[PATCH v4 2/2] media: platform: Add Aspeed Video Engine driver
Hans Verkuil
hverkuil at xs4all.nl
Wed Oct 17 21:41:09 AEDT 2018
On 10/05/2018 09:57 PM, Eddie James wrote:
> The Video Engine (VE) embedded in the Aspeed AST2400 and AST2500 SOCs
> can capture and compress video data from digital or analog sources. With
> the Aspeed chip acting a service processor, the Video Engine can capture
> the host processor graphics output.
>
> Add a V4L2 driver to capture video data and compress it to JPEG images.
> Make the video frames available through the V4L2 streaming interface.
>
> Signed-off-by: Eddie James <eajames at linux.ibm.com>
> ---
> MAINTAINERS | 8 +
> drivers/media/platform/Kconfig | 8 +
> drivers/media/platform/Makefile | 1 +
> drivers/media/platform/aspeed-video.c | 1674 +++++++++++++++++++++++++++++++++
> 4 files changed, 1691 insertions(+)
> create mode 100644 drivers/media/platform/aspeed-video.c
>
<snip>
> +static void aspeed_video_check_polarity(struct aspeed_video *video)
> +{
> + int i;
> + int hsync_counter = 0;
> + int vsync_counter = 0;
> + u32 sts;
> +
> + for (i = 0; i < NUM_POLARITY_CHECKS; ++i) {
> + sts = aspeed_video_read(video, VE_MODE_DETECT_STATUS);
> + if (sts & VE_MODE_DETECT_STATUS_VSYNC)
> + vsync_counter--;
> + else
> + vsync_counter++;
> +
> + if (sts & VE_MODE_DETECT_STATUS_HSYNC)
> + hsync_counter--;
> + else
> + hsync_counter++;
> + }
> +
> + if (hsync_counter < 0 || vsync_counter < 0) {
> + u32 ctrl;
> +
> + if (hsync_counter < 0)
> + ctrl = VE_CTRL_HSYNC_POL;
> + else
> + video->timings.polarities |= V4L2_DV_HSYNC_POS_POL;
> +
> + if (vsync_counter < 0)
> + ctrl = VE_CTRL_VSYNC_POL;
> + else
> + video->timings.polarities |= V4L2_DV_VSYNC_POS_POL;
> +
> + aspeed_video_update(video, VE_CTRL, 0, ctrl);
> + }
> +}
> +
> +static bool aspeed_video_alloc_buf(struct aspeed_video *video,
> + struct aspeed_video_addr *addr,
> + unsigned int size)
> +{
> + addr->virt = dma_alloc_coherent(video->dev, size, &addr->dma,
> + GFP_KERNEL);
> + if (!addr->virt)
> + return false;
> +
> + addr->size = size;
> + return true;
> +}
> +
> +static void aspeed_video_free_buf(struct aspeed_video *video,
> + struct aspeed_video_addr *addr)
> +{
> + dma_free_coherent(video->dev, addr->size, addr->virt, addr->dma);
> + addr->size = 0;
> + addr->dma = 0ULL;
> + addr->virt = NULL;
> +}
> +
> +/*
> + * Get the minimum HW-supported compression buffer size for the frame size.
> + * Assume worst-case JPEG compression size is 1/8 raw size. This should be
> + * plenty even for maximum quality; any worse and the engine will simply return
> + * incomplete JPEGs.
