.start  = AT91SAM9260_BASE_RTT,
                .end    = AT91SAM9260_BASE_RTT + SZ_16 - 1,
                .flags  = IORESOURCE_MEM,
-       }
+       }, {
+               .flags  = IORESOURCE_MEM,
+       },
 };
 
 static struct platform_device at91sam9260_rtt_device = {
        .name           = "at91_rtt",
        .id             = 0,
        .resource       = rtt_resources,
-       .num_resources  = ARRAY_SIZE(rtt_resources),
 };
 
 
 static void __init at91_add_device_rtt_rtc(void)
 {
        at91sam9260_rtt_device.name = "rtc-at91sam9";
+       /*
+        * The second resource is needed:
+        * GPBR will serve as the storage for RTC time offset
+        */
+       at91sam9260_rtt_device.num_resources = 2;
+       rtt_resources[1].start = AT91SAM9260_BASE_GPBR +
+                                4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
+       rtt_resources[1].end = rtt_resources[1].start + 3;
 }
 #else
-static void __init at91_add_device_rtt_rtc(void) {}
+static void __init at91_add_device_rtt_rtc(void)
+{
+       /* Only one resource is needed: RTT not used as RTC */
+       at91sam9260_rtt_device.num_resources = 1;
+}
 #endif
 
 static void __init at91_add_device_rtt(void)
 
                .start  = AT91SAM9261_BASE_RTT,
                .end    = AT91SAM9261_BASE_RTT + SZ_16 - 1,
                .flags  = IORESOURCE_MEM,
+       }, {
+               .flags  = IORESOURCE_MEM,
        }
 };
 
        .name           = "at91_rtt",
        .id             = 0,
        .resource       = rtt_resources,
-       .num_resources  = ARRAY_SIZE(rtt_resources),
 };
 
 #if IS_ENABLED(CONFIG_RTC_DRV_AT91SAM9)
 static void __init at91_add_device_rtt_rtc(void)
 {
        at91sam9261_rtt_device.name = "rtc-at91sam9";
+       /*
+        * The second resource is needed:
+        * GPBR will serve as the storage for RTC time offset
+        */
+       at91sam9261_rtt_device.num_resources = 2;
+       rtt_resources[1].start = AT91SAM9261_BASE_GPBR +
+                                4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
+       rtt_resources[1].end = rtt_resources[1].start + 3;
 }
 #else
-static void __init at91_add_device_rtt_rtc(void) {}
+static void __init at91_add_device_rtt_rtc(void)
+{
+       /* Only one resource is needed: RTT not used as RTC */
+       at91sam9261_rtt_device.num_resources = 1;
+}
 #endif
 
 static void __init at91_add_device_rtt(void)
 
                .start  = AT91SAM9263_BASE_RTT0,
                .end    = AT91SAM9263_BASE_RTT0 + SZ_16 - 1,
                .flags  = IORESOURCE_MEM,
+       }, {
+               .flags  = IORESOURCE_MEM,
        }
 };
 
        .name           = "at91_rtt",
        .id             = 0,
        .resource       = rtt0_resources,
-       .num_resources  = ARRAY_SIZE(rtt0_resources),
 };
 
 static struct resource rtt1_resources[] = {
                .start  = AT91SAM9263_BASE_RTT1,
                .end    = AT91SAM9263_BASE_RTT1 + SZ_16 - 1,
                .flags  = IORESOURCE_MEM,
+       }, {
+               .flags  = IORESOURCE_MEM,
        }
 };
 
        .name           = "at91_rtt",
        .id             = 1,
        .resource       = rtt1_resources,
-       .num_resources  = ARRAY_SIZE(rtt1_resources),
 };
 
 #if IS_ENABLED(CONFIG_RTC_DRV_AT91SAM9)
 static void __init at91_add_device_rtt_rtc(void)
 {
        struct platform_device *pdev;
+       struct resource *r;
 
        switch (CONFIG_RTC_DRV_AT91SAM9_RTT) {
        case 0:
+               /*
+                * The second resource is needed only for the chosen RTT:
+                * GPBR will serve as the storage for RTC time offset
+                */
+               at91sam9263_rtt0_device.num_resources = 2;
+               at91sam9263_rtt1_device.num_resources = 1;
                pdev = &at91sam9263_rtt0_device;
+               r = rtt0_resources;
                break;
        case 1:
+               at91sam9263_rtt0_device.num_resources = 1;
+               at91sam9263_rtt1_device.num_resources = 2;
                pdev = &at91sam9263_rtt1_device;
+               r = rtt1_resources;
                break;
        default:
-               pr_err("at91sam9263: support only 2 RTT (%d)\n",
-                        CONFIG_RTC_DRV_AT91SAM9_RTT);
+               pr_err("at91sam9263: only supports 2 RTT (%d)\n",
+                      CONFIG_RTC_DRV_AT91SAM9_RTT);
                return;
        }
 
        pdev->name = "rtc-at91sam9";
+       r[1].start = AT91SAM9263_BASE_GPBR + 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
+       r[1].end = r[1].start + 3;
 }
 #else
-static void __init at91_add_device_rtt_rtc(void) {}
+static void __init at91_add_device_rtt_rtc(void)
+{
+       /* Only one resource is needed: RTT not used as RTC */
+       at91sam9263_rtt0_device.num_resources = 1;
+       at91sam9263_rtt1_device.num_resources = 1;
+}
 #endif
 
 static void __init at91_add_device_rtt(void)
 
