diff options
| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-12-08 16:08:48 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-12-08 16:56:22 +0000 |
| commit | 3afb6e9c635f735c751148beddc195daec0e35ec (patch) | |
| tree | 5ce51a4a09d3d11df751a43c7c6f4b5eeee0cf8e /arch/arm/kernel/dma.c | |
| parent | 1df8130278c4543555fea697e5714fbac300b899 (diff) | |
| download | linux-3afb6e9c635f735c751148beddc195daec0e35ec.tar.gz | |
[ARM] dma: factor out code looking up the DMA channel
This is a preparitory patch to allow us to easily change the way we add and lookup DMA channel structures. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/dma.c')
| -rw-r--r-- | arch/arm/kernel/dma.c | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c index c31bf00e5bae..0ffea3fc22db 100644 --- a/arch/arm/kernel/dma.c +++ b/arch/arm/kernel/dma.c @@ -25,6 +25,16 @@ EXPORT_SYMBOL(dma_spin_lock); static dma_t dma_chan[MAX_DMA_CHANNELS]; +static inline dma_t *dma_channel(unsigned int chan) +{ + dma_t *dma = dma_chan + chan; + + if (chan >= MAX_DMA_CHANNELS || !dma->d_ops) + return NULL; + + return dma; +} + /* * Request DMA channel * @@ -32,10 +42,10 @@ static dma_t dma_chan[MAX_DMA_CHANNELS]; */ int request_dma(unsigned int chan, const char *device_id) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); int ret; - if (chan >= MAX_DMA_CHANNELS || !dma->d_ops) + if (!dma) goto bad_dma; if (xchg(&dma->lock, 1) != 0) @@ -70,9 +80,9 @@ EXPORT_SYMBOL(request_dma); */ void free_dma(unsigned int chan) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); - if (chan >= MAX_DMA_CHANNELS || !dma->d_ops) + if (!dma) goto bad_dma; if (dma->active) { @@ -99,7 +109,7 @@ EXPORT_SYMBOL(free_dma); */ void set_dma_sg (unsigned int chan, struct scatterlist *sg, int nr_sg) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); if (dma->active) printk(KERN_ERR "dma%d: altering DMA SG while " @@ -117,7 +127,7 @@ EXPORT_SYMBOL(set_dma_sg); */ void __set_dma_addr (unsigned int chan, void *addr) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); if (dma->active) printk(KERN_ERR "dma%d: altering DMA address while " @@ -135,7 +145,7 @@ EXPORT_SYMBOL(__set_dma_addr); */ void set_dma_count (unsigned int chan, unsigned long count) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); if (dma->active) printk(KERN_ERR "dma%d: altering DMA count while " @@ -151,7 +161,7 @@ EXPORT_SYMBOL(set_dma_count); */ void set_dma_mode (unsigned int chan, dmamode_t mode) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); if (dma->active) printk(KERN_ERR "dma%d: altering DMA mode while " @@ -166,7 +176,7 @@ EXPORT_SYMBOL(set_dma_mode); */ void enable_dma (unsigned int chan) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); if (!dma->lock) goto free_dma; @@ -187,7 +197,7 @@ EXPORT_SYMBOL(enable_dma); */ void disable_dma (unsigned int chan) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); if (!dma->lock) goto free_dma; @@ -209,7 +219,8 @@ EXPORT_SYMBOL(disable_dma); */ int dma_channel_active(unsigned int chan) { - return dma_chan[chan].active; + dma_t *dma = dma_channel(chan); + return dma->active; } EXPORT_SYMBOL(dma_channel_active); @@ -221,7 +232,7 @@ EXPORT_SYMBOL(set_dma_page); void set_dma_speed(unsigned int chan, int cycle_ns) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); int ret = 0; if (dma->d_ops->setspeed) @@ -232,7 +243,7 @@ EXPORT_SYMBOL(set_dma_speed); int get_dma_residue(unsigned int chan) { - dma_t *dma = dma_chan + chan; + dma_t *dma = dma_channel(chan); int ret = 0; if (dma->d_ops->residue) @@ -247,5 +258,4 @@ static int __init init_dma(void) arch_dma_init(dma_chan); return 0; } - core_initcall(init_dma); |