[PATCH v3] media: i2c-polling: add i2c-polling driver

Matt Ranostay
2016-11-23T01:19:52Z

There are several thermal sensors that only have a low-speed bus
interface but output valid video data. This patchset enables support
for the AMG88xx "Grid-Eye" sensor family.

Cc: Attila Kinali <attila@kinali.ch>
Cc: Marek Vasut <marex@denx.de>
Cc: Luca Barbato <lu_zero@gentoo.org>
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
---
Changes from v1:
* correct i2c_polling_remove() operations
* fixed delay calcuation in buffer_queue()
* add include linux/slab.h

Changes from v2:
* fix build error due to typo in include of slab.h

drivers/media/i2c/Kconfig | 8 +
drivers/media/i2c/Makefile | 1 +
drivers/media/i2c/i2c-polling.c | 469 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 478 insertions(+)
create mode 100644 drivers/media/i2c/i2c-polling.c

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index b31fa6fae009..d840e7be0036 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -768,6 +768,14 @@ config VIDEO_M52790

To compile this driver as a module, choose M here: the
module will be called m52790.
+
+config VIDEO_I2C_POLLING
+ tristate "I2C polling video support"
+ depends on VIDEO_V4L2 && I2C
+ select VIDEOBUF2_VMALLOC
+ ---help---
+ Enable the I2C polling video support which supports the following:
+ * Panasonic AMG88xx Grid-Eye Sensors
endmenu