> + */
> +static void aspeed_video_calc_compressed_size(struct aspeed_video *video)
> +{
> + int i, j;
> + u32 compression_buffer_size_reg = 0;
> + unsigned int size;
> + const unsigned int num_compression_packets = 4;
> + const unsigned int compression_packet_size = 1024;
> + const unsigned int max_compressed_size =
> + video->width * video->height / 2; /* 4 Bpp / 8 */
> +
> + video->max_compressed_size = UINT_MAX;
> +
> + for (i = 0; i < 6; ++i) {
> + for (j = 0; j < 8; ++j) {
> + size = (num_compression_packets << i) *
> + (compression_packet_size << j);
> + if (size < max_compressed_size)
> + continue;
> +
> + if (size < video->max_compressed_size) {
> + compression_buffer_size_reg = (i << 3) | j;
> + video->max_compressed_size = size;
> + }
> + }
> + }
> +
> + aspeed_video_write(video, VE_STREAM_BUF_SIZE,
> + compression_buffer_size_reg);
> +
> + dev_dbg(video->dev, "max compressed size: %x\n",
> + video->max_compressed_size);
> +}
> +
> +#define res_check(v) test_and_clear_bit(VIDEO_MODE_DETECT_DONE, &(v)->flags)
> +
> +static int aspeed_video_get_resolution(struct aspeed_video *video)
> +{
> + bool invalid_resolution = true;
> + int rc;
> + int tries = 0;
> + unsigned int bottom;
> + unsigned int left;
> + unsigned int right;
> + unsigned int size;
> + unsigned int top;
> + u32 mds;
> + u32 src_lr_edge;
> + u32 src_tb_edge;
> + u32 sync;
> + struct aspeed_video_addr src;
> +
> + if (video->srcs[1].size)
> + aspeed_video_free_buf(video, &video->srcs[1]);
> +
> + if (video->srcs[0].size >= VE_MAX_SRC_BUFFER_SIZE) {
> + src = video->srcs[0];
> + } else {
> + if (video->srcs[0].size)
> + aspeed_video_free_buf(video, &video->srcs[0]);
> +
> + if (!aspeed_video_alloc_buf(video, &src,
> + VE_MAX_SRC_BUFFER_SIZE))
> + goto err_mem;
> + }
> +
> + aspeed_video_write(video, VE_SRC0_ADDR, src.dma);
> +
> + video->width = 0;
> + video->height = 0;
> +
> + do {
> + if (tries) {
> + set_current_state(TASK_INTERRUPTIBLE);
> + if (schedule_timeout(INVALID_RESOLUTION_DELAY))
> + return -EINTR;
> + }
> +
> + aspeed_video_start_mode_detect(video);
> +
> + rc = wait_event_interruptible_timeout(video->wait,
> + res_check(video),
> + MODE_DETECT_TIMEOUT);
> + if (!rc) {
> + dev_err(video->dev, "timed out on 1st mode detect\n");
> + aspeed_video_disable_mode_detect(video);
> + return -ETIMEDOUT;
> + }
> +
> + /* Disable mode detect in order to re-trigger */
> + aspeed_video_update(video, VE_SEQ_CTRL,
> + VE_SEQ_CTRL_TRIG_MODE_DET, 0);
> +
> + aspeed_video_check_polarity(video);
> +
> + aspeed_video_start_mode_detect(video);
> +
> + rc = wait_event_interruptible_timeout(video->wait,
> + res_check(video),
> + MODE_DETECT_TIMEOUT);
> + if (!rc) {
> + dev_err(video->dev, "timed out on 2nd mode detect\n");
> + aspeed_video_disable_mode_detect(video);
> + return -ETIMEDOUT;
> + }
> +
> + src_lr_edge = aspeed_video_read(video, VE_SRC_LR_EDGE_DET);
> + src_tb_edge = aspeed_video_read(video, VE_SRC_TB_EDGE_DET);
> + mds = aspeed_video_read(video, VE_MODE_DETECT_STATUS);
> + sync = aspeed_video_read(video, VE_SYNC_STATUS);
> +
> + bottom = (src_tb_edge & VE_SRC_TB_EDGE_DET_BOT) >>
> + VE_SRC_TB_EDGE_DET_BOT_SHF;
> + top = src_tb_edge & VE_SRC_TB_EDGE_DET_TOP;
> + video->timings.vfrontporch = top;
> + video->timings.vbackporch = ((mds & VE_MODE_DETECT_V_LINES) >>
> + VE_MODE_DETECT_V_LINES_SHF) - bottom;
> + video->timings.vsync = (sync & VE_SYNC_STATUS_VSYNC) >>
> + VE_SYNC_STATUS_VSYNC_SHF;
> + if (top > bottom)
> + continue;
> +
> + right = (src_lr_edge & VE_SRC_LR_EDGE_DET_RT) >>
> + VE_SRC_LR_EDGE_DET_RT_SHF;
> + left = src_lr_edge & VE_SRC_LR_EDGE_DET_LEFT;
> + video->timings.hfrontporch = left;
> + video->timings.hbackporch = (mds & VE_MODE_DETECT_H_PIXELS) -
> + right;
> + video->timings.hsync = sync & VE_SYNC_STATUS_HSYNC;
It's a bit odd that timings.width/height isn't set here.
