MIPS: Alchemy: Simplify DMA channel allocation code.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
diff --git a/arch/mips/alchemy/common/dbdma.c b/arch/mips/alchemy/common/dbdma.c
index 493e570..99ae84c 100644
--- a/arch/mips/alchemy/common/dbdma.c
+++ b/arch/mips/alchemy/common/dbdma.c
@@ -237,7 +237,7 @@
void (*callback)(int, void *), void *callparam)
{
unsigned long flags;
- u32 used, chan, rv;
+ u32 used, chan;
u32 dcp;
int i;
dbdev_tab_t *stp, *dtp;
@@ -260,7 +260,6 @@
return 0;
used = 0;
- rv = 0;
/* Check to see if we can get both channels. */
spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
@@ -281,63 +280,65 @@
used++;
spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
- if (!used) {
- /* Let's see if we can allocate a channel for it. */
- ctp = NULL;
- chan = 0;
- spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
- for (i = 0; i < NUM_DBDMA_CHANS; i++)
- if (chan_tab_ptr[i] == NULL) {
- /*
- * If kmalloc fails, it is caught below same
- * as a channel not available.
- */
- ctp = kmalloc(sizeof(chan_tab_t), GFP_ATOMIC);
- chan_tab_ptr[i] = ctp;
- break;
- }
- spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
+ if (used)
+ return 0;
- if (ctp != NULL) {
- memset(ctp, 0, sizeof(chan_tab_t));
- ctp->chan_index = chan = i;
- dcp = DDMA_CHANNEL_BASE;
- dcp += (0x0100 * chan);
- ctp->chan_ptr = (au1x_dma_chan_t *)dcp;
- cp = (au1x_dma_chan_t *)dcp;
- ctp->chan_src = stp;
- ctp->chan_dest = dtp;
- ctp->chan_callback = callback;
- ctp->chan_callparam = callparam;
-
- /* Initialize channel configuration. */
- i = 0;
- if (stp->dev_intlevel)
- i |= DDMA_CFG_SED;
- if (stp->dev_intpolarity)
- i |= DDMA_CFG_SP;
- if (dtp->dev_intlevel)
- i |= DDMA_CFG_DED;
- if (dtp->dev_intpolarity)
- i |= DDMA_CFG_DP;
- if ((stp->dev_flags & DEV_FLAGS_SYNC) ||
- (dtp->dev_flags & DEV_FLAGS_SYNC))
- i |= DDMA_CFG_SYNC;
- cp->ddma_cfg = i;
- au_sync();
-
- /* Return a non-zero value that can be used to
- * find the channel information in subsequent
- * operations.
+ /* Let's see if we can allocate a channel for it. */
+ ctp = NULL;
+ chan = 0;
+ spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
+ for (i = 0; i < NUM_DBDMA_CHANS; i++)
+ if (chan_tab_ptr[i] == NULL) {
+ /*
+ * If kmalloc fails, it is caught below same
+ * as a channel not available.
*/
- rv = (u32)(&chan_tab_ptr[chan]);
- } else {
- /* Release devices */
- stp->dev_flags &= ~DEV_FLAGS_INUSE;
- dtp->dev_flags &= ~DEV_FLAGS_INUSE;
+ ctp = kmalloc(sizeof(chan_tab_t), GFP_ATOMIC);
+ chan_tab_ptr[i] = ctp;
+ break;
}
+ spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
+
+ if (ctp != NULL) {
+ memset(ctp, 0, sizeof(chan_tab_t));
+ ctp->chan_index = chan = i;
+ dcp = DDMA_CHANNEL_BASE;
+ dcp += (0x0100 * chan);
+ ctp->chan_ptr = (au1x_dma_chan_t *)dcp;
+ cp = (au1x_dma_chan_t *)dcp;
+ ctp->chan_src = stp;
+ ctp->chan_dest = dtp;
+ ctp->chan_callback = callback;
+ ctp->chan_callparam = callparam;
+
+ /* Initialize channel configuration. */
+ i = 0;
+ if (stp->dev_intlevel)
+ i |= DDMA_CFG_SED;
+ if (stp->dev_intpolarity)
+ i |= DDMA_CFG_SP;
+ if (dtp->dev_intlevel)
+ i |= DDMA_CFG_DED;
+ if (dtp->dev_intpolarity)
+ i |= DDMA_CFG_DP;
+ if ((stp->dev_flags & DEV_FLAGS_SYNC) ||
+ (dtp->dev_flags & DEV_FLAGS_SYNC))
+ i |= DDMA_CFG_SYNC;
+ cp->ddma_cfg = i;
+ au_sync();
+
+ /*
+ * Return a non-zero value that can be used to find the channel
+ * information in subsequent operations.
+ */
+ return (u32)(&chan_tab_ptr[chan]);
}
- return rv;
+
+ /* Release devices */
+ stp->dev_flags &= ~DEV_FLAGS_INUSE;
+ dtp->dev_flags &= ~DEV_FLAGS_INUSE;
+
+ return 0;
}
EXPORT_SYMBOL(au1xxx_dbdma_chan_alloc);