Merge tag 'media/v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull media updates from Mauro Carvalho Chehab:

 - new framework support for HDMI CEC and remote control support

 - new encoding codec driver for Mediatek SoC

 - new frontend driver: helene tuner

 - added support for NetUp almost universal devices, with supports
   DVB-C/S/S2/T/T2 and ISDB-T

 - the mn88472 frontend driver got promoted from staging

 - a new driver for RCar video input

 - some soc_camera legacy drivers got removed: timb, omap1, mx2, mx3

 - lots of driver cleanups, improvements and fixups

* tag 'media/v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (377 commits)
  [media] cec: always check all_device_types and features
  [media] cec: poll should check if there is room in the tx queue
  [media] vivid: support monitor all mode
  [media] cec: fix test for unconfigured adapter in main message loop
  [media] cec: limit the size of the transmit queue
  [media] cec: zero unused msg part after msg->len
  [media] cec: don't set fh to NULL in CEC_TRANSMIT
  [media] cec: clear all status fields before transmit and always fill in sequence
  [media] cec: CEC_RECEIVE overwrote the timeout field
  [media] cxd2841er: Reading SNR for DVB-C added
  [media] cxd2841er: Reading BER and UCB for DVB-C added
  [media] cxd2841er: fix switch-case for DVB-C
  [media] cxd2841er: fix signal strength scale for ISDB-T
  [media] cxd2841er: adjust the dB scale for DVB-C
  [media] cxd2841er: provide signal strength for DVB-C
  [media] cxd2841er: fix BER report via DVBv5 stats API
  [media] mb86a20s: apply mask to val after checking for read failure
  [media] airspy: fix error logic during device register
  [media] s5p-cec/TODO: add TODO item
  [media] cec/TODO: drop comment about sphinx documentation
  ...

6 files changed, 612 insertions, 184 deletions

diff --git a/drivers/media/pci/tw686x/Kconfig b/drivers/media/pci/tw686x/Kconfig
index fb8536974052..34ff37712313 100644
--- a/drivers/media/pci/tw686x/Kconfig
+++ b/drivers/media/pci/tw686x/Kconfig
@@ -3,6 +3,8 @@ config VIDEO_TW686X
 	depends on PCI && VIDEO_DEV && VIDEO_V4L2 && SND
 	depends on HAS_DMA
 	select VIDEOBUF2_VMALLOC
+	select VIDEOBUF2_DMA_CONTIG
+	select VIDEOBUF2_DMA_SG
 	select SND_PCM
 	help
 	  Support for Intersil/Techwell TW686x-based frame grabber cards.
diff --git a/drivers/media/pci/tw686x/tw686x-audio.c b/drivers/media/pci/tw686x/tw686x-audio.c
index 91459ab715b2..96e444c49173 100644
--- a/drivers/media/pci/tw686x/tw686x-audio.c
+++ b/drivers/media/pci/tw686x/tw686x-audio.c
@@ -62,12 +62,22 @@ void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
 		}
 		spin_unlock_irqrestore(&ac->lock, flags);
 
+		if (!done || !next)
+			continue;
+		/*
+		 * Checking for a non-nil dma_desc[pb]->virt buffer is
+		 * the same as checking for memcpy DMA mode.
+		 */
 		desc = &ac->dma_descs[pb];
-		if (done && next && desc->virt) {
-			memcpy(done->virt, desc->virt, desc->size);
-			ac->ptr = done->dma - ac->buf[0].dma;
-			snd_pcm_period_elapsed(ac->ss);
+		if (desc->virt) {
+			memcpy(done->virt, desc->virt,
+			       dev->period_size);
+		} else {
+			u32 reg = pb ? ADMA_B_ADDR[ch] : ADMA_P_ADDR[ch];
+			reg_write(dev, reg, next->dma);
 		}
+		ac->ptr = done->dma - ac->buf[0].dma;
+		snd_pcm_period_elapsed(ac->ss);
 	}
 }
 
@@ -83,10 +93,9 @@ static int tw686x_pcm_hw_free(struct snd_pcm_substream *ss)
 }
 
 /*
- * The audio device rate is global and shared among all
- * capture channels. The driver makes no effort to prevent
- * rate modifications. User is free change the rate, but it
- * means changing the rate for all capture sub-devices.
+ * Audio parameters are global and shared among all
+ * capture channels. The driver prevents changes to
+ * the parameters if any audio channel is capturing.
  */
 static const struct snd_pcm_hardware tw686x_capture_hw = {
 	.info			= (SNDRV_PCM_INFO_MMAP |
@@ -99,9 +108,9 @@ static const struct snd_pcm_hardware tw686x_capture_hw = {
 	.rate_max		= 48000,
 	.channels_min		= 1,
 	.channels_max		= 1,
-	.buffer_bytes_max	= TW686X_AUDIO_PAGE_MAX * TW686X_AUDIO_PAGE_SZ,
-	.period_bytes_min	= TW686X_AUDIO_PAGE_SZ,
-	.period_bytes_max	= TW686X_AUDIO_PAGE_SZ,
+	.buffer_bytes_max	= TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX,
+	.period_bytes_min	= AUDIO_DMA_SIZE_MIN,
+	.period_bytes_max	= AUDIO_DMA_SIZE_MAX,
 	.periods_min		= TW686X_AUDIO_PERIODS_MIN,
 	.periods_max		= TW686X_AUDIO_PERIODS_MAX,
 };
@@ -143,6 +152,14 @@ static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
 	int i;
 
 	spin_lock_irqsave(&dev->lock, flags);
+	/*
+	 * Given the audio parameters are global (i.e. shared across
+	 * DMA channels), we need to check new params are allowed.
+	 */
+	if (((dev->audio_rate != rt->rate) ||
+	     (dev->period_size != period_size)) && dev->audio_enabled)
+		goto err_audio_busy;
+
 	tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
 	spin_unlock_irqrestore(&dev->lock, flags);
 
@@ -156,12 +173,21 @@ static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
 		reg_write(dev, AUDIO_CONTROL2, reg);
 	}
 
-	if (period_size != TW686X_AUDIO_PAGE_SZ ||
-	    rt->periods < TW686X_AUDIO_PERIODS_MIN ||
-	    rt->periods > TW686X_AUDIO_PERIODS_MAX) {
-		return -EINVAL;
+	if (dev->period_size != period_size) {
+		u32 reg;
+
+		dev->period_size = period_size;
+		reg = reg_read(dev, AUDIO_CONTROL1);
+		reg &= ~(AUDIO_DMA_SIZE_MASK << AUDIO_DMA_SIZE_SHIFT);
+		reg |= period_size << AUDIO_DMA_SIZE_SHIFT;
+
+		reg_write(dev, AUDIO_CONTROL1, reg);
 	}
 
