/* * cx18 init/start/stop/exit stream functions * * Derived from ivtv-streams.c * * Copyright (C) 2007 Hans Verkuil * Copyright (C) 2008 Andy Walls * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA * 02111-1307 USA */ #include "cx18-driver.h" #include "cx18-io.h" #include "cx18-fileops.h" #include "cx18-mailbox.h" #include "cx18-i2c.h" #include "cx18-queue.h" #include "cx18-ioctl.h" #include "cx18-streams.h" #include "cx18-cards.h" #include "cx18-scb.h" #include "cx18-dvb.h" #define CX18_DSP0_INTERRUPT_MASK 0xd0004C static struct v4l2_file_operations cx18_v4l2_enc_fops = { .owner = THIS_MODULE, .read = cx18_v4l2_read, .open = cx18_v4l2_open, /* FIXME change to video_ioctl2 if serialization lock can be removed */ .ioctl = cx18_v4l2_ioctl, .release = cx18_v4l2_close, .poll = cx18_v4l2_enc_poll, }; /* offset from 0 to register ts v4l2 minors on */ #define CX18_V4L2_ENC_TS_OFFSET 16 /* offset from 0 to register pcm v4l2 minors on */ #define CX18_V4L2_ENC_PCM_OFFSET 24 /* offset from 0 to register yuv v4l2 minors on */ #define CX18_V4L2_ENC_YUV_OFFSET 32 static struct { const char *name; int vfl_type; int num_offset; int dma; enum v4l2_buf_type buf_type; } cx18_stream_info[] = { { /* CX18_ENC_STREAM_TYPE_MPG */ "encoder MPEG", VFL_TYPE_GRABBER, 0, PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE, }, { /* CX18_ENC_STREAM_TYPE_TS */ "TS", VFL_TYPE_GRABBER, -1, PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE, }, { /* CX18_ENC_STREAM_TYPE_YUV */ "encoder YUV", VFL_TYPE_GRABBER, CX18_V4L2_ENC_YUV_OFFSET, PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE, }, { /* CX18_ENC_STREAM_TYPE_VBI */ "encoder VBI", VFL_TYPE_VBI, 0, PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VBI_CAPTURE, }, { /* CX18_ENC_STREAM_TYPE_PCM */ "encoder PCM audio", VFL_TYPE_GRABBER, CX18_V4L2_ENC_PCM_OFFSET, PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_PRIVATE, }, { /* CX18_ENC_STREAM_TYPE_IDX */ "encoder IDX", VFL_TYPE_GRABBER, -1, PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE, }, { /* CX18_ENC_STREAM_TYPE_RAD */ "encoder radio", VFL_TYPE_RADIO, 0, PCI_DMA_NONE, V4L2_BUF_TYPE_PRIVATE, }, }; static void cx18_stream_init(struct cx18 *cx, int type) { struct cx18_stream *s = &cx->streams[type]; struct video_device *video_dev = s->video_dev; /* we need to keep video_dev, so restore it afterwards */ memset(s, 0, sizeof(*s)); s->video_dev = video_dev; /* initialize cx18_stream fields */ s->cx = cx; s->type = type; s->name = cx18_stream_info[type].name; s->handle = CX18_INVALID_TASK_HANDLE; s->dma = cx18_stream_info[type].dma; s->buffers = cx->stream_buffers[type]; s->buf_size = cx->stream_buf_size[type]; init_waitqueue_head(&s->waitq); s->id = -1; spin_lock_init(&s->q_free.lock); cx18_queue_init(&s->q_free); spin_lock_init(&s->q_busy.lock); cx18_queue_init(&s->q_busy); spin_lock_init(&s->q_full.lock); cx18_queue_init(&s->q_full); INIT_WORK(&s->out_work_order, cx18_out_work_handler); } static int cx18_prep_dev(struct cx18 *cx, int type) { struct cx18_stream *s = &cx->streams[type]; u32 cap = cx->v4l2_cap; int num_offset = cx18_stream_info[type].num_offset; int num = cx->instance + cx18_first_minor + num_offset; /* These four fields are always initialized. If video_dev == NULL, then this stream is not in use. In that case no other fields but these four can be used. */ s->video_dev = NULL; s->cx = cx; s->type = type; s->name = cx18_stream_info[type].name; /* Check whether the radio is supported */ if (type == CX18_ENC_STREAM_TYPE_RAD && !