From 94a73e30dfe6722e9f4ef19f7892901d7d00eab1 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Mon, 17 Nov 2014 14:42:00 +0100 Subject: [PATCH] dmaengine: Introduce a device_config callback The fact that the channel configuration is done in device_control is rather misleading, since it's not really advertised as such, plus, the fact that the framework exposes a function of its own makes it not really intuitive, while we're losing the type checking whenever we pass that unsigned long argument. Add a device_config callback to dma_device, with a fallback on the old behaviour for now for existing drivers to opt in. Signed-off-by: Maxime Ripard Acked-by: Laurent Pinchart Signed-off-by: Vinod Koul --- include/linux/dmaengine.h | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -607,6 +607,8 @@ struct dma_tx_state { * The function takes a buffer of size buf_len. The callback function will * be called after period_len bytes have been transferred. * @device_prep_interleaved_dma: Transfer expression in a generic way. + * @device_config: Pushes a new configuration to a channel, return 0 or an error + * code * @device_control: manipulate all pending operations on a channel, returns * zero or error code * @device_tx_status: poll for transaction completion, the optional @@ -673,6 +675,9 @@ struct dma_device { struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)( struct dma_chan *chan, struct dma_interleaved_template *xt, unsigned long flags); + + int (*device_config)(struct dma_chan *chan, + struct dma_slave_config *config); int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg); @@ -696,6 +701,9 @@ static inline int dmaengine_device_contr static inline int dmaengine_slave_config(struct dma_chan *chan, struct dma_slave_config *config) { + if (chan->device->device_config) + return chan->device->device_config(chan, config); + return dmaengine_device_control(chan, DMA_SLAVE_CONFIG, (unsigned long)config); }