On Fri, Apr 1, 2016 at 3:38 PM, Ezequiel Garcia
<ezequiel@xxxxxxxxxxxxxxxxxxxx> wrote:
> Now that the driver has the infrastructure to support more
> DMA modes, let's add the DMA scatter-gather mode.
>
> In this mode, the device delivers sequential top-bottom
> frames.
>
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/media/pci/tw686x/Kconfig | 1 +
> drivers/media/pci/tw686x/tw686x-core.c | 4 +
> drivers/media/pci/tw686x/tw686x-video.c | 188 ++++++++++++++++++++++++++++++++
> drivers/media/pci/tw686x/tw686x.h | 14 +++
> 4 files changed, 207 insertions(+)
>
> diff --git a/drivers/media/pci/tw686x/Kconfig b/drivers/media/pci/tw686x/Kconfig
> index ef8ca85522f8..34ff37712313 100644
> --- a/drivers/media/pci/tw686x/Kconfig
> +++ b/drivers/media/pci/tw686x/Kconfig
> @@ -4,6 +4,7 @@ config VIDEO_TW686X
> 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-core.c b/drivers/media/pci/tw686x/tw686x-core.c
> index 9a7646c0f9f6..586bc6723c93 100644
> --- a/drivers/media/pci/tw686x/tw686x-core.c
> +++ b/drivers/media/pci/tw686x/tw686x-core.c
> @@ -65,6 +65,8 @@ static const char *dma_mode_name(unsigned int mode)
> return "memcpy";
> case TW686X_DMA_MODE_CONTIG:
> return "contig";
> + case TW686X_DMA_MODE_SG:
> + return "sg";
> default:
> return "unknown";
> }
> @@ -81,6 +83,8 @@ static int tw686x_dma_mode_set(const char *val, struct kernel_param *kp)
> 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;
> diff --git a/drivers/media/pci/tw686x/tw686x-video.c b/drivers/media/pci/tw686x/tw686x-video.c
> index ed6abb4c41c2..16228c559f9a 100644
> --- a/drivers/media/pci/tw686x/tw686x-video.c
> +++ b/drivers/media/pci/tw686x/tw686x-video.c
> @@ -20,6 +20,7 @@
> #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"
> @@ -28,6 +29,10 @@
> #define TW686X_VIDEO_WIDTH 720
> #define TW686X_VIDEO_HEIGHT(id) ((id & V4L2_STD_625_50) ? 576 : 480)
>
> +#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[] = {
> {
> .fourcc = V4L2_PIX_FMT_UYVY,
> @@ -196,6 +201,174 @@ const struct tw686x_dma_ops contig_dma_ops = {
> .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 {
> + virt = dev->video_channels[0].dma_descs[pb].virt +
> + vc->ch * TW686X_SG_TABLE_SIZE;
> + }
> +
> + vc->sg_descs[pb] = virt;
> + return 0;
> +}
> +
> +static void tw686x_sg_cleanup(struct tw686x_dev *dev)
> +{
> + vb2_dma_sg_cleanup_ctx(dev->alloc_ctx);
> +}
> +
> +static int tw686x_sg_setup(struct tw686x_dev *dev)
> +{
> + unsigned int sg_table_size, pb, ch, channels;
> +
> + dev->alloc_ctx = vb2_dma_sg_init_ctx(&dev->pci_dev->dev);
> + if (IS_ERR(dev->alloc_ctx)) {
> + dev_err(&dev->pci_dev->dev, "unable to init DMA context\n");
> + return PTR_ERR(dev->alloc_ctx);
> + }
> +
> + 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;
> +}
> +
> +const struct tw686x_dma_ops sg_dma_ops = {
> + .setup = tw686x_sg_setup,
> + .cleanup = tw686x_sg_cleanup,
> + .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 unsigned int tw686x_fields_map(v4l2_std_id std, unsigned int fps)
> {
> static const unsigned int map[15] = {
> @@ -545,6 +718,19 @@ 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);
> @@ -882,6 +1068,8 @@ int tw686x_video_init(struct tw686x_dev *dev)
> 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;
>
> diff --git a/drivers/media/pci/tw686x/tw686x.h b/drivers/media/pci/tw686x/tw686x.h
> index 938f16b2449a..fe848a40f9d0 100644
> --- a/drivers/media/pci/tw686x/tw686x.h
> +++ b/drivers/media/pci/tw686x/tw686x.h
> @@ -34,6 +34,7 @@
>
> #define TW686X_DMA_MODE_MEMCPY 0
> #define TW686X_DMA_MODE_CONTIG 1
> +#define TW686X_DMA_MODE_SG 2
>
> struct tw686x_format {
> char *name;
> @@ -48,6 +49,12 @@ struct tw686x_dma_desc {
> unsigned 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;
> @@ -80,6 +87,7 @@ 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;
> @@ -154,6 +162,12 @@ static inline unsigned 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);
>
> --
> 2.7.0
>
> --
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Ezequiel,
Thanks for adding this support, and thanks to Krzysztof for the
original driver and efforts as well!
As with the TW686X_DMA_MODE_CONTIG, this one also helps out in the
hardware config I have with limited coherent_pool mem.
Tested-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
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