menu "Sensors used on soc_camera driver"
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 92773b2e6225..8182ec9f66b9 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -79,6 +79,7 @@ obj-$(CONFIG_VIDEO_LM3646) += lm3646.o
obj-$(CONFIG_VIDEO_SMIAPP_PLL) += smiapp-pll.o
obj-$(CONFIG_VIDEO_AK881X) += ak881x.o
obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o
+obj-$(CONFIG_VIDEO_I2C_POLLING) += i2c-polling.o
obj-$(CONFIG_VIDEO_ML86V7667) += ml86v7667.o
obj-$(CONFIG_VIDEO_OV2659) += ov2659.o
obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
diff --git a/drivers/media/i2c/i2c-polling.c b/drivers/media/i2c/i2c-polling.c
new file mode 100644
index 000000000000..46a4eecde2d2
--- /dev/null
+++ b/drivers/media/i2c/i2c-polling.c
@@ -0,0 +1,469 @@
+/*
+ * i2c_polling.c - Support for polling I2C video devices
+ *
+ * Copyright (C) 2016 Matt Ranostay <mranostay@ranostay.consulting>
+ *
+ * Based on the orginal work drivers/media/parport/bw-qcam.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Supported:
+ * - Panasonic AMG88xx Grid-Eye Sensors
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/videodev2.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/videobuf2-vmalloc.h>
+
+#define I2C_POLLING_DRIVER "i2c-polling"
+
+struct i2c_polling_chip;
+
+struct i2c_polling_data {
+ struct i2c_client *client;
+ const struct i2c_polling_chip *chip;
+ struct mutex lock;
+ struct mutex queue_lock;
+ unsigned int last_update;
+
+ struct v4l2_device v4l2_dev;
+ struct video_device vdev;
+ struct vb2_queue vb_vidq;
+};
+
+static struct v4l2_fmtdesc amg88xx_format = {
+ .description = "12-bit Greyscale",
+ .pixelformat = V4L2_PIX_FMT_Y12,
+};
+
+static struct v4l2_frmsize_discrete amg88xx_size = {
+ .width = 8,
+ .height = 8,
+};
+
+struct i2c_polling_chip {
+ /* video dimensions */
+ struct v4l2_fmtdesc *format;
+ struct v4l2_frmsize_discrete *size;
+
+ /* max frames per second */
+ unsigned int max_fps;
+
+ /* pixel buffer size */
+ unsigned int buffer_size;
+
+ /* xfer function */
+ int (*xfer)(struct i2c_polling_data *data, char *buf);
+};
+
+enum {
+ AMG88XX = 0,
+ I2C_POLLING_CHIP_CNT,
+};
+
+static int amg88xx_xfer(struct i2c_polling_data *data, char *buf)
+{
+ struct i2c_client *client = data->client;
+ struct i2c_msg msg[2];
+ u8 reg = 0x80;
+ int ret;
+
+ msg[0].addr = client->addr;
+ msg[0].flags = 0;
+ msg[0].len = 1;
+ msg[0].buf = (char *) &reg;
+
+ msg[1].addr = client->addr;
+ msg[1].flags = I2C_M_RD;
+ msg[1].len = data->chip->buffer_size;
+ msg[1].buf = (char *) buf;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+
+ return (ret == 2) ? 0 : -EIO;
+}
+
+static const struct i2c_polling_chip i2c_polling_chips[I2C_POLLING_CHIP_CNT] = {
+ [AMG88XX] = {
+ .size = &amg88xx_size,
+ .format = &amg88xx_format,
+ .max_fps = 10,
+ .buffer_size = 128,
+ .xfer = &amg88xx_xfer,
+ },
+};
+
+static const struct v4l2_file_operations i2c_polling_fops = {
+ .owner = THIS_MODULE,
+ .open = v4l2_fh_open,
+ .release = vb2_fop_release,
+ .poll = vb2_fop_poll,
+ .unlocked_ioctl = video_ioctl2,
+ .read = vb2_fop_read,
+ .mmap = vb2_fop_mmap,
+};
+
+static int queue_setup(struct vb2_queue *vq,
+ unsigned int *nbuffers, unsigned int *nplanes,
+ unsigned int sizes[], struct device *alloc_devs[])
+{
+ struct i2c_polling_data *data = vb2_get_drv_priv(vq);
+
+ if (!(*nbuffers))
+ *nbuffers = 3;
+
+ *nplanes = 1;
+ sizes[0] = data->chip->buffer_size;
+
+ return 0;
+}
+
+static void buffer_queue(struct vb2_buffer *vb)
+{
+ struct i2c_polling_data *data = vb2_get_drv_priv(vb->vb2_queue);
+ unsigned int delay = 1000 / data->chip->max_fps;
+ int delta;
+
+ mutex_lock(&data->lock);
+
+ delta = jiffies - data->last_update;
+
+ if (delta < msecs_to_jiffies(delay)) {
+ int tmp = (delay - jiffies_to_msecs(delta)) * 1000;
+
+ usleep_range(tmp, tmp + 1000);
+ }
+ data->last_update = jiffies;
+
+ mutex_unlock(&data->lock);
+
+ vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
+}
+
+static void buffer_finish(struct vb2_buffer *vb)
+{
+ struct i2c_polling_data *data = vb2_get_drv_priv(vb->vb2_queue);
+ void *vbuf = vb2_plane_vaddr(vb, 0);
