int dma_release_channel (unsigned int chn)
{
unsigned int mask = (0x3 << (chn * 2));
unsigned long flags;
if (chn >= DMA_MAX_CHANNELS || !dma_channels[chn].name) {
return -EINVAL;
}
lpc313x_dma_lock();
local_irq_save(flags);
/* Otherwise an unexpected interrupt can occur when the channel is reallocated for another purpose */
DMACH_IRQ_STATUS = mask;
dma_irq_mask |= mask;
DMACH_IRQ_MASK = dma_irq_mask;
/* reset counter */
DMACH_TCNT(chn) = 0;
local_irq_restore(flags);
dma_channels[chn].name = NULL;
dma_channels[chn].callback_handler = NULL;
dma_channels[chn].data = NULL;
lpc313x_dma_unlock();
dma_decrement_usage();
return 0;
}
int dma_release_sg_channel (unsigned int chn)
{
unsigned long flags;
if (chn >= DMA_MAX_CHANNELS || !dma_channels[chn].name) {
return -EINVAL;
}
lpc313x_dma_lock();
if (softirqmask[chn] != 0) {
local_irq_save(flags);
softirqen = 0;
softirqmask[chn] = 0;
dma_irq_mask |= DMA_IRQS_SOFT;
DMACH_IRQ_MASK = dma_irq_mask;
local_irq_restore(flags);
}
dma_channels[chn].name = NULL;
dma_channels[chn].callback_handler = NULL;
dma_channels[chn].data = NULL;
chn--;
dma_channels[chn].name = NULL;
dma_channels[chn].callback_handler = NULL;
dma_channels[chn].data = NULL;
sg_higher_channel[chn] = 0;
lpc313x_dma_unlock();
dma_decrement_usage();
return 0;
}
void pnx4008_free_channel(int ch)
{
if (!dma_channels[ch].name) {
printk(KERN_CRIT
"%s: trying to free channel %d which is already freed\n",
__FUNCTION__, ch);
return;
}
pnx4008_dma_lock();
pnx4008_free_ll(dma_channels[ch].ll_dma, dma_channels[ch].ll);
dma_channels[ch].ll = NULL;
dma_decrement_usage();
dma_channels[ch].name = NULL;
pnx4008_dma_unlock();
}