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>

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
@@ -29,20 +32,121 @@
 #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);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	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:

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);

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;

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 */