arm: pmu: support pmu/perf on OMAP4

This patch fixes the bug #702999 (oprofile failure on panda (omap4)). It is based on [1] that fixes the issue by enabling pmu events for omap4, which are routed from CTI. The patch attached is a modified version of [1] with removal of some CTI register reads that cause hang in the initial phase of booting. The patch has been verified on Panda board and the profile data could be generated that are shown by opreport. Although, there is a lockdep warning "possible circular locking dependency detected" when "opcontrol --start" is called for the first time.

Regards,
Avik

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2011-March/045283.html

Signed-off-by: Avik Sil <avik.sil@linaro.org>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>

1 files changed, 79 insertions, 3 deletions

diff --git a/arch/arm/mach-omap2/devices.c b/arch/arm/mach-omap2/devices.c
index d478f53f908..cbd6b3550ff 100644
--- a/arch/arm/mach-omap2/devices.c
+++ b/arch/arm/mach-omap2/devices.c
@@ -22,6 +22,7 @@
 #include <asm/mach-types.h>
 #include <asm/mach/map.h>
 #include <asm/pmu.h>
+#include <asm/cti.h>
 
 #include <plat/tc.h>
 #include <plat/board.h>
@@ -386,20 +387,95 @@ static struct resource omap3_pmu_resource = {
 	.flags	= IORESOURCE_IRQ,
 };
 
+static struct resource omap4_pmu_resource[] = {
+	{
+		.start	= OMAP44XX_IRQ_CTI0,
+		.end	= OMAP44XX_IRQ_CTI0,
+		.flags	= IORESOURCE_IRQ,
+	},
+	{
+		.start	= OMAP44XX_IRQ_CTI1,
+		.end	= OMAP44XX_IRQ_CTI1,
+		.flags	= IORESOURCE_IRQ,
+	}
+};
+
 static struct platform_device omap_pmu_device = {
 	.name		= "arm-pmu",
 	.id		= ARM_PMU_DEVICE_CPU,
 	.num_resources	= 1,
 };
 
+static struct arm_pmu_platdata omap4_pmu_data;
+static struct cti omap4_cti[2];
+
+static void omap4_enable_cti(int irq)
+{
+	if (irq == OMAP44XX_IRQ_CTI0)
+		cti_enable(&omap4_cti[0]);
+	else if (irq == OMAP44XX_IRQ_CTI1)
+		cti_enable(&omap4_cti[1]);
+}
+
+static void omap4_disable_cti(int irq)
+{
+	if (irq == OMAP44XX_IRQ_CTI0)
+		cti_disable(&omap4_cti[0]);
+	else if (irq == OMAP44XX_IRQ_CTI1)
+		cti_disable(&omap4_cti[1]);
+}
+
+static irqreturn_t omap4_pmu_handler(int irq, void *dev, irq_handler_t handler)
+{
+	if (irq == OMAP44XX_IRQ_CTI0)
+		cti_irq_ack(&omap4_cti[0]);
+	else if (irq == OMAP44XX_IRQ_CTI1)
+		cti_irq_ack(&omap4_cti[1]);
+
+	return handler(irq, dev);
+}
+
+static void omap4_configure_pmu_irq(void)
+{
+	void __iomem *base0;
+	void __iomem *base1;
+
+	base0 = ioremap(OMAP44XX_CTI0_BASE, SZ_4K);
+	base1 = ioremap(OMAP44XX_CTI1_BASE, SZ_4K);
+	if (!base0 && !base1) {
+		pr_err("ioremap for OMAP4 CTI failed\n");
+		return;
+	}
+
+	/*configure CTI0 for pmu irq routing*/
+	cti_init(&omap4_cti[0], base0, OMAP44XX_IRQ_CTI0, 6);
+	cti_unlock(&omap4_cti[0]);
+	cti_map_trigger(&omap4_cti[0], 1, 6, 2);
+
+	/*configure CTI1 for pmu irq routing*/
+	cti_init(&omap4_cti[1], base1, OMAP44XX_IRQ_CTI1, 6);
+	cti_unlock(&omap4_cti[1]);
+	cti_map_trigger(&omap4_cti[1], 1, 6, 2);
+
+	omap4_pmu_data.handle_irq = omap4_pmu_handler;
+	omap4_pmu_data.enable_irq = omap4_enable_cti;
+	omap4_pmu_data.disable_irq = omap4_disable_cti;
+}
+
 static void omap_init_pmu(void)
 {
-	if (cpu_is_omap24xx())
+	if (cpu_is_omap24xx()) {
 		omap_pmu_device.resource = &omap2_pmu_resource;
-	else if (cpu_is_omap34xx())
+	} else if (cpu_is_omap34xx()) {
 		omap_pmu_device.resource = &omap3_pmu_resource;
-	else
+	} else if (cpu_is_omap44xx()) {
+		omap_pmu_device.resource = omap4_pmu_resource;
+		omap_pmu_device.num_resources = 2;
+		omap_pmu_device.dev.platform_data = &omap4_pmu_data;
+		omap4_configure_pmu_irq();
+	} else {
 		return;
+	}
 
 	platform_device_register(&omap_pmu_device);
 }