1 files changed, 354 insertions, 0 deletions

diff --git a/drivers/media/video/cx18/cx18-alsa-pcm.c b/drivers/media/video/cx18/cx18-alsa-pcm.c
new file mode 100644
index 000000000000..2bd312daeb1e
--- /dev/null
+++ b/drivers/media/video/cx18/cx18-alsa-pcm.c
@@ -0,0 +1,354 @@
+/*
+ *  ALSA PCM device for the
+ *  ALSA interface to cx18 PCM capture streams
+ *
+ *  Copyright (C) 2009  Andy Walls <awalls@radix.net>
+ *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
+ *
+ *  Portions of this work were sponsored by ONELAN Limited.
+ *
+ *  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 <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/vmalloc.h>
+
+#include <media/v4l2-device.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+#include "cx18-driver.h"
+#include "cx18-queue.h"
+#include "cx18-streams.h"
+#include "cx18-fileops.h"
+#include "cx18-alsa.h"
+
+static unsigned int pcm_debug;
+module_param(pcm_debug, int, 0644);
+MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
+
+#define dprintk(fmt, arg...) do {                                       \
+            if (pcm_debug)                                              \
+                printk(KERN_INFO "cx18-alsa-pcm %s: " fmt,              \
+                                  __func__, ##arg);                     \
+        } while (0)
+
+static struct snd_pcm_hardware snd_cx18_hw_capture = {
+        .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
+                SNDRV_PCM_INFO_MMAP           |
+                SNDRV_PCM_INFO_INTERLEAVED    |
+                SNDRV_PCM_INFO_MMAP_VALID,
+
+        .formats = SNDRV_PCM_FMTBIT_S16_LE,
+
+        .rates = SNDRV_PCM_RATE_48000,
+
+        .rate_min = 48000,
+        .rate_max = 48000,
+        .channels_min = 2,
+        .channels_max = 2,
+        .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
+        .period_bytes_min = 64,         /* 12544/2, */
+        .period_bytes_max = 12544,
+        .periods_min = 2,
+        .periods_max = 98,              /* 12544, */
+};
+
+void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
+                                 size_t num_bytes)
+{
+        struct snd_pcm_substream *substream;
+        struct snd_pcm_runtime *runtime;
+        unsigned int oldptr;
+        unsigned int stride;
+        int period_elapsed = 0;
+        int length;
+
+        dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zd\n", cxsc,
+                pcm_data, num_bytes);
+
+        substream = cxsc->capture_pcm_substream;
+        if (substream == NULL) {
+                dprintk("substream was NULL\n");
+                return;
+        }
+
+        runtime = substream->runtime;
+        if (runtime == NULL) {
+                dprintk("runtime was NULL\n");
+                return;
+        }
+
+        stride = runtime->frame_bits >> 3;
+        if (stride == 0) {
+                dprintk("stride is zero\n");
+                return;
+        }
+
+        length = num_bytes / stride;
+        if (length == 0) {
+                dprintk("%s: length was zero\n", __func__);
+                return;
+        }
+
+        if (runtime->dma_area == NULL) {
+                dprintk("dma area was NULL - ignoring\n");
+                return;
+        }
+
+        oldptr = cxsc->hwptr_done_capture;
+        if (oldptr + length >= runtime->buffer_size) {
+                unsigned int cnt =
+                        runtime->buffer_size - oldptr;
+                memcpy(runtime->dma_area + oldptr * stride, pcm_data,
+                       cnt * stride);
+                memcpy(runtime->dma_area, pcm_data + cnt * stride,
+                       length * stride - cnt * stride);
+        } else {
+                memcpy(runtime->dma_area + oldptr * stride, pcm_data,
+                       length * stride);
+        }
+        snd_pcm_stream_lock(substream);
+
+        cxsc->hwptr_done_capture += length;
+        if (cxsc->hwptr_done_capture >=
+            runtime->buffer_size)
+                cxsc->hwptr_done_capture -=
+                        runtime->buffer_size;
+
+        cxsc->capture_transfer_done += length;
+        if (cxsc->capture_transfer_done >=
+            runtime->period_size) {
+                cxsc->capture_transfer_done -=
+                        runtime->period_size;
+                period_elapsed = 1;
+        }
+
+        snd_pcm_stream_unlock(substream);
+
+        if (period_elapsed)
+                snd_pcm_period_elapsed(substream);
+}
+
+static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
+{
+        struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
+        struct cx18 *cx = to_cx18(v4l2_dev);
+        struct cx18_stream *s;
+        struct cx18_open_id item;
+        int ret;
+
+        /* Instruct the cx18 to start sending packets */
+        snd_cx18_lock(cxsc);
+        s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
+
+        item.cx = cx;
+        item.type = s->type;
+        item.open_id = cx->open_id++;
+
+        /* See if the stream is available */
+        if (cx18_claim_stream(&item, item.type)) {
+                /* No, it's already in use */
+                snd_cx18_unlock(cxsc);
+                return -EBUSY;
+        }
+
+        if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
+            test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
+                /* We're already streaming.  No additional action required */
