Re: [PATCH v3 4/8] Input: atmel_mxt_ts - output diagnostic debug via v4l2 device

Dmitry Torokhov
2016-06-01T18:14:14Z

On Wed, Jun 01, 2016 at 05:39:48PM +0100, 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 | 247 +++++++++++++++++++++++++++++++
> 2 files changed, 249 insertions(+)
>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 8ecdc38..73154b6 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

Hmm.. can we possibly stub this out? I do not think we want to depend on
V4L2 unconditionally.

> + 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 21f42ed..8608cb1 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 +2183,191 @@ 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;
> + size_t size = data->dbg.t37_nodes * sizeof(u16);
> +
> + if (*nplanes)
> + return sizes[0] < size ? -EINVAL : 0;
> +
> + *nplanes = 1;
> + sizes[0] = size;
> +
> + 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_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 | VB2_USERPTR | VB2_DMABUF | VB2_READ,
> + .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));
> + snprintf(cap->bus_info, sizeof(cap->bus_info),
> + "I2C:%s", dev_name(&data->client->dev));
> + 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_TOUCH_SENSOR;
> + 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_RAW;
> + 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->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> + 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;
> + return 0;
> +}
> +
> +static int mxt_vidioc_g_parm(struct file *file, void *fh,
> + struct v4l2_streamparm *a)
> +{
> + if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> + return -EINVAL;
> +
> + a->parm.capture.readbuffers = 1;
> + a->parm.capture.timeperframe.numerator = 1;
> + a->parm.capture.timeperframe.denominator = 10;
> + 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_try_fmt_vid_cap = mxt_vidioc_fmt,
> + .vidioc_g_parm = mxt_vidioc_g_parm,
> +
> + .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,
> + .device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
> + V4L2_CAP_STREAMING,
> +};
> +
> 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 +2397,45 @@ 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
>

--
Dmitry