[PATCH 2/2] usb: dwc3: core: allow overwrite reqinfo in GSBUSCFG0 by dts

[Frank Li]

Add function dwc3_set_bus_req_info() to allow dts overwrite bus request
info in GSBUSCFG0. Some platform (such as Layerscape) require correct
setting for dma-coherent. But default value is wrong in chips.

Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/usb/dwc3/core.c | 33 +++++++++++++++++++++++++++++++++
 drivers/usb/dwc3/core.h |  4 ++++
 2 files changed, 37 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 3b68e8e45b8b9..c72929b122014 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -948,6 +948,37 @@ static void dwc3_core_setup_global_control(struct dwc3 *dwc)
 static int dwc3_core_get_phy(struct dwc3 *dwc);
 static int dwc3_core_ulpi_init(struct dwc3 *dwc);
 
+static void dwc3_set_bus_req_info(struct dwc3 *dwc)
+{
+	struct device *dev = dwc->dev;
+	u32 cfg;
+	u8 val;
+
+	cfg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
+
+	if (!device_property_read_u8(dev, "snps,des-wr-reqinfo", &val)) {
+		cfg &= ~DWC3_GSBUSCFG0_DESWRREQINFO_MASK;
+		cfg |= FIELD_PREP(DWC3_GSBUSCFG0_DESWRREQINFO_MASK, val);
+	}
+
+	if (!device_property_read_u8(dev, "snps,des-rd-reqinfo", &val)) {
+		cfg &= ~DWC3_GSBUSCFG0_DESRDREQINFO_MASK;
+		cfg |= FIELD_PREP(DWC3_GSBUSCFG0_DESRDREQINFO_MASK, val);
+	}
+
+	if (!device_property_read_u8(dev, "snps,dat-wr-reqinfo", &val)) {
+		cfg &= ~DWC3_GSBUSCFG0_DATWRREQINFO_MASK;
+		cfg |= FIELD_PREP(DWC3_GSBUSCFG0_DATWRREQINFO_MASK, val);
+	}
+
+	if (!device_property_read_u8(dev, "snps,dat-rd-reqinfo", &val)) {
+		cfg &= ~DWC3_GSBUSCFG0_DATRDREQINFO_MASK;
+		cfg |= FIELD_PREP(DWC3_GSBUSCFG0_DATRDREQINFO_MASK, val);
+	}
+
+	dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, cfg);
+}
+
 /* set global incr burst type configuration registers */
 static void dwc3_set_incr_burst_type(struct dwc3 *dwc)
 {
@@ -1256,6 +1287,8 @@ static int dwc3_core_init(struct dwc3 *dwc)
 
 	dwc3_set_incr_burst_type(dwc);
 
+	dwc3_set_bus_req_info(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 df544ec730d22..cf64cfc0f208a 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -186,6 +186,10 @@
 #define DWC3_GSBUSCFG0_INCR4BRSTENA	(1 << 1) /* INCR4 burst */
 #define DWC3_GSBUSCFG0_INCRBRSTENA	(1 << 0) /* undefined length enable */
 #define DWC3_GSBUSCFG0_INCRBRST_MASK	0xff
+#define DWC3_GSBUSCFG0_DESWRREQINFO_MASK	GENMASK(19, 16)
+#define DWC3_GSBUSCFG0_DATWRREQINFO_MASK	GENMASK(23, 20)
+#define DWC3_GSBUSCFG0_DESRDREQINFO_MASK	GENMASK(27, 24)
+#define DWC3_GSBUSCFG0_DATRDREQINFO_MASK	GENMASK(31, 28)
 
 /* Global Debug LSP MUX Select */
 #define DWC3_GDBGLSPMUX_ENDBC		BIT(15)	/* Host only */
-- 
2.34.1