drivers/media/common/saa7146/saa7146_vbi.c
Source file repositories/reference/linux-study-clean/drivers/media/common/saa7146/saa7146_vbi.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/media/common/saa7146/saa7146_vbi.c- Extension
.c- Size
- 12341 bytes
- Lines
- 446
- Domain
- Driver Families
- Bucket
- drivers/media
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
media/drv-intf/saa7146_vv.h
Detected Declarations
function vbi_workaroundfunction saa7146_set_vbi_capturefunction buffer_activatefunction queue_setupfunction buf_queuefunction buf_initfunction buf_preparefunction buf_cleanupfunction return_buffersfunction vbi_stopfunction vbi_read_timeoutfunction vbi_beginfunction start_streamingfunction stop_streamingfunction vbi_initfunction vbi_irq_done
Annotated Snippet
if(signal_pending(current)) {
DEB_VBI("aborted (rps:0x%08x)\n",
saa7146_read(dev, RPS_ADDR1));
/* stop rps1 for sure */
saa7146_write(dev, MC1, MASK_29);
dma_free_coherent(&dev->pci->dev, 4096, cpu, dma_addr);
return -EINTR;
}
}
dma_free_coherent(&dev->pci->dev, 4096, cpu, dma_addr);
return 0;
}
static void saa7146_set_vbi_capture(struct saa7146_dev *dev, struct saa7146_buf *buf, struct saa7146_buf *next)
{
struct saa7146_vv *vv = dev->vv_data;
struct saa7146_video_dma vdma3;
int count = 0;
unsigned long e_wait = vv->current_hps_sync == SAA7146_HPS_SYNC_PORT_A ? CMD_E_FID_A : CMD_E_FID_B;
unsigned long o_wait = vv->current_hps_sync == SAA7146_HPS_SYNC_PORT_A ? CMD_O_FID_A : CMD_O_FID_B;
/*
vdma3.base_even = 0xc8000000+2560*70;
vdma3.base_odd = 0xc8000000;
vdma3.prot_addr = 0xc8000000+2560*164;
vdma3.pitch = 2560;
vdma3.base_page = 0;
vdma3.num_line_byte = (64<<16)|((vbi_pixel_to_capture)<<0); // set above!
*/
vdma3.base_even = buf->pt[2].offset;
vdma3.base_odd = buf->pt[2].offset + 16 * vbi_pixel_to_capture;
vdma3.prot_addr = buf->pt[2].offset + 16 * 2 * vbi_pixel_to_capture;
vdma3.pitch = vbi_pixel_to_capture;
vdma3.base_page = buf->pt[2].dma | ME1;
vdma3.num_line_byte = (16 << 16) | vbi_pixel_to_capture;
saa7146_write_out_dma(dev, 3, &vdma3);
/* write beginning of rps-program */
count = 0;
/* wait for o_fid_a/b / e_fid_a/b toggle only if bit 1 is not set */
/* we don't wait here for the first field anymore. this is different from the video
capture and might cause that the first buffer is only half filled (with only
one field). but since this is some sort of streaming data, this is not that negative.
but by doing this, we can use the whole engine from videobuf-dma-sg.c... */
/*
WRITE_RPS1(CMD_PAUSE | CMD_OAN | CMD_SIG1 | e_wait);
WRITE_RPS1(CMD_PAUSE | CMD_OAN | CMD_SIG1 | o_wait);
*/
/* set bit 1 */
WRITE_RPS1(CMD_WR_REG | (1 << 8) | (MC2/4));
WRITE_RPS1(MASK_28 | MASK_12);
/* turn on video-dma3 */
WRITE_RPS1(CMD_WR_REG_MASK | (MC1/4));
WRITE_RPS1(MASK_04 | MASK_20); /* => mask */
WRITE_RPS1(MASK_04 | MASK_20); /* => values */
/* wait for o_fid_a/b / e_fid_a/b toggle */
WRITE_RPS1(CMD_PAUSE | o_wait);
WRITE_RPS1(CMD_PAUSE | e_wait);
/* generate interrupt */
WRITE_RPS1(CMD_INTERRUPT);
/* stop */
WRITE_RPS1(CMD_STOP);
/* enable rps1 irqs */
SAA7146_IER_ENABLE(dev, MASK_28);
/* write the address of the rps-program */
saa7146_write(dev, RPS_ADDR1, dev->d_rps1.dma_handle);
/* turn on rps */
saa7146_write(dev, MC1, (MASK_13 | MASK_29));
}
static int buffer_activate(struct saa7146_dev *dev,
struct saa7146_buf *buf,
struct saa7146_buf *next)
Annotation
- Immediate include surface: `media/drv-intf/saa7146_vv.h`.
- Detected declarations: `function vbi_workaround`, `function saa7146_set_vbi_capture`, `function buffer_activate`, `function queue_setup`, `function buf_queue`, `function buf_init`, `function buf_prepare`, `function buf_cleanup`, `function return_buffers`, `function vbi_stop`.
- Atlas domain: Driver Families / drivers/media.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.