diff --git a/arch/arm/mach-at91/at91cap9.c b/arch/arm/mach-at91/at91cap9.c
index 0fc0adaebd583ed0718366f354fb970078d35c2d..0a38c69fdbc450f3d09ed7545ef60af14e45fb50 100644
--- a/arch/arm/mach-at91/at91cap9.c
+++ b/arch/arm/mach-at91/at91cap9.c
@@ -17,6 +17,8 @@
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
+
+#include <mach/cpu.h>
 #include <mach/at91cap9.h>
 #include <mach/at91_pmc.h>
 #include <mach/at91_rstc.h>
@@ -317,6 +319,12 @@ void __init at91cap9_initialize(unsigned long main_clock)
 
 	/* Register GPIO subsystem */
 	at91_gpio_init(at91cap9_gpio, 4);
+
+	/* Remember the silicon revision */
+	if (cpu_is_at91cap9_revB())
+		system_rev = 0xB;
+	else if (cpu_is_at91cap9_revC())
+		system_rev = 0xC;
 }
 
 /* --------------------------------------------------------------------
diff --git a/arch/arm/mach-at91/at91cap9_devices.c b/arch/arm/mach-at91/at91cap9_devices.c
index 3a36182c50cc6f03253c0a98d1fdfca42959d1ed..9eca2209cde630dd656491ef5c964461f2c8b5b2 100644
--- a/arch/arm/mach-at91/at91cap9_devices.c
+++ b/arch/arm/mach-at91/at91cap9_devices.c
@@ -13,6 +13,7 @@
  */
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
+#include <asm/mach/irq.h>
 
 #include <linux/dma-mapping.h>
 #include <linux/platform_device.h>
@@ -21,6 +22,7 @@
 #include <video/atmel_lcdc.h>
 
 #include <mach/board.h>
+#include <mach/cpu.h>
 #include <mach/gpio.h>
 #include <mach/at91cap9.h>
 #include <mach/at91cap9_matrix.h>
@@ -69,6 +71,9 @@ void __init at91_add_device_usbh(struct at91_usbh_data *data)
 	if (!data)
 		return;
 
+	if (cpu_is_at91cap9_revB())
+		set_irq_type(AT91CAP9_ID_UHP, IRQ_TYPE_LEVEL_HIGH);
+
 	/* Enable VBus control for UHP ports */
 	for (i = 0; i < data->ports; i++) {
 		if (data->vbus_pin[i])
@@ -151,8 +156,13 @@ static struct platform_device at91_usba_udc_device = {
 
 void __init at91_add_device_usba(struct usba_platform_data *data)
 {
-	at91_sys_write(AT91_MATRIX_UDPHS, AT91_MATRIX_SELECT_UDPHS |
-					  AT91_MATRIX_UDPHS_BYPASS_LOCK);
+	if (cpu_is_at91cap9_revB()) {
+		set_irq_type(AT91CAP9_ID_UDPHS, IRQ_TYPE_LEVEL_HIGH);
+		at91_sys_write(AT91_MATRIX_UDPHS, AT91_MATRIX_SELECT_UDPHS |
+						  AT91_MATRIX_UDPHS_BYPASS_LOCK);
+	}
+	else
+		at91_sys_write(AT91_MATRIX_UDPHS, AT91_MATRIX_SELECT_UDPHS);
 
 	/*
 	 * Invalid pins are 0 on AT91, but the usba driver is shared
@@ -850,6 +860,9 @@ void __init at91_add_device_lcdc(struct atmel_lcdfb_info *data)
 	if (!data)
 		return;
 
