On Mon, 2013-01-28 at 21:58 +0000, Arnd Bergmann wrote: > With the new OF DMA binding, it is possible to completely avoid the > need for platform_data for configuring a DMA channel. In cases where the > platform has already been converted, calling dma_request_slave_channel > should get all the necessary information from the device tree. > > Like the patch that converts the dw_dma controller, this is completely > untested and is looking for someone to try it out. > > Signed-off-by: Arnd Bergmann <a...@arndb.de> > Cc: Grant Likely <grant.lik...@secretlab.ca> > Cc: Mark Brown <broo...@opensource.wolfsonmicro.com> > Cc: spi-devel-general@lists.sourceforge.net > Cc: Viresh Kumar <viresh.ku...@linaro.org> > Cc: Andy Shevchenko <andriy.shevche...@linux.intel.com> > Cc: Vinod Koul <vinod.k...@linux.intel.com> > Cc: devicetree-disc...@lists.ozlabs.org > Cc: linux-arm-ker...@lists.infradead.org > --- > .../devicetree/bindings/spi/spi_pl022.txt | 36 ++++++++++++++++++ > drivers/spi/spi-pl022.c | 43 > +++++++++++++++++++++- > 2 files changed, 77 insertions(+), 2 deletions(-) >
> --- a/drivers/spi/spi-pl022.c > +++ b/drivers/spi/spi-pl022.c > @@ -1139,6 +1139,35 @@ err_no_rxchan: > return -ENODEV; > } > > +static int pl022_dma_autoprobe(struct pl022 *pl022) > +{ > + struct device *dev = &pl022->adev->dev; > + > + /* automatically configure DMA channels from platform, normally using > DT */ > + pl022->dma_rx_channel = dma_request_slave_channel(dev, "rx"); > + if (!pl022->dma_rx_channel) > + goto err_no_rxchan; > + > + pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx"); > + if (!pl022->dma_tx_channel) > + goto err_no_txchan; > + > + pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL); Where this memory will be freed? In dependence of the answer could you consider to use devm_kmalloc or __get_free_page? > + if (!pl022->dummypage) > + goto err_no_dummypage; > + > + return 0; > + > +err_no_dummypage: > + dma_release_channel(pl022->dma_tx_channel); > + pl022->dma_tx_channel = NULL; > +err_no_txchan: > + dma_release_channel(pl022->dma_rx_channel); > + pl022->dma_rx_channel = NULL; > +err_no_rxchan: > + return -ENODEV; > +} > + > static void terminate_dma(struct pl022 *pl022) > { > struct dma_chan *rxchan = pl022->dma_rx_channel; > @@ -1167,6 +1196,11 @@ static inline int configure_dma(struct pl022 *pl022) > return -ENODEV; > } > > +static inline int pl022_dma_autoprobe(struct pl022 *pl022) > +{ > + return 0; > +} > + > static inline int pl022_dma_probe(struct pl022 *pl022) > { > return 0; > @@ -2226,8 +2260,13 @@ static int pl022_probe(struct amba_device *adev, const > struct amba_id *id) > goto err_no_irq; > } > > - /* Get DMA channels */ > - if (platform_info->enable_dma) { > + /* Get DMA channels, try autoconfiguration first */ > + status = pl022_dma_autoprobe(pl022); > + > + /* If that failed, use channels from platform_info */ > + if (status == 0) > + platform_info->enable_dma = 1; > + else if (platform_info->enable_dma) { > status = pl022_dma_probe(pl022); > if (status != 0) > platform_info->enable_dma = 0; -- Andy Shevchenko <andriy.shevche...@linux.intel.com> Intel Finland Oy ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general