ARM: EXYNOS: Setup legacy i2c controller interrupts

On Exynos5 we have a new high-speed i2c controller. The interrupt
sources for the legacy and new controller are muxed and are controlled
via the SYSCON I2C_CFG register. At reset the interrupt source is
configured for the high-speed controller, to continue using the old
i2c controller we need to modify the I2C_CFG register.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

2 files changed, 26 insertions, 0 deletions

diff --git a/arch/arm/mach-exynos/include/mach/regs-pmu.h b/arch/arm/mach-exynos/include/mach/regs-pmu.h
index d4e392b811a3..684625ad3f39 100644
--- a/arch/arm/mach-exynos/include/mach/regs-pmu.h
+++ b/arch/arm/mach-exynos/include/mach/regs-pmu.h
@@ -15,6 +15,7 @@
 #include <mach/map.h>
 
 #define S5P_PMUREG(x)                           (S5P_VA_PMU + (x))
+#define S5P_SYSREG(x)                           (S3C_VA_SYS + (x))
 
 #define S5P_CENTRAL_SEQ_CONFIGURATION           S5P_PMUREG(0x0200)
 
@@ -230,6 +231,7 @@
 
 /* For EXYNOS5 */
 
+#define EXYNOS5_SYS_I2C_CFG                                     S5P_SYSREG(0x0234)
 #define EXYNOS5_USB_CFG                                         S5P_PMUREG(0x0230)
 
 #define EXYNOS5_AUTO_WDTRESET_DISABLE                           S5P_PMUREG(0x0408)
diff --git a/arch/arm/mach-exynos/mach-exynos5-dt.c b/arch/arm/mach-exynos/mach-exynos5-dt.c
index db035374087e..f906f599a141 100644
--- a/arch/arm/mach-exynos/mach-exynos5-dt.c
+++ b/arch/arm/mach-exynos/mach-exynos5-dt.c
@@ -11,10 +11,12 @@
 
 #include <linux/of_platform.h>
 #include <linux/serial_core.h>
+#include <linux/io.h>
 
 #include <asm/mach/arch.h>
 #include <asm/hardware/gic.h>
 #include <mach/map.h>
+#include <mach/regs-pmu.h>
 
 #include <plat/cpu.h>
 #include <plat/regs-serial.h>
@@ -91,6 +93,28 @@ static void __init exynos5250_dt_map_io(void)
 
 static void __init exynos5250_dt_machine_init(void)
 {
+        struct device_node *i2c_np;
+        const char *i2c_compat = "samsung,s3c2440-i2c";
+        unsigned int tmp;
+
+        /*
+         * Exynos5's legacy i2c controller and new high speed i2c
+         * controller have muxed interrupt sources. By default the
+         * interrupts for 4-channel HS-I2C controller are enabled.
+         * If node for first four channels of legacy i2c controller
+         * are available then re-configure the interrupts via the
+         * system register.
+         */
+        for_each_compatible_node(i2c_np, NULL, i2c_compat) {
+                if (of_device_is_available(i2c_np)) {
+                        if (of_alias_get_id(i2c_np, "i2c") < 4) {
+                                tmp = readl(EXYNOS5_SYS_I2C_CFG);
+                                writel(tmp & ~(0x1 << of_alias_get_id(i2c_np, "i2c")),
+                                                EXYNOS5_SYS_I2C_CFG);
+                        }
+                }
+        }
+
         of_platform_populate(NULL, of_default_bus_match_table,
                                 exynos5250_auxdata_lookup, NULL);
 }