target/linux/ipq806x/patches-3.18/153-dmaengine-Introduce-a-device_config-callback.patch

   1 From 94a73e30dfe6722e9f4ef19f7892901d7d00eab1 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime.ripard@free-electrons.com>
   3 Date: Mon, 17 Nov 2014 14:42:00 +0100
   4 Subject: [PATCH] dmaengine: Introduce a device_config callback
   5
   6 The fact that the channel configuration is done in device_control is rather
   7 misleading, since it's not really advertised as such, plus, the fact that the
   8 framework exposes a function of its own makes it not really intuitive, while
   9 we're losing the type checking whenever we pass that unsigned long argument.
  10
  11 Add a device_config callback to dma_device, with a fallback on the old
  12 behaviour for now for existing drivers to opt in.
  13
  14 Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
  15 Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  16 Signed-off-by: Vinod Koul <vinod.koul@intel.com>
  17 ---
  18  include/linux/dmaengine.h | 8 ++++++++
  19  1 file changed, 8 insertions(+)
  20
  21 --- a/include/linux/dmaengine.h
  22 +++ b/include/linux/dmaengine.h
  23 @@ -607,6 +607,8 @@ struct dma_tx_state {
  24   *     The function takes a buffer of size buf_len. The callback function will
  25   *     be called after period_len bytes have been transferred.
  26   * @device_prep_interleaved_dma: Transfer expression in a generic way.
  27 + * @device_config: Pushes a new configuration to a channel, return 0 or an error
  28 + *     code
  29   * @device_control: manipulate all pending operations on a channel, returns
  30   *     zero or error code
  31   * @device_tx_status: poll for transaction completion, the optional
  32 @@ -673,6 +675,9 @@ struct dma_device {
  33         struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
  34                 struct dma_chan *chan, struct dma_interleaved_template *xt,
  35                 unsigned long flags);
  36 +
  37 +       int (*device_config)(struct dma_chan *chan,
  38 +                            struct dma_slave_config *config);
  39         int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
  40                 unsigned long arg);
  41
  42 @@ -696,6 +701,9 @@ static inline int dmaengine_device_contr
  43  static inline int dmaengine_slave_config(struct dma_chan *chan,
  44                                           struct dma_slave_config *config)
  45  {
  46 +       if (chan->device->device_config)
  47 +               return chan->device->device_config(chan, config);
  48 +
  49         return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
  50                         (unsigned long)config);
  51  }