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
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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 
> ---
>  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 
>  #include 
>  #include 
> +#include 
> +#include 
> +#include 
> +#include 
>  
>  /* 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_headlist;
> +};
> +
>  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(>dbg.vdev);
> + v4l2_device_unregister(>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(>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 = _queue_ops,
> + .mem_ops = _vmalloc_memops,
> + .timestamp_flags = 

[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 
---
 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 
 #include 
 #include 
+#include 
+#include 
+#include 
+#include 
 
 /* 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_headlist;
+};
+
 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(>dbg.vdev);
+   v4l2_device_unregister(>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(>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 = _queue_ops,
+   .mem_ops = _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