From 3b6d694eb3eebd86ec44a119e730943ac8e03a6b Mon Sep 17 00:00:00 2001 From: Serge Semin Date: Thu, 23 Jul 2020 03:58:43 +0300 Subject: dmaengine: Introduce DMA-device device_caps callback There are DMA devices (like ours version of Synopsys DW DMAC) which have DMA capabilities non-uniformly redistributed between the device channels. In order to provide a way of exposing the channel-specific parameters to the DMA engine consumers, we introduce a new DMA-device callback. In case if provided it gets called from the dma_get_slave_caps() method and is able to override the generic DMA-device capabilities. Signed-off-by: Serge Semin Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20200723005848.31907-6-Sergey.Semin@baikalelectronics.ru Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/dma') diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 8177f78faeda..a53e71d2bbd4 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -601,6 +601,16 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) caps->cmd_resume = !!device->device_resume; caps->cmd_terminate = !!device->device_terminate_all; + /* + * DMA engine device might be configured with non-uniformly + * distributed slave capabilities per device channels. In this + * case the corresponding driver may provide the device_caps + * callback to override the generic capabilities with + * channel-specific ones. + */ + if (device->device_caps) + device->device_caps(chan, caps); + return 0; } EXPORT_SYMBOL_GPL(dma_get_slave_caps); -- cgit v1.2.3