usb: dwc3: enable CCI support for AMD-xilinx DWC3 controller

The GSBUSCFG0 register bits [31:16] are used to configure the cache type
settings of the descriptor and data write/read transfers (Cacheable,
Bufferable/Posted). When CCI is enabled in the design, DWC3 core GSBUSCFG0
cache bits must be updated to support CCI enabled transfers in USB.

To program GSBUSCFG0 cache bits create a software node property
in AMD-xilinx dwc3 glue driver and pass it to dwc3 core. The core
then reads this property value and configures it in dwc3_core_init()
sequence.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/1720548651-726412-1-git-send-email-radhey.shyam.pandey@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index ea6b1613152f..734de2a8bd21 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -604,6 +604,18 @@ static void dwc3_cache_hwparams(struct dwc3 *dwc)
 		parms->hwparams9 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS9);
 }
 
+static void dwc3_config_soc_bus(struct dwc3 *dwc)
+{
+	if (dwc->gsbuscfg0_reqinfo != DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED) {
+		u32 reg;
+
+		reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
+		reg &= ~DWC3_GSBUSCFG0_REQINFO(~0);
+		reg |= DWC3_GSBUSCFG0_REQINFO(dwc->gsbuscfg0_reqinfo);
+		dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);
+	}
+}
+
 static int dwc3_core_ulpi_init(struct dwc3 *dwc)
 {
 	int intf;
@@ -1343,6 +1355,8 @@ static int dwc3_core_init(struct dwc3 *dwc)
 
 	dwc3_set_incr_burst_type(dwc);
 
+	dwc3_config_soc_bus(dwc);
+
 	ret = dwc3_phy_power_on(dwc);
 	if (ret)
 		goto err_exit_phy;
@@ -1581,6 +1595,27 @@ static void dwc3_core_exit_mode(struct dwc3 *dwc)
 	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 }
 
+static void dwc3_get_software_properties(struct dwc3 *dwc)
+{
+	struct device *tmpdev;
+	u16 gsbuscfg0_reqinfo;
+	int ret;
+
+	dwc->gsbuscfg0_reqinfo = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED;
+
+	/*
+	 * Iterate over all parent nodes for finding swnode properties
+	 * and non-DT (non-ABI) properties.
+	 */
+	for (tmpdev = dwc->dev; tmpdev; tmpdev = tmpdev->parent) {
+		ret = device_property_read_u16(tmpdev,
+					       "snps,gsbuscfg0-reqinfo",
+					       &gsbuscfg0_reqinfo);
+		if (!ret)
+			dwc->gsbuscfg0_reqinfo = gsbuscfg0_reqinfo;
+	}
+}
+
 static void dwc3_get_properties(struct dwc3 *dwc)
 {
 	struct device		*dev = dwc->dev;
@@ -2095,6 +2130,8 @@ static int dwc3_probe(struct platform_device *pdev)
 
 	dwc3_get_properties(dwc);
 
+	dwc3_get_software_properties(dwc);
+
 	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
 	if (IS_ERR(dwc->reset)) {
 		ret = PTR_ERR(dwc->reset);