From 223c19076f8b6808ffcb3772dd91d890d180cd65 Mon Sep 17 00:00:00 2001
From: Ran Wang
Date: Wed, 5 Aug 2020 15:07:27 +0800
Subject: fsl-layerscape: enable dwc3 snooping feature

Configure DWC3’s cache type to ‘cacheable’ for better
performance. Actually related register definition and values are SoC
specific, which means this setting is only applicable to Layerscape SoC,
not generic for all platforms which have integrated DWC3 IP.

Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
---
 arch/arm/cpu/armv8/fsl-layerscape/soc.c | 37 +++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

(limited to 'arch/arm')

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/soc.c b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
index fde893e8c9b..5254cdf366d 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
@@ -36,6 +36,8 @@
 #ifdef CONFIG_TFABOOT
 #include <env_internal.h>
 #endif
+#include <dm.h>
+#include <linux/err.h>
 #if defined(CONFIG_TFABOOT) || defined(CONFIG_GIC_V3_ITS)
 DECLARE_GLOBAL_DATA_PTR;
 #endif
@@ -897,6 +899,38 @@ __weak int fsl_board_late_init(void)
 	return 0;
 }
 
+#define DWC3_GSBUSCFG0			0xc100
+#define DWC3_GSBUSCFG0_CACHETYPE_SHIFT	16
+#define DWC3_GSBUSCFG0_CACHETYPE(n)        (((n) & 0xffff)            \
+	<< DWC3_GSBUSCFG0_CACHETYPE_SHIFT)
+
+void enable_dwc3_snooping(void)
+{
+	int ret;
+	u32 val;
+	struct udevice *bus;
+	struct uclass *uc;
+	fdt_addr_t dwc3_base;
+
+	ret = uclass_get(UCLASS_USB, &uc);
+	if (ret)
+		return;
+
+	uclass_foreach_dev(bus, uc) {
+		if (!strcmp(bus->driver->of_match->compatible, "fsl,layerscape-dwc3")) {
+			dwc3_base = devfdt_get_addr(bus);
+			if (dwc3_base == FDT_ADDR_T_NONE) {
+				dev_err(bus, "dwc3 regs missing\n");
+				continue;
+			}
+			val = in_le32(dwc3_base + DWC3_GSBUSCFG0);
+			val &= ~DWC3_GSBUSCFG0_CACHETYPE(~0);
+			val |= DWC3_GSBUSCFG0_CACHETYPE(0x2222);
+			writel(val, dwc3_base + DWC3_GSBUSCFG0);
+		}
+	}
+}
+
 int board_late_init(void)
 {
 #ifdef CONFIG_CHAIN_OF_TRUST
@@ -934,6 +968,9 @@ int board_late_init(void)
 	fspi_ahb_init();
 #endif
 
+	if (IS_ENABLED(CONFIG_DM))
+		enable_dwc3_snooping();
+
 	return fsl_board_late_init();
 }
 #endif
-- 
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