                .start  = AT91SAM9G45_BASE_RTT,
                .end    = AT91SAM9G45_BASE_RTT + SZ_16 - 1,
                .flags  = IORESOURCE_MEM,
+       }, {
+               .flags  = IORESOURCE_MEM,
        }
 };
 
        .name           = "at91_rtt",
        .id             = 0,
        .resource       = rtt_resources,
-       .num_resources  = ARRAY_SIZE(rtt_resources),
 };
 
 #if IS_ENABLED(CONFIG_RTC_DRV_AT91SAM9)
 static void __init at91_add_device_rtt_rtc(void)
 {
        at91sam9g45_rtt_device.name = "rtc-at91sam9";
+       /*
+        * The second resource is needed:
+        * GPBR will serve as the storage for RTC time offset
+        */
+       at91sam9g45_rtt_device.num_resources = 2;
+       rtt_resources[1].start = AT91SAM9G45_BASE_GPBR +
+                                4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
+       rtt_resources[1].end = rtt_resources[1].start + 3;
 }
 #else
-static void __init at91_add_device_rtt_rtc(void) {}
+static void __init at91_add_device_rtt_rtc(void)
+{
+       /* Only one resource is needed: RTT not used as RTC */
+       at91sam9g45_rtt_device.num_resources = 1;
+}
 #endif
 
 static void __init at91_add_device_rtt(void)
 
                .start  = AT91SAM9RL_BASE_RTT,
                .end    = AT91SAM9RL_BASE_RTT + SZ_16 - 1,
                .flags  = IORESOURCE_MEM,
+       }, {
+               .flags  = IORESOURCE_MEM,
        }
 };
 
        .name           = "at91_rtt",
        .id             = 0,
        .resource       = rtt_resources,
-       .num_resources  = ARRAY_SIZE(rtt_resources),
 };
 
 #if IS_ENABLED(CONFIG_RTC_DRV_AT91SAM9)
 static void __init at91_add_device_rtt_rtc(void)
 {
        at91sam9rl_rtt_device.name = "rtc-at91sam9";
+       /*
+        * The second resource is needed:
+        * GPBR will serve as the storage for RTC time offset
+        */
+       at91sam9rl_rtt_device.num_resources = 2;
+       rtt_resources[1].start = AT91SAM9RL_BASE_GPBR +
+                                4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
+       rtt_resources[1].end = rtt_resources[1].start + 3;
 }
 #else
-static void __init at91_add_device_rtt_rtc(void) {}
+static void __init at91_add_device_rtt_rtc(void)
+{
+       /* Only one resource is needed: RTT not used as RTC */
+       at91sam9rl_rtt_device.num_resources = 1;
+}
 #endif
 
 static void __init at91_add_device_rtt(void)
 
 #define AT91SAM9260_BASE_ADC           0xfffe0000
 
 /*
- * System Peripherals (offset from AT91_BASE_SYS)
+ * System Peripherals
  */
-#define AT91_GPBR      (0xfffffd50 - AT91_BASE_SYS)
-
 #define AT91SAM9260_BASE_ECC   0xffffe800
 #define AT91SAM9260_BASE_SDRAMC        0xffffea00
 #define AT91SAM9260_BASE_SMC   0xffffec00
 #define AT91SAM9260_BASE_RTT   0xfffffd20
 #define AT91SAM9260_BASE_PIT   0xfffffd30
 #define AT91SAM9260_BASE_WDT   0xfffffd40
+#define AT91SAM9260_BASE_GPBR  0xfffffd50
 
 #define AT91_USART0    AT91SAM9260_BASE_US0
 #define AT91_USART1    AT91SAM9260_BASE_US1
 
 
 
 /*
- * System Peripherals (offset from AT91_BASE_SYS)
+ * System Peripherals
  */
-#define AT91_GPBR      (0xfffffd50 - AT91_BASE_SYS)
-
 #define AT91SAM9261_BASE_SMC   0xffffec00
 #define AT91SAM9261_BASE_MATRIX        0xffffee00
 #define AT91SAM9261_BASE_SDRAMC        0xffffea00
 #define AT91SAM9261_BASE_RTT   0xfffffd20
 #define AT91SAM9261_BASE_PIT   0xfffffd30
 #define AT91SAM9261_BASE_WDT   0xfffffd40
+#define AT91SAM9261_BASE_GPBR  0xfffffd50
 
 #define AT91_USART0    AT91SAM9261_BASE_US0
 #define AT91_USART1    AT91SAM9261_BASE_US1
 
