[media] v4l: omap3isp: Use dma_request_chan_by_mask() to request the DMA channel

When requesting the DMA channel it was mandatory that we do not have DMA
resource nor valid DMA channel via DT. In this case the
dma_request_slave_channel_compat() would fall back and request any channel
with SW trigger.

The same can be achieved with the dma_request_chan_by_mask() without the
misleading use of the DMAengine API - implying that the omap3isp does
need to have DMA resource or valid dma binding in DT.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/platform/omap3isp/isphist.c b/drivers/media/platform/omap3isp/isphist.c
index 7138b04..a4ed5d1 100644 (file)
--- a/drivers/media/platform/omap3isp/isphist.c
+++ b/drivers/media/platform/omap3isp/isphist.c
@@ -18,7 +18,6 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dmaengine.h>
-#include <linux/omap-dmaengine.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 
@@ -486,27 +485,30 @@ int omap3isp_hist_init(struct isp_device *isp)
        hist->isp = isp;
 
        if (HIST_CONFIG_DMA) {
-               struct platform_device *pdev = to_platform_device(isp->dev);
-               struct resource *res;
-               unsigned int sig = 0;
                dma_cap_mask_t mask;
 
+               /*
+                * We need slave capable channel without DMA request line for
+                * reading out the data.
+                * For this we can use dma_request_chan_by_mask() as we are
+                * happy with any channel as long as it is capable of slave
+                * configuration.
+                */
                dma_cap_zero(mask);
                dma_cap_set(DMA_SLAVE, mask);
+               hist->dma_ch = dma_request_chan_by_mask(&mask);
+               if (IS_ERR(hist->dma_ch)) {
+                       ret = PTR_ERR(hist->dma_ch);
+                       if (ret == -EPROBE_DEFER)
+                               return ret;
 
-               res = platform_get_resource_byname(pdev, IORESOURCE_DMA,
-                                                  "hist");
-               if (res)
-                       sig = res->start;
-
-               hist->dma_ch = dma_request_slave_channel_compat(mask,
-                               omap_dma_filter_fn, &sig, isp->dev, "hist");
-               if (!hist->dma_ch)
+                       hist->dma_ch = NULL;
                        dev_warn(isp->dev,
                                 "hist: DMA channel request failed, using PIO\n");
-               else
+               } else {
                        dev_dbg(isp->dev, "hist: using DMA channel %s\n",
                                dma_chan_name(hist->dma_ch));
+               }
        }
 
        hist->ops = &hist_ops;