(cap & V4L2_CAP_RADIO)) return 0; /* Check whether VBI is supported */ if (type == CX18_ENC_STREAM_TYPE_VBI && !(cap & (V4L2_CAP_VBI_CAPTURE | V4L2_CAP_SLICED_VBI_CAPTURE))) return 0; /* User explicitly selected 0 buffers for these streams, so don't create them. */ if (cx18_stream_info[type].dma != PCI_DMA_NONE && cx->stream_buffers[type] == 0) { CX18_INFO("Disabled %s device\n", cx18_stream_info[type].name); return 0; } cx18_stream_init(cx, type); if (num_offset == -1) return 0; /* allocate and initialize the v4l2 video device structure */ s->video_dev = video_device_alloc(); if (s->video_dev == NULL) { CX18_ERR("Couldn't allocate v4l2 video_device for %s\n", s->name); return -ENOMEM; } snprintf(s->video_dev->name, sizeof(s->video_dev->name), "%s %s", cx->v4l2_dev.name, s->name); s->video_dev->num = num; s->video_dev->v4l2_dev = &cx->v4l2_dev; s->video_dev->fops = &cx18_v4l2_enc_fops; s->video_dev->release = video_device_release; s->video_dev->tvnorms = V4L2_STD_ALL; cx18_set_funcs(s->video_dev); return 0; } /* Initialize v4l2 variables and register v4l2 devices */ int cx18_streams_setup(struct cx18 *cx) { int type, ret; /* Setup V4L2 Devices */ for (type = 0; type < CX18_MAX_STREAMS; type++) { /* Prepare device */ ret = cx18_prep_dev(cx, type); if (ret < 0) break; /* Allocate Stream */ ret = cx18_stream_alloc(&cx->streams[type]); if (ret < 0) break; } if (type == CX18_MAX_STREAMS) return 0; /* One or more streams could not be initialized. Clean 'em all up. */ cx18_streams_cleanup(cx, 0); return ret; } static int cx18_reg_dev(struct cx18 *cx, int type) { struct cx18_stream *s = &cx->streams[type]; int vfl_type = cx18_stream_info[type].vfl_type; int num, ret; /* TODO: Shouldn't this be a VFL_TYPE_TRANSPORT or something? * We need a VFL_TYPE_TS defined. */ if (strcmp("TS", s->name) == 0) { /* just return if no DVB is supported */ if ((cx->card->hw_all & CX18_HW_DVB) == 0) return 0; ret = cx18_dvb_register(s); if (ret < 0) { CX18_ERR("DVB failed to register\n"); return ret; } } if (s->video_dev == NULL) return 0; num = s->video_dev->num; /* card number + user defined offset + device offset */ if (type != CX18_ENC_STREAM_TYPE_MPG) { struct cx18_stream *s_mpg = &cx->streams[CX18_ENC_STREAM_TYPE_MPG]; if (s_mpg->video_dev) num = s_mpg->video_dev->num + cx18_stream_info[type].num_offset; } video_set_drvdata(s->video_dev, s); /* Register device. First try the desired minor, then any free one. */ ret = video_register_device(s->video_dev, vfl_type, num); if (ret < 0) { CX18_ERR("Couldn't register v4l2 device for %s kernel number %d\n", s->name, num); video_device_release(s->video_dev); s->video_dev = NULL; return ret; } num = s->video_dev->num; switch (vfl_type) { case VFL_TYPE_GRABBER: CX18_INFO("Registered device video%d for %s (%d x %d kB)\n", num, s->name, cx->stream_buffers[type], cx->stream_buf_size[type]/1024); break; case VFL_TYPE_RADIO: CX18_INFO("Registered