[media] cx23885: convert to vb2

As usual, this patch is very large due to the fact that half a vb2 conversion
isn't possible. And since this affects 417, alsa, core, dvb, vbi and video the
changes are all over.

What made this more difficult was the peculiar way the risc program was setup.
The driver allowed for running out of buffers in which case the DMA would stop
and restart when the next buffer was queued. There was also a complicated
timeout system for when buffers weren't filled. This was replaced by a much
simpler scheme where there is always one buffer around and the DMA will just
cycle that buffer until a new buffer is queued. In that case the previous
buffer will be chained to the new buffer. An interrupt is generated at the
start of the new buffer telling the driver that the previous buffer can be
passed on to userspace.

Much simpler and more robust. The old code seems to be copied from the
cx88 driver. But it didn't fit the vb2 ops very well and replacing it with
the new scheme made the code easier to understand. Not to mention that this
patch removes 600 lines of code.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 128 insertions, 147 deletions

diff --git a/drivers/media/pci/cx23885/cx23885-vbi.c b/drivers/media/pci/cx23885/cx23885-vbi.c
index 23790fadc6d5..67b71f9b41f4 100644
--- a/drivers/media/pci/cx23885/cx23885-vbi.c
+++ b/drivers/media/pci/cx23885/cx23885-vbi.c
@@ -38,9 +38,8 @@ MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");
 /* ------------------------------------------------------------------ */
 
 #define VBI_LINE_LENGTH 1440
-#define NTSC_VBI_START_LINE 10        /* line 10 - 21 */
-#define NTSC_VBI_END_LINE   21
-#define NTSC_VBI_LINES      (NTSC_VBI_END_LINE - NTSC_VBI_START_LINE + 1)
+#define VBI_NTSC_LINE_COUNT 12
+#define VBI_PAL_LINE_COUNT 18
 
 
 int cx23885_vbi_fmt(struct file *file, void *priv,
@@ -48,22 +47,23 @@ int cx23885_vbi_fmt(struct file *file, void *priv,
 {
 	struct cx23885_dev *dev = video_drvdata(file);
 
+	f->fmt.vbi.sampling_rate = 27000000;
+	f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
+	f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
+	f->fmt.vbi.offset = 0;
+	f->fmt.vbi.flags = 0;
 	if (dev->tvnorm & V4L2_STD_525_60) {
 		/* ntsc */
-		f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
-		f->fmt.vbi.sampling_rate = 27000000;
-		f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
-		f->fmt.vbi.offset = 0;
-		f->fmt.vbi.flags = 0;
 		f->fmt.vbi.start[0] = 10;
-		f->fmt.vbi.count[0] = 17;
-		f->fmt.vbi.start[1] = 263 + 10 + 1;
-		f->fmt.vbi.count[1] = 17;
+		f->fmt.vbi.start[1] = 272;
+		f->fmt.vbi.count[0] = VBI_NTSC_LINE_COUNT;
+		f->fmt.vbi.count[1] = VBI_NTSC_LINE_COUNT;
 	} else if (dev->tvnorm & V4L2_STD_625_50) {
 		/* pal */
-		f->fmt.vbi.sampling_rate = 35468950;
-		f->fmt.vbi.start[0] = 7 - 1;
-		f->fmt.vbi.start[1] = 319 - 1;
+		f->fmt.vbi.start[0] = 6;
+		f->fmt.vbi.start[1] = 318;
+		f->fmt.vbi.count[0] = VBI_PAL_LINE_COUNT;
+		f->fmt.vbi.count[1] = VBI_PAL_LINE_COUNT;
 	}
 
 	return 0;
@@ -89,15 +89,6 @@ int cx23885_vbi_irq(struct cx23885_dev *dev, u32 status)
 		handled++;
 	}
 
-	if (status & VID_BC_MSK_VBI_RISCI2) {
-		dprintk(1, "%s() VID_BC_MSK_VBI_RISCI2\n", __func__);
-		dprintk(2, "stopper vbi\n");
-		spin_lock(&dev->slock);
-		cx23885_restart_vbi_queue(dev, &dev->vbiq);
-		spin_unlock(&dev->slock);
-		handled++;
-	}
-
 	return handled;
 }
 
