 +252,7 @@ struct mxt_data {
 	u8 num_touchids;
 	u8 multitouch;
 	struct t7_config t7_cfg;
+	struct mxt_dbg dbg;
 
 	/* Cached parameters from object table */
 	u16 T5_address;
@@ -2043,6 +2063,136 @@ recheck:
 	return 0;
 }
 
+static u16 mxt_get_debug_value(struct mxt_data *data, unsigned int x,
+			       unsigned int y)
+{
+	struct mxt_dbg *dbg = &data->dbg;
+	unsigned int ofs, page;
+
+	ofs = (y + (x * data->info.matrix_ysize)) * sizeof(u16);
+	page = ofs / MXT_DIAGNOSTIC_SIZE;
+	ofs %= MXT_DIAGNOSTIC_SIZE;
+
+	return get_unaligned_le16(&dbg->t37_buf[page].data[ofs]);
+}
+
+static int mxt_convert_debug_pages(struct mxt_data *data, u16 *outbuf)
+{
+	struct mxt_dbg *dbg = &data->dbg;
+	unsigned int x = 0;
+	unsigned int y = 0;
+	unsigned int i;
+
+	for (i = 0; i < dbg->t37_nodes; i++) {
+		outbuf[i] = mxt_get_debug_value(data, x, y);
+
+		/* Next value */
+		if (++x >= data->info.matrix_xsize) {
+			x = 0;
+			y++;
+		}
+	}
+
+	return 0;
+}
+
+static int mxt_read_diagnostic_debug(struct mxt_data *data, u8 mode,
+				     u16 *outbuf)
+{
+	struct mxt_dbg *dbg = &data->dbg;
+	int retries = 0;
+	int page;
+	int ret;
+	u8 cmd = mode;
+	struct t37_debug *p;
+	u8 cmd_poll;
+
+	for (page = 0; page < dbg->t37_pages; page++) {
+		p = dbg->t37_buf + page;
+
+		ret = mxt_write_reg(data->client, dbg->diag_cmd_address,
+				    cmd);
+		if (ret)
+			return ret;
+
+		retries = 0;
+		msleep(20);
+wait_cmd:
+		/* Read back command byte */
+		ret = __mxt_read_reg(data->client, dbg->diag_cmd_address,
+				     sizeof(cmd_poll), &cmd_poll);
+		if (ret)
+			return ret;
+
+		/* Field is cleared once the command has been processed */
+		if (cmd_poll) {
+			if (retries++ > 100)
+				return -EINVAL;
+
+			msleep(20);
+			goto wait_cmd;
+		}
+
+		/* Read T37 page */
+		ret = __mxt_read_reg(data->client, dbg->t37_address,
+				sizeof(struct t37_debug), p);
+		if (ret)
+			return ret;
+
+		if ((p->mode != mode) || (p->page != page)) {
+			dev_err(&data->client->dev, "T37 page mismatch\n");
+			return -EINVAL;
+		}
+
+		dev_dbg(&data->client->dev, "%s page:%d retries:%d\n",
+			__func__, page, retries);
+
+		/* For remaining pages, write PAGEUP rather than mode */
+		cmd = MXT_DIAGNOSTIC_PAGEUP;
+	}
+
+	return mxt_convert_debug_pages(data, outbuf);
+}
+
+static void mxt_debug_init(struct mxt_data *data)
+{
+	struct mxt_dbg *dbg = &data->dbg;
+	struct mxt_object *object;
+
+	object = mxt_get_object(data, MXT_GEN_COMMAND_T6);
+	if (!object)
+		return;
+
+	dbg->diag_cmd_address = object->start_address + MXT_COMMAND_DIAGNOSTIC;
+
+	object = mxt_get_object(data, MXT_DEBUG_DIAGNOSTIC_T37);
+	if (!object)
+		return;
+
+	if (mxt_obj_size(object) != sizeof(struct t37_debug)) {
+		dev_warn(&data->client->dev, "Bad T37 size");
+		return;
+	}
+
+	dbg->t37_address = object->start_address;
+
+	/* Calculate size of data and allocate buffer */
+	dbg->t37_nodes = data->info.matrix_xsize * data->info.matrix_ysize;
+	dbg->t37_pages = dbg->t37_nodes * sizeof(u16)
+					/ sizeof(dbg->t37_buf->data) + 1;
+
+	dbg->t37_buf = devm_kzalloc(&data->client->dev,
+				     sizeof(struct t37_debug) * dbg->t37_pages,
+				     GFP_KERNEL);
+	if (!dbg->t37_buf)
+		goto error;
+
+	return;
+
+error:
+	dev_err(&data->client->dev, "Error initialising T37 diagnostic data\n");
+}
+
 static int mxt_configure_objects(struct mxt_data *data,
 				 const struct firmware *cfg)
 {
@@ -2070,6 +2220,8 @@ static int mxt_configure_objects(struct mxt_data *data,
 		dev_warn(dev, "No touch object detected\n");
 	}
 
+	mxt_debug_init(data);
+
 	dev_info(dev,
 		 "Family: %u Variant: %u Firmware V%u.%u.%02X Objects: %u\n",
 		 info->family_id, info->variant_id, info->version >> 4,
-- 
2.5.0

[PATCH v2 2/8] [media] Add signed 16-bit pixel format

[Nick Dyer]

This will be used for output of raw touch data.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 Documentation/DocBook/media/v4l/pixfmt-ys16.xml | 79 +++++++++++++++++++++++++
 Documentation/DocBook/media/v4l/pixfmt.xml      |  1 +
 drivers/media/v4l2-core/v4l2-ioctl.c            |  1 +
 include/uapi/linux/videodev2.h                  |  1 +
 4 files changed, 82 insertions(+)
 create mode 100644 Documentation/DocBook/media/v4l/pixfmt-ys16.xml

diff --git a/Documentation/DocBook/media/v4l/pixfmt-ys16.xml b/Documentation/DocBook/media/v4l/pixfmt-ys16.xml
new file mode 100644
index 0000000..f92d65e
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/pixfmt-ys16.xml
@@ -0,0 +1,79 @@
+<refentry id="V4L2-PIX-FMT-YS16">
+  <refmeta>
+    <refentrytitle>V4L2_PIX_FMT_YS16 ('YS16')</refentrytitle>
+    &manvol;
+  </refmeta>
+  <refnamediv>
+    <refname><constant>V4L2_PIX_FMT_YS16</constant></refname>
+    <refpurpose>Grey-scale image</refpurpose>
+  </refnamediv>
+  <refsect1>
+    <title>Description</title>
+
+    <para>This is a signed grey-scale image with a depth of 16 bits per
+pixel. The most significant byte is stored at higher memory addresses
+(little-endian).</para>
+
+    <example>
+      <title><constant>V4L2_PIX_FMT_YS16</constant> 4 &times; 4
+pixel image</title>
+
+      <formalpara>
+	<title>Byte Order.</title>
+	<para>Each cell is one byte.
+	  <informaltable frame="none">
+	    <tgroup cols="9" align="center">
+	      <colspec align="left" colwidth="2*" />
+	      <tbody valign="top">
+		<row>
+		  <entry>start&nbsp;+&nbsp;0:</entry>
+		  <entry>Y'<subscript>00low</subscript></entry>
+		  <entry>Y'<subscript>00high</subscript></entry>
+		  <entry>Y'<subscript>01low</subscript></entry>
+		  <entry>Y'<subscript>01high</subscript></entry>
+		  <entry>Y'<subscript>02low</subscript></entry>
+		  <entry>Y'<subscript>02high</subscript></entry>
+		  <entry>Y'<subscript>03low</subscript></entry>
+		  <entry>Y'<subscript>03high</subscript></entry>
+		</row>
+		<row>
+		  <entry>start&nbsp;+&nbsp;8:</entry>
+		  <entry>Y'<subscript>10low</subscript></entry>
+		  <entry>Y'<subscript>10high</subscript></entry>
+		  <entry>Y'<subscript>11low</subscript></entry>
+		  <entry>Y'<subscript>11high</subscript></entry>
+		  <entry>Y'<subscript>12low</subscript></entry>
+		  <entry>Y'<subscript>12high</subscript></entry>
+		  <entry>Y'<subscript>13low</subscript></entry>
+		  <entry>Y'<subscript>13high</subscript></entry>
+		</row>
+		<row>
+		  <entry>start&nbsp;+&nbsp;16:</entry>
+		  <entry>Y'<subscript>20low</subscript></entry>
+		  <entry>Y'<subscript>20high</subscript></entry>
+		  <entry>Y'<subscript>21low</subscript></entry>
+		  <entry>Y'<subscript>21high</subscript></entry>
+		  <entry>Y'<subscript>22low</subscript></entry>
+		  <entry>Y'<subscript>22high</subscript></entry>
+		  <entry>Y'<subscript>23low</subscript></entry>
+		  <entry>Y'<subscript>23high</subscript></entry>
+		</row>
+		<row>
+		  <entry>start&nbsp;+&nbsp;24:</entry>
+		  <entry>Y'<subscript>30low</subscript></entry>
+		  <entry>Y'<subscript>30high</subscript></entry>
+		  <entry>Y'<subscript>31low</subscript></entry>
+		  <entry>Y'<subscript>31high</subscript></entry>
+		  <entry>Y'<subscript>32low</subscript></entry>
+		  <entry>Y'<subscript>32high</subscript></entry>
+		  <entry>Y'<subscript>33low</subscript></entry>
+		  <entry>Y'<subscript>33high</subscript></entry>
+		</row>
+	      </tbody>
+	    </tgroup>
+	  </informaltable>
+	</para>
+      </formalpara>
+    </example>
+  </refsect1>
+</refentry>
diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml
index d871245..6f7aa0e 100644
--- a/Documentation/DocBook/media/v4l/pixfmt.xml
+++ b/Documentation/DocBook/media/v4l/pixfmt.xml
@@ -1619,6 +1619,7 @@ information.</para>
     &sub-y12;
     &sub-y10b;
     &sub-y16;
+    &sub-ys16;
     &sub-y16-be;
     &sub-uv8;
     &sub-yuyv;
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 8a018c6..c7dabaa 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1154,6 +1154,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_PIX_FMT_Y10:		descr = "10-bit Greyscale"; break;
 	case V4L2_PIX_FMT_Y12:		descr = "12-bit Greyscale"; break;
 	case V4L2_PIX_FMT_Y16:		descr = "16-bit Greyscale"; break;
+	case V4L2_PIX_FMT_YS16:		descr = "16-bit Greyscale (Signed)"; break;
 	case V4L2_PIX_FMT_Y16_BE:	descr = "16-bit Greyscale BE"; break;
 	case V4L2_PIX_FMT_Y10BPACK:	descr = "10-bit Greyscale (Packed)"; break;
 	case V4L2_PIX_FMT_PAL8:		descr = "8-bit Palette"; break;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 14cd5eb..ab577dd 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -496,6 +496,7 @@ struct v4l2_pix_format {
 #define V4L2_PIX_FMT_Y12     v4l2_fourcc('Y', '1', '2', ' ') /* 12  Greyscale     */
 #define V4L2_PIX_FMT_Y16     v4l2_fourcc('Y', '1', '6', ' ') /* 16  Greyscale     */
 #define V4L2_PIX_FMT_Y16_BE  v4l2_fourcc_be('Y', '1', '6', ' ') /* 16  Greyscale BE  */
+#define V4L2_PIX_FMT_YS16    v4l2_fourcc('Y', 'S', '1', '6') /* signed 16-bit Greyscale */
 