+	if (rt->periods < TW686X_AUDIO_PERIODS_MIN ||
+	    rt->periods > TW686X_AUDIO_PERIODS_MAX)
+		return -EINVAL;
+
 	spin_lock_irqsave(&ac->lock, flags);
 	INIT_LIST_HEAD(&ac->buf_list);
 
@@ -181,9 +207,19 @@ static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
 	ac->curr_bufs[0] = p_buf;
 	ac->curr_bufs[1] = b_buf;
 	ac->ptr = 0;
+
+	if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY) {
+		reg_write(dev, ADMA_P_ADDR[ac->ch], p_buf->dma);
+		reg_write(dev, ADMA_B_ADDR[ac->ch], b_buf->dma);
+	}
+
 	spin_unlock_irqrestore(&ac->lock, flags);
 
 	return 0;
+
+err_audio_busy:
+	spin_unlock_irqrestore(&dev->lock, flags);
+	return -EBUSY;
 }
 
 static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
@@ -197,6 +233,7 @@ static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
 	case SNDRV_PCM_TRIGGER_START:
 		if (ac->curr_bufs[0] && ac->curr_bufs[1]) {
 			spin_lock_irqsave(&dev->lock, flags);
+			dev->audio_enabled = 1;
 			tw686x_enable_channel(dev,
 				AUDIO_CHANNEL_OFFSET + ac->ch);
 			spin_unlock_irqrestore(&dev->lock, flags);
@@ -209,6 +246,7 @@ static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		spin_lock_irqsave(&dev->lock, flags);
+		dev->audio_enabled = 0;
 		tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
 		spin_unlock_irqrestore(&dev->lock, flags);
 
@@ -266,8 +304,8 @@ static int tw686x_snd_pcm_init(struct tw686x_dev *dev)
 	return snd_pcm_lib_preallocate_pages_for_all(pcm,
 				SNDRV_DMA_TYPE_DEV,
 				snd_dma_pci_data(dev->pci_dev),
-				TW686X_AUDIO_PAGE_MAX * TW686X_AUDIO_PAGE_SZ,
-				TW686X_AUDIO_PAGE_MAX * TW686X_AUDIO_PAGE_SZ);
+				TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX,
+				TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX);
 }
 
 static void tw686x_audio_dma_free(struct tw686x_dev *dev,
@@ -290,11 +328,19 @@ static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
 {
 	int pb;
 
+	/*
+	 * In the memcpy DMA mode we allocate a consistent buffer
+	 * and use it for the DMA capture. Otherwise, DMA
+	 * acts on the ALSA buffers as received in pcm_prepare.
+	 */
+	if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY)
+		return 0;
+
 	for (pb = 0; pb < 2; pb++) {
 		u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch];
 		void *virt;
 
-		virt = pci_alloc_consistent(dev->pci_dev, TW686X_AUDIO_PAGE_SZ,
+		virt = pci_alloc_consistent(dev->pci_dev, AUDIO_DMA_SIZE_MAX,
 					    &ac->dma_descs[pb].phys);
 		if (!virt) {
 			dev_err(&dev->pci_dev->dev,
@@ -303,7 +349,7 @@ static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
 			return -ENOMEM;
 		}
 		ac->dma_descs[pb].virt = virt;
-		ac->dma_descs[pb].size = TW686X_AUDIO_PAGE_SZ;
+		ac->dma_descs[pb].size = AUDIO_DMA_SIZE_MAX;
 		reg_write(dev, reg, ac->dma_descs[pb].phys);
 	}
 	return 0;
@@ -334,12 +380,8 @@ int tw686x_audio_init(struct tw686x_dev *dev)
 	struct snd_card *card;
 	int err, ch;
 
-	/*
-	 * AUDIO_CONTROL1
-	 * DMA byte length [31:19] = 4096 (i.e. ALSA period)
-	 * External audio enable [0] = enabled
-	 */
-	reg_write(dev, AUDIO_CONTROL1, 0x80000001);
+	/* Enable external audio */
+	reg_write(dev, AUDIO_CONTROL1, BIT(0));
 
 	err = snd_card_new(&pci_dev->dev, SNDRV_DEFAULT_IDX1,
 			   SNDRV_DEFAULT_STR1,
diff --git a/drivers/media/pci/tw686x/tw686x-core.c b/drivers/media/pci/tw686x/tw686x-core.c
index cf53b0e97be2..71a0453b1af1 100644
--- a/drivers/media/pci/tw686x/tw686x-core.c
+++ b/drivers/media/pci/tw686x/tw686x-core.c
@@ -21,12 +21,14 @@
  * under stress testings it has been found that the machine can
  * freeze completely if DMA registers are programmed while streaming
  * is active.
- * This driver tries to access hardware registers as infrequently
- * as possible by:
- *   i.  allocating fixed DMA buffers and memcpy'ing into
- *       vmalloc'ed buffers
- *   ii. using a timer to mitigate the rate of DMA reset operations,
- *       on DMA channels error.
+ *
+ * Therefore, driver implements a dma_mode called 'memcpy' which
+ * avoids cycling the DMA buffers, and insteads allocates extra DMA buffers
+ * and then copies into vmalloc'ed user buffers.
+ *
+ * In addition to this, when streaming is on, the driver tries to access
+ * hardware registers as infrequently as possible. This is done by using
+ * a timer to limit the rate at which DMA is reset on DMA channels error.
  */
 
 #include <linux/init.h>
@@ -55,6 +57,42 @@ static u32 dma_interval = 0x00098968;
 module_param(dma_interval, int, 0444);
 MODULE_PARM_DESC(dma_interval, "Minimum time span for DMA interrupting host");
 
