From da4afffc1d03c4f0334dabd28ce4c2325ee8f092 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Sat, 27 Feb 2010 12:53:37 +0100 Subject: MIPS: Alchemy: Simplify DMA channel allocation code. Signed-off-by: Ralf Baechle Cc: Manuel Lauss --- arch/mips/alchemy/common/dbdma.c | 111 ++++++++++++++++++++------------------- 1 file changed, 56 insertions(+), 55 deletions(-) diff --git a/arch/mips/alchemy/common/dbdma.c b/arch/mips/alchemy/common/dbdma.c index 493e5708f664..99ae84ce5af3 100644 --- a/arch/mips/alchemy/common/dbdma.c +++ b/arch/mips/alchemy/common/dbdma.c @@ -237,7 +237,7 @@ u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid, 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 @@ u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid, 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 @@ u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid, 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 (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(); + if (used) + return 0; - /* 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); -- cgit v1.2.3