From 3997cab391b38e126f217e36ad7bdc9672c9fb4d Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 2 Nov 2013 18:04:17 +0000 Subject: dmaengine: omap-dma: move reading of dma position to omap-dma.c Read the current DMA position from the hardware directly rather than via arch/arm/plat-omap/dma.c. Acked-by: Tony Lindgren Acked-by: Vinod Koul Signed-off-by: Russell King --- drivers/dma/omap-dma.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 64 insertions(+), 2 deletions(-) (limited to 'drivers/dma/omap-dma.c') diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c index 7aa5ff7ab935..323eae2c9d08 100644 --- a/drivers/dma/omap-dma.c +++ b/drivers/dma/omap-dma.c @@ -427,6 +427,68 @@ static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr) return size; } +static dma_addr_t omap_dma_get_src_pos(struct omap_chan *c) +{ + struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device); + dma_addr_t addr; + + if (__dma_omap15xx(od->plat->dma_attr)) + addr = c->plat->dma_read(CPC, c->dma_ch); + else + addr = c->plat->dma_read(CSAC, c->dma_ch); + + if (od->plat->errata & DMA_ERRATA_3_3 && addr == 0) + addr = c->plat->dma_read(CSAC, c->dma_ch); + + if (!__dma_omap15xx(od->plat->dma_attr)) { + /* + * CDAC == 0 indicates that the DMA transfer on the channel has + * not been started (no data has been transferred so far). + * Return the programmed source start address in this case. + */ + if (c->plat->dma_read(CDAC, c->dma_ch)) + addr = c->plat->dma_read(CSAC, c->dma_ch); + else + addr = c->plat->dma_read(CSSA, c->dma_ch); + } + + if (dma_omap1()) + addr |= c->plat->dma_read(CSSA, c->dma_ch) & 0xffff0000; + + return addr; +} + +static dma_addr_t omap_dma_get_dst_pos(struct omap_chan *c) +{ + struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device); + dma_addr_t addr; + + if (__dma_omap15xx(od->plat->dma_attr)) + addr = c->plat->dma_read(CPC, c->dma_ch); + else + addr = c->plat->dma_read(CDAC, c->dma_ch); + + /* + * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is + * read before the DMA controller finished disabling the channel. + */ + if (!__dma_omap15xx(od->plat->dma_attr) && addr == 0) { + addr = c->plat->dma_read(CDAC, c->dma_ch); + /* + * CDAC == 0 indicates that the DMA transfer on the channel has + * not been started (no data has been transferred so far). + * Return the programmed destination start address in this case. + */ + if (addr == 0) + addr = c->plat->dma_read(CDSA, c->dma_ch); + } + + if (dma_omap1()) + addr |= c->plat->dma_read(CDSA, c->dma_ch) & 0xffff0000; + + return addr; +} + static enum dma_status omap_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) { @@ -448,9 +510,9 @@ static enum dma_status omap_dma_tx_status(struct dma_chan *chan, dma_addr_t pos; if (d->dir == DMA_MEM_TO_DEV) - pos = omap_get_dma_src_pos(c->dma_ch); + pos = omap_dma_get_src_pos(c); else if (d->dir == DMA_DEV_TO_MEM) - pos = omap_get_dma_dst_pos(c->dma_ch); + pos = omap_dma_get_dst_pos(c); else pos = 0; -- cgit v1.2.3