+                snd_cx18_unlock(cxsc);
+                return 0;
+        }
+
+
+        runtime->hw = snd_cx18_hw_capture;
+        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+        cxsc->capture_pcm_substream = substream;
+        runtime->private_data = cx;
+
+        cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
+
+        /* Not currently streaming, so start it up */
+        set_bit(CX18_F_S_STREAMING, &s->s_flags);
+        ret = cx18_start_v4l2_encode_stream(s);
+        snd_cx18_unlock(cxsc);
+
+        return 0;
+}
+
+static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
+{
+        struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
+        struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
+        struct cx18 *cx = to_cx18(v4l2_dev);
+        struct cx18_stream *s;
+        int ret;
+
+        /* Instruct the cx18 to stop sending packets */
+        snd_cx18_lock(cxsc);
+        s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
+        ret = cx18_stop_v4l2_encode_stream(s, 0);
+        clear_bit(CX18_F_S_STREAMING, &s->s_flags);
+
+        cx18_release_stream(s);
+
+        cx->pcm_announce_callback = NULL;
+        snd_cx18_unlock(cxsc);
+
+        return 0;
+}
+
+static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
+                     unsigned int cmd, void *arg)
+{
+        return snd_pcm_lib_ioctl(substream, cmd, arg);
+}
+
+
+static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
+                                        size_t size)
+{
+        struct snd_pcm_runtime *runtime = subs->runtime;
+
+        dprintk("Allocating vbuffer\n");
+        if (runtime->dma_area) {
+                if (runtime->dma_bytes > size)
+                        return 0;
+
+                vfree(runtime->dma_area);
+        }
+        runtime->dma_area = vmalloc(size);
+        if (!runtime->dma_area)
+                return -ENOMEM;
+
+        runtime->dma_bytes = size;
+
+        return 0;
+}
+
+static int snd_cx18_pcm_hw_params(struct snd_pcm_substream *substream,
+                         struct snd_pcm_hw_params *params)
+{
+        int ret;
+
+        dprintk("%s called\n", __func__);
+
+        ret = snd_pcm_alloc_vmalloc_buffer(substream,
+                                           params_buffer_bytes(params));
+        return 0;
+}
+
+static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+        struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
+        unsigned long flags;
+
+        spin_lock_irqsave(&cxsc->slock, flags);
+        if (substream->runtime->dma_area) {
+                dprintk("freeing pcm capture region\n");
+                vfree(substream->runtime->dma_area);
+                substream->runtime->dma_area = NULL;
+        }
+        spin_unlock_irqrestore(&cxsc->slock, flags);
+
+        return 0;
+}
+
+static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
+{
+        struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
+
+        cxsc->hwptr_done_capture = 0;
+        cxsc->capture_transfer_done = 0;
+
+        return 0;
+}
+
+static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+        return 0;
+}
+
+static
+snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
+{
+        unsigned long flags;
+        snd_pcm_uframes_t hwptr_done;
+        struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
+
+        spin_lock_irqsave(&cxsc->slock, flags);
+        hwptr_done = cxsc->hwptr_done_capture;
+        spin_unlock_irqrestore(&cxsc->slock, flags);
+
+        return hwptr_done;
+}
+
+static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
+                                             unsigned long offset)
+{
+        void *pageptr = subs->runtime->dma_area + offset;
+
+        return vmalloc_to_page(pageptr);
+}
+
+static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
+        .open           = snd_cx18_pcm_capture_open,
+        .close          = snd_cx18_pcm_capture_close,
+        .ioctl          = snd_cx18_pcm_ioctl,
+        .hw_params      = snd_cx18_pcm_hw_params,
+        .hw_free        = snd_cx18_pcm_hw_free,
+        .prepare        = snd_cx18_pcm_prepare,
+        .trigger        = snd_cx18_pcm_trigger,
+        .pointer        = snd_cx18_pcm_pointer,
+        .page           = snd_pcm_get_vmalloc_page,
+};
+
+int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
+{
+        struct snd_pcm *sp;
+        struct snd_card *sc = cxsc->sc;
+        struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
+        struct cx18 *cx = to_cx18(v4l2_dev);
+        int ret;
+
+        ret = snd_pcm_new(sc, "CX23418 PCM",
+                          0, /* PCM device 0, the only one for this card */
+                          0, /* 0 playback substreams */
+                          1, /* 1 capture substream */
+                          &sp);
+        if (ret) {
+                CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
+                              __func__, ret);
+                goto err_exit;
+        }
+
+        spin_lock_init(&cxsc->slock);
+
+        snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
+                        &snd_cx18_pcm_capture_ops);
+        sp->info_flags = 0;
+        sp->private_data = cxsc;
+        strlcpy(sp->name, cx->card_name, sizeof(sp->name));
+
+        return 0;
+
+err_exit:
+        return ret;
+}