sDMA can support maximum of 65535 number of bursts in one transfer. The limitation is because the CFN counter is 16bit unsigned.
Signed-off-by: Peter Ujfalusi <[email protected]> --- drivers/dma/omap-dma.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c index f6dd849159d8..6418be98a782 100644 --- a/drivers/dma/omap-dma.c +++ b/drivers/dma/omap-dma.c @@ -1297,6 +1297,28 @@ static int omap_dma_slave_config(struct dma_chan *chan, struct dma_slave_config return 0; } +static u32 omap_dma_get_max_len(struct dma_chan *chan, + enum dma_transfer_direction dir) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + enum dma_slave_buswidth dev_width; + u32 burst; + + if (!is_slave_direction(dir)) + return 0; + + if (dir == DMA_DEV_TO_MEM) { + dev_width = c->cfg.src_addr_width; + burst = c->cfg.src_maxburst; + } else { + burst = c->cfg.dst_maxburst; + dev_width = c->cfg.dst_addr_width; + } + + /* CFN: 16bit unsigned. Number of bursts */ + return dev_width * burst * (SZ_64K - 1); +} + static int omap_dma_terminate_all(struct dma_chan *chan) { struct omap_chan *c = to_omap_dma_chan(chan); @@ -1478,6 +1500,7 @@ static int omap_dma_probe(struct platform_device *pdev) od->ddev.device_prep_dma_memcpy = omap_dma_prep_dma_memcpy; od->ddev.device_prep_interleaved_dma = omap_dma_prep_dma_interleaved; od->ddev.device_config = omap_dma_slave_config; + od->ddev.device_get_max_len = omap_dma_get_max_len; od->ddev.device_pause = omap_dma_pause; od->ddev.device_resume = omap_dma_resume; od->ddev.device_terminate_all = omap_dma_terminate_all; -- 2.14.1 Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