> + if (left > right)
> + continue;
> +
> + invalid_resolution = false;
> + } while (invalid_resolution && (tries++ < INVALID_RESOLUTION_RETRIES));
> +
> + if (invalid_resolution) {
> + dev_err(video->dev, "invalid resolution detected\n");
> + return -ERANGE;
> + }
So far, so good. You now have detected the new resolution, but...
> +
> + video->height = (bottom - top) + 1;
> + video->width = (right - left) + 1;
> + size = video->height * video->width;
here and below you appear to actually switch the capture timings to the new
resolution as well.
That should only happen when s_dv_timings is called.
It is always very dangerous to automatically switch resolution since a new
resolution might mean larger buffers, and userspace has to prepare for that.
The normal sequence is:
1) the driver detects a change in resolution (or the video signal disappears
completely). It will send V4L2_EVENT_SOURCE_CHANGE to let userspace know.
2) Userspace stops streaming, frees all buffers, calls QUERY_DV_TIMINGS and,
if valid, follows with S_DV_TIMINGS.
3) Userspace calls REQBUFS to allocate the new buffers sized for the new timings
and starts streaming again.
That way everything remains under control of the application.
> +
> + /* Don't use direct mode below 1024 x 768 (irqs don't fire) */
> + if (size < DIRECT_FETCH_THRESHOLD) {
> + aspeed_video_write(video, VE_TGS_0,
> + FIELD_PREP(VE_TGS_FIRST, left - 1) |
> + FIELD_PREP(VE_TGS_LAST, right));
> + aspeed_video_write(video, VE_TGS_1,
> + FIELD_PREP(VE_TGS_FIRST, top) |
> + FIELD_PREP(VE_TGS_LAST, bottom + 1));
> + aspeed_video_update(video, VE_CTRL, 0, VE_CTRL_INT_DE);
> + } else {
> + aspeed_video_update(video, VE_CTRL, 0, VE_CTRL_DIRECT_FETCH);
> + }
> +
> + aspeed_video_write(video, VE_CAP_WINDOW,
> + video->width << 16 | video->height);
> + aspeed_video_write(video, VE_COMP_WINDOW,
> + video->width << 16 | video->height);
> + aspeed_video_write(video, VE_SRC_SCANLINE_OFFSET, video->width * 4);
> +
> + aspeed_video_update(video, VE_INTERRUPT_CTRL, 0,
> + VE_INTERRUPT_MODE_DETECT_WD);
> + aspeed_video_update(video, VE_SEQ_CTRL, 0,
> + VE_SEQ_CTRL_AUTO_COMP | VE_SEQ_CTRL_EN_WATCHDOG);
> +
> + dev_dbg(video->dev, "got resolution[%dx%d]\n", video->width,
> + video->height);
> +
> + size *= 4;
> + if (size == src.size / 2) {
> + aspeed_video_write(video, VE_SRC1_ADDR, src.dma + size);
> + video->srcs[0] = src;
> + } else if (size == src.size) {
> + video->srcs[0] = src;
> +
> + if (!aspeed_video_alloc_buf(video, &video->srcs[1], size))
> + goto err_mem;
> +
> + aspeed_video_write(video, VE_SRC1_ADDR, video->srcs[1].dma);
> + } else {
> + aspeed_video_free_buf(video, &src);
> +
> + if (!aspeed_video_alloc_buf(video, &video->srcs[0], size))
> + goto err_mem;
> +
> + if (!aspeed_video_alloc_buf(video, &video->srcs[1], size))
> + goto err_mem;
> +
> + aspeed_video_write(video, VE_SRC0_ADDR, video->srcs[0].dma);
> + aspeed_video_write(video, VE_SRC1_ADDR, video->srcs[1].dma);
> + }
> +
> + aspeed_video_calc_compressed_size(video);
> +
> + return 0;
> +
> +err_mem:
> + dev_err(video->dev, "failed to allocate source buffers\n");
> +
> + if (video->srcs[0].size)
> + aspeed_video_free_buf(video, &video->srcs[0]);
> +
> + return -ENOMEM;
> +}
Regards,
Hans
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