[PATCH] usb: dwc3: core: enable CCI support

[Piyush Mehta]

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.

Signed-off-by: Piyush Mehta <piyush.mehta@xxxxxxx>
---
DWC3 Register Map Link:
https://docs.xilinx.com/r/en-US/ug1087-zynq-ultrascale-registers/GSBUSCFG0-USB3_XHCI-Register
Register Name	GSBUSCFG0
Description	Global SoC Bus Configuration Register 0

GSBUSCFG0 (USB3_XHCI) Register Bit-Field:
DATRDREQINFO	31:28
DESRDREQINFO	27:24
DATWRREQINFO	23:20
DESWRREQINFO	19:16
---
 drivers/usb/dwc3/core.c | 17 +++++++++++++++++
 drivers/usb/dwc3/core.h |  5 +++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 9c6bf054f15d..fc6892c63abf 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -23,6 +23,7 @@
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/of_graph.h>
 #include <linux/acpi.h>
 #include <linux/pinctrl/consumer.h>
@@ -559,6 +560,20 @@ 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 (of_dma_is_coherent(dwc->dev->of_node)) {
+		u32 reg;
+
+		reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
+		reg |= DWC3_GSBUSCFG0_DATRDREQINFO_MASK |
+			DWC3_GSBUSCFG0_DESRDREQINFO_MASK |
+			DWC3_GSBUSCFG0_DATWRREQINFO_MASK |
+			DWC3_GSBUSCFG0_DESWRREQINFO_MASK;
+		dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);
+	}
+}
+
 static int dwc3_core_ulpi_init(struct dwc3 *dwc)
 {
 	int intf;
@@ -1137,6 +1152,8 @@ 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;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index a69ac67d89fe..bd937025ce05 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -173,6 +173,11 @@
 #define DWC3_OSTS		0xcc10
 
 /* Bit fields */
+/* Global SoC Bus Configuration Register: AHB-prot/AXI-cache/OCP-ReqInfo */
+#define DWC3_GSBUSCFG0_DATRDREQINFO_MASK	GENMASK(31, 28)
+#define DWC3_GSBUSCFG0_DESRDREQINFO_MASK	GENMASK(27, 24)
+#define DWC3_GSBUSCFG0_DATWRREQINFO_MASK	GENMASK(23, 20)
+#define DWC3_GSBUSCFG0_DESWRREQINFO_MASK	GENMASK(19, 16)
 
 /* Global SoC Bus Configuration INCRx Register 0 */
 #define DWC3_GSBUSCFG0_INCR256BRSTENA	(1 << 7) /* INCR256 burst */
-- 
2.17.1