From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Thu, 24 Jul 2014 10:53:09 +0200 Subject: [PATCH v2 1/8] dma: sun4i: Add support for the DMA engine on sun[457]i SoCs In-Reply-To: <53C843DC.8090808@elopez.com.ar> References: <1404619518-7592-1-git-send-email-emilio@elopez.com.ar> <1404619518-7592-2-git-send-email-emilio@elopez.com.ar> <20140717205639.GH20328@lukather> <53C843DC.8090808@elopez.com.ar> Message-ID: <20140724085309.GR20328@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On Thu, Jul 17, 2014 at 06:45:00PM -0300, Emilio L?pez wrote: > >>+ depends on (MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || (COMPILE_TEST && OF && ARM)) > > > >This pretty much defeats the purpose of COMPILE_TEST > > QCOM_BAM_DMA does it that way; it's better to get some coverage than > none I guess? You'll get that kind of coverage with multi_v7 already, so that looks quite redundant. > >>+ help > >>+ Enable support for the DMA controller present in the sun4i, > >>+ sun5i and sun7i Allwinner ARM SoCs. > >>+ > (...) > >>+ > >>+/** Normal DMA register values **/ > >>+ > >>+/* Normal DMA source/destination data request type values */ > >>+#define NDMA_DRQ_TYPE_SDRAM 0x16 > >>+#define NDMA_DRQ_TYPE_LIMIT (0x1F + 1) > > > >Hmmm, I'm unsure what this is about... What is it supposed to do, and > >how is it different from BIT(5) ? > > if (val < NDMA_DRQ_TYPE_LIMIT) > /* valid value */ > else > /* invalid value */ > > 0x1F is the last valid value Ok. > >>+ > >>+static void set_pchan_interrupt(struct sun4i_dma_dev *priv, > >>+ struct sun4i_dma_pchan *pchan, > >>+ int half, int end) > >>+{ > >>+ u32 reg = readl_relaxed(priv->base + DMA_IRQ_ENABLE_REG); > >>+ int pchan_number = pchan - priv->pchans; > >>+ > >>+ if (half) > >>+ reg |= BIT(pchan_number * 2); > >>+ else > >>+ reg &= ~BIT(pchan_number * 2); > >>+ > >>+ if (end) > >>+ reg |= BIT(pchan_number * 2 + 1); > >>+ else > >>+ reg &= ~BIT(pchan_number * 2 + 1); > >>+ > >>+ writel_relaxed(reg, priv->base + DMA_IRQ_ENABLE_REG); > > > >I don't see any interrupts here. > > Hm? I'm not sure, but I think I meant spinlocks, it doesn't make much sense otherwise. > >>+ for_each_sg(sgl, sg, sg_len, i) { > >>+ /* Figure out addresses */ > >>+ if (dir == DMA_MEM_TO_DEV) { > >>+ srcaddr = sg_dma_address(sg); > >>+ dstaddr = sconfig->dst_addr; > >>+ } else { > >>+ srcaddr = sconfig->src_addr; > >>+ dstaddr = sg_dma_address(sg); > >>+ } > >>+ > >>+ /* TODO: should this be configurable? */ > >>+ para = DDMA_MAGIC_SPI_PARAMETERS; > > > >What is it? Is it supposed to change from one client device to > >another? > > These are the magic DMA engine timings that keep SPI going. I > haven't seen any interface on DMAEngine to configure timings, and so > far they seem to work for everything we support, so I've kept them > here. I don't know if other devices need different timings because, > as usual, we only have the "para" bitfield meanings, but no comment > on what the values should be when doing a certain operation :| If it works for everything you tested so far, I guess you can leave it that way, only adding what you just replied to the TODO. > >>+static enum dma_status sun4i_dma_tx_status(struct dma_chan *chan, > >>+ dma_cookie_t cookie, > >>+ struct dma_tx_state *state) > >>+{ > >>+ struct sun4i_dma_vchan *vchan = to_sun4i_dma_vchan(chan); > >>+ struct sun4i_dma_pchan *pchan = vchan->pchan; > >>+ struct sun4i_dma_contract *contract; > >>+ struct sun4i_dma_promise *promise; > >>+ struct virt_dma_desc *vd; > >>+ unsigned long flags; > >>+ enum dma_status ret; > >>+ size_t bytes = 0; > >>+ > >>+ ret = dma_cookie_status(chan, cookie, state); > >>+ if (ret == DMA_COMPLETE) > >>+ return ret; > >>+ > >>+ spin_lock_irqsave(&vchan->vc.lock, flags); > >>+ vd = vchan_find_desc(&vchan->vc, cookie); > >>+ if (!vd) /* TODO */ > > > >TODO what? > > > > /* TODO: remove the TODO */ :) Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: