static int s3c2410_dma_dostop(struct s3c2410_dma_chan *chan) { unsigned long flags; unsigned long tmp; pr_debug("%s:\n", __func__); dbg_showchan(chan); local_irq_save(flags); s3c2410_dma_call_op(chan, S3C2410_DMAOP_STOP); tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); tmp |= S3C2410_DMASKTRIG_STOP; //tmp &= ~S3C2410_DMASKTRIG_ON; dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); #if 0 /* should also clear interrupts, according to WinCE BSP */ tmp = dma_rdreg(chan, S3C2410_DMA_DCON); tmp |= S3C2410_DCON_NORELOAD; dma_wrreg(chan, S3C2410_DMA_DCON, tmp); #endif /* should stop do this, or should we wait for flush? */ chan->state = S3C2410_DMA_IDLE; chan->load_state = S3C2410_DMALOAD_NONE; local_irq_restore(flags); return 0; }
static int s3c2410_dma_dostop(s3c2410_dma_chan_t *chan) { unsigned long tmp; unsigned long flags; pr_debug("%s:\n", __FUNCTION__); dbg_showchan(chan); local_irq_save(flags); s3c2410_dma_call_op(chan, S3C2410_DMAOP_STOP); tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); tmp |= S3C2410_DMASKTRIG_STOP; dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); #if 0 /* should also clear interrupts, according to WinCE BSP */ tmp = dma_rdreg(chan, S3C2410_DMA_DCON); tmp |= S3C2410_DCON_NORELOAD; dma_wrreg(chan, S3C2410_DMA_DCON, tmp); #endif chan->state = S3C2410_DMA_IDLE; chan->load_state = S3C2410_DMALOAD_NONE; local_irq_restore(flags); return 0; }
static int s3c2410_dma_start(struct s3c2410_dma_chan *chan) { unsigned long tmp; unsigned long flags; pr_debug("s3c2410_start_dma: channel=%d\n", chan->number); local_irq_save(flags); if (chan->state == S3C2410_DMA_RUNNING) { pr_debug("s3c2410_start_dma: already running (%d)\n", chan->state); local_irq_restore(flags); return 0; } chan->state = S3C2410_DMA_RUNNING; /* check wether there is anything to load, and if not, see * if we can find anything to load */ if (chan->load_state == S3C2410_DMALOAD_NONE) { if (chan->next == NULL) { printk(KERN_ERR "dma%d: channel has nothing loaded\n", chan->number); chan->state = S3C2410_DMA_IDLE; local_irq_restore(flags); return -EINVAL; } s3c2410_dma_loadbuffer(chan, chan->next); } dbg_showchan(chan); /* enable the channel */ if (!chan->irq_enabled) { enable_irq(chan->irq); chan->irq_enabled = 1; } /* start the channel going */ tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); tmp &= ~S3C2410_DMASKTRIG_STOP; tmp |= S3C2410_DMASKTRIG_ON; dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); pr_debug("dma%d: %08lx to DMASKTRIG\n", chan->number, tmp); #if 0 /* the dma buffer loads should take care of clearing the AUTO * reloading feature */ tmp = dma_rdreg(chan, S3C2410_DMA_DCON); tmp &= ~S3C2410_DCON_NORELOAD; dma_wrreg(chan, S3C2410_DMA_DCON, tmp); #endif s3c2410_dma_call_op(chan, S3C2410_DMAOP_START); dbg_showchan(chan); /* if we've only loaded one buffer onto the channel, then chec * to see if we have another, and if so, try and load it so when * the first buffer is finished, the new one will be loaded onto * the channel */ if (chan->next != NULL) { if (chan->load_state == S3C2410_DMALOAD_1LOADED) { if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { pr_debug("%s: buff not yet loaded, no more todo\n", __func__); } else { chan->load_state = S3C2410_DMALOAD_1RUNNING; s3c2410_dma_loadbuffer(chan, chan->next); } } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) { s3c2410_dma_loadbuffer(chan, chan->next); } } local_irq_restore(flags); return 0; }
static int s3c2410_dma_start(s3c2410_dma_chan_t *chan) { unsigned long tmp; unsigned long flags; pr_debug("s3c2410_start_dma: channel=%d\n", chan->number); local_irq_save(flags); if (chan->state == S3C2410_DMA_RUNNING) { pr_debug("s3c2410_start_dma: already running (%d)\n", chan->state); local_irq_restore(flags); return 0; } chan->state = S3C2410_DMA_RUNNING; /* check wether there is anything to load, and if not, see * if we can find anything to load */ if (chan->load_state == S3C2410_DMALOAD_NONE) { if (chan->next == NULL) { printk(KERN_ERR "dma%d: channel has nothing loaded\n", chan->number); chan->state = S3C2410_DMA_IDLE; local_irq_restore(flags); return -EINVAL; } s3c2410_dma_loadbuffer(chan, chan->next); } dbg_showchan(chan); /* enable the channel */ if (!chan->irq_enabled) { enable_irq(chan->irq); chan->irq_enabled = 1; } /* start the channel going */ tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); tmp &= ~S3C2410_DMASKTRIG_STOP; tmp |= S3C2410_DMASKTRIG_ON; dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); pr_debug("wrote %08lx to DMASKTRIG\n", tmp); #if 0 /* the dma buffer loads should take care of clearing the AUTO * reloading feature */ tmp = dma_rdreg(chan, S3C2410_DMA_DCON); tmp &= ~S3C2410_DCON_NORELOAD; dma_wrreg(chan, S3C2410_DMA_DCON, tmp); #endif s3c2410_dma_call_op(chan, S3C2410_DMAOP_START); dbg_showchan(chan); local_irq_restore(flags); return 0; }
static irqreturn_t s3c2410_dma_irq(int irq, void *devpw) { struct s3c2410_dma_chan *chan = (struct s3c2410_dma_chan *)devpw; struct s3c2410_dma_buf *buf; buf = chan->curr; dbg_showchan(chan); /* modify the channel state */ switch (chan->load_state) { case S3C2410_DMALOAD_1RUNNING: /* TODO - if we are running only one buffer, we probably * want to reload here, and then worry about the buffer * callback */ chan->load_state = S3C2410_DMALOAD_NONE; break; case S3C2410_DMALOAD_1LOADED: /* iirc, we should go back to NONE loaded here, we * had a buffer, and it was never verified as being * loaded. */ chan->load_state = S3C2410_DMALOAD_NONE; break; case S3C2410_DMALOAD_1LOADED_1RUNNING: /* we'll worry about checking to see if another buffer is * ready after we've called back the owner. This should * ensure we do not wait around too long for the DMA * engine to start the next transfer */ chan->load_state = S3C2410_DMALOAD_1LOADED; break; case S3C2410_DMALOAD_NONE: printk(KERN_ERR "dma%d: IRQ with no loaded buffer?\n", chan->number); break; default: printk(KERN_ERR "dma%d: IRQ in invalid load_state %d\n", chan->number, chan->load_state); break; } if (buf != NULL) { /* update the chain to make sure that if we load any more * buffers when we call the callback function, things should * work properly */ chan->curr = buf->next; buf->next = NULL; if (buf->magic != BUF_MAGIC) { printk(KERN_ERR "dma%d: %s: buf %p incorrect magic\n", chan->number, __func__, buf); return IRQ_HANDLED; } s3c2410_dma_buffdone(chan, buf, S3C2410_RES_OK); /* free resouces */ s3c2410_dma_freebuf(buf); } else { } /* only reload if the channel is still running... our buffer done * routine may have altered the state by requesting the dma channel * to stop or shutdown... */ /* todo: check that when the channel is shut-down from inside this * function, we cope with unsetting reload, etc */ if (chan->next != NULL && chan->state != S3C2410_DMA_IDLE) { unsigned long flags; unsigned long tmp; switch (chan->load_state) { case S3C2410_DMALOAD_1RUNNING: /* don't need to do anything for this state */ break; case S3C2410_DMALOAD_NONE: /* can load buffer immediately */ break; case S3C2410_DMALOAD_1LOADED: /* printk(KERN_INFO "DMA: 1 LOADED\n"); */ //if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { // /* flag error? */ // printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n", // chan->number, __func__); // return IRQ_HANDLED; //} break; case S3C2410_DMALOAD_1LOADED_1RUNNING: goto no_load; default: printk(KERN_ERR "dma%d: unknown load_state in irq, %d\n", chan->number, chan->load_state); return IRQ_HANDLED; } /* * Since we are not using the auto-reload feature, we must restart * the DMA-channel at this point * (Luis Galdos) */ local_irq_save(flags); chan->load_state = S3C2410_DMALOAD_NONE; s3c2410_dma_loadbuffer(chan, chan->curr); tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); tmp &= ~S3C2410_DMASKTRIG_STOP; tmp |= S3C2410_DMASKTRIG_ON; dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); s3c2410_dma_call_op(chan, S3C2410_DMAOP_START); local_irq_restore(flags); } else { s3c2410_dma_lastxfer(chan); /* see if we can stop this channel.. */ if (chan->load_state == S3C2410_DMALOAD_NONE) { pr_debug("dma%d: end of transfer, stopping channel (%ld)\n", chan->number, jiffies); s3c2410_dma_ctrl(chan->number | DMACH_LOW_LEVEL, S3C2410_DMAOP_STOP); } } no_load: return IRQ_HANDLED; }