+ int size = vb2_plane_size(vb, 0);
+ int ret;
+
+ mutex_lock(&data->lock);
+
+ ret = data->chip->xfer(data, vbuf);
+ if (ret < 0)
+ vb->state = VB2_BUF_STATE_ERROR;
+
+ mutex_unlock(&data->lock);
+
+ vb->timestamp = ktime_get_ns();
+ vb2_set_plane_payload(vb, 0, ret ? 0 : size);
+}
+
+static struct vb2_ops i2c_polling_video_qops = {
+ .queue_setup = queue_setup,
+ .buf_queue = buffer_queue,
+ .buf_finish = buffer_finish,
+ .wait_prepare = vb2_ops_wait_prepare,
+ .wait_finish = vb2_ops_wait_finish,
+};
+
+static int i2c_polling_querycap(struct file *file, void *priv,
+ struct v4l2_capability *vcap)
+{
+ struct i2c_polling_data *data = video_drvdata(file);
+
+ strlcpy(vcap->driver, data->v4l2_dev.name, sizeof(vcap->driver));
+ strlcpy(vcap->card, "I2C Polling Video", sizeof(vcap->card));
+
+ strlcpy(vcap->bus_info, "I2C:i2c-polling", sizeof(vcap->bus_info));
+ vcap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
+ V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
+ vcap->capabilities = vcap->device_caps | V4L2_CAP_DEVICE_CAPS;
+
+ return 0;
+}
+
+static int i2c_polling_g_input(struct file *file, void *fh, unsigned int *inp)
+{
+ *inp = 0;
+
+ return 0;
+}
+
+static int i2c_polling_s_input(struct file *file, void *fh, unsigned int inp)
+{
+ return (inp > 0) ? -EINVAL : 0;
+}
+
+static int i2c_polling_enum_input(struct file *file, void *fh,
+ struct v4l2_input *vin)
+{
+ if (vin->index > 0)
+ return -EINVAL;
+
+ strlcpy(vin->name, "Camera", sizeof(vin->name));
+
+ vin->type = V4L2_INPUT_TYPE_CAMERA;
+ vin->audioset = 0;
+ vin->tuner = 0;
+ vin->std = 0;
+ vin->status = 0;
+
+ return 0;
+}
+
+static int i2c_polling_enum_fmt_vid_cap(struct file *file, void *fh,
+ struct v4l2_fmtdesc *fmt)
+{
+ struct i2c_polling_data *data = video_drvdata(file);
+ enum v4l2_buf_type type = fmt->type;
+
+ if (fmt->index > 0)
+ return -EINVAL;
+
+ *fmt = *data->chip->format;
+ fmt->type = type;
+
+ return 0;
+}
+
+static int i2c_polling_enum_framesizes(struct file *file, void *fh,
+ struct v4l2_frmsizeenum *fsize)
+{
+ struct i2c_polling_data *data = video_drvdata(file);
+ struct v4l2_frmsize_discrete *size = data->chip->size;
+
+ /* currently only one frame size is allowed */
+ if (fsize->index > 0)
+ return -EINVAL;
+
+ if (fsize->pixel_format != data->chip->format->pixelformat)
+ return -EINVAL;
+
+ fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+ fsize->discrete.width = size->width;
+ fsize->discrete.height = size->height;
+
+ return 0;
+}
+
+static int i2c_polling_enum_frameintervals(struct file *file, void *priv,
+ struct v4l2_frmivalenum *fe)
+{
+ struct i2c_polling_data *data = video_drvdata(file);
+ struct v4l2_frmsize_discrete *size = data->chip->size;
+
+ if (fe->index > 0)
+ return -EINVAL;
+
+ if ((fe->width != size->width) || (fe->height != size->height))
+ return -EINVAL;
+
+ fe->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+ fe->discrete.numerator = 1;
+ fe->discrete.denominator = data->chip->max_fps;
+
+ return 0;
+}
+
+static int i2c_polling_try_fmt_vid_cap(struct file *file, void *fh,
+ struct v4l2_format *fmt)
+{
+ struct i2c_polling_data *data = video_drvdata(file);
+ struct v4l2_pix_format *pix = &fmt->fmt.pix;
+ struct v4l2_frmsize_discrete *size = data->chip->size;
+
+ pix->width = size->width;
+ pix->height = size->height;
+ pix->pixelformat = data->chip->format->pixelformat;
+ pix->field = V4L2_FIELD_NONE;
+ pix->bytesperline = pix->width * 2;
+ pix->sizeimage = pix->width * pix->height * 2;
+ pix->colorspace = V4L2_COLORSPACE_SRGB;
+ pix->priv = 0;
+
+ return 0;
+}
+
+static int i2c_polling_fmt_vid_cap(struct file *file, void *fh,
+ struct v4l2_format *fmt)
+{
+ struct i2c_polling_data *data = video_drvdata(file);
+ int ret = i2c_polling_try_fmt_vid_cap(file, fh, fmt);
+
+ if (ret < 0)
+ return ret;
+
+ if (vb2_is_busy(&data->vb_vidq))
+ return -EBUSY;
+
+ return 0;
+}
+
+static int i2c_polling_g_parm(struct file *filp, void *priv,
+ struct v4l2_streamparm *parm)
+{
+ struct i2c_polling_data *data = video_drvdata(filp);
+
+ if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+ return -EINVAL;