 /* Grey bit-packed formats */
 #define V4L2_PIX_FMT_Y10BPACK    v4l2_fourcc('Y', '1', '0', 'B') /* 10  Greyscale bit-packed */
-- 
2.5.0

[PATCH v2 3/8] [media] v4l2-core: Add VFL_TYPE_TOUCH_SENSOR

[Nick Dyer]

Some touch controllers send out raw touch data in a similar way to a
greyscale frame grabber. Add a new device type for these devices.

Use a new device prefix v4l-touch for these devices, to stop generic
capture software from treating them as webcams.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/sur40.c    |  2 +-
 drivers/media/v4l2-core/v4l2-dev.c   | 13 ++++++++++---
 drivers/media/v4l2-core/v4l2-ioctl.c |  6 ++++--
 include/media/v4l2-dev.h             |  3 ++-
 4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c
index 880c40b..7e5fe2b 100644
--- a/drivers/input/touchscreen/sur40.c
+++ b/drivers/input/touchscreen/sur40.c
@@ -599,7 +599,7 @@ static int sur40_probe(struct usb_interface *interface,
 	sur40->vdev.queue = &sur40->queue;
 	video_set_drvdata(&sur40->vdev, sur40);
 
-	error = video_register_device(&sur40->vdev, VFL_TYPE_GRABBER, -1);
+	error = video_register_device(&sur40->vdev, VFL_TYPE_TOUCH_SENSOR, -1);
 	if (error) {
 		dev_err(&interface->dev,
 			"Unable to register video subdevice.");
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index d8e5994..8d41248 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -529,6 +529,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
 	bool is_sdr = vdev->vfl_type == VFL_TYPE_SDR;
 	bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
 	bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
+	bool is_touch = vdev->vfl_type == VFL_TYPE_TOUCH_SENSOR;
 
 	bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
 
@@ -573,7 +574,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
 	if (ops->vidioc_enum_freq_bands || ops->vidioc_g_tuner || ops->vidioc_g_modulator)
 		set_bit(_IOC_NR(VIDIOC_ENUM_FREQ_BANDS), valid_ioctls);
 
-	if (is_vid) {
+	if (is_vid || is_touch) {
 		/* video specific ioctls */
 		if ((is_rx && (ops->vidioc_enum_fmt_vid_cap ||
 			       ops->vidioc_enum_fmt_vid_cap_mplane ||
@@ -662,7 +663,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
 	}
 
-	if (is_vid || is_vbi || is_sdr) {
+	if (is_vid || is_vbi || is_sdr || is_touch) {
 		/* ioctls valid for video, vbi or sdr */
 		SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
 		SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
@@ -675,7 +676,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
 		SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff);
 	}
 
-	if (is_vid || is_vbi) {
+	if (is_vid || is_vbi || is_touch) {
 		/* ioctls valid for video or vbi */
 		if (ops->vidioc_s_std)
 			set_bit(_IOC_NR(VIDIOC_ENUMSTD), valid_ioctls);
@@ -738,6 +739,7 @@ static int video_register_media_controller(struct video_device *vdev, int type)
 	vdev->entity.function = MEDIA_ENT_F_UNKNOWN;
 
 	switch (type) {
+	case VFL_TYPE_TOUCH_SENSOR:
 	case VFL_TYPE_GRABBER:
 		intf_type = MEDIA_INTF_T_V4L_VIDEO;
 		vdev->entity.function = MEDIA_ENT_F_IO_V4L;
@@ -844,6 +846,8 @@ static int video_register_media_controller(struct video_device *vdev, int type)
  *	%VFL_TYPE_SUBDEV - A subdevice
  *
  *	%VFL_TYPE_SDR - Software Defined Radio
+ *
+ *	%VFL_TYPE_TOUCH_SENSOR - A touch sensor
  */
 int __video_register_device(struct video_device *vdev, int type, int nr,
 		int warn_if_nr_in_use, struct module *owner)
@@ -887,6 +891,9 @@ int __video_register_device(struct video_device *vdev, int type, int nr,
 		/* Use device name 'swradio' because 'sdr' was already taken. */
 		name_base = "swradio";
 		break;
+	case VFL_TYPE_TOUCH_SENSOR:
+		name_base = "v4l-touch";
+		break;
 	default:
 		printk(KERN_ERR "%s called with unknown type: %d\n",
 		       __func__, type);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index c7dabaa..4a1093a 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -925,13 +925,14 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
 	bool is_sdr = vfd->vfl_type == VFL_TYPE_SDR;
 	bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
 	bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
+	bool is_touch = vfd->vfl_type == VFL_TYPE_TOUCH_SENSOR;
 
 	if (ops == NULL)
 		return -EINVAL;
 
 	switch (type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
-		if (is_vid && is_rx &&
+		if ((is_vid || is_touch) && is_rx &&
 		    (ops->vidioc_g_fmt_vid_cap || ops->vidioc_g_fmt_vid_cap_mplane))
 			return 0;
 		break;
@@ -1349,6 +1350,7 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
 	struct video_device *vfd = video_devdata(file);
 	bool is_vid = vfd->vfl_type == VFL_TYPE_GRABBER;
 	bool is_sdr = vfd->vfl_type == VFL_TYPE_SDR;
+	bool is_touch = vfd->vfl_type == VFL_TYPE_TOUCH_SENSOR;
 	bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
 	bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
 	int ret;
@@ -1379,7 +1381,7 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
 
 	switch (p->type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
-		if (unlikely(!is_rx || !is_vid || !ops->vidioc_g_fmt_vid_cap))
+		if (unlikely(!is_rx || (!is_vid && !is_touch) || !ops->vidioc_g_fmt_vid_cap))
 			break;
 		p->fmt.pix.priv = V4L2_PIX_FMT_PRIV_MAGIC;
 		ret = ops->vidioc_g_fmt_vid_cap(file, fh, arg);
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index eeabf20..8a4e446 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -25,7 +25,8 @@
 #define VFL_TYPE_RADIO		2
 #define VFL_TYPE_SUBDEV		3
 #define VFL_TYPE_SDR		4
-#define VFL_TYPE_MAX		5
+#define VFL_TYPE_TOUCH_SENSOR	5
+#define VFL_TYPE_MAX		6
 
 /* Is this a receiver, transmitter or mem-to-mem? */
 /* Ignored for VFL_TYPE_SUBDEV. */
-- 
2.5.0

[PATCH v2 4/8] Input: atmel_mxt_ts - output diagnostic debug via v4l2 device

[Nick Dyer]

Register a video device to output T37 diagnostic data.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/Kconfig        |   2 +
 drivers/input/touchscreen/atmel_mxt_ts.c | 271 +++++++++++++++++++++++++++++++
 2 files changed, 273 insertions(+)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 1f99e7f..4aa7609 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -105,6 +105,8 @@ config TOUCHSCREEN_AR1021_I2C
 config TOUCHSCREEN_ATMEL_MXT
 	tristate "Atmel mXT I2C Touchscreen"
 	depends on I2C
+	depends on VIDEO_V4L2
+	select VIDEOBUF2_VMALLOC
 	select FW_LOADER
 	help
 	  Say Y here if you have Atmel mXT series I2C touchscreen,
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index cd97713..8945235 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -28,6 +28,10 @@
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <asm/unaligned.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-v4l2.h>
+#include <media/videobuf2-vmalloc.h>
 
 /* Firmware files */
 #define MXT_FW_NAME		"maxtouch.fw"
@@ -222,6 +226,23 @@ struct mxt_dbg {
 	struct t37_debug *t37_buf;
 	unsigned int t37_pages;
 	unsigned int t37_nodes;
+
+	struct v4l2_device v4l2;
+	struct v4l2_pix_format format;
+	struct video_device vdev;
+	struct vb2_queue queue;
+	struct mutex lock;
+	int input;
+};
+
+static const struct v4l2_file_operations mxt_video_fops = {
+	.owner = THIS_MODULE,
+	.open = v4l2_fh_open,
+	.release = vb2_fop_release,
+	.unlocked_ioctl = video_ioctl2,
+	.read = vb2_fop_read,
+	.mmap = vb2_fop_mmap,
+	.poll = vb2_fop_poll,
 };
 
 /* Each client has this additional data */
@@ -277,6 +298,11 @@ struct mxt_data {
 	struct completion crc_completion;
 };
 
+struct mxt_vb2_buffer {
+	struct vb2_buffer	vb;
+	struct list_head	list;
+};
+
 static size_t mxt_obj_size(const struct mxt_object *obj)
 {
 	return obj->size_minus_one + 1;
@@ -1523,6 +1549,9 @@ static void mxt_free_input_device(struct mxt_data *data)
 
 static void mxt_free_object_table(struct mxt_data *data)
 {
+	video_unregister_device(&data->dbg.vdev);
+	v4l2_device_unregister(&data->dbg.v4l2);
+
 	kfree(data->object_table);
 	data->object_table = NULL;
 	kfree(data->msg_buf);
@@ -2154,10 +2183,215 @@ wait_cmd:
 	return mxt_convert_debug_pages(data, outbuf);
 }
 
