Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755565Ab3DORNF (ORCPT ); Mon, 15 Apr 2013 13:13:05 -0400 Received: from mga02.intel.com ([134.134.136.20]:56724 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751410Ab3DORNB (ORCPT ); Mon, 15 Apr 2013 13:13:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,476,1363158000"; d="scan'208";a="295203679" Date: Mon, 15 Apr 2013 22:12:38 +0530 From: Vinod Koul To: Guennadi Liakhovetski , Arnd Bergmann Cc: linux-sh@vger.kernel.org, Magnus Damm , linux-kernel@vger.kernel.org, Guennadi Liakhovetski Subject: Re: [PATCH/RFC 3/6] DMA: shdma: add DT support Message-ID: <20130415164238.GG12436@intel.com> References: <1365632389-2249-1-git-send-email-g.liakhovetski@gmx.de> <1365632389-2249-4-git-send-email-g.liakhovetski@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1365632389-2249-4-git-send-email-g.liakhovetski@gmx.de> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8572 Lines: 260 On Thu, Apr 11, 2013 at 12:19:46AM +0200, Guennadi Liakhovetski wrote: > This patch adds Device Tree support to the shdma driver. No special DT > properties are used, only standard DMA DT bindings are implemented. Since > shdma controllers reside on SoCs, their configuration is SoC-specific and > shall be passed to the driver from the SoC platform data, using the > auxdata procedure. > > Signed-off-by: Guennadi Liakhovetski > --- Need Arnd to review :) > > Note concerning the filtering parameter. Without DT slave channels are > configured, based on a purely virtual slave ID, passed by DMA clients > to the shdma dmaengine driver. In the DT case we cannot use such > virtual IDs, we use a hardware MID/RID (DMA request ID) value. This is > confusing, ideally, all existing users should be converted to also use > MID/RID. This patch doesn't do that, it leaves existing users > unaffected and only uses MID/RID for DT. > > drivers/dma/sh/shdma-base.c | 51 +++++++++++++++++++++++++++++++++++++----- > drivers/dma/sh/shdma.c | 44 ++++++++++++++++++++++++++++++++----- > include/linux/shdma-base.h | 5 ++++ > 3 files changed, 88 insertions(+), 12 deletions(-) > > diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c > index 4acb85a..4fd8293 100644 > --- a/drivers/dma/sh/shdma-base.c > +++ b/drivers/dma/sh/shdma-base.c > @@ -14,6 +14,8 @@ > */ > > #include > +#include > +#include > #include > #include > #include > @@ -175,7 +177,18 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) > { > struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); > const struct shdma_ops *ops = sdev->ops; > - int ret; > + int ret, match; > + > + if (schan->dev->of_node) { > + match = schan->hw_req; > + ret = ops->set_slave(schan, match, true); > + if (ret < 0) > + return ret; > + > + slave_id = schan->slave_id; > + } else { > + match = slave_id; > + } > > if (slave_id < 0 || slave_id >= slave_num) > return -EINVAL; > @@ -183,7 +196,7 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) > if (test_and_set_bit(slave_id, shdma_slave_used)) > return -EBUSY; > > - ret = ops->set_slave(schan, slave_id, false); > + ret = ops->set_slave(schan, match, false); > if (ret < 0) { > clear_bit(slave_id, shdma_slave_used); > return ret; > @@ -206,23 +219,26 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) > * services would have to provide their own filters, which first would check > * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do > * this, and only then, in case of a match, call this common filter. > + * NOTE 2: This filter function is also used in the DT case by shdma_xlate(). > + * In that case the MID-RID value is used for slave channel filtering and is > + * passed to this function in the "arg" parameter. > */ > bool shdma_chan_filter(struct dma_chan *chan, void *arg) > { > struct shdma_chan *schan = to_shdma_chan(chan); > struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); > const struct shdma_ops *ops = sdev->ops; > - int slave_id = (int)arg; > + int match = (int)arg; > int ret; > > - if (slave_id < 0) > + if (match < 0) > /* No slave requested - arbitrary channel */ > return true; > > - if (slave_id >= slave_num) > + if (!schan->dev->of_node && match >= slave_num) > return false; > > - ret = ops->set_slave(schan, slave_id, true); > + ret = ops->set_slave(schan, match, true); > if (ret < 0) > return false; > > @@ -867,6 +883,29 @@ void shdma_chan_remove(struct shdma_chan *schan) > } > EXPORT_SYMBOL(shdma_chan_remove); > > +struct dma_chan *shdma_xlate(struct of_phandle_args *dma_spec, > + struct of_dma *ofdma) > +{ > + struct shdma_dev *sdev = ofdma->of_dma_data; > + u32 id = dma_spec->args[0]; > + dma_cap_mask_t mask; > + struct dma_chan *chan; > + > + if (dma_spec->args_count != 1 || !sdev) > + return NULL; > + > + dma_cap_zero(mask); > + /* Only slave DMA channels can be allocated via DT */ > + dma_cap_set(DMA_SLAVE, mask); > + > + chan = dma_request_channel(mask, shdma_chan_filter, (void *)id); > + if (chan) > + to_shdma_chan(chan)->hw_req = id; > + > + return chan; > +} > +EXPORT_SYMBOL(shdma_xlate); > + > int shdma_init(struct device *dev, struct shdma_dev *sdev, > int chan_num) > { > diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c > index a5a1887..db497d6 100644 > --- a/drivers/dma/sh/shdma.c > +++ b/drivers/dma/sh/shdma.c > @@ -20,6 +20,8 @@ > > #include > #include > +#include > +#include > #include > #include > #include > @@ -301,20 +303,32 @@ static void sh_dmae_setup_xfer(struct shdma_chan *schan, > } > } > > +/* > + * Find a slave channel configuration from the contoller list by either a slave > + * ID in the non-DT case, or by a MID/RID value in the DT case > + */ > static const struct sh_dmae_slave_config *dmae_find_slave( > - struct sh_dmae_chan *sh_chan, int slave_id) > + struct sh_dmae_chan *sh_chan, int match) > { > struct sh_dmae_device *shdev = to_sh_dev(sh_chan); > struct sh_dmae_pdata *pdata = shdev->pdata; > const struct sh_dmae_slave_config *cfg; > int i; > > - if (slave_id >= SH_DMA_SLAVE_NUMBER) > - return NULL; > + if (!sh_chan->shdma_chan.dev->of_node) { > + if (match >= SH_DMA_SLAVE_NUMBER) > + return NULL; > > - for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) > - if (cfg->slave_id == slave_id) > - return cfg; > + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) > + if (cfg->slave_id == match) > + return cfg; > + } else { > + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) > + if (cfg->mid_rid == match) { > + sh_chan->shdma_chan.slave_id = cfg->slave_id; > + return cfg; > + } > + } > > return NULL; > } > @@ -841,6 +855,14 @@ static int sh_dmae_probe(struct platform_device *pdev) > if (err < 0) > goto edmadevreg; > > + if (pdev->dev.of_node) { > + int of_err = of_dma_controller_register(pdev->dev.of_node, > + shdma_xlate, shdev); > + if (of_err < 0 && of_err != -ENODEV) > + dev_err(&pdev->dev, > + "could not register of_dma_controller\n"); > + } > + > return err; > > edmadevreg: > @@ -889,6 +911,9 @@ static int sh_dmae_remove(struct platform_device *pdev) > > dma_async_device_unregister(dma_dev); > > + if (pdev->dev.of_node) > + of_dma_controller_free(pdev->dev.of_node); > + > if (errirq > 0) > free_irq(errirq, shdev); > > @@ -920,11 +945,18 @@ static int sh_dmae_remove(struct platform_device *pdev) > return 0; > } > > +static const struct of_device_id sh_dmae_of_match[] = { > + { .compatible = "renesas,shdma", }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, sh_dmae_of_match); > + > static struct platform_driver sh_dmae_driver = { > .driver = { > .owner = THIS_MODULE, > .pm = &sh_dmae_pm, > .name = SH_DMAE_DRV_NAME, > + .of_match_table = sh_dmae_of_match, > }, > .remove = sh_dmae_remove, > .shutdown = sh_dmae_shutdown, > diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h > index 9a93897..0815a0e 100644 > --- a/include/linux/shdma-base.h > +++ b/include/linux/shdma-base.h > @@ -19,6 +19,7 @@ > #include > #include > #include > +#include > #include > > /** > @@ -68,6 +69,8 @@ struct shdma_chan { > int id; /* Raw id of this channel */ > int irq; /* Channel IRQ */ > int slave_id; /* Client ID for slave DMA */ > + int hw_req; /* DMA request line for slave DMA - same > + * as MID/RID, used with DT */ > enum shdma_pm_state pm_state; > }; > > @@ -123,5 +126,7 @@ int shdma_init(struct device *dev, struct shdma_dev *sdev, > int chan_num); > void shdma_cleanup(struct shdma_dev *sdev); > bool shdma_chan_filter(struct dma_chan *chan, void *arg); > +struct dma_chan *shdma_xlate(struct of_phandle_args *dma_spec, > + struct of_dma *ofdma); > > #endif > -- > 1.7.2.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/