+	if (cpu_is_at91cap9_revB())
+		set_irq_type(AT91CAP9_ID_LCDC, IRQ_TYPE_LEVEL_HIGH);
+
 	at91_set_A_periph(AT91_PIN_PC1, 0);	/* LCDHSYNC */
 	at91_set_A_periph(AT91_PIN_PC2, 0);	/* LCDDOTCK */
 	at91_set_A_periph(AT91_PIN_PC3, 0);	/* LCDDEN */
diff --git a/arch/arm/mach-at91/board-cap9adk.c b/arch/arm/mach-at91/board-cap9adk.c
index 43b37bc91e5feb069bd4eb14b1fc7ddd40647141..83a1a0fef47be359b7138f4584d734a6f1ff5ae0 100644
--- a/arch/arm/mach-at91/board-cap9adk.c
+++ b/arch/arm/mach-at91/board-cap9adk.c
@@ -36,11 +36,9 @@
 #include <mach/hardware.h>
 #include <asm/setup.h>
 #include <asm/mach-types.h>
-#include <asm/irq.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
-#include <asm/mach/irq.h>
 
 #include <mach/board.h>
 #include <mach/gpio.h>
@@ -376,10 +374,8 @@ static void __init cap9adk_board_init(void)
 	/* Serial */
 	at91_add_device_serial();
 	/* USB Host */
-	set_irq_type(AT91CAP9_ID_UHP, IRQ_TYPE_LEVEL_HIGH);
 	at91_add_device_usbh(&cap9adk_usbh_data);
 	/* USB HS */
-	set_irq_type(AT91CAP9_ID_UDPHS, IRQ_TYPE_LEVEL_HIGH);
 	at91_add_device_usba(&cap9adk_usba_udc_data);
 	/* SPI */
 	at91_add_device_spi(cap9adk_spi_devices, ARRAY_SIZE(cap9adk_spi_devices));
@@ -396,7 +392,6 @@ static void __init cap9adk_board_init(void)
 	/* I2C */
 	at91_add_device_i2c(NULL, 0);
 	/* LCD Controller */
-	set_irq_type(AT91CAP9_ID_LCDC, IRQ_TYPE_LEVEL_HIGH);
 	at91_add_device_lcdc(&cap9adk_lcdc_data);
 	/* AC97 */
 	at91_add_device_ac97(&cap9adk_ac97_data);
diff --git a/arch/arm/mach-at91/include/mach/at91_pmc.h b/arch/arm/mach-at91/include/mach/at91_pmc.h
index 2e3f2894b70496535660883a29fd21cd0bf76deb..9561e33b8a9af76ecd3eb91670254f549065b639 100644
--- a/arch/arm/mach-at91/include/mach/at91_pmc.h
+++ b/arch/arm/mach-at91/include/mach/at91_pmc.h
@@ -23,6 +23,7 @@
 #define		AT91_PMC_PCK		(1 <<  0)		/* Processor Clock */
 #define		AT91RM9200_PMC_UDP	(1 <<  1)		/* USB Devcice Port Clock [AT91RM9200 only] */
 #define		AT91RM9200_PMC_MCKUDP	(1 <<  2)		/* USB Device Port Master Clock Automatic Disable on Suspend [AT91RM9200 only] */
+#define		AT91CAP9_PMC_DDR	(1 <<  2)		/* DDR Clock [AT91CAP9 revC only] */
 #define		AT91RM9200_PMC_UHP	(1 <<  4)		/* USB Host Port Clock [AT91RM9200 only] */
 #define		AT91SAM926x_PMC_UHP	(1 <<  6)		/* USB Host Port Clock [AT91SAM926x only] */
 #define		AT91CAP9_PMC_UHP	(1 <<  6)		/* USB Host Port Clock [AT91CAP9 only] */
@@ -102,10 +103,16 @@
 #define		AT91_PMC_LOCKB		(1 <<  2)		/* PLLB Lock */
 #define		AT91_PMC_MCKRDY		(1 <<  3)		/* Master Clock */
 #define		AT91_PMC_LOCKU		(1 <<  6)		/* UPLL Lock [AT91CAP9 only] */
+#define		AT91_PMC_OSCSEL		(1 <<  7)		/* Slow Clock Oscillator [AT91CAP9 revC only] */
 #define		AT91_PMC_PCK0RDY	(1 <<  8)		/* Programmable Clock 0 */
 #define		AT91_PMC_PCK1RDY	(1 <<  9)		/* Programmable Clock 1 */
 #define		AT91_PMC_PCK2RDY	(1 << 10)		/* Programmable Clock 2 */
 #define		AT91_PMC_PCK3RDY	(1 << 11)		/* Programmable Clock 3 */
 #define	AT91_PMC_IMR		(AT91_PMC + 0x6c)	/* Interrupt Mask Register */
 