+static int mxt_queue_setup(struct vb2_queue *q,
+		       unsigned int *nbuffers, unsigned int *nplanes,
+		       unsigned int sizes[], void *alloc_ctxs[])
+{
+	struct mxt_data *data = q->drv_priv;
+
+	*nbuffers = 1;
+	*nplanes = 1;
+	sizes[0] = data->dbg.t37_nodes * sizeof(u16);
+
+	return 0;
+}
+
+static int mxt_buffer_prepare(struct vb2_buffer *vb)
+{
+	return 0;
+}
+
+static void mxt_buffer_queue(struct vb2_buffer *vb)
+{
+	struct mxt_data *data = vb2_get_drv_priv(vb->vb2_queue);
+	u16 *ptr;
+	int ret;
+
+	ptr = vb2_plane_vaddr(vb, 0);
+	if (!ptr) {
+		dev_err(&data->client->dev, "Error acquiring frame ptr\n");
+		goto fault;
+	}
+
+	ret = mxt_read_diagnostic_debug(data, MXT_DIAGNOSTIC_DELTAS, ptr);
+	if (ret)
+		goto fault;
+
+	vb2_set_plane_payload(vb, 0, data->dbg.t37_nodes * sizeof(u16));
+	vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
+	return;
+
+fault:
+	vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
+}
+
+/* V4L2 structures */
+static const struct vb2_ops mxt_queue_ops = {
+	.queue_setup		= mxt_queue_setup,
+	.buf_prepare		= mxt_buffer_prepare,
+	.buf_queue		= mxt_buffer_queue,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+};
+
+static const struct vb2_queue mxt_queue = {
+	.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
+	.io_modes = VB2_MMAP,
+	.buf_struct_size = sizeof(struct mxt_vb2_buffer),
+	.ops = &mxt_queue_ops,
+	.mem_ops = &vb2_vmalloc_memops,
+	.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
+	.min_buffers_needed = 1,
+};
+
+static int mxt_vidioc_querycap(struct file *file, void *priv,
+				 struct v4l2_capability *cap)
+{
+	struct mxt_data *data = video_drvdata(file);
+
+	strlcpy(cap->driver, "atmel_mxt_ts", sizeof(cap->driver));
+	strlcpy(cap->card, "atmel_mxt_ts touch", sizeof(cap->card));
+	strlcpy(cap->bus_info, data->phys, sizeof(cap->bus_info));
+	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
+		V4L2_CAP_READWRITE |
+		V4L2_CAP_STREAMING;
+	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
+
+	return 0;
+}
+
+static int mxt_vidioc_enum_input(struct file *file, void *priv,
+				   struct v4l2_input *i)
+{
+	if (i->index > 0)
+		return -EINVAL;
+
+	i->type = V4L2_INPUT_TYPE_CAMERA;
+	i->std = V4L2_STD_UNKNOWN;
+	i->capabilities = 0;
+	strlcpy(i->name, "Mutual References", sizeof(i->name));
+	return 0;
+}
+
+static int mxt_set_input(struct mxt_data *data, unsigned int i)
+{
+	struct v4l2_pix_format *f = &data->dbg.format;
+
+	if (i > 0)
+		return -EINVAL;
+
+	f->width = data->info.matrix_xsize;
+	f->height = data->info.matrix_ysize;
+	f->pixelformat = V4L2_PIX_FMT_YS16;
+	f->field = V4L2_FIELD_NONE;
+	f->colorspace = V4L2_COLORSPACE_SRGB;
+	f->bytesperline = f->width * sizeof(u16);
+	f->sizeimage = f->width * f->height * sizeof(u16);
+
+	data->dbg.input = i;
+
+	return 0;
+}
+
+static int mxt_vidioc_s_input(struct file *file, void *priv, unsigned int i)
+{
+	return mxt_set_input(video_drvdata(file), i);
+}
+
+static int mxt_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
+{
+	struct mxt_data *data = video_drvdata(file);
+
+	*i = data->dbg.input;
+
+	return 0;
+}
+
+static int mxt_vidioc_fmt(struct file *file, void *priv, struct v4l2_format *f)
+{
+	struct mxt_data *data = video_drvdata(file);
+
+	f->fmt.pix = data->dbg.format;
+
+	return 0;
+}
+
+static int mxt_vidioc_enum_fmt(struct file *file, void *priv,
+				 struct v4l2_fmtdesc *fmt)
+{
+	if (fmt->index > 0 || fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	fmt->pixelformat = V4L2_PIX_FMT_YS16;
+	strlcpy(fmt->description, "16-bit raw debug data",
+		sizeof(fmt->description));
+	fmt->flags = 0;
+	return 0;
+}
+
+static int mxt_vidioc_enum_framesizes(struct file *file, void *priv,
+					struct v4l2_frmsizeenum *f)
+{
+	struct mxt_data *data = video_drvdata(file);
+
+	if (f->index > 0)
+		return -EINVAL;
+
+	f->discrete.width = data->info.matrix_xsize;
+	f->discrete.height = data->info.matrix_ysize;
+	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+	return 0;
+}
+
+static int mxt_vidioc_enum_frameintervals(struct file *file, void *priv,
+					  struct v4l2_frmivalenum *f)
+{
+	if ((f->index > 0) || (f->pixel_format != V4L2_PIX_FMT_YS16))
+		return -EINVAL;
+
+	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+	f->discrete.denominator  = 10;
+	f->discrete.numerator = 1;
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops mxt_video_ioctl_ops = {
+	.vidioc_querycap        = mxt_vidioc_querycap,
+
+	.vidioc_enum_fmt_vid_cap = mxt_vidioc_enum_fmt,
+	.vidioc_s_fmt_vid_cap   = mxt_vidioc_fmt,
+	.vidioc_g_fmt_vid_cap   = mxt_vidioc_fmt,
+
+	.vidioc_enum_framesizes = mxt_vidioc_enum_framesizes,
+	.vidioc_enum_frameintervals = mxt_vidioc_enum_frameintervals,
+
+	.vidioc_enum_input      = mxt_vidioc_enum_input,
+	.vidioc_g_input         = mxt_vidioc_g_input,
+	.vidioc_s_input         = mxt_vidioc_s_input,
+
+	.vidioc_reqbufs         = vb2_ioctl_reqbufs,
+	.vidioc_create_bufs     = vb2_ioctl_create_bufs,
+	.vidioc_querybuf        = vb2_ioctl_querybuf,
+	.vidioc_qbuf            = vb2_ioctl_qbuf,
+	.vidioc_dqbuf           = vb2_ioctl_dqbuf,
+	.vidioc_expbuf          = vb2_ioctl_expbuf,
+
+	.vidioc_streamon        = vb2_ioctl_streamon,
+	.vidioc_streamoff       = vb2_ioctl_streamoff,
+};
+
+static const struct video_device mxt_video_device = {
+	.name = "Atmel maxTouch",
+	.fops = &mxt_video_fops,
+	.ioctl_ops = &mxt_video_ioctl_ops,
+	.release = video_device_release_empty,
+};
+
 static void mxt_debug_init(struct mxt_data *data)
 {
 	struct mxt_dbg *dbg = &data->dbg;
 	struct mxt_object *object;
+	int error;
 
 	object = mxt_get_object(data, MXT_GEN_COMMAND_T6);
 	if (!object)
@@ -2187,8 +2421,45 @@ static void mxt_debug_init(struct mxt_data *data)
 	if (!dbg->t37_buf)
 		goto error;
 
+	/* init channel to zero */
+	mxt_set_input(data, 0);
+
+	/* register video device */
+	snprintf(dbg->v4l2.name, sizeof(dbg->v4l2.name), "%s", "atmel_mxt_ts");
+	error = v4l2_device_register(&data->client->dev, &dbg->v4l2);
+	if (error) {
+		dev_err(&data->client->dev, "Unable to register video master device.");
+		goto error;
+	}
+
+	/* initialize the queue */
+	mutex_init(&dbg->lock);
+	dbg->queue = mxt_queue;
+	dbg->queue.drv_priv = data;
+	dbg->queue.lock = &dbg->lock;
+
+	error = vb2_queue_init(&dbg->queue);
+	if (error)
+		goto error_unreg_v4l2;
+
+	dbg->vdev = mxt_video_device;
+	dbg->vdev.v4l2_dev = &dbg->v4l2;
+	dbg->vdev.lock = &dbg->lock;
+	dbg->vdev.vfl_dir = VFL_DIR_RX;
+	dbg->vdev.queue = &dbg->queue;
+	video_set_drvdata(&dbg->vdev, data);
+
+	error = video_register_device(&dbg->vdev, VFL_TYPE_TOUCH_SENSOR, -1);
+	if (error) {
+		dev_err(&data->client->dev,
+				"Unable to register video subdevice.");
+		goto error_unreg_v4l2;
+	}
+
 	return;
 
+error_unreg_v4l2:
+	v4l2_device_unregister(&dbg->v4l2);
 error:
 	dev_err(&data->client->dev, "Error initialising T37 diagnostic data\n");
 }
-- 
2.5.0

[PATCH v2 5/8] Input: atmel_mxt_ts - read touchscreen size

[Nick Dyer]

The touchscreen may have a margin where not all the matrix is used. Read
the parameters from T9 and T100 and take account of the difference.

