drivers: usb: xhci-fsl: Change burst beat and outstanding pipelined transfers requests

This is required for better performance, and performs below tuning:
1. Enable burst length set, and define it as 4/8/16.
2. Set burst request limit to 16 requests.

Signed-off-by: Rajesh Bhagat <rajesh.bhagat@nxp.com>
Signed-off-by: Sriram Dash <sriram.dash@nxp.com>

drivers/usb/host/xhci-fsl.c

@@ -58,6 +58,13 @@ static void fsl_apply_xhci_errata(void)
 	}
 }
 
+static void fsl_xhci_set_beat_burst_length(struct dwc3 *dwc3_reg)
+{
+	clrsetbits_le32(&dwc3_reg->g_sbuscfg0, USB3_ENABLE_BEAT_BURST_MASK,
+			USB3_ENABLE_BEAT_BURST);
+	setbits_le32(&dwc3_reg->g_sbuscfg1, USB3_SET_BEAT_BURST_LIMIT);
+}
+
 static int fsl_xhci_core_init(struct fsl_xhci *fsl_xhci)
 {
 	int ret = 0;
@@ -74,6 +81,9 @@ static int fsl_xhci_core_init(struct fsl_xhci *fsl_xhci)
 	/* Set GFLADJ_30MHZ as 20h as per XHCI spec default value */
 	dwc3_set_fladj(fsl_xhci->dwc3_reg, GFLADJ_30MHZ_DEFAULT);
 
+	/* Change beat burst and outstanding pipelined transfers requests */
+	fsl_xhci_set_beat_burst_length(fsl_xhci->dwc3_reg);
+
 	return ret;
 }
 

include/linux/usb/xhci-fsl.h

@@ -20,6 +20,9 @@
 #define USB3_PHY_TX_RX_POWERON	(USB3_PHY_RX_POWERON | USB3_PHY_TX_POWERON)
 #define USB3_PWRCTL_CLK_CMD_SHIFT   14
 #define USB3_PWRCTL_CLK_FREQ_SHIFT	22
+#define USB3_ENABLE_BEAT_BURST		0xF
+#define USB3_ENABLE_BEAT_BURST_MASK	0xFF
+#define USB3_SET_BEAT_BURST_LIMIT	0xF00
 
 /* USBOTGSS_WRAPPER definitions */
 #define USBOTGSS_WRAPRESET	BIT(17)