Messages in this thread | | | Subject | Re: [PATCH 2/2] dmaengine: omap-dma: Support for slave devices with data port window | From | Peter Ujfalusi <> | Date | Mon, 14 Nov 2016 13:56:30 +0200 |
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On 11/14/2016 12:53 PM, Russell King - ARM Linux wrote: > On Tue, Oct 25, 2016 at 01:50:19PM +0300, Peter Ujfalusi wrote: >> Based on the src/dst_port_window_size - if it is set - configure the DMA >> channel to use double indexing in order to be able to loop within the >> address window. >> >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> >> --- >> drivers/dma/omap-dma.c | 45 +++++++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 43 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c >> index 025f499cb20d..29350f936154 100644 >> --- a/drivers/dma/omap-dma.c >> +++ b/drivers/dma/omap-dma.c >> @@ -166,6 +166,9 @@ enum { >> CSDP_DST_BURST_16 = 1 << 14, >> CSDP_DST_BURST_32 = 2 << 14, >> CSDP_DST_BURST_64 = 3 << 14, >> + CSDP_WRITE_NON_POSTED = (0 << 16), >> + CSDP_WRITE_POSTED = (1 << 16), >> + CSDP_WRITE_LAST_NON_POSTED = (2 << 16), > > Why the useless parens?
I will get rid of them.
> >> + if (port_window) { >> + d->ccr |= CCR_SRC_AMODE_DBLIDX; >> + d->ei = 1; >> + d->fi = (-1) * (port_window - 1); > > You know that's 1 - port_window, or -(port_window - 1).
Yes, I know. "-(port_window - 1)" might be a bit better.
> >> + >> + if (port_window / 64) >> + d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED; >> + else if (port_window / 32) >> + d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED; >> + else if (port_window / 16) >> + d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED; > > Why these divisions? Wouldn't >= be more suitable here? Do they even > make sense here?
I'll revisit these.
> >> + } else { >> + d->ccr |= CCR_SRC_AMODE_CONSTANT; >> + } >> } else { >> - d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC; >> d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED; >> + >> + d->ccr |= CCR_SRC_AMODE_POSTINC; >> + if (port_window) { >> + d->ccr |= CCR_DST_AMODE_DBLIDX; >> + >> + if (port_window / 64) >> + d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED; >> + else if (port_window / 32) >> + d->csdp = CSDP_DST_BURST_32 | CSDP_DST_PACKED; >> + else if (port_window / 16) >> + d->csdp = CSDP_DST_BURST_16 | CSDP_DST_PACKED; > > Ditto. > >> + } else { >> + d->ccr |= CCR_DST_AMODE_CONSTANT; >> + } >> } >> >> d->cicr = CICR_DROP_IE | CICR_BLOCK_IE; >> @@ -945,6 +979,9 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( >> d->ccr |= CCR_TRIGGER_SRC; >> >> d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE; >> + >> + if (port_window) >> + d->csdp |= CSDP_WRITE_LAST_NON_POSTED; >> } >> if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS) >> d->clnk_ctrl = c->dma_ch; >> @@ -970,6 +1007,10 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( >> osg->addr = sg_dma_address(sgent); >> osg->en = en; >> osg->fn = sg_dma_len(sgent) / frame_bytes; >> + if (port_window && dir == DMA_MEM_TO_DEV) { >> + osg->ei = 1; >> + osg->fi = (-1) * (port_window - 1); > > Same as above. >
-- Péter
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