[ARM] dma: rejig DMA initialization
Rather than having the central DMA multiplexer call the architecture
specific DMA initialization function, have each architecture DMA
initialization function use core_initcall(), and register each DMA
channel separately with the multiplexer.
This removes the array of dma structures in the central multiplexer,
replacing it with an array of pointers instead; this is more flexible
since it allows the drivers to wrap the DMA structure (eventually
allowing us to transition non-ISA DMA drivers away.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c
index 0ffea3f..aab24f0 100644
--- a/arch/arm/kernel/dma.c
+++ b/arch/arm/kernel/dma.c
@@ -23,16 +23,24 @@
DEFINE_SPINLOCK(dma_spin_lock);
EXPORT_SYMBOL(dma_spin_lock);
-static dma_t dma_chan[MAX_DMA_CHANNELS];
+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)
+ if (chan >= MAX_DMA_CHANNELS)
return NULL;
- return dma;
+ return dma_chan[chan];
+}
+
+int __init isa_dma_add(unsigned int chan, dma_t *dma)
+{
+ if (!dma->d_ops)
+ return -EINVAL;
+ if (dma_chan[chan])
+ return -EBUSY;
+ dma_chan[chan] = dma;
+ return 0;
}
/*
@@ -252,10 +260,3 @@
return ret;
}
EXPORT_SYMBOL(get_dma_residue);
-
-static int __init init_dma(void)
-{
- arch_dma_init(dma_chan);
- return 0;
-}
-core_initcall(init_dma);