+
+ parm->parm.capture.readbuffers = 3;
+ parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
+ parm->parm.capture.timeperframe.numerator = 1;
+ parm->parm.capture.timeperframe.denominator = data->chip->max_fps;
+
+ return 0;
+}
+
+static int i2c_polling_s_parm(struct file *filp, void *priv,
+ struct v4l2_streamparm *parm)
+{
+ if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+ return -EINVAL;
+
+ return i2c_polling_g_parm(filp, priv, parm);
+}
+
+static const struct v4l2_ioctl_ops i2c_polling_ioctl_ops = {
+ .vidioc_querycap = i2c_polling_querycap,
+ .vidioc_g_input = i2c_polling_g_input,
+ .vidioc_s_input = i2c_polling_s_input,
+ .vidioc_enum_input = i2c_polling_enum_input,
+ .vidioc_enum_fmt_vid_cap = i2c_polling_enum_fmt_vid_cap,
+ .vidioc_enum_framesizes = i2c_polling_enum_framesizes,
+ .vidioc_enum_frameintervals = i2c_polling_enum_frameintervals,
+ .vidioc_g_fmt_vid_cap = i2c_polling_fmt_vid_cap,
+ .vidioc_s_fmt_vid_cap = i2c_polling_fmt_vid_cap,
+ .vidioc_g_parm = i2c_polling_g_parm,
+ .vidioc_s_parm = i2c_polling_s_parm,
+ .vidioc_try_fmt_vid_cap = i2c_polling_try_fmt_vid_cap,
+ .vidioc_reqbufs = vb2_ioctl_reqbufs,
+ .vidioc_create_bufs = vb2_ioctl_create_bufs,
+ .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
+ .vidioc_querybuf = vb2_ioctl_querybuf,
+ .vidioc_qbuf = vb2_ioctl_qbuf,
+ .vidioc_dqbuf = vb2_ioctl_dqbuf,
+ .vidioc_streamon = vb2_ioctl_streamon,
+ .vidioc_streamoff = vb2_ioctl_streamoff,
+ .vidioc_log_status = v4l2_ctrl_log_status,
+ .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
+ .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+};
+
+static int i2c_polling_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_polling_data *data;
+ struct v4l2_device *v4l2_dev;
+ struct vb2_queue *queue;
+ int ret;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->chip = &i2c_polling_chips[id->driver_data];
+ data->client = client;
+ data->last_update = jiffies;
+ v4l2_dev = &data->v4l2_dev;
+ strlcpy(v4l2_dev->name, I2C_POLLING_DRIVER, sizeof(v4l2_dev->name));
+
+ ret = v4l2_device_register(&client->dev, v4l2_dev);
+ if (ret < 0)
+ goto error_free_device;
+
+ mutex_init(&data->lock);
+ mutex_init(&data->queue_lock);
+
+ queue = &data->vb_vidq;
+ queue->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ queue->io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
+ queue->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+ queue->drv_priv = data;
+ queue->ops = &i2c_polling_video_qops;
+ queue->mem_ops = &vb2_vmalloc_memops;
+
+ ret = vb2_queue_init(queue);
+ if (ret < 0)
+ goto error_free_device;
+
+ data->vdev.queue = queue;
+ data->vdev.queue->lock = &data->queue_lock;
+
+ strlcpy(data->vdev.name, "I2C Polling Video", sizeof(data->vdev.name));
+
+ data->vdev.v4l2_dev = v4l2_dev;
+ data->vdev.fops = &i2c_polling_fops;
+ data->vdev.lock = &data->lock;
+ data->vdev.ioctl_ops = &i2c_polling_ioctl_ops;
+ data->vdev.release = video_device_release_empty;
+
+ video_set_drvdata(&data->vdev, data);
+ i2c_set_clientdata(client, data);
+
+ ret = video_register_device(&data->vdev, VFL_TYPE_GRABBER, -1);
+ if (ret < 0)
+ goto error_unregister_device;
+
+ return 0;
+
+error_unregister_device:
+ v4l2_device_unregister(v4l2_dev);
+
+error_free_device:
+ kfree(data);
+
+ return ret;
+}
+
+static int i2c_polling_remove(struct i2c_client *client)
+{
+ struct i2c_polling_data *data = i2c_get_clientdata(client);
+
+ v4l2_device_unregister(&data->v4l2_dev);
+ video_unregister_device(&data->vdev);
+ kfree(data);
+
+ return 0;
+}
+
+static const struct i2c_device_id i2c_polling_id_table[] = {
+ { "amg88xx", AMG88XX },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, i2c_polling_id_table);
+
+static struct i2c_driver i2c_polling_driver = {
+ .driver = {
+ .name = I2C_POLLING_DRIVER,
+ },
+ .probe = i2c_polling_probe,
+ .remove = i2c_polling_remove,
+ .id_table = i2c_polling_id_table,
+};
+
+module_i2c_driver(i2c_polling_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@ranostay.consulting>");
+MODULE_DESCRIPTION("I2C polling video support");
+MODULE_LICENSE("GPL");
--
2.7.4