device radio%d for %s\n", num, s->name); break; case VFL_TYPE_VBI: if (cx->stream_buffers[type]) CX18_INFO("Registered device vbi%d for %s " "(%d x %d bytes)\n", num, s->name, cx->stream_buffers[type], cx->stream_buf_size[type]); else CX18_INFO("Registered device vbi%d for %s\n", num, s->name); break; } return 0; } /* Register v4l2 devices */ int cx18_streams_register(struct cx18 *cx) { int type; int err; int ret = 0; /* Register V4L2 devices */ for (type = 0; type < CX18_MAX_STREAMS; type++) { err = cx18_reg_dev(cx, type); if (err && ret == 0) ret = err; } if (ret == 0) return 0; /* One or more streams could not be initialized. Clean 'em all up. */ cx18_streams_cleanup(cx, 1); return ret; } /* Unregister v4l2 devices */ void cx18_streams_cleanup(struct cx18 *cx, int unregister) { struct video_device *vdev; int type; /* Teardown all streams */ for (type = 0; type < CX18_MAX_STREAMS; type++) { if (cx->streams[type].dvb.enabled) { cx18_dvb_unregister(&cx->streams[type]); cx->streams[type].dvb.enabled = false; } vdev = cx->streams[type].video_dev; cx->streams[type].video_dev = NULL; if (vdev == NULL) continue; cx18_stream_free(&cx->streams[type]); /* Unregister or release device */ if (unregister) video_unregister_device(vdev); else video_device_release(vdev); } } static void cx18_vbi_setup(struct cx18_stream *s) { struct cx18 *cx = s->cx; int raw = cx18_raw_vbi(cx); u32 data[CX2341X_MBOX_MAX_DATA]; int lines; if (cx->is_60hz) { cx->vbi.count = 12; cx->vbi.start[0] = 10; cx->vbi.start[1] = 273; } else { /* PAL/SECAM */ cx->vbi.count = 18; cx->vbi.start[0] = 6; cx->vbi.start[1] = 318; } /* setup VBI registers */ v4l2_subdev_call(cx->sd_av, video, s_fmt, &cx->vbi.in); /* * Send the CX18_CPU_SET_RAW_VBI_PARAM API command to setup Encoder Raw * VBI when the first analog capture channel starts, as once it starts * (e.g. MPEG), we can't effect any change in the Encoder Raw VBI setup * (i.e. for the VBI capture channels). We also send it for each * analog capture channel anyway just to make sure we get the proper * behavior */ if (raw) { lines = cx->vbi.count * 2; } else { /* * For 525/60 systems, according to the VIP 2 & BT.656 std: * The EAV RP code's Field bit toggles on line 4, a few lines * after the Vertcal Blank bit has already toggled. * Tell the encoder to capture 21-4+1=18 lines per field, * since we want lines 10 through 21. * * FIXME - revisit for 625/50 systems */ lines = cx->is_60hz ? (21 - 4 + 1) * 2 : 38; } data[0] = s->handle; /* Lines per field */ data[1] = (lines / 2) | ((lines / 2) << 16); /* bytes per line */ data[2] = (raw ? vbi_active_samples : (cx->is_60hz ? vbi_hblank_samples_60Hz : vbi_hblank_samples_50Hz)); /* Every X number of frames a VBI interrupt arrives (frames as in 25 or 30 fps) */ data[3] = 1; /* * Set the SAV/EAV RP codes to look for as start/stop points * when in VIP-1.1 mode */ if (raw) { /* * Start codes for beginning of "active" line in vertical blank * 0x20 ( VerticalBlank ) * 0x60 ( EvenField VerticalBlank ) */ data[4] = 0x20602060; /* * End codes for end of "active" raw lines and regular lines * 0x30 ( VerticalBlank HorizontalBlank) * 0x70 ( EvenField VerticalBlank HorizontalBlank) * 0x90 (Task HorizontalBlank) * 0xd0 (Task EvenField HorizontalBlank) */ data[5] = 0x307090d0; } else { /* * End codes for active video, we want data in the hblank region * 0xb0 (Task 0 VerticalBlank HorizontalBlank) * 0xf0 (Task EvenField VerticalBlank HorizontalBlank) * * Since the V bit is only allowed to toggle in the EAV RP code, * just before the first active region line, these two * are problematic: * 0x90 (Task HorizontalBlank) * 0xd0 (Task EvenField HorizontalBlank) * * We have set the digitzer such that we don't have to worry * about these problem codes. */ data[4] = 0xB0F0B0F0; /* * Start codes for beginning of active line in vertical blank * 0xa0 (Task VerticalBlank ) * 0xe0 (Task EvenField VerticalBlank ) */ data[5] = 0xA0E0A0E0; } CX18_DEBUG_INFO("Setup VBI h: %d lines %x bpl %d fr %d %x %x\n", data[0], data[1], data[2], data[3], data[4], data[5]); cx18_api(cx, CX18_CPU_SET_RAW_VBI_PARAM, 6, data); } static struct cx18_queue *_cx18_stream_put_buf_fw(struct cx18_stream *s, struct cx18_buffer *buf) { struct cx18 *cx = s->cx; struct cx18_queue *q; /* Don't give it to the firmware, if we're not running a capture */ if (s->handle == CX18_INVALID_TASK_HANDLE || test_bit(CX18_F_S_STOPPING, &s->s_flags) || !test_bit(CX18_F_S_STREAMING, &s->s_flags)) return cx18_enqueue(s, buf, &s->q_free); q = cx18_enqueue(s, buf, &s->q_busy); if (q != &s->q_busy) return q; /* The firmware has the max buffers it can handle */ cx18_buf_sync_for_device(s, buf); cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle, (void __iomem *) &cx->scb->cpu_mdl[buf->id] - cx->enc_mem, 1, buf->id, s->buf_size); return q; } static void _cx18_stream_load_fw_queue(struct cx18_stream *s) { struct cx18_queue *q; struct cx18_buffer *buf; if (atomic_read(&s->q_free.buffers) == 0 || atomic_read(&s->q_busy.buffers) >= CX18_MAX_FW_MDLS_PER_STREAM) return; /* Move from q_free to q_busy notifying the firmware, until the limit */ do { buf = cx18_dequeue(s, &s->q_free); if (buf == NULL) break; q = _cx18_stream_put_buf_fw(s, buf); } while (atomic_read(&s->q_busy.buffers) < CX18_MAX_FW_MDLS_PER_STREAM && q == &s->q_busy); } void cx18_out_work_handler(struct work_struct *work) { struct cx18_stream *s = container_of(work, struct cx18_stream, out_work_order); _cx18_stream_load_fw_queue(s); } int cx18_start_v4l2_encode_stream(struct cx18_stream *s) { u32 data[MAX_MB_ARGUMENTS]; struct cx18 *cx = s->cx; struct cx18_buffer *buf; int captype = 0; struct cx18_api_func_private priv; if (s->video_dev == NULL && s->dvb.enabled == 0) return -EINVAL; CX18_DEBUG_INFO("Start encoder stream %s\n", s->name); switch (s->type) { case CX18_ENC_STREAM_TYPE_MPG: captype = CAPTURE_CHANNEL_TYPE_MPEG; cx->mpg_data_received = cx->vbi_data_inserted = 0; cx->dualwatch_jiffies = jiffies; cx->dualwatch_stereo_mode = cx->params.audio_properties & 0x300; cx->search_pack_header = 0; break; case CX18_ENC_STREAM_TYPE_TS: captype = CAPTURE_CHANNEL_TYPE_TS; break; case CX18_ENC_STREAM_TYPE_YUV: captype = CAPTURE_CHANNEL_TYPE_YUV; break; case CX18_ENC_STREAM_TYPE_PCM: captype = CAPTURE_CHANNEL_TYPE_PCM; break; case CX18_ENC_STREAM_TYPE_VBI: #ifdef CX18_ENCODER_PARSES_SLICED captype = cx18_raw_vbi(cx) ? CAPTURE_CHANNEL_TYPE_VBI : CAPTURE_CHANNEL_TYPE_SLICED_VBI; #else /* * Currently we set things up so that Sliced VBI from the * digitizer is handled as Raw VBI by the encoder */ captype = CAPTURE_CHANNEL_TYPE_VBI; #endif cx->vbi.frame = 0; cx->vbi.inserted_frame = 0; memset(cx->vbi.sliced_mpeg_size, 0, sizeof(cx->vbi.sliced_mpeg_size)); break; default: return -EINVAL; } /* Clear Streamoff flags in case left from last capture */ clear_bit(CX18_F_S_STREAMOFF, &s->s_flags); cx18_vapi_result(cx, data, CX18_CREATE_TASK, 1, CPU_CMD_MASK_CAPTURE); s->handle = data[0]; cx18_vapi(cx, CX18_CPU_SET_CHANNEL_TYPE, 2, s->handle, captype); /* * For everything but CAPTURE_CHANNEL_TYPE_TS, play it safe and * set up all the parameters, as it is not obvious which parameters the * firmware shares across capture channel types and which it does not. * * Some of the cx18_vapi() calls below apply to only certain capture * channel types. We're hoping there's no harm in calling most of them * anyway, as long as the values are all consistent. Setting some * shared parameters will have no effect once an analog capture channel * has started streaming. */ if (captype != CAPTURE_CHANNEL_TYPE_TS) { cx18_vapi(cx, CX18_CPU_SET_VER_CROP_LINE, 2, s->handle, 0); cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 3, 1); cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 8, 0); cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 4, 1); /* * Audio related reset according to * Documentation/video4linux/cx2341x/fw-encoder-api.txt */ if (atomic_read(&cx->ana_capturing) == 0) cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 2, s->handle, 12); /* * Number of lines for Field 1 & Field 2 according to * Documentation/video4linux/cx2341x/fw-encoder-api.txt * Field 1 is 312 for 625 line systems in BT.656 * Field 2 is 313 for 625 line systems in BT.656 */ cx18_vapi(cx, CX18_CPU_SET_CAPTURE_LINE_NO, 3, s->handle, 312, 313); if (cx->v4l2_cap & V4L2_CAP_VBI_CAPTURE) cx18_vbi_setup(s); /* * assign program index info. * Mask 7: select I/P/B, Num_req: 400 max * FIXME - currently we have this hardcoded as disabled */ cx18_vapi_result(cx, data, CX18_CPU_SET_INDEXTABLE, 1, 0); /* Call out to the common CX2341x API setup for user controls */ priv.cx = cx; priv.s = s; cx2341x_update(&priv, cx18_api_func, NULL, &cx->params); /* * When starting a capture and we're set for radio, * ensure the video is muted, despite the user control. */ if (!cx->params.video_mute && test_bit(CX18_F_I_RADIO_USER, &cx->i_flags)) cx18_vapi(cx, CX18_CPU_SET_VIDEO_MUTE, 2, s->handle, (cx->params.video_mute_yuv << 8) | 1); } if (atomic_read(&cx->tot_capturing) == 0) { clear_bit(CX18_F_I_EOS, &cx->i_flags); cx18_write_reg(cx, 7, CX18_DSP0_INTERRUPT_MASK); } cx18_vapi(cx, CX18_CPU_DE_SET_MDL_ACK, 3, s->handle, (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][0] - cx->enc_mem, (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][1] - cx->enc_mem); /* Init all the cpu_mdls for this stream */ cx18_flush_queues(s); spin_lock(&s->q_free.lock); list_for_each_entry(buf, &s->q_free.list, list) { cx18_writel(cx, buf->dma_handle, &cx->scb->cpu_mdl[buf->id].paddr); cx18_writel(cx, s->buf_size, &cx->scb->cpu_mdl[buf->id].length); } spin_unlock(&s->q_free.lock); _cx18_stream_load_fw_queue(s); /* begin_capture */ if (cx18_vapi(cx, CX18_CPU_CAPTURE_START, 1, s->handle)) { CX18_DEBUG_WARN("Error starting capture!