+#define AT91_PMC_PROT		(AT91_PMC + 0xe4)	/* Protect Register [AT91CAP9 revC only] */
+#define		AT91_PMC_PROTKEY	0x504d4301	/* Activation Code */
+
+#define AT91_PMC_VER		(AT91_PMC + 0xfc)	/* PMC Module Version [AT91CAP9 only] */
+
 #endif
diff --git a/arch/arm/mach-at91/include/mach/at91cap9.h b/arch/arm/mach-at91/include/mach/at91cap9.h
index 4a4b64135a922a16ebb72e3c38e0c09acfc39361..d8c1ededaa75aea4ab8835ade94c2dda544068f7 100644
--- a/arch/arm/mach-at91/include/mach/at91cap9.h
+++ b/arch/arm/mach-at91/include/mach/at91cap9.h
@@ -101,7 +101,9 @@
 #define AT91_RTT	(0xfffffd20 - AT91_BASE_SYS)
 #define AT91_PIT	(0xfffffd30 - AT91_BASE_SYS)
 #define AT91_WDT	(0xfffffd40 - AT91_BASE_SYS)
-#define AT91_GPBR	(0xfffffd50 - AT91_BASE_SYS)
+#define AT91_GPBR	(cpu_is_at91cap9_revB() ?	\
+			(0xfffffd50 - AT91_BASE_SYS) :	\
+			(0xfffffd60 - AT91_BASE_SYS))
 
 #define AT91_USART0	AT91CAP9_BASE_US0
 #define AT91_USART1	AT91CAP9_BASE_US1
diff --git a/arch/arm/mach-at91/include/mach/cpu.h b/arch/arm/mach-at91/include/mach/cpu.h
index dbfd9f73f80bb4aa531e8a6ec063de0082fb2195..c554c3e4d5532c09a96eef3270c3e5a71f68fb99 100644
--- a/arch/arm/mach-at91/include/mach/cpu.h
+++ b/arch/arm/mach-at91/include/mach/cpu.h
@@ -49,6 +49,17 @@ static inline unsigned long at91_arch_identify(void)
 	return (at91_sys_read(AT91_DBGU_CIDR) & AT91_CIDR_ARCH);
 }
 
+#ifdef CONFIG_ARCH_AT91CAP9
+#include <mach/at91_pmc.h>
+
+#define ARCH_REVISION_CAP9_B	0x399
+#define ARCH_REVISION_CAP9_C	0x601
+
+static inline unsigned long at91cap9_rev_identify(void)
+{
+	return (at91_sys_read(AT91_PMC_VER));
+}
+#endif
 
 #ifdef CONFIG_ARCH_AT91RM9200
 #define cpu_is_at91rm9200()	(at91_cpu_identify() == ARCH_ID_AT91RM9200)
@@ -90,8 +101,12 @@ static inline unsigned long at91_arch_identify(void)
 
 #ifdef CONFIG_ARCH_AT91CAP9
 #define cpu_is_at91cap9()	(at91_cpu_identify() == ARCH_ID_AT91CAP9)
+#define cpu_is_at91cap9_revB()	(at91cap9_rev_identify() == ARCH_REVISION_CAP9_B)
+#define cpu_is_at91cap9_revC()	(at91cap9_rev_identify() == ARCH_REVISION_CAP9_C)
 #else
 #define cpu_is_at91cap9()	(0)
+#define cpu_is_at91cap9_revB()	(0)
+#define cpu_is_at91cap9_revC()	(0)
 #endif
 
 /*
diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index 2133f37906f2928f8d3ccacf0fc7bcd77aa7d3ce..d5e4e637ddecb5a4f63db385510e3962cb0bb3dc 100644
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -21,6 +21,7 @@
 
 #include <mach/board.h>
 #include <mach/at91_rtt.h>
+#include <mach/cpu.h>
 
 
 /*