Re: [PATCH 01/18] dmaengine: of-dma: Add support for optional router configuration callback
From: Vinod Koul <vkoul@kernel.org>
Date: 2020-10-07 05:44:12
Also in:
dmaengine, linux-devicetree, lkml
Hi Peter, On 30-09-20, 12:13, Peter Ujfalusi wrote:
Additional configuration for the DMA event router might be needed for a channel which can not be done during device_alloc_chan_resources callback since the router information is not yet present for the drivers. If there is a need for additional configuration for the channel if DMA router is in use, then the driver can implement the device_router_config callback.
So what is the additional information you need, I am looking at the code below and xlate invokes device_router_config() which driver will implement.. Are you using this to configure channels based on info from DT?
quoted hunk ↗ jump to hunk
Signed-off-by: Peter Ujfalusi <redacted> --- drivers/dma/of-dma.c | 10 ++++++++++ include/linux/dmaengine.h | 2 ++ 2 files changed, 12 insertions(+)diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index 8a4f608904b9..ec00b20ae8e4 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c@@ -75,8 +75,18 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, ofdma->dma_router->route_free(ofdma->dma_router->dev, route_data); } else { + int ret = 0; + chan->router = ofdma->dma_router; chan->route_data = route_data; + + if (chan->device->device_router_config) + ret = chan->device->device_router_config(chan); + + if (ret) { + dma_release_channel(chan); + chan = ERR_PTR(ret); + } } /*diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index dd357a747780..d6197fe875af 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h@@ -800,6 +800,7 @@ struct dma_filter { * by tx_status * @device_alloc_chan_resources: allocate resources and return the * number of allocated descriptors + * @device_router_config: optional callback for DMA router configuration * @device_free_chan_resources: release DMA channel's resources * @device_prep_dma_memcpy: prepares a memcpy operation * @device_prep_dma_xor: prepares a xor operation@@ -874,6 +875,7 @@ struct dma_device { enum dma_residue_granularity residue_granularity; int (*device_alloc_chan_resources)(struct dma_chan *chan); + int (*device_router_config)(struct dma_chan *chan); void (*device_free_chan_resources)(struct dma_chan *chan); struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(-- Peter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
-- ~Vinod _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel