static inline void omap_enable_channel_irq(int lch)
{
- u32 status;
-
/* Clear CSR */
if (cpu_class_is_omap1())
- status = p->dma_read(CSR, lch);
- else if (cpu_class_is_omap2())
+ p->dma_read(CSR, lch);
+ else
p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
/* Enable some nice interrupts. */
p->dma_write(dma_chan[lch].enabled_irqs, CICR, lch);
}
-static void omap_disable_channel_irq(int lch)
+static inline void omap_disable_channel_irq(int lch)
{
- if (cpu_class_is_omap2())
- p->dma_write(0, CICR, lch);
+ /* disable channel interrupts */
+ p->dma_write(0, CICR, lch);
+ /* Clear CSR */
+ if (cpu_class_is_omap1())
+ p->dma_read(CSR, lch);
+ else
+ p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
}
void omap_enable_dma_irq(int lch, u16 bits)
l = p->dma_read(CLNK_CTRL, lch);
/* Disable interrupts */
+ omap_disable_channel_irq(lch);
+
if (cpu_class_is_omap1()) {
- p->dma_write(0, CICR, lch);
/* Set the STOP_LNK bit */
l |= 1 << 14;
}
if (cpu_class_is_omap2()) {
- omap_disable_channel_irq(lch);
/* Clear the ENABLE_LNK bit */
l &= ~(1 << 15);
}
return;
spin_lock_irqsave(&dma_chan_lock, flags);
+ /* clear IRQ STATUS */
+ p->dma_write(1 << lch, IRQSTATUS_L0, lch);
+ /* Enable interrupt */
val = p->dma_read(IRQENABLE_L0, lch);
val |= 1 << lch;
p->dma_write(val, IRQENABLE_L0, lch);
return;
spin_lock_irqsave(&dma_chan_lock, flags);
+ /* Disable interrupt */
val = p->dma_read(IRQENABLE_L0, lch);
val &= ~(1 << lch);
p->dma_write(val, IRQENABLE_L0, lch);
+ /* clear IRQ STATUS */
+ p->dma_write(1 << lch, IRQSTATUS_L0, lch);
spin_unlock_irqrestore(&dma_chan_lock, flags);
}
for (ch = 0; ch < dma_chan_count; ch++) {
if (free_ch == -1 && dma_chan[ch].dev_id == -1) {
free_ch = ch;
- if (dev_id == 0)
- break;
+ /* Exit after first free channel found */
+ break;
}
}
if (free_ch == -1) {
}
if (cpu_class_is_omap2()) {
- omap2_enable_irq_lch(free_ch);
omap_enable_channel_irq(free_ch);
- /* Clear the CSR register and IRQ status register */
- p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, free_ch);
- p->dma_write(1 << free_ch, IRQSTATUS_L0, 0);
+ omap2_enable_irq_lch(free_ch);
}
*dma_ch_out = free_ch;
return;
}
- if (cpu_class_is_omap1()) {
- /* Disable all DMA interrupts for the channel. */
- p->dma_write(0, CICR, lch);
- /* Make sure the DMA transfer is stopped. */
- p->dma_write(0, CCR, lch);
- }
-
- if (cpu_class_is_omap2()) {
+ /* Disable interrupt for logical channel */
+ if (cpu_class_is_omap2())
omap2_disable_irq_lch(lch);
- /* Clear the CSR register and IRQ status register */
- p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
- p->dma_write(1 << lch, IRQSTATUS_L0, lch);
+ /* Disable all DMA interrupts for the channel. */
+ omap_disable_channel_irq(lch);
- /* Disable all DMA interrupts for the channel. */
- p->dma_write(0, CICR, lch);
+ /* Make sure the DMA transfer is stopped. */
+ p->dma_write(0, CCR, lch);
- /* Make sure the DMA transfer is stopped. */
- p->dma_write(0, CCR, lch);
+ /* Clear registers */
+ if (cpu_class_is_omap2())
omap_clear_dma(lch);
- }
spin_lock_irqsave(&dma_chan_lock, flags);
dma_chan[lch].dev_id = -1;
int next_lch, cur_lch;
char dma_chan_link_map[dma_lch_count];
- dma_chan_link_map[lch] = 1;
/* Set the link register of the first channel */
enable_lnk(lch);
memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
+ dma_chan_link_map[lch] = 1;
+
cur_lch = dma_chan[lch].next_lch;
do {
next_lch = dma_chan[cur_lch].next_lch;
l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
l |= OMAP_DMA_CCR_EN;
+ /*
+ * As dma_write() uses IO accessors which are weakly ordered, there
+ * is no guarantee that data in coherent DMA memory will be visible
+ * to the DMA device. Add a memory barrier here to ensure that any
+ * such data is visible prior to enabling DMA.
+ */
+ mb();
p->dma_write(l, CCR, lch);
dma_chan[lch].flags |= OMAP_DMA_ACTIVE;
u32 l;
/* Disable all interrupts on the channel */
- if (cpu_class_is_omap1())
- p->dma_write(0, CICR, lch);
+ omap_disable_channel_irq(lch);
l = p->dma_read(CCR, lch);
if (IS_DMA_ERRATA(DMA_ERRATA_i541) &&
p->dma_write(l, CCR, lch);
}
+ /*
+ * Ensure that data transferred by DMA is visible to any access
+ * after DMA has been disabled. This is important for coherent
+ * DMA regions.
+ */
+ mb();
+
if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
int next_lch, cur_lch = lch;
char dma_chan_link_map[dma_lch_count];
errata = p->errata;
if ((d->dev_caps & RESERVE_CHANNEL) && omap_dma_reserve_channels
- && (omap_dma_reserve_channels <= dma_lch_count))
+ && (omap_dma_reserve_channels < d->lch_count))
d->lch_count = omap_dma_reserve_channels;
dma_lch_count = d->lch_count;