Note: this does not read the XORIGIN/YORIGIN fields so it assumes that
the touchscreen starts at (0,0)

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 47 ++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 8 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 8945235..dbe0f2f 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -103,6 +103,8 @@ struct t7_config {
 
 /* MXT_TOUCH_MULTI_T9 field */
 #define MXT_T9_CTRL		0
+#define MXT_T9_XSIZE		3
+#define MXT_T9_YSIZE		4
 #define MXT_T9_ORIENT		9
 #define MXT_T9_RANGE		18
 
@@ -148,7 +150,9 @@ struct t37_debug {
 #define MXT_T100_CTRL		0
 #define MXT_T100_CFG1		1
 #define MXT_T100_TCHAUX		3
+#define MXT_T100_XSIZE		9
 #define MXT_T100_XRANGE		13
+#define MXT_T100_YSIZE		20
 #define MXT_T100_YRANGE		24
 
 #define MXT_T100_CFG_SWITCHXY	BIT(5)
@@ -257,6 +261,8 @@ struct mxt_data {
 	unsigned int max_x;
 	unsigned int max_y;
 	bool xy_switch;
+	u8 xsize;
+	u8 ysize;
 	bool in_bootloader;
 	u16 mem_size;
 	u8 t100_aux_ampl;
@@ -1710,6 +1716,18 @@ static int mxt_read_t9_resolution(struct mxt_data *data)
 		return -EINVAL;
 
 	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T9_XSIZE,
+			       sizeof(data->xsize), &data->xsize);
+	if (error)
+		return error;
+
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T9_YSIZE,
+			       sizeof(data->ysize), &data->ysize);
+	if (error)
+		return error;
+
+	error = __mxt_read_reg(client,
 			       object->start_address + MXT_T9_RANGE,
 			       sizeof(range), &range);
 	if (error)
@@ -1759,6 +1777,18 @@ static int mxt_read_t100_config(struct mxt_data *data)
 
 	data->max_y = get_unaligned_le16(&range_y);
 
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T100_XSIZE,
+			       sizeof(data->xsize), &data->xsize);
+	if (error)
+		return error;
+
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T100_YSIZE,
+			       sizeof(data->ysize), &data->ysize);
+	if (error)
+		return error;
+
 	/* read orientation config */
 	error =  __mxt_read_reg(client,
 				object->start_address + MXT_T100_CFG1,
@@ -2116,7 +2146,7 @@ static int mxt_convert_debug_pages(struct mxt_data *data, u16 *outbuf)
 		outbuf[i] = mxt_get_debug_value(data, x, y);
 
 		/* Next value */
-		if (++x >= data->info.matrix_xsize) {
+		if (++x >= data->xsize) {
 			x = 0;
 			y++;
 		}
@@ -2280,8 +2310,8 @@ static int mxt_set_input(struct mxt_data *data, unsigned int i)
 	if (i > 0)
 		return -EINVAL;
 
-	f->width = data->info.matrix_xsize;
-	f->height = data->info.matrix_ysize;
+	f->width = data->xsize;
+	f->height = data->ysize;
 	f->pixelformat = V4L2_PIX_FMT_YS16;
 	f->field = V4L2_FIELD_NONE;
 	f->colorspace = V4L2_COLORSPACE_SRGB;
@@ -2337,8 +2367,8 @@ static int mxt_vidioc_enum_framesizes(struct file *file, void *priv,
 	if (f->index > 0)
 		return -EINVAL;
 
-	f->discrete.width = data->info.matrix_xsize;
-	f->discrete.height = data->info.matrix_ysize;
+	f->discrete.width = data->xsize;
+	f->discrete.height = data->ysize;
 	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 	return 0;
 }
@@ -2411,9 +2441,10 @@ static void mxt_debug_init(struct mxt_data *data)
 	dbg->t37_address = object->start_address;
 
 	/* Calculate size of data and allocate buffer */
-	dbg->t37_nodes = data->info.matrix_xsize * data->info.matrix_ysize;
-	dbg->t37_pages = dbg->t37_nodes * sizeof(u16)
-					/ sizeof(dbg->t37_buf->data) + 1;
+	dbg->t37_nodes = data->xsize * data->ysize;
+	dbg->t37_pages = ((data->xsize * data->info.matrix_ysize)
+			  * sizeof(u16) / sizeof(dbg->t37_buf->data)) + 1;
+
 
 	dbg->t37_buf = devm_kzalloc(&data->client->dev,
 				     sizeof(struct t37_debug) * dbg->t37_pages,
-- 
2.5.0

[PATCH v2 6/8] Input: atmel_mxt_ts - handle diagnostic data orientation

[Nick Dyer]

Invert the diagnostic data to match the orientation of the input device.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index dbe0f2f..b4abd78 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -125,6 +125,8 @@ struct t9_range {
 
 /* MXT_TOUCH_MULTI_T9 orient */
 #define MXT_T9_ORIENT_SWITCH	(1 << 0)
+#define MXT_T9_ORIENT_INVERTX	(1 << 1)
+#define MXT_T9_ORIENT_INVERTY	(1 << 2)
 
 /* MXT_SPT_COMMSCONFIG_T18 */
 #define MXT_COMMS_CTRL		0
@@ -156,6 +158,8 @@ struct t37_debug {
 #define MXT_T100_YRANGE		24
 
 #define MXT_T100_CFG_SWITCHXY	BIT(5)
+#define MXT_T100_CFG_INVERTY	BIT(6)
+#define MXT_T100_CFG_INVERTX	BIT(7)
 
 #define MXT_T100_TCHAUX_VECT	BIT(0)
 #define MXT_T100_TCHAUX_AMPL	BIT(1)
@@ -260,6 +264,8 @@ struct mxt_data {
 	unsigned int irq;
 	unsigned int max_x;
 	unsigned int max_y;
+	bool invertx;
+	bool inverty;
 	bool xy_switch;
 	u8 xsize;
 	u8 ysize;
@@ -1743,6 +1749,8 @@ static int mxt_read_t9_resolution(struct mxt_data *data)
 		return error;
 
 	data->xy_switch = orient & MXT_T9_ORIENT_SWITCH;
+	data->invertx = orient & MXT_T9_ORIENT_INVERTX;
+	data->inverty = orient & MXT_T9_ORIENT_INVERTY;
 
 	return 0;
 }
@@ -1797,6 +1805,8 @@ static int mxt_read_t100_config(struct mxt_data *data)
 		return error;
 
 	data->xy_switch = cfg & MXT_T100_CFG_SWITCHXY;
+	data->invertx = cfg & MXT_T100_CFG_INVERTX;
+	data->inverty = cfg & MXT_T100_CFG_INVERTY;
 
 	/* allocate aux bytes */
 	error =  __mxt_read_reg(client,
@@ -2140,13 +2150,19 @@ static int mxt_convert_debug_pages(struct mxt_data *data, u16 *outbuf)
 	struct mxt_dbg *dbg = &data->dbg;
 	unsigned int x = 0;
 	unsigned int y = 0;
-	unsigned int i;
+	unsigned int i, rx, ry;
 
 	for (i = 0; i < dbg->t37_nodes; i++) {
-		outbuf[i] = mxt_get_debug_value(data, x, y);
+		/* Handle orientation */
+		rx = data->xy_switch ? y : x;
+		ry = data->xy_switch ? x : y;
+		rx = data->invertx ? (data->xsize - 1 - rx) : rx;
+		ry = data->inverty ? (data->ysize - 1 - ry) : ry;
+
+		outbuf[i] = mxt_get_debug_value(data, rx, ry);
 
 		/* Next value */
-		if (++x >= data->xsize) {
+		if (++x >= (data->xy_switch ? data->ysize : data->xsize)) {
 			x = 0;
 			y++;
 		}
@@ -2310,8 +2326,8 @@ static int mxt_set_input(struct mxt_data *data, unsigned int i)
 	if (i > 0)
 		return -EINVAL;
 
-	f->width = data->xsize;
-	f->height = data->ysize;
+	f->width = data->xy_switch ? data->ysize : data->xsize;
+	f->height = data->xy_switch ? data->xsize : data->ysize;
 	f->pixelformat = V4L2_PIX_FMT_YS16;
 	f->field = V4L2_FIELD_NONE;
 	f->colorspace = V4L2_COLORSPACE_SRGB;
@@ -2367,8 +2383,8 @@ static int mxt_vidioc_enum_framesizes(struct file *file, void *priv,
 	if (f->index > 0)
 		return -EINVAL;
 
-	f->discrete.width = data->xsize;
-	f->discrete.height = data->ysize;
+	f->discrete.width = data->xy_switch ? data->ysize : data->xsize;
+	f->discrete.height = data->xy_switch ? data->xsize : data->ysize;
 	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 	return 0;
 }
-- 
2.5.0

[PATCH v2 7/8] Input: atmel_mxt_ts - add diagnostic data support for mXT1386

[Nick Dyer]

The mXT1386 family of chips have a different architecture which splits
the diagnostic data into 3 columns.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index b4abd78..fca1096 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -137,6 +137,10 @@ struct t9_range {
 #define MXT_DIAGNOSTIC_DELTAS	0x10
 #define MXT_DIAGNOSTIC_SIZE	128
 
+#define MXT_FAMILY_1386			160
+#define MXT1386_COLUMNS			3
+#define MXT1386_PAGES_PER_COLUMN	8
+
 struct t37_debug {
 	u8 mode;
 	u8 page;
@@ -2135,13 +2139,27 @@ recheck:
 static u16 mxt_get_debug_value(struct mxt_data *data, unsigned int x,
 			       unsigned int y)
 {
+	struct mxt_info *info = &data->info;
 	struct mxt_dbg *dbg = &data->dbg;
 	unsigned int ofs, page;
+	unsigned int col = 0;
+	unsigned int col_width;
+
+	if (info->family_id == MXT_FAMILY_1386) {
+		col_width = info->matrix_ysize / MXT1386_COLUMNS;
+		col = y / col_width;
+		y = y % col_width;
+	} else {
+		col_width = info->matrix_ysize;
+	}
 
-	ofs = (y + (x * data->info.matrix_ysize)) * sizeof(u16);
+	ofs = (y + (x * col_width)) * sizeof(u16);
 	page = ofs / MXT_DIAGNOSTIC_SIZE;
 	ofs %= MXT_DIAGNOSTIC_SIZE;
 
+	if (info->family_id == MXT_FAMILY_1386)
+		page += col * MXT1386_PAGES_PER_COLUMN;
+
 	return get_unaligned_le16(&dbg->t37_buf[page].data[ofs]);
 }
 
@@ -2435,6 +2453,7 @@ static const struct video_device mxt_video_device = {
 
 static void mxt_debug_init(struct mxt_data *data)
 {
+	struct mxt_info *info = &data->info;
 	struct mxt_dbg *dbg = &data->dbg;
 	struct mxt_object *object;
 	int error;
@@ -2458,9 +2477,13 @@ static void mxt_debug_init(struct mxt_data *data)
 
 	/* Calculate size of data and allocate buffer */
 	dbg->t37_nodes = data->xsize * data->ysize;
-	dbg->t37_pages = ((data->xsize * data->info.matrix_ysize)
-			  * sizeof(u16) / sizeof(dbg->t37_buf->data)) + 1;
 
+	if (info->family_id == MXT_FAMILY_1386)
+		dbg->t37_pages = MXT1386_COLUMNS * MXT1386_PAGES_PER_COLUMN;
+	else
+		dbg->t37_pages = ((data->xsize * info->matrix_ysize)
+				   * sizeof(u16) / sizeof(dbg->t37_buf->data))
+				   + 1;
 
 	dbg->t37_buf = devm_kzalloc(&data->client->dev,
 				     sizeof(struct t37_debug) * dbg->t37_pages,
-- 
2.5.0

