[media] media: davinci: vpif_display: improve start/stop_streaming callbacks

this patch drops unnecessary check from start_streaming() callback
as this is already done in try/s_fmt and some minor code cleanups,
drops check for vb2_is_streaming() as this check is done by vb2
itself before calling this callback.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/platform/davinci/vpif_display.c b/drivers/media/platform/davinci/vpif_display.c
index 1b6cbe8..933d28f 100644 (file)
--- a/drivers/media/platform/davinci/vpif_display.c
+++ b/drivers/media/platform/davinci/vpif_display.c
@@ -62,11 +62,18 @@ static struct vpif_config_params config_params = {
        .channel_bufsize[1]     = 720 * 576 * 2,
 };
 
+static u8 channel_first_int[VPIF_NUMOBJECTS][2] = { {1, 1} };
+
 static struct vpif_device vpif_obj = { {NULL} };
 static struct device *vpif_dev;
 static void vpif_calculate_offsets(struct channel_obj *ch);
 static void vpif_config_addr(struct channel_obj *ch, int muxmode);
 
+static inline struct vpif_disp_buffer *to_vpif_buffer(struct vb2_buffer *vb)
+{
+       return container_of(vb, struct vpif_disp_buffer, vb);
+}
+
 /**
  * vpif_buffer_prepare :  callback function for buffer prepare
  * @vb: ptr to vb2_buffer
@@ -139,13 +146,15 @@ static int vpif_buffer_queue_setup(struct vb2_queue *vq,
        return 0;
 }
 
-/*
- * vpif_buffer_queue: This function adds the buffer to DMA queue
+/**
+ * vpif_buffer_queue : Callback function to add buffer to DMA queue
+ * @vb: ptr to vb2_buffer
+ *
+ * This callback fucntion queues the buffer to DMA engine
  */
 static void vpif_buffer_queue(struct vb2_buffer *vb)
 {
-       struct vpif_disp_buffer *buf = container_of(vb,
-                               struct vpif_disp_buffer, vb);
+       struct vpif_disp_buffer *buf = to_vpif_buffer(vb);
        struct channel_obj *ch = vb2_get_drv_priv(vb->vb2_queue);
        struct common_obj *common;
        unsigned long flags;
@@ -158,8 +167,11 @@ static void vpif_buffer_queue(struct vb2_buffer *vb)
        spin_unlock_irqrestore(&common->irqlock, flags);
 }
 
-static u8 channel_first_int[VPIF_NUMOBJECTS][2] = { {1, 1} };
-
+/**
+ * vpif_start_streaming : Starts the DMA engine for streaming
+ * @vb: ptr to vb2_buffer
+ * @count: number of buffers
+ */
 static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
 {
        struct vpif_display_config *vpif_config_data =
@@ -177,16 +189,6 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
        ch->field_id = 0;
        common->started = 1;
 
-       if ((ch->vpifparams.std_info.frm_fmt &&
-               ((common->fmt.fmt.pix.field != V4L2_FIELD_NONE)
-               && (common->fmt.fmt.pix.field != V4L2_FIELD_ANY)))
-               || (!ch->vpifparams.std_info.frm_fmt
-               && (common->fmt.fmt.pix.field == V4L2_FIELD_NONE))) {
-               vpif_err("conflict in field format and std format\n");
-               ret = -EINVAL;
-               goto err;
-       }
-
        /* clock settings */
        if (vpif_config_data->set_clock) {
                ret = vpif_config_data->set_clock(ch->vpifparams.std_info.
@@ -220,8 +222,10 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
                            (addr + common->ctop_off),
                            (addr + common->cbtm_off));
 
-       /* Set interrupt for both the fields in VPIF
-           Register enable channel in VPIF register */
+       /*
+        * Set interrupt for both the fields in VPIF
+        * Register enable channel in VPIF register
+        */
        channel_first_int[VPIF_VIDEO_INDEX][ch->channel_id] = 1;
        if (VPIF_CHANNEL2_VIDEO == ch->channel_id) {
                channel2_intr_assert();
@@ -231,8 +235,8 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
                        channel2_clipping_enable(1);
        }
 
-       if ((VPIF_CHANNEL3_VIDEO == ch->channel_id)
-               || (common->started == 2)) {
+       if (VPIF_CHANNEL3_VIDEO == ch->channel_id ||
+               common->started == 2) {
                channel3_intr_assert();
                channel3_intr_enable(1);
                enable_channel3(1);
@@ -251,16 +255,19 @@ err:
        return ret;
 }
 
-/* abort streaming and wait for last buffer */
+/**
+ * vpif_stop_streaming : Stop the DMA engine
+ * @vq: ptr to vb2_queue
+ *
+ * This callback stops the DMA engine and any remaining buffers
+ * in the DMA queue are released.
+ */
 static void vpif_stop_streaming(struct vb2_queue *vq)
 {
        struct channel_obj *ch = vb2_get_drv_priv(vq);
        struct common_obj *common;
        unsigned long flags;
 
-       if (!vb2_is_streaming(vq))
-               return;
-
        common = &ch->common[VPIF_VIDEO_INDEX];
 
        /* Disable channel */
@@ -268,8 +275,8 @@ static void vpif_stop_streaming(struct vb2_queue *vq)
                enable_channel2(0);
                channel2_intr_enable(0);
        }
-       if ((VPIF_CHANNEL3_VIDEO == ch->channel_id) ||
-               (2 == common->started)) {
+       if (VPIF_CHANNEL3_VIDEO == ch->channel_id ||
+               2 == common->started) {
                enable_channel3(0);
                channel3_intr_enable(0);
        }