V4L/DVB (13128): sh_mobile_ceu_camera: add VBP error support
Kuninori Morimoto [Mon, 5 Oct 2009 15:48:59 +0000 (12:48 -0300)]
If CEU driver can not receive data from camera,
CETCR has VBP error state.
Then, CEU is stopped and cure operation is needed.
This patch add VBP error cure operation.

Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/sh_mobile_ceu_camera.c

index edb6ec3..a4f3472 100644 (file)
@@ -236,26 +236,45 @@ static void free_buffer(struct videobuf_queue *vq,
 #define CEU_CETCR_MAGIC 0x0317f313 /* acknowledge magical interrupt sources */
 #define CEU_CETCR_IGRW (1 << 4) /* prohibited register access interrupt bit */
 #define CEU_CEIER_CPEIE (1 << 0) /* one-frame capture end interrupt */
+#define CEU_CEIER_VBP   (1 << 20) /* vbp error */
 #define CEU_CAPCR_CTNCP (1 << 16) /* continuous capture mode (if set) */
+#define CEU_CEIER_MASK (CEU_CEIER_CPEIE | CEU_CEIER_VBP)
 
 
-static void sh_mobile_ceu_capture(struct sh_mobile_ceu_dev *pcdev)
+/*
+ * return value doesn't reflex the success/failure to queue the new buffer,
+ * but rather the status of the previous buffer.
+ */
+static int sh_mobile_ceu_capture(struct sh_mobile_ceu_dev *pcdev)
 {
        struct soc_camera_device *icd = pcdev->icd;
        dma_addr_t phys_addr_top, phys_addr_bottom;
+       u32 status;
+       int ret = 0;
 
        /* The hardware is _very_ picky about this sequence. Especially
         * the CEU_CETCR_MAGIC value. It seems like we need to acknowledge
         * several not-so-well documented interrupt sources in CETCR.
         */
-       ceu_write(pcdev, CEIER, ceu_read(pcdev, CEIER) & ~CEU_CEIER_CPEIE);
-       ceu_write(pcdev, CETCR, ~ceu_read(pcdev, CETCR) & CEU_CETCR_MAGIC);
-       ceu_write(pcdev, CEIER, ceu_read(pcdev, CEIER) | CEU_CEIER_CPEIE);
+       ceu_write(pcdev, CEIER, ceu_read(pcdev, CEIER) & ~CEU_CEIER_MASK);
+       status = ceu_read(pcdev, CETCR);
+       ceu_write(pcdev, CETCR, ~status & CEU_CETCR_MAGIC);
+       ceu_write(pcdev, CEIER, ceu_read(pcdev, CEIER) | CEU_CEIER_MASK);
        ceu_write(pcdev, CAPCR, ceu_read(pcdev, CAPCR) & ~CEU_CAPCR_CTNCP);
        ceu_write(pcdev, CETCR, CEU_CETCR_MAGIC ^ CEU_CETCR_IGRW);
 
+       /*
+        * When a VBP interrupt occurs, a capture end interrupt does not occur
+        * and the image of that frame is not captured correctly. So, soft reset
+        * is needed here.
+        */
+       if (status & CEU_CEIER_VBP) {
+               sh_mobile_ceu_soft_reset(pcdev);
+               ret = -EIO;
+       }
+
        if (!pcdev->active)
-               return;
+               return ret;
 
        phys_addr_top = videobuf_to_dma_contig(pcdev->active);
        ceu_write(pcdev, CDAYR, phys_addr_top);
@@ -281,6 +300,8 @@ static void sh_mobile_ceu_capture(struct sh_mobile_ceu_dev *pcdev)
 
        pcdev->active->state = VIDEOBUF_ACTIVE;
        ceu_write(pcdev, CAPSR, 0x1); /* start capture */
+
+       return ret;
 }
 
 static int sh_mobile_ceu_videobuf_prepare(struct videobuf_queue *vq,
@@ -353,6 +374,11 @@ static void sh_mobile_ceu_videobuf_queue(struct videobuf_queue *vq,
        list_add_tail(&vb->queue, &pcdev->capture);
 
        if (!pcdev->active) {
+               /*
+                * Because there were no active buffer at this moment,
+                * we are not interested in the return value of
+                * sh_mobile_ceu_capture here.
+                */
                pcdev->active = vb;
                sh_mobile_ceu_capture(pcdev);
        }
@@ -413,9 +439,8 @@ static irqreturn_t sh_mobile_ceu_irq(int irq, void *data)
        else
                pcdev->active = NULL;
 
-       sh_mobile_ceu_capture(pcdev);
-
-       vb->state = VIDEOBUF_DONE;
+       vb->state = (sh_mobile_ceu_capture(pcdev) < 0) ?
+               VIDEOBUF_ERROR : VIDEOBUF_DONE;
        do_gettimeofday(&vb->ts);
        vb->field_count++;
        wake_up(&vb->done);