[PATCH v2 8/8] Input: atmel_mxt_ts - add support for reference data

[Nick Dyer]

There are different datatypes available from a maXTouch chip. Add
support to retrieve reference data as well.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 66 +++++++++++++++++++++++++++-----
 1 file changed, 56 insertions(+), 10 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index fca1096..1d9909f 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -135,6 +135,7 @@ struct t9_range {
 /* MXT_DEBUG_DIAGNOSTIC_T37 */
 #define MXT_DIAGNOSTIC_PAGEUP	0x01
 #define MXT_DIAGNOSTIC_DELTAS	0x10
+#define MXT_DIAGNOSTIC_REFS	0x11
 #define MXT_DIAGNOSTIC_SIZE	128
 
 #define MXT_FAMILY_1386			160
@@ -247,6 +248,12 @@ struct mxt_dbg {
 	int input;
 };
 
+enum v4l_dbg_inputs {
+	MXT_V4L_INPUT_DELTAS,
+	MXT_V4L_INPUT_REFS,
+	MXT_V4L_INPUT_MAX,
+};
+
 static const struct v4l2_file_operations mxt_video_fops = {
 	.owner = THIS_MODULE,
 	.open = v4l2_fh_open,
@@ -2270,6 +2277,7 @@ static void mxt_buffer_queue(struct vb2_buffer *vb)
 	struct mxt_data *data = vb2_get_drv_priv(vb->vb2_queue);
 	u16 *ptr;
 	int ret;
+	u8 mode;
 
 	ptr = vb2_plane_vaddr(vb, 0);
 	if (!ptr) {
@@ -2277,7 +2285,18 @@ static void mxt_buffer_queue(struct vb2_buffer *vb)
 		goto fault;
 	}
 
-	ret = mxt_read_diagnostic_debug(data, MXT_DIAGNOSTIC_DELTAS, ptr);
+	switch (data->dbg.input) {
+	case MXT_V4L_INPUT_DELTAS:
+	default:
+		mode = MXT_DIAGNOSTIC_DELTAS;
+		break;
+
+	case MXT_V4L_INPUT_REFS:
+		mode = MXT_DIAGNOSTIC_REFS;
+		break;
+	}
+
+	ret = mxt_read_diagnostic_debug(data, mode, ptr);
 	if (ret)
 		goto fault;
 
@@ -2327,13 +2346,22 @@ static int mxt_vidioc_querycap(struct file *file, void *priv,
 static int mxt_vidioc_enum_input(struct file *file, void *priv,
 				   struct v4l2_input *i)
 {
-	if (i->index > 0)
+	if (i->index >= MXT_V4L_INPUT_MAX)
 		return -EINVAL;
 
 	i->type = V4L2_INPUT_TYPE_CAMERA;
 	i->std = V4L2_STD_UNKNOWN;
 	i->capabilities = 0;
-	strlcpy(i->name, "Mutual References", sizeof(i->name));
+
+	switch (i->index) {
+	case MXT_V4L_INPUT_REFS:
+		strlcpy(i->name, "Mutual References", sizeof(i->name));
+		break;
+	case MXT_V4L_INPUT_DELTAS:
+		strlcpy(i->name, "Mutual Deltas", sizeof(i->name));
+		break;
+	}
+
 	return 0;
 }
 
@@ -2341,12 +2369,16 @@ static int mxt_set_input(struct mxt_data *data, unsigned int i)
 {
 	struct v4l2_pix_format *f = &data->dbg.format;
 
-	if (i > 0)
+	if (i >= MXT_V4L_INPUT_MAX)
 		return -EINVAL;
 
+	if (i == MXT_V4L_INPUT_DELTAS)
+		f->pixelformat = V4L2_PIX_FMT_YS16;
+	else
+		f->pixelformat = V4L2_PIX_FMT_Y16;
+
 	f->width = data->xy_switch ? data->ysize : data->xsize;
 	f->height = data->xy_switch ? data->xsize : data->ysize;
-	f->pixelformat = V4L2_PIX_FMT_YS16;
 	f->field = V4L2_FIELD_NONE;
 	f->colorspace = V4L2_COLORSPACE_SRGB;
 	f->bytesperline = f->width * sizeof(u16);
@@ -2383,12 +2415,26 @@ static int mxt_vidioc_fmt(struct file *file, void *priv, struct v4l2_format *f)
 static int mxt_vidioc_enum_fmt(struct file *file, void *priv,
 				 struct v4l2_fmtdesc *fmt)
 {
-	if (fmt->index > 0 || fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	switch (fmt->index) {
+	case 0:
+		fmt->pixelformat = V4L2_PIX_FMT_Y16;
+		strlcpy(fmt->description, "16-bit unsigned raw debug data",
+			sizeof(fmt->description));
+		break;
+
+	case 1:
+		fmt->pixelformat = V4L2_PIX_FMT_YS16;
+		strlcpy(fmt->description, "16-bit signed raw debug data",
+			sizeof(fmt->description));
+		break;
+
+	default:
 		return -EINVAL;
+	}
 
-	fmt->pixelformat = V4L2_PIX_FMT_YS16;
-	strlcpy(fmt->description, "16-bit raw debug data",
-		sizeof(fmt->description));
 	fmt->flags = 0;
 	return 0;
 }
@@ -2410,7 +2456,7 @@ static int mxt_vidioc_enum_framesizes(struct file *file, void *priv,
 static int mxt_vidioc_enum_frameintervals(struct file *file, void *priv,
 					  struct v4l2_frmivalenum *f)
 {
-	if ((f->index > 0) || (f->pixel_format != V4L2_PIX_FMT_YS16))
+	if (f->index > 0)
 		return -EINVAL;
 
 	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
-- 
2.5.0

Re: [PATCH v2 0/8] Input: atmel_mxt_ts - output raw touch diagnostic data via V4L

[Nick Dyer]

Hi Mauro, Hans, Dmitry, Henrik-

You kindly passed comment on this feature in its earlier form - would it be
possible to have some feedback on the updates?

It would be good to know whether we are on the right track with the V4L2
approach, because there is additional work that we want to base on it.

best regards

Nick

On 04/05/2016 18:07, Nick Dyer wrote:
> This is a series of patches to add diagnostic data support to the Atmel
> maXTouch driver. It's a rewrite of the previous implementation which output via
> debugfs: it now uses a V4L2 device in a similar way to the sur40 driver.
> 
> There are significant performance advantages to putting this code into the
> driver.  The algorithm for retrieving the data has been fairly consistent
> across a range of chips, with the exception of the mXT1386 series (see patch).
> 
> We have a utility which can read the data and display it in a useful format:
>     https://github.com/ndyer/heatmap/commits/heatmap-v4l
> 
> These patches are also available from
>     https://github.com/ndyer/linux/commits/diagnostic-v4l
> 
> Changes in v2:
> - Split pixfmt changes into separate commit and add DocBook
> - Introduce VFL_TYPE_TOUCH_SENSOR and /dev/v4l-touch
> - Remove "single node" support for now, it may be better to treat it as metadata later
> - Explicitly set VFL_DIR_RX
> - Fix Kconfig
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

Re: [PATCH v2 2/8] [media] Add signed 16-bit pixel format

[Hans Verkuil]

On 05/04/2016 07:07 PM, Nick Dyer wrote:
> This will be used for output of raw touch data.
> 
> Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
> ---
>  Documentation/DocBook/media/v4l/pixfmt-ys16.xml | 79 +++++++++++++++++++++++++
>  Documentation/DocBook/media/v4l/pixfmt.xml      |  1 +
>  drivers/media/v4l2-core/v4l2-ioctl.c            |  1 +
>  include/uapi/linux/videodev2.h                  |  1 +
>  4 files changed, 82 insertions(+)
>  create mode 100644 Documentation/DocBook/media/v4l/pixfmt-ys16.xml
> 
> diff --git a/Documentation/DocBook/media/v4l/pixfmt-ys16.xml b/Documentation/DocBook/media/v4l/pixfmt-ys16.xml
> new file mode 100644
> index 0000000..f92d65e
> --- /dev/null
> +++ b/Documentation/DocBook/media/v4l/pixfmt-ys16.xml
> @@ -0,0 +1,79 @@
> +<refentry id="V4L2-PIX-FMT-YS16">
> +  <refmeta>
> +    <refentrytitle>V4L2_PIX_FMT_YS16 ('YS16')</refentrytitle>
> +    &manvol;
> +  </refmeta>
> +  <refnamediv>
> +    <refname><constant>V4L2_PIX_FMT_YS16</constant></refname>
> +    <refpurpose>Grey-scale image</refpurpose>
> +  </refnamediv>
> +  <refsect1>
> +    <title>Description</title>
> +
> +    <para>This is a signed grey-scale image with a depth of 16 bits per
> +pixel. The most significant byte is stored at higher memory addresses
> +(little-endian).</para>

I'm not sure this should be described in terms of grey-scale, since negative
values make no sense for that. How are these values supposed to be interpreted
if you want to display them? -32768 == black and 32767 is white?

