V4L/DVB (8611): Add suspend/resume to pxa_camera driver

PXA suspend switches off DMA core, which loses all context
of previously assigned descriptors. As pxa_camera driver
relies on DMA transfers, setup the lost descriptors on
resume and retrigger frame acquisition if needed.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/drivers/media/video/pxa_camera.c b/drivers/media/video/pxa_camera.c
index 28d8fd0679b4..ead87ddaf7fb 100644
--- a/drivers/media/video/pxa_camera.c
+++ b/drivers/media/video/pxa_camera.c
@@ -128,6 +128,8 @@ struct pxa_camera_dev {
 
         struct pxa_buffer       *active;
         struct pxa_dma_desc     *sg_tail[3];
+
+        u32                     save_cicr[5];
 };
 
 static const char *pxa_cam_driver_description = "PXA_Camera";
@@ -997,10 +999,64 @@ static int pxa_camera_querycap(struct soc_camera_host *ici,
         return 0;
 }
 
+static int pxa_camera_suspend(struct soc_camera_device *icd, pm_message_t state)
+{
+        struct soc_camera_host *ici =
+                to_soc_camera_host(icd->dev.parent);
+        struct pxa_camera_dev *pcdev = ici->priv;
+        int i = 0, ret = 0;
+
+        pcdev->save_cicr[i++] = CICR0;
+        pcdev->save_cicr[i++] = CICR1;
+        pcdev->save_cicr[i++] = CICR2;
+        pcdev->save_cicr[i++] = CICR3;
+        pcdev->save_cicr[i++] = CICR4;
+
+        if ((pcdev->icd) && (pcdev->icd->ops->suspend))
+                ret = pcdev->icd->ops->suspend(pcdev->icd, state);
+
+        return ret;
+}
+
+static int pxa_camera_resume(struct soc_camera_device *icd)
+{
+        struct soc_camera_host *ici =
+                to_soc_camera_host(icd->dev.parent);
+        struct pxa_camera_dev *pcdev = ici->priv;
+        int i = 0, ret = 0;
+
+        DRCMR68 = pcdev->dma_chans[0] | DRCMR_MAPVLD;
+        DRCMR69 = pcdev->dma_chans[1] | DRCMR_MAPVLD;
+        DRCMR70 = pcdev->dma_chans[2] | DRCMR_MAPVLD;
+
+        CICR0 = pcdev->save_cicr[i++] & ~CICR0_ENB;
+        CICR1 = pcdev->save_cicr[i++];
+        CICR2 = pcdev->save_cicr[i++];
+        CICR3 = pcdev->save_cicr[i++];
+        CICR4 = pcdev->save_cicr[i++];
+
+        if ((pcdev->icd) && (pcdev->icd->ops->resume))
+                ret = pcdev->icd->ops->resume(pcdev->icd);
+
+        /* Restart frame capture if active buffer exists */
+        if (!ret && pcdev->active) {
+                /* Reset the FIFOs */
+                CIFR |= CIFR_RESET_F;
+                /* Enable End-Of-Frame Interrupt */
+                CICR0 &= ~CICR0_EOFM;
+                /* Restart the Capture Interface */
+                CICR0 |= CICR0_ENB;
+        }
+
+        return ret;
+}
+
 static struct soc_camera_host_ops pxa_soc_camera_host_ops = {
         .owner          = THIS_MODULE,
         .add            = pxa_camera_add_device,
         .remove         = pxa_camera_remove_device,
+        .suspend        = pxa_camera_suspend,
+        .resume         = pxa_camera_resume,
         .set_fmt_cap    = pxa_camera_set_fmt_cap,
         .try_fmt_cap    = pxa_camera_try_fmt_cap,
         .init_videobuf  = pxa_camera_init_videobuf,