@@ -109,13 +100,13 @@ static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
 
 	/* setup fifo + format */
 	cx23885_sram_channel_setup(dev, &dev->sram_channels[SRAM_CH02],
-				buf->vb.width, buf->risc.dma);
+				VBI_LINE_LENGTH, buf->risc.dma);
 
 	/* reset counter */
 	cx_write(VID_A_GPCNT_CTL, 3);
 	cx_write(VID_A_VBI_CTRL, 3);
 	cx_write(VBI_A_GPCNT_CTL, 3);
-	q->count = 1;
+	q->count = 0;
 
 	/* enable irq */
 	cx23885_irq_add_enable(dev, 0x01);
@@ -128,163 +119,153 @@ static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
 	return 0;
 }
 
+/* ------------------------------------------------------------------ */
 
-int cx23885_restart_vbi_queue(struct cx23885_dev    *dev,
-			     struct cx23885_dmaqueue *q)
+static int queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
+			   unsigned int *num_buffers, unsigned int *num_planes,
+			   unsigned int sizes[], void *alloc_ctxs[])
 {
-	struct cx23885_buffer *buf;
-	struct list_head *item;
-
-	if (list_empty(&q->active))
-		return 0;
-
-	buf = list_entry(q->active.next, struct cx23885_buffer, vb.queue);
-	dprintk(2, "restart_queue [%p/%d]: restart dma\n",
-		buf, buf->vb.i);
-	cx23885_start_vbi_dma(dev, q, buf);
-	list_for_each(item, &q->active) {
-		buf = list_entry(item, struct cx23885_buffer, vb.queue);
-		buf->count = q->count++;
-	}
-	mod_timer(&q->timeout, jiffies + (BUFFER_TIMEOUT / 30));
+	struct cx23885_dev *dev = q->drv_priv;
+	unsigned lines = VBI_PAL_LINE_COUNT;
+
+	if (dev->tvnorm & V4L2_STD_525_60)
+		lines = VBI_NTSC_LINE_COUNT;
+	*num_planes = 1;
+	sizes[0] = lines * VBI_LINE_LENGTH * 2;
 	return 0;
 }
 
-void cx23885_vbi_timeout(unsigned long data)
+static int buffer_prepare(struct vb2_buffer *vb)
 {
-	struct cx23885_dev *dev = (struct cx23885_dev *)data;
-	struct cx23885_dmaqueue *q = &dev->vbiq;
-	struct cx23885_buffer *buf;
-	unsigned long flags;
+	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
+	struct cx23885_buffer *buf = container_of(vb,
+		struct cx23885_buffer, vb);
+	struct sg_table *sgt = vb2_dma_sg_plane_desc(vb, 0);
+	unsigned lines = VBI_PAL_LINE_COUNT;
+	int ret;
 
-	/* Stop the VBI engine */
-	cx_clear(VID_A_DMA_CTL, 0x22);
+	if (dev->tvnorm & V4L2_STD_525_60)
+		lines = VBI_NTSC_LINE_COUNT;
 
-	spin_lock_irqsave(&dev->slock, flags);
-	while (!list_empty(&q->active)) {
-		buf = list_entry(q->active.next, struct cx23885_buffer,
-			vb.queue);
-		list_del(&buf->vb.queue);
-		buf->vb.state = VIDEOBUF_ERROR;
-		wake_up(&buf->vb.done);
-		printk("%s/0: [%p/%d] timeout - dma=0x%08lx\n", dev->name,
-		       buf, buf->vb.i, (unsigned long)buf->risc.dma);
-	}
-	cx23885_restart_vbi_queue(dev, q);
-	spin_unlock_irqrestore(&dev->slock, flags);
-}
+	if (vb2_plane_size(vb, 0) < lines * VBI_LINE_LENGTH * 2)
+		return -EINVAL;
+	vb2_set_plane_payload(vb, 0, lines * VBI_LINE_LENGTH * 2);
 