+static unsigned int dma_mode = TW686X_DMA_MODE_MEMCPY;
+static const char *dma_mode_name(unsigned int mode)
+{
+	switch (mode) {
+	case TW686X_DMA_MODE_MEMCPY:
+		return "memcpy";
+	case TW686X_DMA_MODE_CONTIG:
+		return "contig";
+	case TW686X_DMA_MODE_SG:
+		return "sg";
+	default:
+		return "unknown";
+	}
+}
+
+static int tw686x_dma_mode_get(char *buffer, struct kernel_param *kp)
+{
+	return sprintf(buffer, dma_mode_name(dma_mode));
+}
+
+static int tw686x_dma_mode_set(const char *val, struct kernel_param *kp)
+{
+	if (!strcasecmp(val, dma_mode_name(TW686X_DMA_MODE_MEMCPY)))
+		dma_mode = TW686X_DMA_MODE_MEMCPY;
+	else if (!strcasecmp(val, dma_mode_name(TW686X_DMA_MODE_CONTIG)))
+		dma_mode = TW686X_DMA_MODE_CONTIG;
+	else if (!strcasecmp(val, dma_mode_name(TW686X_DMA_MODE_SG)))
+		dma_mode = TW686X_DMA_MODE_SG;
+	else
+		return -EINVAL;
+	return 0;
+}
+module_param_call(dma_mode, tw686x_dma_mode_set, tw686x_dma_mode_get,
+		  &dma_mode, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(dma_mode, "DMA operation mode (memcpy/contig/sg, default=memcpy)");
+
 void tw686x_disable_channel(struct tw686x_dev *dev, unsigned int channel)
 {
 	u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE);
@@ -212,6 +250,7 @@ static int tw686x_probe(struct pci_dev *pci_dev,
 	if (!dev)
 		return -ENOMEM;
 	dev->type = pci_id->driver_data;
+	dev->dma_mode = dma_mode;
 	sprintf(dev->name, "tw%04X", pci_dev->device);
 
 	dev->video_channels = kcalloc(max_channels(dev),
@@ -228,9 +267,10 @@ static int tw686x_probe(struct pci_dev *pci_dev,
 		goto free_video;
 	}
 
-	pr_info("%s: PCI %s, IRQ %d, MMIO 0x%lx\n", dev->name,
+	pr_info("%s: PCI %s, IRQ %d, MMIO 0x%lx (%s mode)\n", dev->name,
 		pci_name(pci_dev), pci_dev->irq,
-		(unsigned long)pci_resource_start(pci_dev, 0));
+		(unsigned long)pci_resource_start(pci_dev, 0),
+		dma_mode_name(dma_mode));
 
 	dev->pci_dev = pci_dev;
 	if (pci_enable_device(pci_dev)) {
diff --git a/drivers/media/pci/tw686x/tw686x-regs.h b/drivers/media/pci/tw686x/tw686x-regs.h
index fcef586a4c8c..15a956642ef4 100644
--- a/drivers/media/pci/tw686x/tw686x-regs.h
+++ b/drivers/media/pci/tw686x/tw686x-regs.h
@@ -105,6 +105,10 @@
 						  0x2d0, 0x2d1, 0x2d2, 0x2d3 })
 
 #define SYS_MODE_DMA_SHIFT	13
+#define AUDIO_DMA_SIZE_SHIFT	19
+#define AUDIO_DMA_SIZE_MIN	SZ_512
+#define AUDIO_DMA_SIZE_MAX	SZ_4K
+#define AUDIO_DMA_SIZE_MASK	(SZ_8K - 1)
 
 #define DMA_CMD_ENABLE		BIT(31)
 #define INT_STATUS_DMA_TOUT	BIT(17)
@@ -119,4 +123,9 @@
 #define TW686X_STD_PAL_CN	5
 #define TW686X_STD_PAL_60	6
 
+#define TW686X_FIELD_MODE	0x3
+#define TW686X_FRAME_MODE	0x2
+/* 0x1 is reserved */
+#define TW686X_SG_MODE		0x0
+
 #define TW686X_FIFO_ERROR(x)	(x & ~(0xff))
diff --git a/drivers/media/pci/tw686x/tw686x-video.c b/drivers/media/pci/tw686x/tw686x-video.c
index 253e10823ba3..cdb16de770fe 100644
--- a/drivers/media/pci/tw686x/tw686x-video.c
+++ b/drivers/media/pci/tw686x/tw686x-video.c
@@ -19,6 +19,8 @@
 #include <linux/slab.h>
 #include <media/v4l2-common.h>
 #include <media/v4l2-event.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-dma-sg.h>
 #include <media/videobuf2-vmalloc.h>
 #include "tw686x.h"
 #include "tw686x-regs.h"
@@ -26,6 +28,11 @@
 #define TW686X_INPUTS_PER_CH		4
 #define TW686X_VIDEO_WIDTH		720
 #define TW686X_VIDEO_HEIGHT(id)		((id & V4L2_STD_525_60) ? 480 : 576)
+#define TW686X_MAX_FPS(id)		((id & V4L2_STD_525_60) ? 30 : 25)
+
+#define TW686X_MAX_SG_ENTRY_SIZE	4096
+#define TW686X_MAX_SG_DESC_COUNT	256 /* PAL 720x576 needs 203 4-KB pages */
+#define TW686X_SG_TABLE_SIZE		(TW686X_MAX_SG_DESC_COUNT * sizeof(struct tw686x_sg_desc))
 
 static const struct tw686x_format formats[] = {
 	{
@@ -43,53 +50,367 @@ static const struct tw686x_format formats[] = {
 	}
 };
 
-static unsigned int tw686x_fields_map(v4l2_std_id std, unsigned int fps)
+static void tw686x_buf_done(struct tw686x_video_channel *vc,
+			    unsigned int pb)
 {
-	static const unsigned int map[15] = {
-		0x00000000, 0x00000001, 0x00004001, 0x00104001, 0x00404041,
-		0x01041041, 0x01104411, 0x01111111, 0x04444445, 0x04511445,
-		0x05145145, 0x05151515, 0x05515455, 0x05551555, 0x05555555
-	};
+	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
+	struct tw686x_dev *dev = vc->dev;
+	struct vb2_v4l2_buffer *vb;
+	struct vb2_buffer *vb2_buf;
 
-	static const unsigned int std_625_50[26] = {
-		0, 1, 1, 2,  3,  3,  4,  4,  5,  5,  6,  7,  7,
-		   8, 8, 9, 10, 10, 11, 11, 12, 13, 13, 14, 14, 0
-	};
+	if (vc->curr_bufs[pb]) {
+		vb = &vc->curr_bufs[pb]->vb;
 
-	static const unsigned int std_525_60[31] = {
-		0, 1, 1, 1, 2,  2,  3,  3,  4,  4,  5,  5,  6,  6, 7, 7,
-		   8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 0, 0
-	};
+		vb->field = dev->dma_ops->field;
+		vb->sequence = vc->sequence++;
+		vb2_buf = &vb->vb2_buf;
 