Regards,

	Hans

> +
> +    <example>
> +      <title><constant>V4L2_PIX_FMT_YS16</constant> 4 &times; 4
> +pixel image</title>
> +
> +      <formalpara>
> +	<title>Byte Order.</title>
> +	<para>Each cell is one byte.
> +	  <informaltable frame="none">
> +	    <tgroup cols="9" align="center">
> +	      <colspec align="left" colwidth="2*" />
> +	      <tbody valign="top">
> +		<row>
> +		  <entry>start&nbsp;+&nbsp;0:</entry>
> +		  <entry>Y'<subscript>00low</subscript></entry>
> +		  <entry>Y'<subscript>00high</subscript></entry>
> +		  <entry>Y'<subscript>01low</subscript></entry>
> +		  <entry>Y'<subscript>01high</subscript></entry>
> +		  <entry>Y'<subscript>02low</subscript></entry>
> +		  <entry>Y'<subscript>02high</subscript></entry>
> +		  <entry>Y'<subscript>03low</subscript></entry>
> +		  <entry>Y'<subscript>03high</subscript></entry>
> +		</row>
> +		<row>
> +		  <entry>start&nbsp;+&nbsp;8:</entry>
> +		  <entry>Y'<subscript>10low</subscript></entry>
> +		  <entry>Y'<subscript>10high</subscript></entry>
> +		  <entry>Y'<subscript>11low</subscript></entry>
> +		  <entry>Y'<subscript>11high</subscript></entry>
> +		  <entry>Y'<subscript>12low</subscript></entry>
> +		  <entry>Y'<subscript>12high</subscript></entry>
> +		  <entry>Y'<subscript>13low</subscript></entry>
> +		  <entry>Y'<subscript>13high</subscript></entry>
> +		</row>
> +		<row>
> +		  <entry>start&nbsp;+&nbsp;16:</entry>
> +		  <entry>Y'<subscript>20low</subscript></entry>
> +		  <entry>Y'<subscript>20high</subscript></entry>
> +		  <entry>Y'<subscript>21low</subscript></entry>
> +		  <entry>Y'<subscript>21high</subscript></entry>
> +		  <entry>Y'<subscript>22low</subscript></entry>
> +		  <entry>Y'<subscript>22high</subscript></entry>
> +		  <entry>Y'<subscript>23low</subscript></entry>
> +		  <entry>Y'<subscript>23high</subscript></entry>
> +		</row>
> +		<row>
> +		  <entry>start&nbsp;+&nbsp;24:</entry>
> +		  <entry>Y'<subscript>30low</subscript></entry>
> +		  <entry>Y'<subscript>30high</subscript></entry>
> +		  <entry>Y'<subscript>31low</subscript></entry>
> +		  <entry>Y'<subscript>31high</subscript></entry>
> +		  <entry>Y'<subscript>32low</subscript></entry>
> +		  <entry>Y'<subscript>32high</subscript></entry>
> +		  <entry>Y'<subscript>33low</subscript></entry>
> +		  <entry>Y'<subscript>33high</subscript></entry>
> +		</row>
> +	      </tbody>
> +	    </tgroup>
> +	  </informaltable>
> +	</para>
> +      </formalpara>
> +    </example>
> +  </refsect1>
> +</refentry>
> diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml
> index d871245..6f7aa0e 100644
> --- a/Documentation/DocBook/media/v4l/pixfmt.xml
> +++ b/Documentation/DocBook/media/v4l/pixfmt.xml
> @@ -1619,6 +1619,7 @@ information.</para>
>      &sub-y12;
>      &sub-y10b;
>      &sub-y16;
> +    &sub-ys16;
>      &sub-y16-be;
>      &sub-uv8;
>      &sub-yuyv;
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 8a018c6..c7dabaa 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1154,6 +1154,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>  	case V4L2_PIX_FMT_Y10:		descr = "10-bit Greyscale"; break;
>  	case V4L2_PIX_FMT_Y12:		descr = "12-bit Greyscale"; break;
>  	case V4L2_PIX_FMT_Y16:		descr = "16-bit Greyscale"; break;
> +	case V4L2_PIX_FMT_YS16:		descr = "16-bit Greyscale (Signed)"; break;
>  	case V4L2_PIX_FMT_Y16_BE:	descr = "16-bit Greyscale BE"; break;
>  	case V4L2_PIX_FMT_Y10BPACK:	descr = "10-bit Greyscale (Packed)"; break;
>  	case V4L2_PIX_FMT_PAL8:		descr = "8-bit Palette"; break;
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 14cd5eb..ab577dd 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -496,6 +496,7 @@ struct v4l2_pix_format {
>  #define V4L2_PIX_FMT_Y12     v4l2_fourcc('Y', '1', '2', ' ') /* 12  Greyscale     */
>  #define V4L2_PIX_FMT_Y16     v4l2_fourcc('Y', '1', '6', ' ') /* 16  Greyscale     */
>  #define V4L2_PIX_FMT_Y16_BE  v4l2_fourcc_be('Y', '1', '6', ' ') /* 16  Greyscale BE  */
> +#define V4L2_PIX_FMT_YS16    v4l2_fourcc('Y', 'S', '1', '6') /* signed 16-bit Greyscale */
>  
>  /* Grey bit-packed formats */
>  #define V4L2_PIX_FMT_Y10BPACK    v4l2_fourcc('Y', '1', '0', 'B') /* 10  Greyscale bit-packed */
> 

Re: [PATCH v2 2/8] [media] Add signed 16-bit pixel format

[Nick Dyer]

On 27/05/2016 13:38, Hans Verkuil wrote:
> On 05/04/2016 07:07 PM, Nick Dyer wrote:
>> +    <refname><constant>V4L2_PIX_FMT_YS16</constant></refname>
>> +    <refpurpose>Grey-scale image</refpurpose>
>> +  </refnamediv>
>> +  <refsect1>
>> +    <title>Description</title>
>> +
>> +    <para>This is a signed grey-scale image with a depth of 16 bits per
>> +pixel. The most significant byte is stored at higher memory addresses
>> +(little-endian).</para>
> 
> I'm not sure this should be described in terms of grey-scale, since negative
> values make no sense for that. How are these values supposed to be interpreted
> if you want to display them? -32768 == black and 32767 is white?

We have written a utility to display this data and it is able to display
the values mapped to grayscale or color:
https://github.com/ndyer/heatmap/blob/master/src/display.c#L44

An example of the output is here:
https://www.youtube.com/watch?v=Uj4T6fUCySw

The data is intrinsically signed because that's how the low level touch
controller treats it. I'm happy to change it to "Signed image" if you think
that would be better.

Re: [PATCH v2 4/8] Input: atmel_mxt_ts - output diagnostic debug via v4l2 device

[Hans Verkuil]

Hi Nick,

On 05/04/2016 07:07 PM, Nick Dyer wrote:
> Register a video device to output T37 diagnostic data.
> 
> Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
> ---
>  drivers/input/touchscreen/Kconfig        |   2 +
>  drivers/input/touchscreen/atmel_mxt_ts.c | 271 +++++++++++++++++++++++++++++++
>  2 files changed, 273 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 1f99e7f..4aa7609 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -105,6 +105,8 @@ config TOUCHSCREEN_AR1021_I2C
>  config TOUCHSCREEN_ATMEL_MXT
>  	tristate "Atmel mXT I2C Touchscreen"
>  	depends on I2C
> +	depends on VIDEO_V4L2
> +	select VIDEOBUF2_VMALLOC
>  	select FW_LOADER
>  	help
>  	  Say Y here if you have Atmel mXT series I2C touchscreen,
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index cd97713..8945235 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -28,6 +28,10 @@
>  #include <linux/of.h>
>  #include <linux/slab.h>
>  #include <asm/unaligned.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/videobuf2-v4l2.h>
> +#include <media/videobuf2-vmalloc.h>
>  
>  /* Firmware files */
>  #define MXT_FW_NAME		"maxtouch.fw"
> @@ -222,6 +226,23 @@ struct mxt_dbg {
>  	struct t37_debug *t37_buf;
>  	unsigned int t37_pages;
>  	unsigned int t37_nodes;
> +
> +	struct v4l2_device v4l2;
> +	struct v4l2_pix_format format;
> +	struct video_device vdev;
> +	struct vb2_queue queue;
> +	struct mutex lock;
> +	int input;
> +};
> +
> +static const struct v4l2_file_operations mxt_video_fops = {
> +	.owner = THIS_MODULE,
> +	.open = v4l2_fh_open,
> +	.release = vb2_fop_release,
> +	.unlocked_ioctl = video_ioctl2,
> +	.read = vb2_fop_read,
> +	.mmap = vb2_fop_mmap,
> +	.poll = vb2_fop_poll,
>  };
>  
>  /* Each client has this additional data */
> @@ -277,6 +298,11 @@ struct mxt_data {
>  	struct completion crc_completion;
>  };
>  
> +struct mxt_vb2_buffer {
> +	struct vb2_buffer	vb;
> +	struct list_head	list;
> +};
> +
>  static size_t mxt_obj_size(const struct mxt_object *obj)
>  {
>  	return obj->size_minus_one + 1;
> @@ -1523,6 +1549,9 @@ static void mxt_free_input_device(struct mxt_data *data)
>  
>  static void mxt_free_object_table(struct mxt_data *data)
>  {
> +	video_unregister_device(&data->dbg.vdev);
> +	v4l2_device_unregister(&data->dbg.v4l2);
> +
>  	kfree(data->object_table);
>  	data->object_table = NULL;
>  	kfree(data->msg_buf);
> @@ -2154,10 +2183,215 @@ wait_cmd:
>  	return mxt_convert_debug_pages(data, outbuf);
>  }
>  
> +static int mxt_queue_setup(struct vb2_queue *q,
> +		       unsigned int *nbuffers, unsigned int *nplanes,
> +		       unsigned int sizes[], void *alloc_ctxs[])
> +{
> +	struct mxt_data *data = q->drv_priv;
> +
> +	*nbuffers = 1;

That's not right. You can just drop this line since you've already set min_buffers_needed below.

This line forces vb2 to always allocate just one buffer, even if userspace wants more.

And in order to correctly support VIDIOC_CREATE_BUFS you need this:

        if (*nplanes)
                return sizes[0] < data->dbg.t37_nodes * sizeof(u16) ? -EINVAL : 0;

> +	*nplanes = 1;
> +	sizes[0] = data->dbg.t37_nodes * sizeof(u16);
> +
> +	return 0;
> +}
> +
> +static int mxt_buffer_prepare(struct vb2_buffer *vb)
> +{
> +	return 0;
> +}

Just drop this function since it doesn't do anything.

> +
> +static void mxt_buffer_queue(struct vb2_buffer *vb)
> +{
> +	struct mxt_data *data = vb2_get_drv_priv(vb->vb2_queue);
> +	u16 *ptr;
> +	int ret;
> +
> +	ptr = vb2_plane_vaddr(vb, 0);
> +	if (!ptr) {
> +		dev_err(&data->client->dev, "Error acquiring frame ptr\n");
> +		goto fault;
> +	}
> +
> +	ret = mxt_read_diagnostic_debug(data, MXT_DIAGNOSTIC_DELTAS, ptr);
> +	if (ret)
> +		goto fault;
> +
> +	vb2_set_plane_payload(vb, 0, data->dbg.t37_nodes * sizeof(u16));
> +	vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
> +	return;
> +
> +fault:
> +	vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
> +}
> +
> +/* V4L2 structures */
> +static const struct vb2_ops mxt_queue_ops = {
> +	.queue_setup		= mxt_queue_setup,
> +	.buf_prepare		= mxt_buffer_prepare,
> +	.buf_queue		= mxt_buffer_queue,
> +	.wait_prepare		= vb2_ops_wait_prepare,
> +	.wait_finish		= vb2_ops_wait_finish,
> +};
> +
> +static const struct vb2_queue mxt_queue = {
> +	.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
> +	.io_modes = VB2_MMAP,

Add VB2_USERPTR | VB2_DMABUF | VB2_READ here as well. You get that for free, so why not?

