On Mon, Jan 20, 2014 at 09:06:43AM +0000, Jingchang Lu wrote: > > > > -----Original Message----- > > From: Vinod Koul [mailto:vinod.koul@xxxxxxxxx] > > Sent: Monday, January 20, 2014 3:40 PM > > To: Lu Jingchang-B35083 > > Cc: dan.j.williams@xxxxxxxxx; arnd@xxxxxxxx; shawn.guo@xxxxxxxxxx; > > pawel.moll@xxxxxxx; mark.rutland@xxxxxxx; swarren@xxxxxxxxxxxxx; linux- > > kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > > devicetree@xxxxxxxxxxxxxxx; Wang Huan-B18965 > > Subject: Re: [PATCHv10 2/2] dma: Add Freescale eDMA engine driver support > > > > On Fri, Jan 17, 2014 at 02:04:44PM +0800, Jingchang Lu wrote: > > > Add Freescale enhanced direct memory(eDMA) controller support. > > > This module can be found on Vybrid and LS-1 SoCs. > > > > > > Signed-off-by: Alison Wang <b18965@xxxxxxxxxxxxx> > > > Signed-off-by: Jingchang Lu <b35083@xxxxxxxxxxxxx> > > > Acked-by: Arnd Bergmann <arnd@xxxxxxxx> > > > --- > > > > > +static int fsl_edma_control(struct dma_chan *chan, enum dma_ctrl_cmd > > cmd, > > > + unsigned long arg) > > > +{ > > > + struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan); > > > + struct dma_slave_config *cfg = (void *)arg; > > > + unsigned long flags; > > > + LIST_HEAD(head); > > > + > > > + switch (cmd) { > > > + case DMA_TERMINATE_ALL: > > > + spin_lock_irqsave(&fsl_chan->vchan.lock, flags); > > > + fsl_edma_disable_request(fsl_chan); > > > + fsl_chan->edesc = NULL; > > > + vchan_get_all_descriptors(&fsl_chan->vchan, &head); > > > + spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags); > > > + vchan_dma_desc_free_list(&fsl_chan->vchan, &head); > > > + return 0; > > well what happens to the current ongoing transactions, i don't see those > > getting > > terminated? > The fsl_edma_disable_request(fsl_chan) would end the channel's ongoing transaction, then > the eDMA would not response to device dma request, and the vchan_dma_desc_free_list() > will release all associate memory. Thanks. Can you explain a bit more how terminate will happen, given taht you are using same thing for pause? > > > > > + > > > + case DMA_SLAVE_CONFIG: > > > + fsl_chan->fsc.dir = cfg->direction; > > > + if (cfg->direction == DMA_DEV_TO_MEM) { > > > + fsl_chan->fsc.dev_addr = cfg->src_addr; > > > + fsl_chan->fsc.addr_width = cfg->src_addr_width; > > > + fsl_chan->fsc.burst = cfg->src_maxburst; > > > + fsl_chan->fsc.attr = fsl_edma_get_tcd_attr(cfg- > > >src_addr_width); > > > + } else if (cfg->direction == DMA_MEM_TO_DEV) { > > > + fsl_chan->fsc.dev_addr = cfg->dst_addr; > > > + fsl_chan->fsc.addr_width = cfg->dst_addr_width; > > > + fsl_chan->fsc.burst = cfg->dst_maxburst; > > > + fsl_chan->fsc.attr = fsl_edma_get_tcd_attr(cfg- > > >dst_addr_width); > > okay atrr is address width, why not save this standard struct instead? > The value saved in fsc.attr is transferred by fsl_edma_get_tcd_attr(), it can > be set into the channel control register later directly. the edma driver doesn't > need to save all dma_slave_config parameters, so it only gets the necessaries. Okay then this apprach looks okay > > > + } else { > > > + return -EINVAL; > > > + } > > > + return 0; > > > + > > > + case DMA_PAUSE: > > > + spin_lock_irqsave(&fsl_chan->vchan.lock, flags); > > > + if (fsl_chan->edesc) { > > > + fsl_edma_disable_request(fsl_chan); > > > + fsl_chan->status = DMA_PAUSED; > > > + } > > > + spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags); > > > + return 0; > > > + > > > + case DMA_RESUME: > > > + spin_lock_irqsave(&fsl_chan->vchan.lock, flags); > > > + if (fsl_chan->edesc) { > > > + fsl_edma_enable_request(fsl_chan); > > > + fsl_chan->status = DMA_IN_PROGRESS; > > > + } > > > + spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags); > > > + return 0; > > > + > > > + default: > > > + return -ENXIO; > > > + } > > > +} > > > + > > > > > +static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan > > *fsl_chan, > > > + int sg_len) > > > +{ > > > + struct fsl_edma_desc *fsl_desc; > > > + int i; > > > + > > > + fsl_desc = kzalloc(sizeof(*fsl_desc) + sizeof(struct > > fsl_edma_sw_tcd) * sg_len, > > > + GFP_NOWAIT); > > > + if (!fsl_desc) > > > + return NULL; > > > + > > > + fsl_desc->echan = fsl_chan; > > > + fsl_desc->n_tcds = sg_len; > > > + for (i = 0; i < sg_len; i++) { > > > + fsl_desc->tcd[i].vtcd = dma_pool_alloc(fsl_chan->tcd_pool, > > > + GFP_NOWAIT, &fsl_desc->tcd[i].ptcd); > > > + if (!fsl_desc->tcd[i].vtcd) > > > + goto err; > > > + } > > > + return fsl_desc; > > > + > > > +err: > > > + while (--i >= 0) > > > + dma_pool_free(fsl_chan->tcd_pool, fsl_desc->tcd[i].vtcd, > > > + fsl_desc->tcd[i].ptcd); > > > + kfree(fsl_desc); > > > + return NULL; > > > +} > > > + > > > +static struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic( > > > + struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len, > > > + size_t period_len, enum dma_transfer_direction direction, > > > + unsigned long flags, void *context) > > > +{ > > you may want to implement the capablities api subsequently for audio > > usage. > Do you mean the device_slave_caps function? If it is, I will add it. Yes, that can be incrementally added.. -- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