-	unsigned int i;
+		if (dev->dma_mode == TW686X_DMA_MODE_MEMCPY)
+			memcpy(vb2_plane_vaddr(vb2_buf, 0), desc->virt,
+			       desc->size);
+		vb2_buf->timestamp = ktime_get_ns();
+		vb2_buffer_done(vb2_buf, VB2_BUF_STATE_DONE);
+	}
+
+	vc->pb = !pb;
+}
+
+/*
+ * We can call this even when alloc_dma failed for the given channel
+ */
+static void tw686x_memcpy_dma_free(struct tw686x_video_channel *vc,
+				   unsigned int pb)
+{
+	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
+	struct tw686x_dev *dev = vc->dev;
+	struct pci_dev *pci_dev;
+	unsigned long flags;
+
+	/* Check device presence. Shouldn't really happen! */
+	spin_lock_irqsave(&dev->lock, flags);
+	pci_dev = dev->pci_dev;
+	spin_unlock_irqrestore(&dev->lock, flags);
+	if (!pci_dev) {
+		WARN(1, "trying to deallocate on missing device\n");
+		return;
+	}
+
+	if (desc->virt) {
+		pci_free_consistent(dev->pci_dev, desc->size,
+				    desc->virt, desc->phys);
+		desc->virt = NULL;
+	}
+}
+
+static int tw686x_memcpy_dma_alloc(struct tw686x_video_channel *vc,
+				   unsigned int pb)
+{
+	struct tw686x_dev *dev = vc->dev;
+	u32 reg = pb ? VDMA_B_ADDR[vc->ch] : VDMA_P_ADDR[vc->ch];
+	unsigned int len;
+	void *virt;
+
+	WARN(vc->dma_descs[pb].virt,
+	     "Allocating buffer but previous still here\n");
+
+	len = (vc->width * vc->height * vc->format->depth) >> 3;
+	virt = pci_alloc_consistent(dev->pci_dev, len,
+				    &vc->dma_descs[pb].phys);
+	if (!virt) {
+		v4l2_err(&dev->v4l2_dev,
+			 "dma%d: unable to allocate %s-buffer\n",
+			 vc->ch, pb ? "B" : "P");
+		return -ENOMEM;
+	}
+	vc->dma_descs[pb].size = len;
+	vc->dma_descs[pb].virt = virt;
+	reg_write(dev, reg, vc->dma_descs[pb].phys);
+
+	return 0;
+}
+
+static void tw686x_memcpy_buf_refill(struct tw686x_video_channel *vc,
+				     unsigned int pb)
+{
+	struct tw686x_v4l2_buf *buf;
+
+	while (!list_empty(&vc->vidq_queued)) {
+
+		buf = list_first_entry(&vc->vidq_queued,
+			struct tw686x_v4l2_buf, list);
+		list_del(&buf->list);
+
+		vc->curr_bufs[pb] = buf;
+		return;
+	}
+	vc->curr_bufs[pb] = NULL;
+}
 
-	if (std & V4L2_STD_525_60) {
-		if (fps >= ARRAY_SIZE(std_525_60))
-			fps = 30;
-		i = std_525_60[fps];
+static const struct tw686x_dma_ops memcpy_dma_ops = {
+	.alloc		= tw686x_memcpy_dma_alloc,
+	.free		= tw686x_memcpy_dma_free,
+	.buf_refill	= tw686x_memcpy_buf_refill,
+	.mem_ops	= &vb2_vmalloc_memops,
+	.hw_dma_mode	= TW686X_FRAME_MODE,
+	.field		= V4L2_FIELD_INTERLACED,
+};
+
+static void tw686x_contig_buf_refill(struct tw686x_video_channel *vc,
+				     unsigned int pb)
+{
+	struct tw686x_v4l2_buf *buf;
+
+	while (!list_empty(&vc->vidq_queued)) {
+		u32 reg = pb ? VDMA_B_ADDR[vc->ch] : VDMA_P_ADDR[vc->ch];
+		dma_addr_t phys;
+
+		buf = list_first_entry(&vc->vidq_queued,
+			struct tw686x_v4l2_buf, list);
+		list_del(&buf->list);
+
+		phys = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
+		reg_write(vc->dev, reg, phys);
+
+		buf->vb.vb2_buf.state = VB2_BUF_STATE_ACTIVE;
+		vc->curr_bufs[pb] = buf;
+		return;
+	}
+	vc->curr_bufs[pb] = NULL;
+}
+
+static const struct tw686x_dma_ops contig_dma_ops = {
+	.buf_refill	= tw686x_contig_buf_refill,
+	.mem_ops	= &vb2_dma_contig_memops,
+	.hw_dma_mode	= TW686X_FRAME_MODE,
+	.field		= V4L2_FIELD_INTERLACED,
+};
+
+static int tw686x_sg_desc_fill(struct tw686x_sg_desc *descs,
+			       struct tw686x_v4l2_buf *buf,
+			       unsigned int buf_len)
+{
+	struct sg_table *vbuf = vb2_dma_sg_plane_desc(&buf->vb.vb2_buf, 0);
+	unsigned int len, entry_len;
+	struct scatterlist *sg;
+	int i, count;
+
+	/* Clear the scatter-gather table */
+	memset(descs, 0, TW686X_SG_TABLE_SIZE);
+
+	count = 0;
+	for_each_sg(vbuf->sgl, sg, vbuf->nents, i) {
+		dma_addr_t phys = sg_dma_address(sg);
+		len = sg_dma_len(sg);
+
+		while (len && buf_len) {
+
+			if (count == TW686X_MAX_SG_DESC_COUNT)
+				return -ENOMEM;
+
+			entry_len = min_t(unsigned int, len,
+					  TW686X_MAX_SG_ENTRY_SIZE);
+			entry_len = min_t(unsigned int, entry_len, buf_len);
+			descs[count].phys = cpu_to_le32(phys);
+			descs[count++].flags_length =
+					cpu_to_le32(BIT(30) | entry_len);
+			phys += entry_len;
+			len -= entry_len;
+			buf_len -= entry_len;
+		}
+
+		if (!buf_len)
+			return 0;
+	}
+
+	return -ENOMEM;
+}
+
+static void tw686x_sg_buf_refill(struct tw686x_video_channel *vc,
+				 unsigned int pb)
+{
+	struct tw686x_dev *dev = vc->dev;
+	struct tw686x_v4l2_buf *buf;
+
+	while (!list_empty(&vc->vidq_queued)) {
+		unsigned int buf_len;
+
+		buf = list_first_entry(&vc->vidq_queued,
+			struct tw686x_v4l2_buf, list);
+		list_del(&buf->list);
+
+		buf_len = (vc->width * vc->height * vc->format->depth) >> 3;
+		if (tw686x_sg_desc_fill(vc->sg_descs[pb], buf, buf_len)) {
+			v4l2_err(&dev->v4l2_dev,
+				 "dma%d: unable to fill %s-buffer\n",
+				 vc->ch, pb ? "B" : "P");
+			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+			continue;
+		}
+
+		buf->vb.vb2_buf.state = VB2_BUF_STATE_ACTIVE;
+		vc->curr_bufs[pb] = buf;
+		return;
+	}
+
+	vc->curr_bufs[pb] = NULL;
+}
+
+static void tw686x_sg_dma_free(struct tw686x_video_channel *vc,
+			       unsigned int pb)
+{
+	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
+	struct tw686x_dev *dev = vc->dev;
+
+	if (desc->size) {
+		pci_free_consistent(dev->pci_dev, desc->size,
+				    desc->virt, desc->phys);
+		desc->virt = NULL;
+	}
+
+	vc->sg_descs[pb] = NULL;
+}
+
+static int tw686x_sg_dma_alloc(struct tw686x_video_channel *vc,
+			       unsigned int pb)
+{
+	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
+	struct tw686x_dev *dev = vc->dev;
+	u32 reg = pb ? DMA_PAGE_TABLE1_ADDR[vc->ch] :
+		       DMA_PAGE_TABLE0_ADDR[vc->ch];
+	void *virt;
+
+	if (desc->size) {
+
+		virt = pci_alloc_consistent(dev->pci_dev, desc->size,
+					    &desc->phys);
+		if (!virt) {
+			v4l2_err(&dev->v4l2_dev,
+				 "dma%d: unable to allocate %s-buffer\n",
+				 vc->ch, pb ? "B" : "P");
+			return -ENOMEM;
+		}
+		desc->virt = virt;
+		reg_write(dev, reg, desc->phys);
 	} else {
-		if (fps >= ARRAY_SIZE(std_625_50))
-			fps = 25;
-		i = std_625_50[fps];
+		virt = dev->video_channels[0].dma_descs[pb].virt +
+		       vc->ch * TW686X_SG_TABLE_SIZE;
 	}
 