-/* ------------------------------------------------------------------ */
-#define VBI_LINE_LENGTH 1440
-#define VBI_LINE_COUNT 17
+	ret = dma_map_sg(&dev->pci->dev, sgt->sgl, sgt->nents, DMA_FROM_DEVICE);
+	if (!ret)
+		return -EIO;
 
-static int
-vbi_setup(struct videobuf_queue *q, unsigned int *count, unsigned int *size)
-{
-	*size = VBI_LINE_COUNT * VBI_LINE_LENGTH * 2;
-	if (0 == *count)
-		*count = vbibufs;
-	if (*count < 2)
-		*count = 2;
-	if (*count > 32)
-		*count = 32;
+	cx23885_risc_vbibuffer(dev->pci, &buf->risc,
+			 sgt->sgl,
+			 0, VBI_LINE_LENGTH * lines,
+			 VBI_LINE_LENGTH, 0,
+			 lines);
 	return 0;
 }
 
-static int
-vbi_prepare(struct videobuf_queue *q, struct videobuf_buffer *vb,
-	    enum v4l2_field field)
+static void buffer_finish(struct vb2_buffer *vb)
 {
-	struct cx23885_fh *fh  = q->priv_data;
-	struct cx23885_dev *dev = fh->q_dev;
+	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
 	struct cx23885_buffer *buf = container_of(vb,
 		struct cx23885_buffer, vb);
-	struct videobuf_dmabuf *dma = videobuf_to_dma(&buf->vb);
-	unsigned int size;
-	int rc;
-
-	size = VBI_LINE_COUNT * VBI_LINE_LENGTH * 2;
-	if (0 != buf->vb.baddr  &&  buf->vb.bsize < size)
-		return -EINVAL;
+	struct sg_table *sgt = vb2_dma_sg_plane_desc(vb, 0);
 
-	if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
-		buf->vb.width  = VBI_LINE_LENGTH;
-		buf->vb.height = VBI_LINE_COUNT;
-		buf->vb.size   = size;
-		buf->vb.field  = V4L2_FIELD_SEQ_TB;
-
-		rc = videobuf_iolock(q, &buf->vb, NULL);
-		if (0 != rc)
-			goto fail;
-		cx23885_risc_vbibuffer(dev->pci, &buf->risc,
-				 dma->sglist,
-				 0, buf->vb.width * buf->vb.height,
-				 buf->vb.width, 0,
-				 buf->vb.height);
-	}
-	buf->vb.state = VIDEOBUF_PREPARED;
-	return 0;
+	cx23885_free_buffer(vb->vb2_queue->drv_priv, buf);
 
- fail:
-	cx23885_free_buffer(q, buf);
-	return rc;
+	dma_unmap_sg(&dev->pci->dev, sgt->sgl, sgt->nents, DMA_FROM_DEVICE);
 }
 
-static void
-vbi_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
+/*
+ * The risc program for each buffer works as follows: it starts with a simple
+ * 'JUMP to addr + 12', which is effectively a NOP. Then the code to DMA the
+ * buffer follows and at the end we have a JUMP back to the start + 12 (skipping
+ * the initial JUMP).
+ *
+ * This is the risc program of the first buffer to be queued if the active list
+ * is empty and it just keeps DMAing this buffer without generating any
+ * interrupts.
+ *
+ * If a new buffer is added then the initial JUMP in the code for that buffer
+ * will generate an interrupt which signals that the previous buffer has been
+ * DMAed successfully and that it can be returned to userspace.
+ *
+ * It also sets the final jump of the previous buffer to the start of the new
+ * buffer, thus chaining the new buffer into the DMA chain. This is a single
+ * atomic u32 write, so there is no race condition.
+ *
+ * The end-result of all this that you only get an interrupt when a buffer
+ * is ready, so the control flow is very easy.
+ */
+static void buffer_queue(struct vb2_buffer *vb)
 {
-	struct cx23885_buffer   *buf =
-		container_of(vb, struct cx23885_buffer, vb);
-	struct cx23885_buffer   *prev;
-	struct cx23885_fh       *fh   = vq->priv_data;
-	struct cx23885_dev      *dev  = fh->q_dev;
-	struct cx23885_dmaqueue *q    = &dev->vbiq;
-
-	/* add jump to stopper */
-	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | RISC_CNT_INC);
-	buf->risc.jmp[1] = cpu_to_le32(q->stopper.dma);
+	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
+	struct cx23885_buffer *buf = container_of(vb, struct cx23885_buffer, vb);
+	struct cx23885_buffer *prev;
+	struct cx23885_dmaqueue *q = &dev->vbiq;
+	unsigned long flags;
+
+	buf->risc.cpu[1] = cpu_to_le32(buf->risc.dma + 12);
+	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_CNT_INC);
+	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma + 12);
 	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
 
