hw/arm/allwinner: add RTC device support

Allwinner System-on-Chips usually contain a Real Time Clock (RTC)
for non-volatile system date and time keeping. This commit adds a generic
Allwinner RTC device that supports the RTC devices found in Allwinner SoC
family sun4i (A10), sun7i (A20) and sun6i and newer (A31, H2+, H3, etc).
The following RTC functionality and features are implemented:

 * Year-Month-Day read/write
 * Hour-Minute-Second read/write
 * General Purpose storage

The following boards are extended with the RTC device:

 * Cubieboard (hw/arm/cubieboard.c)
 * Orange Pi PC (hw/arm/orangepi.c)

Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200311221854.30370-13-nieklinnenbank@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 139 insertions, 0 deletions

diff --git a/include/hw/arm/allwinner-a10.h b/include/hw/arm/allwinner-a10.h
index ae33a84b18..77c82a9982 100644
--- a/include/hw/arm/allwinner-a10.h
+++ b/include/hw/arm/allwinner-a10.h
@@ -11,6 +11,7 @@
 #include "hw/ide/ahci.h"
 #include "hw/usb/hcd-ohci.h"
 #include "hw/usb/hcd-ehci.h"
+#include "hw/rtc/allwinner-rtc.h"
 
 #include "target/arm/cpu.h"
 
@@ -33,6 +34,7 @@ typedef struct AwA10State {
     AwEmacState emac;
     AllwinnerAHCIState sata;
     AwSdHostState mmc0;
+    AwRtcState rtc;
     MemoryRegion sram_a;
     EHCISysBusState ehci[AW_A10_NUM_USB];
     OHCISysBusState ohci[AW_A10_NUM_USB];
diff --git a/include/hw/arm/allwinner-h3.h b/include/hw/arm/allwinner-h3.h
index 065d020c73..82e4e59216 100644
--- a/include/hw/arm/allwinner-h3.h
+++ b/include/hw/arm/allwinner-h3.h
@@ -46,6 +46,7 @@
 #include "hw/misc/allwinner-sid.h"
 #include "hw/sd/allwinner-sdhost.h"
 #include "hw/net/allwinner-sun8i-emac.h"
+#include "hw/rtc/allwinner-rtc.h"
 #include "target/arm/cpu.h"
 #include "sysemu/block-backend.h"
 
@@ -88,6 +89,7 @@ enum {
     AW_H3_GIC_CPU,
     AW_H3_GIC_HYP,
     AW_H3_GIC_VCPU,
+    AW_H3_RTC,
     AW_H3_CPUCFG,
     AW_H3_SDRAM
 };
@@ -129,6 +131,7 @@ typedef struct AwH3State {
     AwSidState sid;
     AwSdHostState mmc0;
     AwSun8iEmacState emac;
+    AwRtcState rtc;
     GICState gic;
     MemoryRegion sram_a1;
     MemoryRegion sram_a2;
diff --git a/include/hw/rtc/allwinner-rtc.h b/include/hw/rtc/allwinner-rtc.h
new file mode 100644
index 0000000000..7893f74795
--- /dev/null
+++ b/include/hw/rtc/allwinner-rtc.h
@@ -0,0 +1,134 @@
+/*
+ * Allwinner Real Time Clock emulation
+ *
+ * Copyright (C) 2019 Niek Linnenbank <nieklinnenbank@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef HW_MISC_ALLWINNER_RTC_H
+#define HW_MISC_ALLWINNER_RTC_H
+
+#include "qom/object.h"
+#include "hw/sysbus.h"
+
+/**
+ * Constants
+ * @{
+ */
+
+/** Highest register address used by RTC device */
+#define AW_RTC_REGS_MAXADDR     (0x200)
+
+/** Total number of known registers */
+#define AW_RTC_REGS_NUM         (AW_RTC_REGS_MAXADDR / sizeof(uint32_t))
+
+/** @} */
+
+/**
+ * Object model types
+ * @{
+ */
+
+/** Generic Allwinner RTC device (abstract) */
+#define TYPE_AW_RTC          "allwinner-rtc"
+
+/** Allwinner RTC sun4i family (A10, A12) */
+#define TYPE_AW_RTC_SUN4I    TYPE_AW_RTC "-sun4i"
+
+/** Allwinner RTC sun6i family and newer (A31, H2+, H3, etc) */
+#define TYPE_AW_RTC_SUN6I    TYPE_AW_RTC "-sun6i"
+
+/** Allwinner RTC sun7i family (A20) */
+#define TYPE_AW_RTC_SUN7I    TYPE_AW_RTC "-sun7i"
+
+/** @} */
+
+/**
+ * Object model macros
+ * @{
+ */
+
+#define AW_RTC(obj) \
+    OBJECT_CHECK(AwRtcState, (obj), TYPE_AW_RTC)
+#define AW_RTC_CLASS(klass) \
+     OBJECT_CLASS_CHECK(AwRtcClass, (klass), TYPE_AW_RTC)
+#define AW_RTC_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(AwRtcClass, (obj), TYPE_AW_RTC)
+
+/** @} */
+
+/**
+ * Allwinner RTC per-object instance state.
+ */
+typedef struct AwRtcState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+    /*< public >*/
+
+    /**
+     * Actual year represented by the device when year counter is zero
+     *
+     * Can be overridden by the user using the corresponding 'base-year'
+     * property. The base year used by the target OS driver can vary, for
+     * example the Linux driver for sun6i uses 1970 while NetBSD uses 2000.
+     */
+    int base_year;
+
+    /** Maps I/O registers in physical memory */
+    MemoryRegion iomem;
+
+    /** Array of hardware registers */
+    uint32_t regs[AW_RTC_REGS_NUM];
+
+} AwRtcState;
+
+/**
+ * Allwinner RTC class-level struct.
+ *
+ * This struct is filled by each sunxi device specific code
+ * such that the generic code can use this struct to support
+ * all devices.
+ */
+typedef struct AwRtcClass {
+    /*< private >*/
+    SysBusDeviceClass parent_class;
+    /*< public >*/
+
+    /** Defines device specific register map */
+    const uint8_t *regmap;
+
+    /** Size of the regmap in bytes */
+    size_t regmap_size;
+
+    /**
+     * Read device specific register
+     *
+     * @offset: register offset to read
+     * @return true if register read successful, false otherwise
+     */
+    bool (*read)(AwRtcState *s, uint32_t offset);
+
+    /**
+     * Write device specific register
+     *
+     * @offset: register offset to write
+     * @data: value to set in register
+     * @return true if register write successful, false otherwise
+     */
+    bool (*write)(AwRtcState *s, uint32_t offset, uint32_t data);
+
+} AwRtcClass;
+
+#endif /* HW_MISC_ALLWINNER_RTC_H */