-	return map[i];
+	vc->sg_descs[pb] = virt;
+	return 0;
+}
+
+static int tw686x_sg_setup(struct tw686x_dev *dev)
+{
+	unsigned int sg_table_size, pb, ch, channels;
+
+	if (is_second_gen(dev)) {
+		/*
+		 * TW6865/TW6869: each channel needs a pair of
+		 * P-B descriptor tables.
+		 */
+		channels = max_channels(dev);
+		sg_table_size = TW686X_SG_TABLE_SIZE;
+	} else {
+		/*
+		 * TW6864/TW6868: we need to allocate a pair of
+		 * P-B descriptor tables, common for all channels.
+		 * Each table will be bigger than 4 KB.
+		 */
+		channels = 1;
+		sg_table_size = max_channels(dev) * TW686X_SG_TABLE_SIZE;
+	}
+
+	for (ch = 0; ch < channels; ch++) {
+		struct tw686x_video_channel *vc = &dev->video_channels[ch];
+
+		for (pb = 0; pb < 2; pb++)
+			vc->dma_descs[pb].size = sg_table_size;
+	}
+
+	return 0;
+}
+
+static const struct tw686x_dma_ops sg_dma_ops = {
+	.setup		= tw686x_sg_setup,
+	.alloc		= tw686x_sg_dma_alloc,
+	.free		= tw686x_sg_dma_free,
+	.buf_refill	= tw686x_sg_buf_refill,
+	.mem_ops	= &vb2_dma_sg_memops,
+	.hw_dma_mode	= TW686X_SG_MODE,
+	.field		= V4L2_FIELD_SEQ_TB,
+};
+
+static const unsigned int fps_map[15] = {
+	/*
+	 * bit 31 enables selecting the field control register
+	 * bits 0-29 are a bitmask with fields that will be output.
+	 * For NTSC (and PAL-M, PAL-60), all 30 bits are used.
+	 * For other PAL standards, only the first 25 bits are used.
+	 */
+	0x00000000, /* output all fields */
+	0x80000006, /* 2 fps (60Hz), 2 fps (50Hz) */
+	0x80018006, /* 4 fps (60Hz), 4 fps (50Hz) */
+	0x80618006, /* 6 fps (60Hz), 6 fps (50Hz) */
+	0x81818186, /* 8 fps (60Hz), 8 fps (50Hz) */
+	0x86186186, /* 10 fps (60Hz), 8 fps (50Hz) */
+	0x86619866, /* 12 fps (60Hz), 10 fps (50Hz) */
+	0x86666666, /* 14 fps (60Hz), 12 fps (50Hz) */
+	0x9999999e, /* 16 fps (60Hz), 14 fps (50Hz) */
+	0x99e6799e, /* 18 fps (60Hz), 16 fps (50Hz) */
+	0x9e79e79e, /* 20 fps (60Hz), 16 fps (50Hz) */
+	0x9e7e7e7e, /* 22 fps (60Hz), 18 fps (50Hz) */
+	0x9fe7f9fe, /* 24 fps (60Hz), 20 fps (50Hz) */
+	0x9ffe7ffe, /* 26 fps (60Hz), 22 fps (50Hz) */
+	0x9ffffffe, /* 28 fps (60Hz), 24 fps (50Hz) */
+};
+
+static unsigned int tw686x_real_fps(unsigned int index, unsigned int max_fps)
+{
+	unsigned long mask;
+
+	if (!index || index >= ARRAY_SIZE(fps_map))
+		return max_fps;
+
+	mask = GENMASK(max_fps - 1, 0);
+	return hweight_long(fps_map[index] & mask);
+}
+
+static unsigned int tw686x_fps_idx(unsigned int fps, unsigned int max_fps)
+{
+	unsigned int idx, real_fps;
+	int delta;
+
+	/* First guess */
+	idx = (12 + 15 * fps) / max_fps;
+
+	/* Minimal possible framerate is 2 frames per second */
+	if (!idx)
+		return 1;
+
+	/* Check if the difference is bigger than abs(1) and adjust */
+	real_fps = tw686x_real_fps(idx, max_fps);
+	delta = real_fps - fps;
+	if (delta < -1)
+		idx++;
+	else if (delta > 1)
+		idx--;
+
+	/* Max framerate */
+	if (idx >= 15)
+		return 0;
+
+	return idx;
 }
 
 static void tw686x_set_framerate(struct tw686x_video_channel *vc,
 				 unsigned int fps)
 {
-	unsigned int map;
-
-	if (vc->fps == fps)
-		return;
+	unsigned int i;
 
