[PATCH v3 2/2] usb: ehci: Add Aspeed AST2700 support

Ryan Chen
2025-09-28T03:24:21Z

Unlike earlier Aspeed SoCs (AST2400/2500/2600) which are limited to
32-bit DMA addressing, the EHCI controller in AST2700 supports 64-bit
DMA. Update the EHCI platform driver to make use of this capability by
selecting a 64-bit DMA mask when the "aspeed,ast2700-ehci" compatible
is present in device tree.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
drivers/usb/host/ehci-platform.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index 6aab45c8525c..bcd1c9073515 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -27,6 +27,7 @@
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/sys_soc.h>
@@ -239,9 +240,11 @@ static int ehci_platform_probe(struct platform_device *dev)
struct usb_hcd *hcd;
struct resource *res_mem;
struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
+ const struct of_device_id *match;
struct ehci_platform_priv *priv;
struct ehci_hcd *ehci;
int err, irq, clk = 0;
+ bool dma_mask_64;

if (usb_disabled())
return -ENODEV;
@@ -253,8 +256,13 @@ static int ehci_platform_probe(struct platform_device *dev)
if (!pdata)
pdata = &ehci_platform_defaults;

+ dma_mask_64 = pdata->dma_mask_64;
+ match = of_match_device(dev->dev.driver->of_match_table, &dev->dev);
+ if (match && match->data)
+ dma_mask_64 = true;
+
err = dma_coerce_mask_and_coherent(&dev->dev,
- pdata->dma_mask_64 ? DMA_BIT_MASK(64) : DMA_BIT_MASK(32));
+ dma_mask_64 ? DMA_BIT_MASK(64) : DMA_BIT_MASK(32));
if (err) {
dev_err(&dev->dev, "Error: DMA mask configuration failed\n");
return err;
@@ -298,7 +306,9 @@ static int ehci_platform_probe(struct platform_device *dev)
if (of_device_is_compatible(dev->dev.of_node,
"aspeed,ast2500-ehci") ||
of_device_is_compatible(dev->dev.of_node,
- "aspeed,ast2600-ehci"))
+ "aspeed,ast2600-ehci") ||
+ of_device_is_compatible(dev->dev.of_node,
+ "aspeed,ast2700-ehci"))
ehci->is_aspeed = 1;

if (soc_device_match(quirk_poll_match))
@@ -485,6 +495,7 @@ static const struct of_device_id vt8500_ehci_ids[] = {
{ .compatible = "wm,prizm-ehci", },
{ .compatible = "generic-ehci", },
{ .compatible = "cavium,octeon-6335-ehci", },
+ { .compatible = "aspeed,ast2700-ehci", .data = (void *)1 },
{}
};
MODULE_DEVICE_TABLE(of, vt8500_ehci_ids);
--
2.34.1