[PATCH RFC 12/12] ARM64: layerscape: configure all DMA masters to be cache-coherent

[Ahmad Fatoum]

Upstream device tree now has /soc/dma-coherent, which breaks USB in
Linux v6.1 when kernel is booted with barebox. Fix this by setting
fixing up cache coherency setting into kernel DT whenever barebox
DT has /soc/dma-coherent.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 arch/arm/Kconfig                            |  1 +
 arch/arm/mach-layerscape/Makefile           |  1 +
 arch/arm/mach-layerscape/dma-coherent.c     | 20 ++++++++++++++++++++
 arch/arm/mach-layerscape/lowlevel-ls1046a.c | 10 ++++++----
 include/soc/fsl/immap_lsch2.h               |  7 +++++++
 5 files changed, 35 insertions(+), 4 deletions(-)
 create mode 100644 arch/arm/mach-layerscape/dma-coherent.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8183f6d54686..0296e227b9ad 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -115,6 +115,7 @@ config ARCH_LAYERSCAPE
 	select HW_HAS_PCI
 	select OFTREE
 	select OFDEVICE
+	select OF_DMA_COHERENCY
 
 config ARCH_MVEBU
 	bool "Marvell EBU platforms"
diff --git a/arch/arm/mach-layerscape/Makefile b/arch/arm/mach-layerscape/Makefile
index 58d3ea820aa3..05965e113bde 100644
--- a/arch/arm/mach-layerscape/Makefile
+++ b/arch/arm/mach-layerscape/Makefile
@@ -4,6 +4,7 @@ obj- := __dummy__.o
 lwl-y += lowlevel.o errata.o
 lwl-$(CONFIG_ARCH_LS1046) += lowlevel-ls1046a.o
 obj-y += icid.o
+obj-y += dma-coherent.o
 obj-pbl-y += boot.o
 pbl-y += xload-qspi.o xload.o
 obj-$(CONFIG_ARCH_LAYERSCAPE_PPA) += ppa.o ppa-entry.o
diff --git a/arch/arm/mach-layerscape/dma-coherent.c b/arch/arm/mach-layerscape/dma-coherent.c
new file mode 100644
index 000000000000..c7bb1cffb080
--- /dev/null
+++ b/arch/arm/mach-layerscape/dma-coherent.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <io.h>
+#include <init.h>
+#include <of_address.h>
+
+static int layerscape_of_fixup_dma_coherent(void)
+{
+	struct device_node *soc;
+
+	soc = of_find_node_by_path("/soc");
+	if (!soc)
+		return -ENOENT;
+
+	if (!of_property_read_bool(soc, "dma-coherent"))
+		return 0;
+
+	return of_register_fixup(of_dma_coherent_fixup, NULL);
+}
+coredevice_initcall(layerscape_of_fixup_dma_coherent);
diff --git a/arch/arm/mach-layerscape/lowlevel-ls1046a.c b/arch/arm/mach-layerscape/lowlevel-ls1046a.c
index 32f825ec2575..320f791164ca 100644
--- a/arch/arm/mach-layerscape/lowlevel-ls1046a.c
+++ b/arch/arm/mach-layerscape/lowlevel-ls1046a.c
@@ -227,11 +227,13 @@ void ls1046a_init_lowlevel(void)
 	set_cntfrq(25000000);
 	syscnt_enable(IOMEM(LSCH2_SYS_COUNTER_ADDR));
 
-	/* Make SEC reads and writes snoopable */
+	/* Make DMA master reads and writes snoopable */
 	setbits_be32(&scfg->snpcnfgcr, SCFG_SNPCNFGCR_SECRDSNP |
-		SCFG_SNPCNFGCR_SECWRSNP |
-		SCFG_SNPCNFGCR_SATARDSNP |
-		SCFG_SNPCNFGCR_SATAWRSNP);
+		SCFG_SNPCNFGCR_SECWRSNP | SCFG_SNPCNFGCR_USB1RDSNP |
+		SCFG_SNPCNFGCR_USB1WRSNP | SCFG_SNPCNFGCR_USB2RDSNP |
+		SCFG_SNPCNFGCR_USB2WRSNP | SCFG_SNPCNFGCR_USB3RDSNP |
+		SCFG_SNPCNFGCR_USB3WRSNP | SCFG_SNPCNFGCR_SATARDSNP |
+		SCFG_SNPCNFGCR_SATAWRSNP | SCFG_SNPCNFGCR_EDMASNP);
 
 	/*
 	 * Enable snoop requests and DVM message requests for
diff --git a/include/soc/fsl/immap_lsch2.h b/include/soc/fsl/immap_lsch2.h
index 1b74c77908d1..969ce93736f9 100644
--- a/include/soc/fsl/immap_lsch2.h
+++ b/include/soc/fsl/immap_lsch2.h
@@ -247,6 +247,13 @@ struct ccsr_gur {
 #define SCFG_SNPCNFGCR_SECWRSNP		0x40000000
 #define SCFG_SNPCNFGCR_SATARDSNP	0x00800000
 #define SCFG_SNPCNFGCR_SATAWRSNP	0x00400000
+#define SCFG_SNPCNFGCR_USB1RDSNP	0x00200000
+#define SCFG_SNPCNFGCR_USB1WRSNP	0x00100000
+#define SCFG_SNPCNFGCR_EDMASNP		0x00020000
+#define SCFG_SNPCNFGCR_USB2RDSNP	0x00008000
+#define SCFG_SNPCNFGCR_USB2WRSNP	0x00010000
+#define SCFG_SNPCNFGCR_USB3RDSNP	0x00002000
+#define SCFG_SNPCNFGCR_USB3WRSNP	0x00004000
 
 /* RGMIIPCR bit definitions*/
 #define SCFG_RGMIIPCR_EN_AUTO		BIT(3)
-- 
2.30.2