diff options
Diffstat (limited to 'drivers/core/device.c')
| -rw-r--r-- | drivers/core/device.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/core/device.c b/drivers/core/device.c index 82a0098960..625134921d 100644 --- a/drivers/core/device.c +++ b/drivers/core/device.c @@ -422,6 +422,43 @@ fail: return ret; } +/** + * device_get_dma_constraints() - Populate device's DMA constraints + * + * Gets a device's DMA constraints from firmware. This information is later + * used by drivers to translate physcal addresses to the device's bus address + * space. For now only device-tree is supported. + * + * @dev: Pointer to target device + * Return: 0 if OK or if no DMA constraints were found, error otherwise + */ +static int device_get_dma_constraints(struct udevice *dev) +{ + struct udevice *parent = dev->parent; + phys_addr_t cpu = 0; + dma_addr_t bus = 0; + u64 size = 0; + int ret; + + if (!CONFIG_IS_ENABLED(DM_DMA) || !parent || !dev_has_ofnode(parent)) + return 0; + + /* + * We start parsing for dma-ranges from the device's bus node. This is + * specially important on nested buses. + */ + ret = dev_get_dma_range(parent, &cpu, &bus, &size); + /* Don't return an error if no 'dma-ranges' were found */ + if (ret && ret != -ENOENT) { + dm_warn("%s: failed to get DMA range, %d\n", dev->name, ret); + return ret; + } + + dev_set_dma_offset(dev, cpu - bus); + + return 0; +} + int device_probe(struct udevice *dev) { const struct driver *drv; @@ -484,6 +521,10 @@ int device_probe(struct udevice *dev) goto fail; } + ret = device_get_dma_constraints(dev); + if (ret) + goto fail; + ret = uclass_pre_probe_device(dev); if (ret) goto fail; |