 #define AT91SAM9263_BASE_2DGE          0xfffc8000
 
 /*
- * System Peripherals (offset from AT91_BASE_SYS)
+ * System Peripherals
  */
-#define AT91_GPBR      (0xfffffd60 - AT91_BASE_SYS)
-
 #define AT91SAM9263_BASE_ECC0  0xffffe000
 #define AT91SAM9263_BASE_SDRAMC0 0xffffe200
 #define AT91SAM9263_BASE_SMC0  0xffffe400
 #define AT91SAM9263_BASE_PIT   0xfffffd30
 #define AT91SAM9263_BASE_WDT   0xfffffd40
 #define AT91SAM9263_BASE_RTT1  0xfffffd50
+#define AT91SAM9263_BASE_GPBR  0xfffffd60
 
 #define AT91_USART0    AT91SAM9263_BASE_US0
 #define AT91_USART1    AT91SAM9263_BASE_US1
 
 #define AT91SAM9G45_BASE_TC5           0xfffd4080
 
 /*
- * System Peripherals (offset from AT91_BASE_SYS)
+ * System Peripherals
  */
-#define AT91_GPBR      (0xfffffd60 - AT91_BASE_SYS)
-
 #define AT91SAM9G45_BASE_ECC   0xffffe200
 #define AT91SAM9G45_BASE_DDRSDRC1 0xffffe400
 #define AT91SAM9G45_BASE_DDRSDRC0 0xffffe600
 #define AT91SAM9G45_BASE_PIT   0xfffffd30
 #define AT91SAM9G45_BASE_WDT   0xfffffd40
 #define AT91SAM9G45_BASE_RTC   0xfffffdb0
+#define AT91SAM9G45_BASE_GPBR  0xfffffd60
 
 #define AT91_USART0    AT91SAM9G45_BASE_US0
 #define AT91_USART1    AT91SAM9G45_BASE_US1
 
  * System Peripherals (offset from AT91_BASE_SYS)
  */
 #define AT91_SCKCR     (0xfffffd50 - AT91_BASE_SYS)
-#define AT91_GPBR      (0xfffffd60 - AT91_BASE_SYS)
 
 #define AT91SAM9RL_BASE_DMA    0xffffe600
 #define AT91SAM9RL_BASE_ECC    0xffffe800
 #define AT91SAM9RL_BASE_RTT    0xfffffd20
 #define AT91SAM9RL_BASE_PIT    0xfffffd30
 #define AT91SAM9RL_BASE_WDT    0xfffffd40
+#define AT91SAM9RL_BASE_GPBR   0xfffffd60
 #define AT91SAM9RL_BASE_RTC    0xfffffe00
 
 #define AT91_USART0    AT91SAM9RL_BASE_US0
 
        void __iomem            *rtt;
        struct rtc_device       *rtcdev;
        u32                     imr;
+       void __iomem            *gpbr;
 };
 
 #define rtt_readl(rtc, field) \
        __raw_writel((val), (rtc)->rtt + AT91_RTT_ ## field)
 
 #define gpbr_readl(rtc) \
-       at91_sys_read(AT91_GPBR + 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR)
+       __raw_readl((rtc)->gpbr)
 #define gpbr_writel(rtc, val) \
-       at91_sys_write(AT91_GPBR + 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR, (val))
+       __raw_writel((val), (rtc)->gpbr)
 
 /*
  * Read current time and date in RTC
  */
 static int __devinit at91_rtc_probe(struct platform_device *pdev)
 {
-       struct resource *r;
+       struct resource *r, *r_gpbr;
        struct sam9_rtc *rtc;
        int             ret;
        u32             mr;
 
        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       if (!r)
+       r_gpbr = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       if (!r || !r_gpbr) {
+               dev_err(&pdev->dev, "need 2 ressources\n");
                return -ENODEV;
+       }
 
        rtc = kzalloc(sizeof *rtc, GFP_KERNEL);
        if (!rtc)
                goto fail;
        }
 
+       rtc->gpbr = ioremap(r_gpbr->start, resource_size(r_gpbr));
+       if (!rtc->gpbr) {
+               dev_err(&pdev->dev, "failed to map gpbr registers, aborting.\n");
+               ret = -ENOMEM;
+               goto fail_gpbr;
+       }
+
        mr = rtt_readl(rtc, MR);
 
        /* unless RTT is counting at 1 Hz, re-initialize it */
        if (ret) {
                dev_dbg(&pdev->dev, "can't share IRQ %d?\n", AT91_ID_SYS);
                rtc_device_unregister(rtc->rtcdev);
-               goto fail;
+               goto fail_register;
        }
 
        /* NOTE:  sam9260 rev A silicon has a ROM bug which resets the
        return 0;
 
 fail_register:
+       iounmap(rtc->gpbr);
+fail_gpbr:
        iounmap(rtc->rtt);
 fail:
        platform_set_drvdata(pdev, NULL);
 
        rtc_device_unregister(rtc->rtcdev);
 
+       iounmap(rtc->gpbr);
        iounmap(rtc->rtt);
        platform_set_drvdata(pdev, NULL);
        kfree(rtc);