V4L/DVB: cx18: overhaul ALSA PCM device handling so it works

Add code so that the PCM ALSA device actually works, and update the
cx18-streams mechanism so that it passes the data off to the cx18-alsa module.

This work was sponsored by ONELAN Limited.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

5 files changed, 293 insertions, 7 deletions

diff --git a/drivers/media/video/cx18/cx18-alsa-pcm.c b/drivers/media/video/cx18/cx18-alsa-pcm.c
index e3157cec5ac..a6502af0771 100644
--- a/drivers/media/video/cx18/cx18-alsa-pcm.c
+++ b/drivers/media/video/cx18/cx18-alsa-pcm.c
@@ -3,6 +3,9 @@
  *  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
@@ -29,8 +32,44 @@
 #include <sound/pcm.h>
 
 #include "cx18-driver.h"
+#include "cx18-queue.h"
+#include "cx18-streams.h"
+#include "cx18-fileops.h"
 #include "cx18-alsa.h"
 
+extern int cx18_alsa_debug;
+
+#define dprintk(fmt, arg...) do {                                       \
+            if (cx18_alsa_debug)                                        \
+                printk(KERN_INFO "cx18-alsa %s: " fmt,                  \
+                                  __func__, ##arg);                     \
+        } while (0)
+
+/* Forward Declaration */
+void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
+                                 size_t num_bytes);
+
+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_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
+
+        .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, */
+};
+
 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
 {
         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
@@ -38,11 +77,76 @@ static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
         struct snd_card *sc = cxsc->sc;
         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 */
+        s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
+
+        /* Allocate memory */
+        item = kmalloc(sizeof(struct cx18_open_id), GFP_KERNEL);
+        if (NULL == item) {
+                CX18_DEBUG_WARN("nomem on v4l2 open\n");
+                return -ENOMEM;
+        }
+        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 */
+                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 */
+                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);
+
         return 0;
 }
 
 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
 {
+        unsigned long flags;
+        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 */
+        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;
+
+        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;
 }
 
@@ -52,9 +156,37 @@ static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
         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;
 }
 
@@ -65,6 +197,11 @@ static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
 
 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;
 }
 
@@ -76,7 +213,24 @@ static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 static
 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
 {
-        return 0;
+        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 = {
@@ -88,9 +242,86 @@ static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
         .prepare        = snd_cx18_pcm_prepare,
         .trigger        = snd_cx18_pcm_trigger,
         .pointer        = snd_cx18_pcm_pointer,
+        .page           = snd_pcm_get_vmalloc_page,
 };
 
-int __init snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
+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=%d\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);
+}
+
+int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
 {
         struct snd_pcm *sp;
         struct snd_card *sc = cxsc->sc;
@@ -108,6 +339,14 @@ int __init snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
                               __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;
+        strcpy(sp->name, "Conexant cx23418 Capture");
+
         return 0;
 
 err_exit:
diff --git a/drivers/media/video/cx18/cx18-alsa-pcm.h b/drivers/media/video/cx18/cx18-alsa-pcm.h
index ff47a1ebe80..325662c647a 100644
--- a/drivers/media/video/cx18/cx18-alsa-pcm.h
+++ b/drivers/media/video/cx18/cx18-alsa-pcm.h
@@ -21,3 +21,7 @@
  */
 
 int __init snd_cx18_pcm_create(struct snd_cx18_card *cxsc);
+
+/* Used by cx18-mailbox to announce the PCM data to the module */
+void cx18_alsa_announce_pcm_data(struct snd_cx18_card *card, u8 *pcm_data,
+                                 size_t num_bytes);
diff --git a/drivers/media/video/cx18/cx18-alsa.h b/drivers/media/video/cx18/cx18-alsa.h
index ea8576fd578..2546779b731 100644
--- a/drivers/media/video/cx18/cx18-alsa.h
+++ b/drivers/media/video/cx18/cx18-alsa.h
@@ -24,6 +24,10 @@ struct snd_card;
 struct snd_cx18_card {
         struct v4l2_device *v4l2_dev;
         struct snd_card *sc;
+        unsigned int capture_transfer_done;
+        unsigned int hwptr_done_capture;
+        struct snd_pcm_substream *capture_pcm_substream;
+        spinlock_t slock;
 };
 