-	map = tw686x_fields_map(vc->video_standard, fps) << 1;
-	map |= map << 1;
-	if (map > 0)
-		map |= BIT(31);
-	reg_write(vc->dev, VIDEO_FIELD_CTRL[vc->ch], map);
-	vc->fps = fps;
+	i = tw686x_fps_idx(fps, TW686X_MAX_FPS(vc->video_standard));
+	reg_write(vc->dev, VIDEO_FIELD_CTRL[vc->ch], fps_map[i]);
+	vc->fps = tw686x_real_fps(i, TW686X_MAX_FPS(vc->video_standard));
 }
 
 static const struct tw686x_format *format_by_fourcc(unsigned int fourcc)
@@ -104,7 +425,7 @@ static const struct tw686x_format *format_by_fourcc(unsigned int fourcc)
 
 static int tw686x_queue_setup(struct vb2_queue *vq,
 			      unsigned int *nbuffers, unsigned int *nplanes,
-			      unsigned int sizes[], void *alloc_ctxs[])
+			      unsigned int sizes[], struct device *alloc_devs[])
 {
 	struct tw686x_video_channel *vc = vb2_get_drv_priv(vq);
 	unsigned int szimage =
@@ -152,75 +473,6 @@ static void tw686x_buf_queue(struct vb2_buffer *vb)
 	spin_unlock_irqrestore(&vc->qlock, flags);
 }
 
-/*
- * We can call this even when alloc_dma failed for the given channel
- */
-static void tw686x_free_dma(struct tw686x_video_channel *vc, unsigned int pb)
-{
-	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
-	struct tw686x_dev *dev = vc->dev;
-	struct pci_dev *pci_dev;
-	unsigned long flags;
-
-	/* Check device presence. Shouldn't really happen! */
-	spin_lock_irqsave(&dev->lock, flags);
-	pci_dev = dev->pci_dev;
-	spin_unlock_irqrestore(&dev->lock, flags);
-	if (!pci_dev) {
-		WARN(1, "trying to deallocate on missing device\n");
-		return;
-	}
-
-	if (desc->virt) {
-		pci_free_consistent(dev->pci_dev, desc->size,
-				    desc->virt, desc->phys);
-		desc->virt = NULL;
-	}
-}
-
-static int tw686x_alloc_dma(struct tw686x_video_channel *vc, unsigned int pb)
-{
-	struct tw686x_dev *dev = vc->dev;
-	u32 reg = pb ? VDMA_B_ADDR[vc->ch] : VDMA_P_ADDR[vc->ch];
-	unsigned int len;
-	void *virt;
-
-	WARN(vc->dma_descs[pb].virt,
-	     "Allocating buffer but previous still here\n");
-
-	len = (vc->width * vc->height * vc->format->depth) >> 3;
-	virt = pci_alloc_consistent(dev->pci_dev, len,
-				    &vc->dma_descs[pb].phys);
-	if (!virt) {
-		v4l2_err(&dev->v4l2_dev,
-			 "dma%d: unable to allocate %s-buffer\n",
-			 vc->ch, pb ? "B" : "P");
-		return -ENOMEM;
-	}
-	vc->dma_descs[pb].size = len;
-	vc->dma_descs[pb].virt = virt;
-	reg_write(dev, reg, vc->dma_descs[pb].phys);
-
-	return 0;
-}
-
-static void tw686x_buffer_refill(struct tw686x_video_channel *vc,
-				 unsigned int pb)
-{
-	struct tw686x_v4l2_buf *buf;
-
-	while (!list_empty(&vc->vidq_queued)) {
-
-		buf = list_first_entry(&vc->vidq_queued,
-			struct tw686x_v4l2_buf, list);
-		list_del(&buf->list);
-
-		vc->curr_bufs[pb] = buf;
-		return;
-	}
-	vc->curr_bufs[pb] = NULL;
-}
-
 static void tw686x_clear_queue(struct tw686x_video_channel *vc,
 			       enum vb2_buffer_state state)
 {
@@ -262,7 +514,8 @@ static int tw686x_start_streaming(struct vb2_queue *vq, unsigned int count)
 	spin_lock_irqsave(&vc->qlock, flags);
 
 	/* Sanity check */
-	if (!vc->dma_descs[0].virt || !vc->dma_descs[1].virt) {
+	if (dev->dma_mode == TW686X_DMA_MODE_MEMCPY &&
+	    (!vc->dma_descs[0].virt || !vc->dma_descs[1].virt)) {
 		spin_unlock_irqrestore(&vc->qlock, flags);
 		v4l2_err(&dev->v4l2_dev,
 			 "video%d: refusing to start without DMA buffers\n",
@@ -272,7 +525,7 @@ static int tw686x_start_streaming(struct vb2_queue *vq, unsigned int count)
 	}
 
 	for (pb = 0; pb < 2; pb++)
-		tw686x_buffer_refill(vc, pb);
+		dev->dma_ops->buf_refill(vc, pb);
 	spin_unlock_irqrestore(&vc->qlock, flags);
 
 	vc->sequence = 0;
@@ -375,10 +628,11 @@ static int tw686x_g_fmt_vid_cap(struct file *file, void *priv,
 				struct v4l2_format *f)
 {
 	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct tw686x_dev *dev = vc->dev;
 
 	f->fmt.pix.width = vc->width;
 	f->fmt.pix.height = vc->height;
-	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
+	f->fmt.pix.field = dev->dma_ops->field;
 	f->fmt.pix.pixelformat = vc->format->fourcc;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
 	f->fmt.pix.bytesperline = (f->fmt.pix.width * vc->format->depth) / 8;
@@ -390,6 +644,7 @@ static int tw686x_try_fmt_vid_cap(struct file *file, void *priv,
 				  struct v4l2_format *f)
 {
 	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct tw686x_dev *dev = vc->dev;
 	unsigned int video_height = TW686X_VIDEO_HEIGHT(vc->video_standard);
 	const struct tw686x_format *format;
 
@@ -412,7 +667,7 @@ static int tw686x_try_fmt_vid_cap(struct file *file, void *priv,
 	f->fmt.pix.bytesperline = (f->fmt.pix.width * format->depth) / 8;
 	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
+	f->fmt.pix.field = dev->dma_ops->field;
 
 	return 0;
 }
@@ -421,6 +676,7 @@ static int tw686x_s_fmt_vid_cap(struct file *file, void *priv,
 				struct v4l2_format *f)
 {
 	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct tw686x_dev *dev = vc->dev;
 	u32 val, width, line_width, height;
 	unsigned long bitsperframe;
 	int err, pb;
@@ -438,15 +694,16 @@ static int tw686x_s_fmt_vid_cap(struct file *file, void *priv,
 	vc->height = f->fmt.pix.height;
 
