[PATCH v3 3/5] ARM: Exynos: add device tree support for MCT controller driver

Thomas Abraham thomas.abraham at linaro.org
Sat Dec 29 15:50:36 EST 2012


Allow the MCT controller base address and interrupts to be obtained from
device tree and remove unused static definitions of these. The non-dt support
for Exynos5250 is removed but retained for Exynos4210 based platforms.

Cc: Changhwan Youn <chaos.youn at samsung.com>
Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
---
 .../bindings/timer/samsung,exynos4210-mct.txt      |   69 ++++++++++++++++++++
 arch/arm/mach-exynos/include/mach/irqs.h           |    6 --
 arch/arm/mach-exynos/mct.c                         |   41 ++++++++----
 3 files changed, 97 insertions(+), 19 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt

diff --git a/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt
new file mode 100644
index 0000000..c1b0a3e
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt
@@ -0,0 +1,69 @@
+Samsung's Multi Core Timer (MCT)
+
+The Samsung's Multi Core Timer (MCT) module includes two main blocks, the
+global timer and CPU local timers. The global timer is a 64-bit free running
+up-counter and can generate 4 interrupts when the counter reaches one of the
+four preset counter values. The CPU local timers are 32-bit free running
+down-counters and generate an interrupt when the counter expires. There is
+one CPU local timer instantiated in MCT for every CPU in the system.
+
+Required properties:
+
+- compatible: should be "samsung,exynos4210-mct".
+- reg: base address of the mct controller and length of the address space
+  it occupies.
+- interrupts: the list of interrupts generated by the controller. The following
+  should be the order of the interrupts specified. The local timer interrupts
+  should be specified after the four global timer interrupts have been
+  specified.
+
+	0: Global Timer Interrupt 0
+	1: Global Timer Interrupt 1
+	2: Global Timer Interrupt 2
+	3: Global Timer Interrupt 3
+	4: Local Timer Interrupt 0
+	5: Local Timer Interrupt 1
+	6: ..
+	7: ..
+	i: Local Timer Interrupt n
+
+- samsung,mct-nr-local-irqs: The number of local timer interrupts supported
+  by the MCT controller.
+
+Example 1: In this example, the system uses only the first global timer
+	   interrupt generated by MCT and the remaining three global timer
+	   interrupts are unused. Two local timer interrupts have been
+	   specified.
+
+	mct at 10050000 {
+		compatible = "samsung,exynos4210-mct";
+		reg = <0x10050000 0x800>;
+		interrupts = <0 57 0>, <0 0 0>, <0 0 0>, <0 0 0>,
+			     <0 42 0>, <0 48 0>;
+		samsung,mct-nr-local-irqs = <2>;
+	};
+
+Example 2: In this example, the MCT global and local timer interrupts are
+	   connected to two seperate interrupt controllers. Hence, an
+	   interrupt-map is created to map the interrupts to the respective
+	   interrupt controllers.
+
+	mct at 101C0000 {
+		compatible = "samsung,exynos4210-mct";
+		reg = <0x101C0000 0x800>;
+		interrupt-controller;
+		#interrups-cells = <2>;
+		interrupt-parent = <&mct_map>;
+		interrupts = <0 0>, <1 0>, <2 0>, <3 0>,
+			     <4 0>, <5 0>;
+		samsung,mct-nr-local-irqs = <2>;
+
+		mct_map: mct-map {
+			#interrupt-cells = <2>;
+			#address-cells = <0>;
+			#size-cells = <0>;
+			interrupt-map = <0x0 0 &combiner 23 3>,
+					<0x4 0 &gic 0 120 0>,
+					<0x5 0 &gic 0 121 0>;
+		};
+	};
diff --git a/arch/arm/mach-exynos/include/mach/irqs.h b/arch/arm/mach-exynos/include/mach/irqs.h
index 6794292..35fe6d5 100644
--- a/arch/arm/mach-exynos/include/mach/irqs.h
+++ b/arch/arm/mach-exynos/include/mach/irqs.h
@@ -30,8 +30,6 @@
 
 /* For EXYNOS4 and EXYNOS5 */
 
-#define EXYNOS_IRQ_MCT_LOCALTIMER	IRQ_PPI(12)
-
 #define EXYNOS_IRQ_EINT16_31		IRQ_SPI(32)
 
 /* For EXYNOS4 SoCs */
@@ -330,8 +328,6 @@
 #define EXYNOS5_IRQ_CEC			IRQ_SPI(114)
 #define EXYNOS5_IRQ_SATA		IRQ_SPI(115)
 
