MIPS: lantiq: Disable xbar fpi burst mode

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11458/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/lantiq/xway/sysctrl.c

@@ -145,7 +145,15 @@ static u32 pmu_clk_cr_b[] = {
 #define pmu_w32(x, y)	ltq_w32((x), pmu_membase + (y))
 #define pmu_r32(x)	ltq_r32(pmu_membase + (x))
 
+#define XBAR_ALWAYS_LAST	0x430
+#define XBAR_FPI_BURST_EN	BIT(1)
+#define XBAR_AHB_BURST_EN	BIT(2)
+
+#define xbar_w32(x, y)	ltq_w32((x), ltq_xbar_membase + (y))
+#define xbar_r32(x)	ltq_r32(ltq_xbar_membase + (x))
+
 static void __iomem *pmu_membase;
+static void __iomem *ltq_xbar_membase;
 void __iomem *ltq_cgu_membase;
 void __iomem *ltq_ebu_membase;
 
@@ -285,6 +293,16 @@ static void pci_ext_disable(struct clk *clk)
 	ltq_cgu_w32((1 << 31) | (1 << 30), pcicr);
 }
 
+static void xbar_fpi_burst_disable(void)
+{
+	u32 reg;
+
+	/* bit 1 as 1 --burst; bit 1 as 0 -- single */
+	reg = xbar_r32(XBAR_ALWAYS_LAST);
+	reg &= ~XBAR_FPI_BURST_EN;
+	xbar_w32(reg, XBAR_ALWAYS_LAST);
+}
+
 /* enable a clockout source */
 static int clkout_enable(struct clk *clk)
 {
@@ -441,6 +459,26 @@ void __init ltq_soc_init(void)
 	if (!pmu_membase || !ltq_cgu_membase || !ltq_ebu_membase)
 		panic("Failed to remap core resources");
 
+	if (of_machine_is_compatible("lantiq,vr9")) {
+		struct resource res_xbar;
+		struct device_node *np_xbar =
+				of_find_compatible_node(NULL, NULL,
+							"lantiq,xbar-xway");
+
+		if (!np_xbar)
+			panic("Failed to load xbar nodes from devicetree");
+		if (of_address_to_resource(np_pmu, 0, &res_xbar))
+			panic("Failed to get xbar resources");
+		if (request_mem_region(res_xbar.start, resource_size(&res_xbar),
+			res_xbar.name) < 0)
+			panic("Failed to get xbar resources");
+
+		ltq_xbar_membase = ioremap_nocache(res_xbar.start,
+						   resource_size(&res_xbar));
+		if (!ltq_xbar_membase)
+			panic("Failed to remap xbar resources");
+	}
+
 	/* make sure to unprotect the memory region where flash is located */
 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_BUSCON0) & ~EBU_WRDIS, LTQ_EBU_BUSCON0);
 
@@ -567,4 +605,7 @@ void __init ltq_soc_init(void)
 		clkdev_add_pmu("1e116000.mei", "dfe", 1, 0, PMU_DFE);
 		clkdev_add_pmu("1e100400.serial", NULL, 1, 0, PMU_ASC0);
 	}
+
+	if (of_machine_is_compatible("lantiq,vr9"))
+		xbar_fpi_burst_disable();
 }