 	/* We need new DMA buffers if the framesize has changed */
-	if (bitsperframe != vc->width * vc->height * vc->format->depth) {
+	if (dev->dma_ops->alloc &&
+	    bitsperframe != vc->width * vc->height * vc->format->depth) {
 		for (pb = 0; pb < 2; pb++)
-			tw686x_free_dma(vc, pb);
+			dev->dma_ops->free(vc, pb);
 
 		for (pb = 0; pb < 2; pb++) {
-			err = tw686x_alloc_dma(vc, pb);
+			err = dev->dma_ops->alloc(vc, pb);
 			if (err) {
 				if (pb > 0)
-					tw686x_free_dma(vc, 0);
+					dev->dma_ops->free(vc, 0);
 				return err;
 			}
 		}
@@ -464,6 +721,19 @@ static int tw686x_s_fmt_vid_cap(struct file *file, void *priv,
 	else
 		val &= ~BIT(24);
 
+	val &= ~0x7ffff;
+
+	/* Program the DMA scatter-gather */
+	if (dev->dma_mode == TW686X_DMA_MODE_SG) {
+		u32 start_idx, end_idx;
+
+		start_idx = is_second_gen(dev) ?
+				0 : vc->ch * TW686X_MAX_SG_DESC_COUNT;
+		end_idx = start_idx + TW686X_MAX_SG_DESC_COUNT - 1;
+
+		val |= (end_idx << 10) | start_idx;
+	}
+
 	val &= ~(0x7 << 20);
 	val |= vc->format->mode << 20;
 	reg_write(vc->dev, VDMA_CHANNEL_CONFIG[vc->ch], val);
@@ -540,6 +810,12 @@ static int tw686x_s_std(struct file *file, void *priv, v4l2_std_id id)
 	ret = tw686x_g_fmt_vid_cap(file, priv, &f);
 	if (!ret)
 		tw686x_s_fmt_vid_cap(file, priv, &f);
+
+	/*
+	 * Frame decimation depends on the chosen standard,
+	 * so reset it to the current value.
+	 */
+	tw686x_set_framerate(vc, vc->fps);
 	return 0;
 }
 
@@ -609,6 +885,40 @@ static int tw686x_g_std(struct file *file, void *priv, v4l2_std_id *id)
 	return 0;
 }
 
+static int tw686x_g_parm(struct file *file, void *priv,
+			 struct v4l2_streamparm *sp)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct v4l2_captureparm *cp = &sp->parm.capture;
+
+	if (sp->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+	sp->parm.capture.readbuffers = 3;
+
+	cp->capability = V4L2_CAP_TIMEPERFRAME;
+	cp->timeperframe.numerator = 1;
+	cp->timeperframe.denominator = vc->fps;
+	return 0;
+}
+
+static int tw686x_s_parm(struct file *file, void *priv,
+			 struct v4l2_streamparm *sp)
+{
+	struct tw686x_video_channel *vc = video_drvdata(file);
+	struct v4l2_captureparm *cp = &sp->parm.capture;
+	unsigned int denominator = cp->timeperframe.denominator;
+	unsigned int numerator = cp->timeperframe.numerator;
+	unsigned int fps;
+
+	if (vb2_is_busy(&vc->vidq))
+		return -EBUSY;
+
+	fps = (!numerator || !denominator) ? 0 : denominator / numerator;
+	if (vc->fps != fps)
+		tw686x_set_framerate(vc, fps);
+	return tw686x_g_parm(file, priv, sp);
+}
+
 static int tw686x_enum_fmt_vid_cap(struct file *file, void *priv,
 				   struct v4l2_fmtdesc *f)
 {
@@ -695,6 +1005,9 @@ static const struct v4l2_ioctl_ops tw686x_video_ioctl_ops = {
 	.vidioc_g_std			= tw686x_g_std,
 	.vidioc_s_std			= tw686x_s_std,
 
+	.vidioc_g_parm			= tw686x_g_parm,
+	.vidioc_s_parm			= tw686x_s_parm,
+
 	.vidioc_enum_input		= tw686x_enum_input,
 	.vidioc_g_input			= tw686x_g_input,
 	.vidioc_s_input			= tw686x_s_input,
@@ -713,26 +1026,11 @@ static const struct v4l2_ioctl_ops tw686x_video_ioctl_ops = {
 	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
 };
 
-static void tw686x_buffer_copy(struct tw686x_video_channel *vc,
-			       unsigned int pb, struct vb2_v4l2_buffer *vb)
-{
-	struct tw686x_dma_desc *desc = &vc->dma_descs[pb];
-	struct vb2_buffer *vb2_buf = &vb->vb2_buf;
-
-	vb->field = V4L2_FIELD_INTERLACED;
-	vb->sequence = vc->sequence++;
-
-	memcpy(vb2_plane_vaddr(vb2_buf, 0), desc->virt, desc->size);
-	vb2_buf->timestamp = ktime_get_ns();
-	vb2_buffer_done(vb2_buf, VB2_BUF_STATE_DONE);
-}
-
 void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
 		      unsigned int pb_status, unsigned int fifo_status,
 		      unsigned int *reset_ch)
 {
 	struct tw686x_video_channel *vc;
-	struct vb2_v4l2_buffer *vb;
 	unsigned long flags;
 	unsigned int ch, pb;
 
@@ -781,14 +1079,9 @@ void tw686x_video_irq(struct tw686x_dev *dev, unsigned long requests,
 			continue;
 		}
 
-		/* handle video stream */
 		spin_lock_irqsave(&vc->qlock, flags);
-		if (vc->curr_bufs[pb]) {
-			vb = &vc->curr_bufs[pb]->vb;
-			tw686x_buffer_copy(vc, pb, vb);
-		}
-		vc->pb = !pb;
-		tw686x_buffer_refill(vc, pb);
+		tw686x_buf_done(vc, pb);
+		dev->dma_ops->buf_refill(vc, pb);
 		spin_unlock_irqrestore(&vc->qlock, flags);
 	}
 }
@@ -803,8 +1096,9 @@ void tw686x_video_free(struct tw686x_dev *dev)
 		if (vc->device)
 			video_unregister_device(vc->device);
 
-		for (pb = 0; pb < 2; pb++)
-			tw686x_free_dma(vc, pb);
+		if (dev->dma_ops->free)
+			for (pb = 0; pb < 2; pb++)
+				dev->dma_ops->free(vc, pb);
 	}
 }
 
@@ -813,10 +1107,25 @@ int tw686x_video_init(struct tw686x_dev *dev)
 	unsigned int ch, val, pb;
 	int err;
 
+	if (dev->dma_mode == TW686X_DMA_MODE_MEMCPY)
+		dev->dma_ops = &memcpy_dma_ops;
+	else if (dev->dma_mode == TW686X_DMA_MODE_CONTIG)
+		dev->dma_ops = &contig_dma_ops;
+	else if (dev->dma_mode == TW686X_DMA_MODE_SG)
+		dev->dma_ops = &sg_dma_ops;
+	else
+		return -EINVAL;
+
 	err = v4l2_device_register(&dev->pci_dev->dev, &dev->v4l2_dev);
 	if (err)
 		return err;
 
