[PATCH v2 1/2] usb: dwc3: core: add support for remapping global register start address

Stanley Chang
2023-04-13T04:24:33Z

The RTK DHC SoCs were designed the global register address offset at
0x8100. The default address is at DWC3_GLOBALS_REGS_START (0xc100).
Therefore, add the property of device-tree to adjust this start address.

Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
---
v1 to v2 change:
1. Change the name of the property "snps,global-regs-starting-offset".
2. Adjust the format of comment.
3. Add initial value of the global_regs_starting_offset
4. Remove the log of dev_info.
---
drivers/usb/dwc3/core.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 476b63618511..8c1d1afbdc65 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1785,6 +1785,21 @@ static int dwc3_probe(struct platform_device *pdev)
dwc_res = *res;
dwc_res.start += DWC3_GLOBALS_REGS_START;

+ /*
+ * For some dwc3 controller, the dwc3 global register start address is
+ * not at DWC3_GLOBALS_REGS_START (0xc100).
+ */
+ if (dev->of_node) {
+ int global_regs_starting_offset = 0;
+
+ device_property_read_u32(dev, "snps,global-regs-starting-offset",
+ &global_regs_starting_offset);
+ if (global_regs_starting_offset) {
+ dwc_res.start -= DWC3_GLOBALS_REGS_START;
+ dwc_res.start += global_regs_starting_offset;
+ }
+ }
+
regs = devm_ioremap_resource(dev, &dwc_res);
if (IS_ERR(regs))
return PTR_ERR(regs);
--
2.34.1