diff options
author | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-11-02 18:04:17 (GMT) |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2014-04-03 23:27:53 (GMT) |
commit | 3997cab391b38e126f217e36ad7bdc9672c9fb4d (patch) | |
tree | 9aac6b3a5ebbd34dde948504f500ea97ed562f22 /drivers/dma/omap-dma.c | |
parent | fa3ad86ae0576b2c721800cc4d46864aa6d31ffd (diff) | |
download | linux-3997cab391b38e126f217e36ad7bdc9672c9fb4d.tar.xz |
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 <tony@atomide.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/dma/omap-dma.c')
-rw-r--r-- | drivers/dma/omap-dma.c | 66 |
1 files changed, 64 insertions, 2 deletions
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c index 7aa5ff7..323eae2 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; |