+	if (dev->dma_ops->setup) {
+		err = dev->dma_ops->setup(dev);
+		if (err)
+			return err;
+	}
+
 	for (ch = 0; ch < max_channels(dev); ch++) {
 		struct tw686x_video_channel *vc = &dev->video_channels[ch];
 		struct video_device *vdev;
@@ -842,10 +1151,12 @@ int tw686x_video_init(struct tw686x_dev *dev)
 		reg_write(dev, HACTIVE_LO[ch], 0xd0);
 		reg_write(dev, VIDEO_SIZE[ch], 0);
 
-		for (pb = 0; pb < 2; pb++) {
-			err = tw686x_alloc_dma(vc, pb);
-			if (err)
-				goto error;
+		if (dev->dma_ops->alloc) {
+			for (pb = 0; pb < 2; pb++) {
+				err = dev->dma_ops->alloc(vc, pb);
+				if (err)
+					goto error;
+			}
 		}
 
 		vc->vidq.io_modes = VB2_READ | VB2_MMAP | VB2_DMABUF;
@@ -853,11 +1164,12 @@ int tw686x_video_init(struct tw686x_dev *dev)
 		vc->vidq.drv_priv = vc;
 		vc->vidq.buf_struct_size = sizeof(struct tw686x_v4l2_buf);
 		vc->vidq.ops = &tw686x_video_qops;
-		vc->vidq.mem_ops = &vb2_vmalloc_memops;
+		vc->vidq.mem_ops = dev->dma_ops->mem_ops;
 		vc->vidq.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
 		vc->vidq.min_buffers_needed = 2;
 		vc->vidq.lock = &vc->vb_mutex;
 		vc->vidq.gfp_flags = GFP_DMA32;
+		vc->vidq.dev = &dev->pci_dev->dev;
 
 		err = vb2_queue_init(&vc->vidq);
 		if (err) {
@@ -915,10 +1227,9 @@ int tw686x_video_init(struct tw686x_dev *dev)
 		vc->num = vdev->num;
 	}
 
-	/* Set DMA frame mode on all channels. Only supported mode for now. */
 	val = TW686X_DEF_PHASE_REF;
 	for (ch = 0; ch < max_channels(dev); ch++)
-		val |= TW686X_FRAME_MODE << (16 + ch * 2);
+		val |= dev->dma_ops->hw_dma_mode << (16 + ch * 2);
 	reg_write(dev, PHASE_REF, val);
 
 	reg_write(dev, MISC2[0], 0xe7);
diff --git a/drivers/media/pci/tw686x/tw686x.h b/drivers/media/pci/tw686x/tw686x.h
index 44b5755acf02..f24a2a9bcdb2 100644
--- a/drivers/media/pci/tw686x/tw686x.h
+++ b/drivers/media/pci/tw686x/tw686x.h
@@ -27,16 +27,14 @@
 #define TYPE_SECOND_GEN		0x10
 #define TW686X_DEF_PHASE_REF	0x1518
 
-#define TW686X_FIELD_MODE	0x3
-#define TW686X_FRAME_MODE	0x2
-/* 0x1 is reserved */
-#define TW686X_SG_MODE		0x0
-
-#define TW686X_AUDIO_PAGE_SZ		4096
 #define TW686X_AUDIO_PAGE_MAX		16
 #define TW686X_AUDIO_PERIODS_MIN	2
 #define TW686X_AUDIO_PERIODS_MAX	TW686X_AUDIO_PAGE_MAX
 
+#define TW686X_DMA_MODE_MEMCPY		0
+#define TW686X_DMA_MODE_CONTIG		1
+#define TW686X_DMA_MODE_SG		2
+
 struct tw686x_format {
 	char *name;
 	unsigned int fourcc;
@@ -50,6 +48,12 @@ struct tw686x_dma_desc {
 	unsigned int size;
 };
 
+struct tw686x_sg_desc {
+	/* 3 MSBits for flags, 13 LSBits for length */
+	__le32 flags_length;
+	__le32 phys;
+};
+
 struct tw686x_audio_buf {
 	dma_addr_t dma;
 	void *virt;
@@ -82,6 +86,7 @@ struct tw686x_video_channel {
 	struct video_device *device;
 	struct tw686x_v4l2_buf *curr_bufs[2];
 	struct tw686x_dma_desc dma_descs[2];
+	struct tw686x_sg_desc *sg_descs[2];
 
 	struct v4l2_ctrl_handler ctrl_handler;
 	const struct tw686x_format *format;
@@ -99,6 +104,16 @@ struct tw686x_video_channel {
 	bool no_signal;
 };
 
+struct tw686x_dma_ops {
+	int (*setup)(struct tw686x_dev *dev);
+	int (*alloc)(struct tw686x_video_channel *vc, unsigned int pb);
+	void (*free)(struct tw686x_video_channel *vc, unsigned int pb);
+	void (*buf_refill)(struct tw686x_video_channel *vc, unsigned int pb);
+	const struct vb2_mem_ops *mem_ops;
+	enum v4l2_field field;
+	u32 hw_dma_mode;
+};
+
 /**
  * struct tw686x_dev - global device status
  * @lock: spinlock controlling access to the
@@ -112,15 +127,18 @@ struct tw686x_dev {
 
 	char name[32];
 	unsigned int type;
+	unsigned int dma_mode;
 	struct pci_dev *pci_dev;
 	__u32 __iomem *mmio;
 
-	void *alloc_ctx;
-
+	const struct tw686x_dma_ops *dma_ops;
 	struct tw686x_video_channel *video_channels;
 	struct tw686x_audio_channel *audio_channels;
 
-	int audio_rate; /* per-device value */
+	/* Per-device audio parameters */
+	int audio_rate;
+	int period_size;
+	int audio_enabled;
 
 	struct timer_list dma_delay_timer;
 	u32 pending_dma_en; /* must be protected by lock */
@@ -143,6 +161,12 @@ static inline unsigned int max_channels(struct tw686x_dev *dev)
 	return dev->type & TYPE_MAX_CHANNELS; /* 4 or 8 channels */
 }
 
+static inline unsigned is_second_gen(struct tw686x_dev *dev)
+{
+	/* each channel has its own DMA SG table */
+	return dev->type & TYPE_SECOND_GEN;
+}
+
 void tw686x_enable_channel(struct tw686x_dev *dev, unsigned int channel);
 void tw686x_disable_channel(struct tw686x_dev *dev, unsigned int channel);