diff options
Diffstat (limited to 'drivers/dma/fsldma.c')
-rw-r--r-- | drivers/dma/fsldma.c | 45 |
1 files changed, 29 insertions, 16 deletions
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 73dd7482319..7a0cb6064f8 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -280,28 +280,40 @@ static void fsl_chan_set_dest_loop_size(struct fsl_dma_chan *fsl_chan, int size) } /** - * fsl_chan_toggle_ext_pause - Toggle channel external pause status + * fsl_chan_set_request_count - Set DMA Request Count for external control * @fsl_chan : Freescale DMA channel - * @size : Pause control size, 0 for disable external pause control. - * The maximum is 1024. + * @size : Number of bytes to transfer in a single request + * + * The Freescale DMA channel can be controlled by the external signal DREQ#. + * The DMA request count is how many bytes are allowed to transfer before + * pausing the channel, after which a new assertion of DREQ# resumes channel + * operation. * - * The Freescale DMA channel can be controlled by the external - * signal DREQ#. The pause control size is how many bytes are allowed - * to transfer before pausing the channel, after which a new assertion - * of DREQ# resumes channel operation. + * A size of 0 disables external pause control. The maximum size is 1024. */ -static void fsl_chan_toggle_ext_pause(struct fsl_dma_chan *fsl_chan, int size) +static void fsl_chan_set_request_count(struct fsl_dma_chan *fsl_chan, int size) { - if (size > 1024) - return; + BUG_ON(size > 1024); + DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, + DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) + | ((__ilog2(size) << 24) & 0x0f000000), + 32); +} - if (size) { - DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, - DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) - | ((__ilog2(size) << 24) & 0x0f000000), - 32); +/** + * fsl_chan_toggle_ext_pause - Toggle channel external pause status + * @fsl_chan : Freescale DMA channel + * @enable : 0 is disabled, 1 is enabled. + * + * The Freescale DMA channel can be controlled by the external signal DREQ#. + * The DMA Request Count feature should be used in addition to this feature + * to set the number of bytes to transfer before pausing the channel. + */ +static void fsl_chan_toggle_ext_pause(struct fsl_dma_chan *fsl_chan, int enable) +{ + if (enable) fsl_chan->feature |= FSL_DMA_CHAN_PAUSE_EXT; - } else + else fsl_chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT; } @@ -885,6 +897,7 @@ static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev, new_fsl_chan->toggle_ext_start = fsl_chan_toggle_ext_start; new_fsl_chan->set_src_loop_size = fsl_chan_set_src_loop_size; new_fsl_chan->set_dest_loop_size = fsl_chan_set_dest_loop_size; + new_fsl_chan->set_request_count = fsl_chan_set_request_count; } spin_lock_init(&new_fsl_chan->desc_lock); |