On Thu, Mar 6, 2014 at 3:19 AM, Santosh Shilimkar <santosh.shilimkar@xxxxxx> wrote: > From: Grygorii Strashko <grygorii.strashko@xxxxxx> > > Retrieve DMA configuration from DT and setup platform device's DMA > parameters. > > The DMA configuration in DT has to be specified using "dma-ranges" > property if supported. The DMA configuration applied > by dt_dma_configure() as following: > - call of_get_dma_range() and get supported DMA range info > (dma_addr, cpu_addr, dma_size); > - if "not found" then fill dma_mask as DMA_BIT_MASK(32) > (this is default behaviour); > - if "failed" then clean up dma_mask (DMA not supported) > - if ok then update devices DMA configuration: > set dma_mask to (dma_addr + dma_size - 1) > set dma_pfn_offset to PFN_DOWN(cpu_addr - dma_addr) > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Russell King <linux@xxxxxxxxxxxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Olof Johansson <olof@xxxxxxxxx> > Cc: Grant Likely <grant.likely@xxxxxxxxxx> > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> > Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx> > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > --- > drivers/of/platform.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 72 insertions(+), 3 deletions(-) > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > index bd080db..53bb12f 100644 > --- a/drivers/of/platform.c > +++ b/drivers/of/platform.c > @@ -187,6 +187,77 @@ struct platform_device *of_device_alloc(struct device_node *np, > EXPORT_SYMBOL(of_device_alloc); > > /** > + * dt_dma_configure - apply default DMA configuration from dt s/dt_/of_/ > + * @dev: Device to apply DMA configuration > + * > + * Try to get devices's DMA configuration from DT and apply it. > + * The DMA configuration is represented in DT by "dma-ranges" property. > + * It configures: > + * dma_pfn_offset, dma_mask and coherent_dma_mask. > + * > + * In case if DMA configuration can't be acquired from DT the default one is > + * applied: > + * dma_pfn_offset = 0, > + * dma_mask = DMA_BIT_MASK(32) This is really set to &coherent_dma_mask. > + * coherent_dma_mask = DMA_BIT_MASK(32). > + > + * In case if platform code need to use own DMA configuration - it can use > + * Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event to fix up > + * DMA configuration. > + */ > +static void dt_dma_configure(struct device *dev) s/dt_/of_/ > +{ > + dma_addr_t dma_addr; > + phys_addr_t paddr, size; > + dma_addr_t dma_mask; > + int ret; > + > + /* > + * if dma-ranges property doesn't exist - use 32 bits DMA mask > + * by default and don't set skip archdata.dma_pfn_offset > + */ > + ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size); > + if (ret == -ENODEV) { > + dev->coherent_dma_mask = DMA_BIT_MASK(32); > + if (!dev->dma_mask) > + dev->dma_mask = &dev->coherent_dma_mask; > + return; > + } > + > + /* if failed - disable DMA for device */ > + if (ret < 0) { > + dev_err(dev, "failed to configure DMA\n"); > + return; > + } > + > + /* DMA ranges found. Calculate and set dma_pfn_offset */ > + dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr); > + > + /* Configure DMA mask */ > + dev->dma_mask = &dev->coherent_dma_mask; > + if (!dev->dma_mask) This condition is impossible. > + return; > + > + dma_mask = dma_addr + size - 1; > + > + ret = dma_set_mask(dev, dma_mask); > + if (ret < 0) { > + dev_err(dev, "failed to set DMA mask %pad\n", &dma_mask); > + dev->dma_mask = NULL; > + return; > + } > + > + dev_dbg(dev, "dma_pfn_offset(%#08lx) dma_mask(%pad)\n", > + dev->dma_pfn_offset, dev->dma_mask); > + > + ret = dma_set_coherent_mask(dev, dma_mask); I think these 2 calls belong in the drivers, not here. > + if (ret < 0) { > + dev_err(dev, "failed to set coherent DMA mask %pad\n", > + &dma_mask); > + } > +} > + > +/** > * of_platform_device_create_pdata - Alloc, initialize and register an of_device > * @np: pointer to node to create device for > * @bus_id: name to assign device > @@ -214,9 +285,7 @@ static struct platform_device *of_platform_device_create_pdata( > #if defined(CONFIG_MICROBLAZE) > dev->archdata.dma_mask = 0xffffffffUL; > #endif > - dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); > - if (!dev->dev.dma_mask) > - dev->dev.dma_mask = &dev->dev.coherent_dma_mask; > + dt_dma_configure(&dev->dev); > dev->dev.bus = &platform_bus_type; > dev->dev.platform_data = platform_data; > > -- > 1.7.9.5 > -- 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