From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawn.guo@freescale.com (Shawn Guo) Date: Wed, 9 Feb 2011 07:28:34 +0800 Subject: [PATCH 1/5] dmaengine: mxs-dma: add dma support for i.MX23/28 In-Reply-To: <20110207082521.GI9041@pengutronix.de> References: <1296871696-21008-1-git-send-email-shawn.guo@freescale.com> <1296871696-21008-2-git-send-email-shawn.guo@freescale.com> <20110207082521.GI9041@pengutronix.de> Message-ID: <20110208232833.GC6963@S2100-06.ap.freescale.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Sascha, Thanks for the review. On Mon, Feb 07, 2011 at 09:25:21AM +0100, Sascha Hauer wrote: > On Sat, Feb 05, 2011 at 10:08:12AM +0800, Shawn Guo wrote: > > This patch adds dma support for Freescale MXS-based SoC i.MX23/28, > > including apbh-dma and apbx-dma. > > > > * apbh-dma and apbx-dma are supported in the driver as two instances, > > and have to be filtered by dma clients via device id. It becomes > > the convention that apbh-dma always gets registered prior to > > apbx-dma. > > > > * apbh-dma is different between mx23 and mx28, hardware version > > register is used to handle the differences. > > > > * Every the mxs dma channel is statically assigned to client device > > by soc design with fixed irq. The irq number is being passed by > > alloc_chan function with mxs_dma_data, and client driver has to > > filter the correct channel by its channel id. > > > > * mxs-dma supports pio function besides data transfer. The driver > > uses dma_data_direction DMA_NONE to identify the pio mode, and > > steals sgl and sg_len to get pio words and numbers from clients. > > > > * mxs dmaengine has some very specific features, like sense function > > and the special NAND support (nand_lock, nand_wait4ready). These > > are too specific to implemented in generic dmaengine driver. > > > > * The parameter "flags" of prep functions is currently being used to > > pass wait4end flag from clients. > > > > * The driver refers to imx-sdma and only a single descriptor is > > statically assigned to each channel. > > > > Signed-off-by: Shawn Guo > > --- > > arch/arm/mach-mxs/include/mach/dma.h | 16 + > > drivers/dma/Kconfig | 8 + > > drivers/dma/Makefile | 1 + > > drivers/dma/mxs-dma.c | 702 ++++++++++++++++++++++++++++++++++ > > 4 files changed, 727 insertions(+), 0 deletions(-) > > create mode 100644 arch/arm/mach-mxs/include/mach/dma.h > > create mode 100644 drivers/dma/mxs-dma.c > > > > diff --git a/arch/arm/mach-mxs/include/mach/dma.h b/arch/arm/mach-mxs/include/mach/dma.h > > new file mode 100644 > > index 0000000..429f431 > > --- /dev/null > > +++ b/arch/arm/mach-mxs/include/mach/dma.h > > + > > +static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg( > > + struct dma_chan *chan, struct scatterlist *sgl, > > + unsigned int sg_len, enum dma_data_direction direction, > > + unsigned long flags) > > +{ > > + struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); > > + struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; > > + struct mxs_dma_ccw *ccw; > > + struct scatterlist *sg; > > + int ret, i, j; > > + u32 *pio; > > + > > + dev_dbg(mxs_dma->dev, "%s: channel %d\n", __func__, chan->chan_id); > > + > > + if (mxs_chan->status == DMA_IN_PROGRESS) > > + return NULL; > > + > > + mxs_chan->status = DMA_IN_PROGRESS; > > + mxs_chan->flags = 