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@xxxxxx>
CC: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
CC: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
---
Hi,
Changes sicne v1:
- use dma_request_chan_by_mask() to request the channel as for the histogram
data reading we do not have hw syncronisation. Add comment about this also to
clarify the reason.
Regards,
Peter
drivers/media/platform/omap3isp/isphist.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
diff --git a/drivers/media/platform/omap3isp/isphist.c b/drivers/media/platform/omap3isp/isphist.c
index 7138b043a4aa..a4ed5d140d48 100644
--- 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;
--
2.10.2
--
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