 extern int cx18_alsa_debug;
diff --git a/drivers/media/video/cx18/cx18-driver.h b/drivers/media/video/cx18/cx18-driver.h
index fcb99531dab..22634cf6a96 100644
--- a/drivers/media/video/cx18/cx18-driver.h
+++ b/drivers/media/video/cx18/cx18-driver.h
@@ -575,6 +575,9 @@ struct cx18 {
         int stream_buf_size[CX18_MAX_STREAMS]; /* Stream buffer size */
         struct cx18_stream streams[CX18_MAX_STREAMS];   /* Stream data */
         struct snd_cx18_card *alsa; /* ALSA interface for PCM capture stream */
+        void (*pcm_announce_callback)(struct snd_cx18_card *card, u8 *pcm_data,
+                                      size_t num_bytes);
+
         unsigned long i_flags;  /* global cx18 flags */
         atomic_t ana_capturing; /* count number of active analog capture streams */
         atomic_t tot_capturing; /* total count number of active capture streams */
diff --git a/drivers/media/video/cx18/cx18-mailbox.c b/drivers/media/video/cx18/cx18-mailbox.c
index 0ac0e2c993a..6dcce297752 100644
--- a/drivers/media/video/cx18/cx18-mailbox.c
+++ b/drivers/media/video/cx18/cx18-mailbox.c
@@ -29,6 +29,7 @@
 #include "cx18-mailbox.h"
 #include "cx18-queue.h"
 #include "cx18-streams.h"
+#include "cx18-alsa-pcm.h" /* FIXME make configurable */
 
 static const char *rpu_str[] = { "APU", "CPU", "EPU", "HPU" };
 
@@ -157,6 +158,34 @@ static void cx18_mdl_send_to_dvb(struct cx18_stream *s, struct cx18_mdl *mdl)
         }
 }
 
+
+static void cx18_mdl_send_to_alsa(struct cx18 *cx, struct cx18_stream *s,
+                                  struct cx18_mdl *mdl)
+{
+        struct cx18_buffer *buf;
+
+        if (mdl->bytesused == 0)
+                return;
+
+        /* We ignore mdl and buf readpos accounting here - it doesn't matter */
+
+        /* The likely case */
+        if (list_is_singular(&mdl->buf_list)) {
+                buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
+                                       list);
+                if (buf->bytesused)
+                        cx->pcm_announce_callback(cx->alsa, buf->buf,
+                                                  buf->bytesused);
+                return;
+        }
+
+        list_for_each_entry(buf, &mdl->buf_list, list) {
+                if (buf->bytesused == 0)
+                        break;
+                cx->pcm_announce_callback(cx->alsa, buf->buf, buf->bytesused);
+        }
+}
+
 static void epu_dma_done(struct cx18 *cx, struct cx18_in_work_order *order)
 {
         u32 handle, mdl_ack_count, id;
@@ -223,15 +252,22 @@ static void epu_dma_done(struct cx18 *cx, struct cx18_in_work_order *order)
                 CX18_DEBUG_HI_DMA("%s recv bytesused = %d\n",
                                   s->name, mdl->bytesused);
 
-                if (s->type != CX18_ENC_STREAM_TYPE_TS) {
+                if (s->type == CX18_ENC_STREAM_TYPE_TS) {
+                        cx18_mdl_send_to_dvb(s, mdl);
+                        cx18_enqueue(s, mdl, &s->q_free);
+                } else if (s->type == CX18_ENC_STREAM_TYPE_PCM) {
+                        /* Pass the data to cx18-alsa */
+                        if (cx->pcm_announce_callback != NULL) {
+                                cx18_mdl_send_to_alsa(cx, s, mdl);
+                                cx18_enqueue(s, mdl, &s->q_free);
+                        } else {
+                                cx18_enqueue(s, mdl, &s->q_full);
+                        }
+                } else {
                         cx18_enqueue(s, mdl, &s->q_full);
                         if (s->type == CX18_ENC_STREAM_TYPE_IDX)
                                 cx18_stream_rotate_idx_mdls(cx);
                 }
-                else {
-                        cx18_mdl_send_to_dvb(s, mdl);
-                        cx18_enqueue(s, mdl, &s->q_free);
-                }
         }
         /* Put as many MDLs as possible back into fw use */
         cx18_stream_load_fw_queue(s);