usb: ehci: Add Aspeed AST2700 support

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>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20250928032407.27764-3-ryan_chen@aspeedtech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index 6aab45c8525c1f43ab3306fd993927a8bf9553c2..bcd1c9073515156687acabbd563a261633eabe97 100644 (file)
--- 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);