\n"); /* Ensure we're really not capturing before releasing MDLs */ set_bit(CX18_F_S_STOPPING, &s->s_flags); if (s->type == CX18_ENC_STREAM_TYPE_MPG) cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, 1); else cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle); clear_bit(CX18_F_S_STREAMING, &s->s_flags); /* FIXME - CX18_F_S_STREAMOFF as well? */ cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle); cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle); s->handle = CX18_INVALID_TASK_HANDLE; clear_bit(CX18_F_S_STOPPING, &s->s_flags); if (atomic_read(&cx->tot_capturing) == 0) { set_bit(CX18_F_I_EOS, &cx->i_flags); cx18_write_reg(cx, 5, CX18_DSP0_INTERRUPT_MASK); } return -EINVAL; } /* you're live! sit back and await interrupts :) */ if (captype != CAPTURE_CHANNEL_TYPE_TS) atomic_inc(&cx->ana_capturing); atomic_inc(&cx->tot_capturing); return 0; } void cx18_stop_all_captures(struct cx18 *cx) { int i; for (i = CX18_MAX_STREAMS - 1; i >= 0; i--) { struct cx18_stream *s = &cx->streams[i]; if (s->video_dev == NULL && s->dvb.enabled == 0) continue; if (test_bit(CX18_F_S_STREAMING, &s->s_flags)) cx18_stop_v4l2_encode_stream(s, 0); } } int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end) { struct cx18 *cx = s->cx; unsigned long then; if (s->video_dev == NULL && s->dvb.enabled == 0) return -EINVAL; /* This function assumes that you are allowed to stop the capture and that we are actually capturing */ CX18_DEBUG_INFO("Stop Capture\n"); if (atomic_read(&cx->tot_capturing) == 0) return 0; set_bit(CX18_F_S_STOPPING, &s->s_flags); if (s->type == CX18_ENC_STREAM_TYPE_MPG) cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, !gop_end); else cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle); then = jiffies; if (s->type == CX18_ENC_STREAM_TYPE_MPG && gop_end) { CX18_INFO("ignoring gop_end: not (yet?) supported by the firmware\n"); } if (s->type != CX18_ENC_STREAM_TYPE_TS) atomic_dec(&cx->ana_capturing); atomic_dec(&cx->tot_capturing); /* Clear capture and no-read bits */ clear_bit(CX18_F_S_STREAMING, &s->s_flags); /* Tell the CX23418 it can't use our buffers anymore */ cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle); cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle); s->handle = CX18_INVALID_TASK_HANDLE; clear_bit(CX18_F_S_STOPPING, &s->s_flags); if (atomic_read(&cx->tot_capturing) > 0) return 0; cx18_write_reg(cx, 5, CX18_DSP0_INTERRUPT_MASK); wake_up(&s->waitq); return 0; } u32 cx18_find_handle(struct cx18 *cx) { int i; /* find first available handle to be used for global settings */ for (i = 0; i < CX18_MAX_STREAMS; i++) { struct cx18_stream *s = &cx->streams[i]; if (s->video_dev && (s->handle != CX18_INVALID_TASK_HANDLE)) return s->handle; } return CX18_INVALID_TASK_HANDLE; } struct cx18_stream *cx18_handle_to_stream(struct cx18 *cx, u32 handle) { int i; struct cx18_stream *s; if (handle == CX18_INVALID_TASK_HANDLE) return NULL; for (i = 0; i < CX18_MAX_STREAMS; i++) { s = &cx->streams[i]; if (s->handle != handle) continue; if (s->video_dev || s->dvb.enabled) return s; } return NULL; }