> -Original Message-
> From: Pawel Osciak [mailto:p.osc...@samsung.com]
> Sent: Monday, April 19, 2010 6:00 PM
> To: linux-media@vger.kernel.org
> Cc: p.osc...@samsung.com; m.szyprow...@samsung.com;
> kyungmin.p...@samsung.com; Hiremath, Vaibhav
> Subject: [PATCH v4 1/2] v4l: Add memory-to-memory device helper framework
> for videobuf.
>
> A mem-to-mem device is a device that uses memory buffers passed by
> userspace applications for both their source and destination data. This
> is different from existing drivers, which utilize memory buffers for either
> input or output, but not both.
>
> In terms of V4L2 such a device would be both of OUTPUT and CAPTURE type.
>
> Examples of such devices would be: image 'resizers', 'rotators',
> 'colorspace converters', etc.
>
> This patch adds a separate Kconfig sub-menu for mem-to-mem devices as well.
[Hiremath, Vaibhav] Some minor comments (which just came across now) -
>
> Signed-off-by: Pawel Osciak
> Signed-off-by: Marek Szyprowski
> Reviewed-by: Kyungmin Park
> ---
> drivers/media/video/Kconfig| 14 +
> drivers/media/video/Makefile |2 +
> drivers/media/video/v4l2-mem2mem.c | 632
>
> include/media/v4l2-mem2mem.h | 201
> 4 files changed, 849 insertions(+), 0 deletions(-)
> create mode 100644 drivers/media/video/v4l2-mem2mem.c
> create mode 100644 include/media/v4l2-mem2mem.h
>
> diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> index f8fc865..5fd041e 100644
> --- a/drivers/media/video/Kconfig
> +++ b/drivers/media/video/Kconfig
> @@ -45,6 +45,10 @@ config VIDEO_TUNER
> tristate
> depends on MEDIA_TUNER
>
> +config V4L2_MEM2MEM_DEV
> + tristate
> + depends on VIDEOBUF_GEN
> +
> #
> # Multimedia Video device configuration
> #
> @@ -1107,3 +,13 @@ config USB_S2255
>
> endif # V4L_USB_DRIVERS
> endif # VIDEO_CAPTURE_DRIVERS
> +
> +menuconfig V4L_MEM2MEM_DRIVERS
> + bool "Memory-to-memory multimedia devices"
> + depends on VIDEO_V4L2
> + default n
> + ---help---
> + Say Y here to enable selecting drivers for V4L devices that
> + use system memory for both source and destination buffers, as
> opposed
> + to capture and output drivers, which use memory buffers for just
> + one of those.
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index b88b617..e974680 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -117,6 +117,8 @@ obj-$(CONFIG_VIDEOBUF_VMALLOC) += videobuf-vmalloc.o
> obj-$(CONFIG_VIDEOBUF_DVB) += videobuf-dvb.o
> obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o
>
> +obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
> +
> obj-$(CONFIG_VIDEO_M32R_AR_M64278) += arv.o
>
> obj-$(CONFIG_VIDEO_CX2341X) += cx2341x.o
> diff --git a/drivers/media/video/v4l2-mem2mem.c b/drivers/media/video/v4l2-
> mem2mem.c
> new file mode 100644
> index 000..eee9514
> --- /dev/null
> +++ b/drivers/media/video/v4l2-mem2mem.c
> @@ -0,0 +1,632 @@
> +/*
> + * Memory-to-memory device framework for Video for Linux 2 and videobuf.
> + *
> + * Helper functions for devices that use videobuf buffers for both their
> + * source and destination.
> + *
> + * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
> + * Pawel Osciak,
> + * Marek Szyprowski,
> + *
> + * 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.
> + */
> +#include
> +#include
> +#include
[Hiremath, Vaibhav] Add one line here.
> +#include
> +#include
> +
> +MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
> +MODULE_AUTHOR("Pawel Osciak, ");
> +MODULE_LICENSE("GPL");
> +
> +static bool debug;
> +module_param(debug, bool, 0644);
> +
> +#define dprintk(fmt, arg...) \
> + do {\
> + if (debug) \
> + printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
> + } while (0)
> +
> +
> +/* Instance is already queued on the job_queue */
> +#define TRANS_QUEUED (1 << 0)
> +/* Instance is currently running in hardware */
> +#define TRANS_RUNNING(1 << 1)
> +
> +
> +/* Offset base for buffers on the destination queue - used to distinguish
> + * between source and destination buffers when mmapping - they receive the
> same
> + * offsets but for different queues */
> +#define DST_QUEUE_OFF_BASE (1 << 30)
> +
> +
> +/**
> + * struct v4l2_m2m_dev - per-device context
> + * @curr_ctx:currently running instance
> + * @job_queue: instances queued to run
> + * @job_spinlock:protects job_queue
> + * @m2m_ops: driver callbacks
> + */
> +stru
