[PATCH v2 4/4] usb: uhci: Add Aspeed AST2700 support

Ryan Chen
2025-09-17T02:19:35Z

Unlike earlier Aspeed SoCs (AST2400/2500/2600) which are limited to
32-bit DMA addressing, the UHCI controller in AST2700 supports 64-bit
DMA. Update the platform UHCI driver to select the appropriate DMA
mask based on the device tree compatible string.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
drivers/usb/host/uhci-platform.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/uhci-platform.c b/drivers/usb/host/uhci-platform.c
index 1c1715bddc27..84867f75dfcd 100644
--- a/drivers/usb/host/uhci-platform.c
+++ b/drivers/usb/host/uhci-platform.c
@@ -71,6 +71,7 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
struct usb_hcd *hcd;
struct uhci_hcd *uhci;
struct resource *res;
+ u64 *dma_mask_ptr;
int ret;

if (usb_disabled())
@@ -81,7 +82,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
* Since shared usb code relies on it, set it here for now.
* Once we have dma capability bindings this can go away.
*/
- ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ dma_mask_ptr = (u64 *)of_device_get_match_data(&pdev->dev);
+ ret = dma_coerce_mask_and_coherent(&pdev->dev, *dma_mask_ptr);
if (ret)
return ret;

@@ -114,7 +116,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
}
if (of_device_is_compatible(np, "aspeed,ast2400-uhci") ||
of_device_is_compatible(np, "aspeed,ast2500-uhci") ||
- of_device_is_compatible(np, "aspeed,ast2600-uhci")) {
+ of_device_is_compatible(np, "aspeed,ast2600-uhci") ||
+ of_device_is_compatible(np, "aspeed,ast2700-uhci")) {
uhci->is_aspeed = 1;
dev_info(&pdev->dev,
"Enabled Aspeed implementation workarounds\n");
@@ -188,9 +191,13 @@ static void uhci_hcd_platform_shutdown(struct platform_device *op)
uhci_hc_died(hcd_to_uhci(hcd));
}

+static const u64 dma_mask_32 = DMA_BIT_MASK(32);
+static const u64 dma_mask_64 = DMA_BIT_MASK(64);
+
static const struct of_device_id platform_uhci_ids[] = {
- { .compatible = "generic-uhci", },
- { .compatible = "platform-uhci", },
+ { .compatible = "generic-uhci", .data = &dma_mask_32},
+ { .compatible = "platform-uhci", .data = &dma_mask_32},
+ { .compatible = "aspeed,ast2700-uhci", .data = &dma_mask_64},
{}
};
MODULE_DEVICE_TABLE(of, platform_uhci_ids);
--
2.34.1