> +	.buf_struct_size = sizeof(struct mxt_vb2_buffer),
> +	.ops = &mxt_queue_ops,
> +	.mem_ops = &vb2_vmalloc_memops,
> +	.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
> +	.min_buffers_needed = 1,
> +};
> +
> +static int mxt_vidioc_querycap(struct file *file, void *priv,
> +				 struct v4l2_capability *cap)
> +{
> +	struct mxt_data *data = video_drvdata(file);
> +
> +	strlcpy(cap->driver, "atmel_mxt_ts", sizeof(cap->driver));
> +	strlcpy(cap->card, "atmel_mxt_ts touch", sizeof(cap->card));
> +	strlcpy(cap->bus_info, data->phys, sizeof(cap->bus_info));
> +	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
> +		V4L2_CAP_READWRITE |
> +		V4L2_CAP_STREAMING;
> +	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;

You can drop this line: it's now done for you by the v4l2 core code.

> +
> +	return 0;
> +}
> +
> +static int mxt_vidioc_enum_input(struct file *file, void *priv,
> +				   struct v4l2_input *i)
> +{
> +	if (i->index > 0)
> +		return -EINVAL;
> +
> +	i->type = V4L2_INPUT_TYPE_CAMERA;

I think we still need an V4L2_INPUT_TYPE_TOUCH_SENSOR here: it's just plain
weird to call this a camera IMHO.

> +	i->std = V4L2_STD_UNKNOWN;
> +	i->capabilities = 0;

Drop these two lines, v4l2_input is zeroed anyway.

> +	strlcpy(i->name, "Mutual References", sizeof(i->name));
> +	return 0;
> +}
> +
> +static int mxt_set_input(struct mxt_data *data, unsigned int i)
> +{
> +	struct v4l2_pix_format *f = &data->dbg.format;
> +
> +	if (i > 0)
> +		return -EINVAL;
> +
> +	f->width = data->info.matrix_xsize;
> +	f->height = data->info.matrix_ysize;
> +	f->pixelformat = V4L2_PIX_FMT_YS16;
> +	f->field = V4L2_FIELD_NONE;
> +	f->colorspace = V4L2_COLORSPACE_SRGB;

This makes no sense. Use COLORSPACE_RAW here.

> +	f->bytesperline = f->width * sizeof(u16);
> +	f->sizeimage = f->width * f->height * sizeof(u16);
> +
> +	data->dbg.input = i;
> +
> +	return 0;
> +}
> +
> +static int mxt_vidioc_s_input(struct file *file, void *priv, unsigned int i)
> +{
> +	return mxt_set_input(video_drvdata(file), i);
> +}
> +
> +static int mxt_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
> +{
> +	struct mxt_data *data = video_drvdata(file);
> +
> +	*i = data->dbg.input;
> +
> +	return 0;
> +}
> +
> +static int mxt_vidioc_fmt(struct file *file, void *priv, struct v4l2_format *f)
> +{
> +	struct mxt_data *data = video_drvdata(file);
> +
> +	f->fmt.pix = data->dbg.format;
> +
> +	return 0;
> +}
> +
> +static int mxt_vidioc_enum_fmt(struct file *file, void *priv,
> +				 struct v4l2_fmtdesc *fmt)
> +{
> +	if (fmt->index > 0 || fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	fmt->pixelformat = V4L2_PIX_FMT_YS16;
> +	strlcpy(fmt->description, "16-bit raw debug data",
> +		sizeof(fmt->description));

Don't set the description here. Instead set it in v4l2-ioctls.c so all drivers
that need this will use a consistent description string.

> +	fmt->flags = 0;

You can drop this line, it's zeroed when this function is called.

> +	return 0;
> +}
> +
> +static int mxt_vidioc_enum_framesizes(struct file *file, void *priv,
> +					struct v4l2_frmsizeenum *f)
> +{
> +	struct mxt_data *data = video_drvdata(file);
> +
> +	if (f->index > 0)
> +		return -EINVAL;
> +
> +	f->discrete.width = data->info.matrix_xsize;
> +	f->discrete.height = data->info.matrix_ysize;
> +	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
> +	return 0;
> +}
> +
> +static int mxt_vidioc_enum_frameintervals(struct file *file, void *priv,
> +					  struct v4l2_frmivalenum *f)
> +{
> +	if ((f->index > 0) || (f->pixel_format != V4L2_PIX_FMT_YS16))
> +		return -EINVAL;
> +
> +	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
> +	f->discrete.denominator  = 10;
> +	f->discrete.numerator = 1;
> +	return 0;
> +}

You can drop these two callbacks: since it is all fixed there is nothing to enumerate.

Instead you should implement g_parm so userspace can discover the framerate. That's all
that is needed.

> +
> +static const struct v4l2_ioctl_ops mxt_video_ioctl_ops = {
> +	.vidioc_querycap        = mxt_vidioc_querycap,
> +
> +	.vidioc_enum_fmt_vid_cap = mxt_vidioc_enum_fmt,
> +	.vidioc_s_fmt_vid_cap   = mxt_vidioc_fmt,
> +	.vidioc_g_fmt_vid_cap   = mxt_vidioc_fmt,
> +
> +	.vidioc_enum_framesizes = mxt_vidioc_enum_framesizes,
> +	.vidioc_enum_frameintervals = mxt_vidioc_enum_frameintervals,
> +
> +	.vidioc_enum_input      = mxt_vidioc_enum_input,
> +	.vidioc_g_input         = mxt_vidioc_g_input,
> +	.vidioc_s_input         = mxt_vidioc_s_input,
> +
> +	.vidioc_reqbufs         = vb2_ioctl_reqbufs,
> +	.vidioc_create_bufs     = vb2_ioctl_create_bufs,
> +	.vidioc_querybuf        = vb2_ioctl_querybuf,
> +	.vidioc_qbuf            = vb2_ioctl_qbuf,
> +	.vidioc_dqbuf           = vb2_ioctl_dqbuf,
> +	.vidioc_expbuf          = vb2_ioctl_expbuf,
> +
> +	.vidioc_streamon        = vb2_ioctl_streamon,
> +	.vidioc_streamoff       = vb2_ioctl_streamoff,
> +};
> +
> +static const struct video_device mxt_video_device = {
> +	.name = "Atmel maxTouch",
> +	.fops = &mxt_video_fops,
> +	.ioctl_ops = &mxt_video_ioctl_ops,
> +	.release = video_device_release_empty,
> +};
> +
>  static void mxt_debug_init(struct mxt_data *data)
>  {
>  	struct mxt_dbg *dbg = &data->dbg;
>  	struct mxt_object *object;
> +	int error;
>  
>  	object = mxt_get_object(data, MXT_GEN_COMMAND_T6);
>  	if (!object)
> @@ -2187,8 +2421,45 @@ static void mxt_debug_init(struct mxt_data *data)
>  	if (!dbg->t37_buf)
>  		goto error;
>  
> +	/* init channel to zero */
> +	mxt_set_input(data, 0);
> +
> +	/* register video device */
> +	snprintf(dbg->v4l2.name, sizeof(dbg->v4l2.name), "%s", "atmel_mxt_ts");
> +	error = v4l2_device_register(&data->client->dev, &dbg->v4l2);
> +	if (error) {
> +		dev_err(&data->client->dev, "Unable to register video master device.");
> +		goto error;
> +	}
> +
> +	/* initialize the queue */
> +	mutex_init(&dbg->lock);
> +	dbg->queue = mxt_queue;
> +	dbg->queue.drv_priv = data;
> +	dbg->queue.lock = &dbg->lock;
> +
> +	error = vb2_queue_init(&dbg->queue);
> +	if (error)
> +		goto error_unreg_v4l2;
> +
> +	dbg->vdev = mxt_video_device;
> +	dbg->vdev.v4l2_dev = &dbg->v4l2;
> +	dbg->vdev.lock = &dbg->lock;
> +	dbg->vdev.vfl_dir = VFL_DIR_RX;
> +	dbg->vdev.queue = &dbg->queue;
> +	video_set_drvdata(&dbg->vdev, data);
> +
> +	error = video_register_device(&dbg->vdev, VFL_TYPE_TOUCH_SENSOR, -1);
> +	if (error) {
> +		dev_err(&data->client->dev,
> +				"Unable to register video subdevice.");
> +		goto error_unreg_v4l2;
> +	}
> +
>  	return;
>  
> +error_unreg_v4l2:
> +	v4l2_device_unregister(&dbg->v4l2);
>  error:
>  	dev_err(&data->client->dev, "Error initialising T37 diagnostic data\n");
>  }
> 

BTW, did you run v4l2-compliance? I think it should work if you just do:

v4l2-compliance -d /dev/v4l-touch0

Regards,

	Hans

Re: [PATCH v2 8/8] Input: atmel_mxt_ts - add support for reference data

[Hans Verkuil]

On 05/04/2016 07:07 PM, Nick Dyer wrote:
> There are different datatypes available from a maXTouch chip. Add
> support to retrieve reference data as well.
> 
> Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
> ---
>  drivers/input/touchscreen/atmel_mxt_ts.c | 66 +++++++++++++++++++++++++++-----
>  1 file changed, 56 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index fca1096..1d9909f 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -135,6 +135,7 @@ struct t9_range {
>  /* MXT_DEBUG_DIAGNOSTIC_T37 */
>  #define MXT_DIAGNOSTIC_PAGEUP	0x01
>  #define MXT_DIAGNOSTIC_DELTAS	0x10
> +#define MXT_DIAGNOSTIC_REFS	0x11
>  #define MXT_DIAGNOSTIC_SIZE	128
>  
>  #define MXT_FAMILY_1386			160
> @@ -247,6 +248,12 @@ struct mxt_dbg {
>  	int input;
>  };
>  
> +enum v4l_dbg_inputs {
> +	MXT_V4L_INPUT_DELTAS,
> +	MXT_V4L_INPUT_REFS,
> +	MXT_V4L_INPUT_MAX,
> +};
> +
>  static const struct v4l2_file_operations mxt_video_fops = {
>  	.owner = THIS_MODULE,
>  	.open = v4l2_fh_open,
> @@ -2270,6 +2277,7 @@ static void mxt_buffer_queue(struct vb2_buffer *vb)
>  	struct mxt_data *data = vb2_get_drv_priv(vb->vb2_queue);
>  	u16 *ptr;
>  	int ret;
> +	u8 mode;
>  
>  	ptr = vb2_plane_vaddr(vb, 0);
>  	if (!ptr) {
> @@ -2277,7 +2285,18 @@ static void mxt_buffer_queue(struct vb2_buffer *vb)
>  		goto fault;
>  	}
>  
> -	ret = mxt_read_diagnostic_debug(data, MXT_DIAGNOSTIC_DELTAS, ptr);
> +	switch (data->dbg.input) {
> +	case MXT_V4L_INPUT_DELTAS:
> +	default:
> +		mode = MXT_DIAGNOSTIC_DELTAS;
> +		break;
> +
> +	case MXT_V4L_INPUT_REFS:
> +		mode = MXT_DIAGNOSTIC_REFS;
> +		break;
> +	}
> +
> +	ret = mxt_read_diagnostic_debug(data, mode, ptr);
>  	if (ret)
>  		goto fault;
>  
> @@ -2327,13 +2346,22 @@ static int mxt_vidioc_querycap(struct file *file, void *priv,
>  static int mxt_vidioc_enum_input(struct file *file, void *priv,
>  				   struct v4l2_input *i)
>  {
> -	if (i->index > 0)
> +	if (i->index >= MXT_V4L_INPUT_MAX)
>  		return -EINVAL;
>  
>  	i->type = V4L2_INPUT_TYPE_CAMERA;
>  	i->std = V4L2_STD_UNKNOWN;
>  	i->capabilities = 0;
> -	strlcpy(i->name, "Mutual References", sizeof(i->name));
> +
> +	switch (i->index) {
> +	case MXT_V4L_INPUT_REFS:
> +		strlcpy(i->name, "Mutual References", sizeof(i->name));
> +		break;
> +	case MXT_V4L_INPUT_DELTAS:
> +		strlcpy(i->name, "Mutual Deltas", sizeof(i->name));
> +		break;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -2341,12 +2369,16 @@ static int mxt_set_input(struct mxt_data *data, unsigned int i)
>  {
>  	struct v4l2_pix_format *f = &data->dbg.format;
>  
> -	if (i > 0)
> +	if (i >= MXT_V4L_INPUT_MAX)
>  		return -EINVAL;
>  
> +	if (i == MXT_V4L_INPUT_DELTAS)
> +		f->pixelformat = V4L2_PIX_FMT_YS16;
> +	else
> +		f->pixelformat = V4L2_PIX_FMT_Y16;
> +
>  	f->width = data->xy_switch ? data->ysize : data->xsize;
>  	f->height = data->xy_switch ? data->xsize : data->ysize;
> -	f->pixelformat = V4L2_PIX_FMT_YS16;
>  	f->field = V4L2_FIELD_NONE;
>  	f->colorspace = V4L2_COLORSPACE_SRGB;
>  	f->bytesperline = f->width * sizeof(u16);
> @@ -2383,12 +2415,26 @@ static int mxt_vidioc_fmt(struct file *file, void *priv, struct v4l2_format *f)
>  static int mxt_vidioc_enum_fmt(struct file *file, void *priv,
>  				 struct v4l2_fmtdesc *fmt)
>  {
> -	if (fmt->index > 0 || fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	switch (fmt->index) {
> +	case 0:
> +		fmt->pixelformat = V4L2_PIX_FMT_Y16;
> +		strlcpy(fmt->description, "16-bit unsigned raw debug data",
> +			sizeof(fmt->description));
> +		break;
> +
> +	case 1:
> +		fmt->pixelformat = V4L2_PIX_FMT_YS16;
> +		strlcpy(fmt->description, "16-bit signed raw debug data",
> +			sizeof(fmt->description));
> +		break;

Same as I mentioned in the other patch: don't set the description here.

> +
> +	default:
>  		return -EINVAL;
> +	}
>  
> -	fmt->pixelformat = V4L2_PIX_FMT_YS16;
> -	strlcpy(fmt->description, "16-bit raw debug data",
> -		sizeof(fmt->description));
>  	fmt->flags = 0;
>  	return 0;
>  }
> @@ -2410,7 +2456,7 @@ static int mxt_vidioc_enum_framesizes(struct file *file, void *priv,
>  static int mxt_vidioc_enum_frameintervals(struct file *file, void *priv,
>  					  struct v4l2_frmivalenum *f)
>  {
> -	if ((f->index > 0) || (f->pixel_format != V4L2_PIX_FMT_YS16))
> +	if (f->index > 0)
>  		return -EINVAL;
>  
>  	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
> 

Regards,

	Hans

Re: [PATCH v2 2/8] [media] Add signed 16-bit pixel format

[Hans Verkuil]

On 05/27/2016 02:52 PM, Nick Dyer wrote:
> On 27/05/2016 13:38, Hans Verkuil wrote:
>> On 05/04/2016 07:07 PM, Nick Dyer wrote:
>>> +    <refname><constant>V4L2_PIX_FMT_YS16</constant></refname>
>>> +    <refpurpose>Grey-scale image</refpurpose>
>>> +  </refnamediv>
>>> +  <refsect1>
>>> +    <title>Description</title>
>>> +
>>> +    <para>This is a signed grey-scale image with a depth of 16 bits per
>>> +pixel. The most significant byte is stored at higher memory addresses
>>> +(little-endian).</para>
>>
>> I'm not sure this should be described in terms of grey-scale, since negative
>> values make no sense for that. How are these values supposed to be interpreted
>> if you want to display them? -32768 == black and 32767 is white?
> 
> We have written a utility to display this data and it is able to display
> the values mapped to grayscale or color:
> https://github.com/ndyer/heatmap/blob/master/src/display.c#L44
> 
> An example of the output is here:
> https://www.youtube.com/watch?v=Uj4T6fUCySw
> 
> The data is intrinsically signed because that's how the low level touch
> controller treats it. I'm happy to change it to "Signed image" if you think
> that would be better.

A V4L2_PIX_FMT_ definition must specify the format unambiguously. So it is not
enough to just say that the data is a signed 16 bit value, you need to document
exactly how it should be interpreted. Looking at the code it seems that the
signed values are within a certain range and are normalized to 0-max by this line:

ssize_t gray = (data[i] - cfg->min) * max / (cfg->max - cfg->min);

Are the min/max values defined by the hardware? Because in that case this pixel
format has to be a hardware-specific define (e.g. V4L2_PIX_FMT_FOO_S16).

Only if the min/max values are -32768 and 32767 can you really use YS16 (not sure
yet about that name, but that's another issue).

Regards,

	Hans

Re: [PATCH v2 2/8] [media] Add signed 16-bit pixel format

[Nick Dyer]

On 27/05/2016 14:18, Hans Verkuil wrote:
> On 05/27/2016 02:52 PM, Nick Dyer wrote:
>> On 27/05/2016 13:38, Hans Verkuil wrote:
>>> On 05/04/2016 07:07 PM, Nick Dyer wrote:
>>>> +    <refname><constant>V4L2_PIX_FMT_YS16</constant></refname>
>>>> +    <refpurpose>Grey-scale image</refpurpose>
>>>> +  </refnamediv>
>>>> +  <refsect1>
>>>> +    <title>Description</title>
>>>> +
>>>> +    <para>This is a signed grey-scale image with a depth of 16 bits per
>>>> +pixel. The most significant byte is stored at higher memory addresses
>>>> +(little-endian).</para>
>>>
>>> I'm not sure this should be described in terms of grey-scale, since negative
>>> values make no sense for that. How are these values supposed to be interpreted
>>> if you want to display them? -32768 == black and 32767 is white?
>>
>> We have written a utility to display this data and it is able to display
>> the values mapped to grayscale or color:
>> https://github.com/ndyer/heatmap/blob/master/src/display.c#L44
>>
>> An example of the output is here:
>> https://www.youtube.com/watch?v=Uj4T6fUCySw
>>
>> The data is intrinsically signed because that's how the low level touch
>> controller treats it. I'm happy to change it to "Signed image" if you think
>> that would be better.
> 
> A V4L2_PIX_FMT_ definition must specify the format unambiguously. So it is not
> enough to just say that the data is a signed 16 bit value, you need to document
> exactly how it should be interpreted. Looking at the code it seems that the
> signed values are within a certain range and are normalized to 0-max by this line:
> 
> ssize_t gray = (data[i] - cfg->min) * max / (cfg->max - cfg->min);
> 
> Are the min/max values defined by the hardware? Because in that case this pixel
> format has to be a hardware-specific define (e.g. V4L2_PIX_FMT_FOO_S16).
> 
> Only if the min/max values are -32768 and 32767 can you really use YS16 (not sure
> yet about that name, but that's another issue).

I'm sorry, perhaps that is slightly misleading.

The data being output is the raw capacitance values from the analogue
front-end in the touch controller. Due to the physical characteristics,
there is a small range in the middle of the possible outputs of the ADC
which is interesting, and the heatmap tool allows mapping just that range
to the possible colors, otherwise everything would look mid-grey. So
heatmap is doing a job conceptually like adjusting the black point and
white point of a greyscale image to bring out the detail.

So the hardware itself doesn't have a conception of what those min/max
values are - from the hardware point of view the values may range from
-32768 to 32767 (in fact such values are commonly seen when one of the
touchscreen lines has a fault or is not connected).

Re: [PATCH v2 4/8] Input: atmel_mxt_ts - output diagnostic debug via v4l2 device

[Nick Dyer]

On 27/05/2016 13:54, Hans Verkuil wrote:
> Hi Nick,

Thanks for the useful review. Most of it is straightforward and I've
updated it in a new version of these patches which I will post now.

I think the open question is whether you're happy with the
V4L2_PIX_FMT_YS16 or whether I need to rename it. For what it's worth,
Synaptics RMI4 also emits 16 bit signed, see

https://github.com/wanam/Adam-Kernel-GS4/blob/master/drivers/input/touchscreen/rmi_f54.c#L1831

> On 05/04/2016 07:07 PM, Nick Dyer wrote:
> BTW, did you run v4l2-compliance? I think it should work if you just do:
> 
> v4l2-compliance -d /dev/v4l-touch0

Yes, and I've now fixed all issues that I could find with it. I had to do
some minor updates to support the touch sensor stuff, see:
    https://github.com/ndyer/v4l-utils/commits/touch-sensor