 	if (list_empty(&q->active)) {
-		list_add_tail(&buf->vb.queue, &q->active);
-		cx23885_start_vbi_dma(dev, q, buf);
-		buf->vb.state = VIDEOBUF_ACTIVE;
-		buf->count    = q->count++;
-		mod_timer(&q->timeout, jiffies + (BUFFER_TIMEOUT / 30));
+		spin_lock_irqsave(&dev->slock, flags);
+		list_add_tail(&buf->queue, &q->active);
+		spin_unlock_irqrestore(&dev->slock, flags);
 		dprintk(2, "[%p/%d] vbi_queue - first active\n",
-			buf, buf->vb.i);
+			buf, buf->vb.v4l2_buf.index);
 
 	} else {
+		buf->risc.cpu[0] |= cpu_to_le32(RISC_IRQ1);
 		prev = list_entry(q->active.prev, struct cx23885_buffer,
-			vb.queue);
-		list_add_tail(&buf->vb.queue, &q->active);
-		buf->vb.state = VIDEOBUF_ACTIVE;
-		buf->count    = q->count++;
+			queue);
+		spin_lock_irqsave(&dev->slock, flags);
+		list_add_tail(&buf->queue, &q->active);
+		spin_unlock_irqrestore(&dev->slock, flags);
 		prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
-		prev->risc.jmp[2] = cpu_to_le32(0); /* Bits 63-32 */
 		dprintk(2, "[%p/%d] buffer_queue - append to active\n",
-			buf, buf->vb.i);
+			buf, buf->vb.v4l2_buf.index);
 	}
 }
 
-static void vbi_release(struct videobuf_queue *q, struct videobuf_buffer *vb)
+static int cx23885_start_streaming(struct vb2_queue *q, unsigned int count)
 {
-	struct cx23885_buffer *buf =
-		container_of(vb, struct cx23885_buffer, vb);
+	struct cx23885_dev *dev = q->drv_priv;
+	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
+	struct cx23885_buffer *buf = list_entry(dmaq->active.next,
+			struct cx23885_buffer, queue);
 
-	cx23885_free_buffer(q, buf);
+	cx23885_start_vbi_dma(dev, dmaq, buf);
+	return 0;
 }
 
-struct videobuf_queue_ops cx23885_vbi_qops = {
-	.buf_setup    = vbi_setup,
-	.buf_prepare  = vbi_prepare,
-	.buf_queue    = vbi_queue,
-	.buf_release  = vbi_release,
-};
+static void cx23885_stop_streaming(struct vb2_queue *q)
+{
+	struct cx23885_dev *dev = q->drv_priv;
+	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
+	unsigned long flags;
 
-/* ------------------------------------------------------------------ */
-/*
- * Local variables:
- * c-basic-offset: 8
- * End:
- */
+	cx_clear(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
+	spin_lock_irqsave(&dev->slock, flags);
+	while (!list_empty(&dmaq->active)) {
+		struct cx23885_buffer *buf = list_entry(dmaq->active.next,
+			struct cx23885_buffer, queue);
+
+		list_del(&buf->queue);
+		vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
+	}
+	spin_unlock_irqrestore(&dev->slock, flags);
+}
+
+
+struct vb2_ops cx23885_vbi_qops = {
+	.queue_setup    = queue_setup,
+	.buf_prepare  = buffer_prepare,
+	.buf_finish = buffer_finish,
+	.buf_queue    = buffer_queue,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish,
+	.start_streaming = cx23885_start_streaming,
+	.stop_streaming = cx23885_stop_streaming,
+};