-#define EXYNOS5_IRQ_MCT_L0		IRQ_SPI(120)
-#define EXYNOS5_IRQ_MCT_L1		IRQ_SPI(121)
 #define EXYNOS5_IRQ_MMC44		IRQ_SPI(123)
 #define EXYNOS5_IRQ_MDMA1		IRQ_SPI(124)
 #define EXYNOS5_IRQ_FIMC_LITE0		IRQ_SPI(125)
@@ -426,8 +422,6 @@
 #define EXYNOS5_IRQ_PMU_CPU1		COMBINER_IRQ(22, 4)
 
 #define EXYNOS5_IRQ_EINT0		COMBINER_IRQ(23, 0)
-#define EXYNOS5_IRQ_MCT_G0		COMBINER_IRQ(23, 3)
-#define EXYNOS5_IRQ_MCT_G1		COMBINER_IRQ(23, 4)
 
 #define EXYNOS5_IRQ_EINT1		COMBINER_IRQ(24, 0)
 #define EXYNOS5_IRQ_SYSMMU_LITE1_0	COMBINER_IRQ(24, 1)
diff --git a/arch/arm/mach-exynos/mct.c b/arch/arm/mach-exynos/mct.c
index 2f4ea16..bf359f6 100644
--- a/arch/arm/mach-exynos/mct.c
+++ b/arch/arm/mach-exynos/mct.c
@@ -20,6 +20,8 @@
 #include <linux/delay.h>
 #include <linux/percpu.h>
 #include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
 
 #include <asm/arch_timer.h>
 #include <asm/hardware/gic.h>
@@ -485,14 +487,16 @@ static struct local_timer_ops exynos4_mct_tick_ops __cpuinitdata = {
 };
 #endif /* CONFIG_LOCAL_TIMERS */
 
-static void __init exynos4_timer_resources(void)
+static void __init exynos4_timer_resources(struct device_node *np)
 {
 	struct clk *mct_clk;
 	mct_clk = clk_get(NULL, "xtal");
 
 	clk_rate = clk_get_rate(mct_clk);
 
-	reg_base = S5P_VA_SYSTIMER;
+	reg_base = np ? of_iomap(np, 0) : S5P_VA_SYSTIMER;
+	if (!reg_base)
+		panic("%s: unable to ioremap mct address space\n", __func__);
 
 #ifdef CONFIG_LOCAL_TIMERS
 	if (mct_int_type == MCT_INT_PPI) {
@@ -511,28 +515,39 @@ static void __init exynos4_timer_resources(void)
 
 static void __init exynos_timer_init(void)
 {
+	struct device_node *np;
+	u32 nr_irqs, i;
+
 	if (soc_is_exynos5440()) {
 		arch_timer_of_register();
 		return;
 	}
 
-	if (soc_is_exynos4210()) {
+	np = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-mct");
+	if (np) {
+		if (of_machine_is_compatible("samsung,exynos4210") ||
+			of_machine_is_compatible("samsung,exynos5250"))
+			mct_int_type = MCT_INT_SPI;
+		else
+			mct_int_type = MCT_INT_PPI;
+
+		if (of_property_read_u32(np, "samsung,mct-nr-local-irqs",
+						&nr_irqs))
+			panic("%s: number of local irqs not specified\n",
+						__func__);
+
+		mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
+		for (i = 0; i < nr_irqs; i++)
+			mct_irqs[MCT_L0_IRQ + i] =
+				irq_of_parse_and_map(np, MCT_L0_IRQ + i);
+	} else if (soc_is_exynos4210()) {
 		mct_irqs[MCT_G0_IRQ] = EXYNOS4_IRQ_MCT_G0;
 		mct_irqs[MCT_L0_IRQ] = EXYNOS4_IRQ_MCT_L0;
 		mct_irqs[MCT_L1_IRQ] = EXYNOS4_IRQ_MCT_L1;
 		mct_int_type = MCT_INT_SPI;
-	} else if (soc_is_exynos5250()) {
-		mct_irqs[MCT_G0_IRQ] = EXYNOS5_IRQ_MCT_G0;
-		mct_irqs[MCT_L0_IRQ] = EXYNOS5_IRQ_MCT_L0;
-		mct_irqs[MCT_L1_IRQ] = EXYNOS5_IRQ_MCT_L1;
-		mct_int_type = MCT_INT_SPI;
-	} else {
-		mct_irqs[MCT_G0_IRQ] = EXYNOS4_IRQ_MCT_G0;
-		mct_irqs[MCT_L0_IRQ] = EXYNOS_IRQ_MCT_LOCALTIMER;
-		mct_int_type = MCT_INT_PPI;
 	}
 
-	exynos4_timer_resources();
+	exynos4_timer_resources(np);
 	exynos4_clocksource_init();
 	exynos4_clockevent_init();
 }
-- 
1.7.5.4




More information about the linux-arm-kernel mailing list