0; > > + > > + dev_dbg(mxs_dma->dev, "%s: setting up %d entries\n", __func__, sg_len); > > + > > + if (sg_len > ((direction == DMA_NONE) ? MXS_PIO_WORDS : NUM_CCW)) { > > + dev_err(mxs_dma->dev, "maximum number of sg exceeded: %d > %d\n", > > + sg_len, NUM_CCW); > > + ret = -EINVAL; > > + goto err_out; > > + } > > + > > + if (direction == DMA_NONE) { > > + ccw = &mxs_chan->ccw[0]; > > + pio = (u32 *) sgl; > > + > > + for (j = 0; j < sg_len;) > > + ccw->pio_words[j++] = *pio++; > > + > > + ccw->next = 0; > > + ccw->bits.chain = 0; > > + ccw->bits.irq = 1; > > + ccw->bits.dec_sem = 1; > > + ccw->bits.wait4end = flags; > > + ccw->bits.halt_on_terminate = 1; > > + ccw->bits.terminate_flush = 1; > > + ccw->bits.pio_num = sg_len; > > + ccw->bits.command = MXS_DMA_NO_XFER; > > Does this have a valid usecase? I would just return some error code > here. pio_num and pio_words are unused in the driver and I don't think > a dmaengine driver should have some kind of PIO fallback. > If you happen to have a look at mxs-mmc patch set, you could find it. > > + } else { > > + for_each_sg(sgl, sg, sg_len, i) { > > + if (sg->length > MAX_XFER_BYTES) { > > + dev_err(mxs_dma->dev, "maximum bytes for sg entry exceeded: %d > %d\n", > > + sg->length, MAX_XFER_BYTES); > > + ret = -EINVAL; > > + goto err_out; > > + } > > + > > + ccw = &mxs_chan->ccw[i]; > > + > > + ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * (i + 1); > > + ccw->bufaddr = sg->dma_address; > > + ccw->bits.xfer_bytes = sg->length; > > + ccw->bits.chain = 1; > > + ccw->bits.irq = 0; > > + ccw->bits.dec_sem = 0; > > + ccw->bits.wait4end = 0; > > + ccw->bits.halt_on_terminate = 1; > > + ccw->bits.terminate_flush = 1; > > + ccw->bits.pio_num = 0; > > + ccw->bits.command = (direction == DMA_FROM_DEVICE) ? > > + MXS_DMA_WRITE : MXS_DMA_READ; > > + > > + if (i + 1 == sg_len) { > > + ccw->next = 0; > > + ccw->bits.chain = 0; > > + ccw->bits.irq = 1; > > + ccw->bits.dec_sem = 1; > > + ccw->bits.wait4end = 1; > > + } > > + } > > + } > > + > > + return &mxs_chan->desc; > > + > > +err_out: > > + mxs_chan->status = DMA_ERROR; > > + return NULL; > > +} > > + > > + > > +static int __init mxs_dma_probe(struct platform_device *pdev) > > +{ > > + const struct platform_device_id *id_entry = > > + platform_get_device_id(pdev); > > + struct mxs_dma_engine *mxs_dma; > > + struct resource *iores; > > + int ret, i; > > + > > + mxs_dma = kzalloc(sizeof(*mxs_dma), GFP_KERNEL); > > + if (!mxs_dma) > > + return -ENOMEM; > > + > > + mxs_dma->dev = &pdev->dev; > > + mxs_dma->dev_id = id_entry->driver_data; > > + > > + iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + > > + if (!request_mem_region(iores->start, resource_size(iores), > > + pdev->name)) { > > + ret = -EBUSY; > > + goto err_request_region; > > + } > > + > > + mxs_dma->base = ioremap(iores->start, resource_size(iores)); > > + if (!mxs_dma->base) { > > + ret = -ENOMEM; > > + goto err_ioremap; > > + } > > + > > + mxs_dma->clk = clk_get(&pdev->dev, NULL); > > + if (IS_ERR(mxs_dma->clk)) { > > + ret = PTR_ERR(mxs_dma->clk); > > + goto err_clk; > > + } > > + > > + dma_cap_set(DMA_SLAVE, mxs_dma->dma_device.cap_mask); > > + dma_cap_set(DMA_CYCLIC, mxs_dma->dma_device.cap_mask); > > + > > + INIT_LIST_HEAD(&mxs_dma->dma_device.channels); > > + > > + /* Initialize channel parameters */ > > + for (i = 0; i < MXS_DMA_CHANNELS; i++) { > > + struct mxs_dma_chan *mxs_chan = &mxs_dma->mxs_chans[i]; > > + > > + mxs_chan->mxs_dma = mxs_dma; > > + spin_lock_init(&mxs_chan->lock); > > + > > + mxs_chan->chan.device = &mxs_dma->dma_device; > > + > > + /* Add the channel to mxs_chan list */ > > + list_add_tail(&mxs_chan->chan.device_node, &mxs_dma->dma_device.channels); > > + } > > + > > + ret = mxs_dma_init(mxs_dma); > > + if (ret) > > + goto err_init; > > + > > + mxs_dma->dma_device.dev = &pdev->dev; > > + > > + /* mxs_dma gets 65535 bytes maximum sg size */ > > + mxs_dma->dma_device.dev->dma_parms = &mxs_dma->dma_parms; > > + dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES); > > + > > + mxs_dma->dma_device.device_alloc_chan_resources = mxs_dma_alloc_chan_resources; > > + mxs_dma->dma_device.device_free_chan_resources = mxs_dma_free_chan_resources; > > + mxs_dma->dma_device.device_tx_status = mxs_dma_tx_status; > > + mxs_dma->dma_device.device_prep_slave_sg = mxs_dma_prep_slave_sg; > > + mxs_dma->dma_device.device_prep_dma_cyclic = mxs_dma_prep_dma_cyclic; > > + mxs_dma->dma_device.device_control = mxs_dma_control; > > + mxs_dma->dma_device.device_issue_pending = mxs_dma_issue_pending; > > + > > + ret = dma_async_device_register(&mxs_dma->dma_device); > > + if (ret) { > > + dev_err(&pdev->dev, "unable to register\n"); > > + goto err_dma_register; > > + } > > + > > + /* > > + * dmaengine clients have to use dma_device.dev_id to filter > > + * dma device between apbh and apbx, so need to ensure it is > > + * identical to mxs_dma_engine.dev_id. > > + */ > > + if (mxs_dma->dma_device.dev_id != mxs_dma->dev_id) { > > + dev_err(&pdev->dev, "dev_id of dma_device %d differs from mxs_dma_engine %d\n", > > + mxs_dma->dma_device.dev_id, mxs_dma->dev_id); > > + goto err_init; > > + } > > I think it makes more sense to match against device names (apbh vs. > apbx) in the client's filter function than to rely on exact numbering. > I agree, if there is already a member like dev_name in dma_device. There is dev_id but no dev_name. Suggestion on how to use device name for matching? Regards, Shawn > > + > > + dev_info(mxs_dma->dev, "initialized\n"); > > + > > + return 0; > > + > > +err_init: > > + dma_async_device_unregister(&mxs_dma->dma_device); > > +err_dma_register: > > + clk_put(mxs_dma->clk); > > +err_clk: > > + iounmap(mxs_dma->base); > > +err_ioremap: > > + release_mem_region(iores->start, resource_size(iores)); > > +err_request_region: > > + kfree(mxs_dma); > > + return ret; > > +} > > + > > +static int __exit mxs_dma_remove(struct platform_device *pdev) > > +{ > > + return -EBUSY; > > +} > > + > > +static struct platform_device_id mxs_dma_type[] = { > > + { > > + .name = "mxs-dma-apbh", > > + .driver_data = MXS_DMA_APBH, > > + }, { > > + .name = "mxs-dma-apbx", > > + .driver_data = MXS_DMA_APBX, > > + } > > +}; > > + > > +static struct platform_driver mxs_dma_driver = { > > + .driver = { > > + .name = "mxs-dma", > > + }, > > + .id_table = mxs_dma_type, > > + .remove = __exit_p(mxs_dma_remove), > > +}; > > + > > +static int __init mxs_dma_module_init(void) > > +{ > > + return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe); > > +} > > +subsys_initcall(mxs_dma_module_init); > > -- > > 1.7.1 > > > > > > > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | >