ast2400: add a memory controller device model

The uboot in the previous release of the SDK was using a hardcoded
value for memory size. This is not true anymore, the value is now
retrieved from the memory controller.

Below is a model for this device, only supporting unlock and
configuration. Without it, we endup running a guest with 64MB, which
is a bit low nowdays. It uses a 'silicon-rev' property and ram_size to
build a default value. Some bits should be linked to SCU strapping
registers but it seems a bit complex to add for the current need.

The model is ready for the AST2500 SOC.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 263 insertions, 0 deletions

diff --git a/hw/misc/aspeed_sdmc.c b/hw/misc/aspeed_sdmc.c
new file mode 100644
index 0000000000..fc4217b3ce
--- /dev/null
+++ b/hw/misc/aspeed_sdmc.c
@@ -0,0 +1,263 @@
+/*
+ * ASPEED SDRAM Memory Controller
+ *
+ * Copyright (C) 2016 IBM Corp.
+ *
+ * This code is licensed under the GPL version 2 or later.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "hw/misc/aspeed_sdmc.h"
+#include "hw/misc/aspeed_scu.h"
+#include "hw/qdev-properties.h"
+#include "qapi/error.h"
+#include "trace.h"
+
+/* Protection Key Register */
+#define R_PROT            (0x00 / 4)
+#define   PROT_KEY_UNLOCK     0xFC600309
+
+/* Configuration Register */
+#define R_CONF            (0x04 / 4)
+
+/*
+ * Configuration register Ox4 (for Aspeed AST2400 SOC)
+ *
+ * These are for the record and future use. ASPEED_SDMC_DRAM_SIZE is
+ * what we care about right now as it is checked by U-Boot to
+ * determine the RAM size.
+ */
+
+#define ASPEED_SDMC_RESERVED            0xFFFFF800 /* 31:11 reserved */
+#define ASPEED_SDMC_AST2300_COMPAT      (1 << 10)
+#define ASPEED_SDMC_SCRAMBLE_PATTERN    (1 << 9)
+#define ASPEED_SDMC_DATA_SCRAMBLE       (1 << 8)
+#define ASPEED_SDMC_ECC_ENABLE          (1 << 7)
+#define ASPEED_SDMC_VGA_COMPAT          (1 << 6) /* readonly */
+#define ASPEED_SDMC_DRAM_BANK           (1 << 5)
+#define ASPEED_SDMC_DRAM_BURST          (1 << 4)
+#define ASPEED_SDMC_VGA_APERTURE(x)     ((x & 0x3) << 2) /* readonly */
+#define     ASPEED_SDMC_VGA_8MB             0x0
+#define     ASPEED_SDMC_VGA_16MB            0x1
+#define     ASPEED_SDMC_VGA_32MB            0x2
+#define     ASPEED_SDMC_VGA_64MB            0x3
+#define ASPEED_SDMC_DRAM_SIZE(x)        (x & 0x3)
+#define     ASPEED_SDMC_DRAM_64MB           0x0
+#define     ASPEED_SDMC_DRAM_128MB          0x1
+#define     ASPEED_SDMC_DRAM_256MB          0x2
+#define     ASPEED_SDMC_DRAM_512MB          0x3
+
+#define ASPEED_SDMC_READONLY_MASK                       \
+    (ASPEED_SDMC_RESERVED | ASPEED_SDMC_VGA_COMPAT |    \
+     ASPEED_SDMC_VGA_APERTURE(ASPEED_SDMC_VGA_64MB))
+/*
+ * Configuration register Ox4 (for Aspeed AST2500 SOC and higher)
+ *
+ * Incompatibilities are annotated in the list. ASPEED_SDMC_HW_VERSION
+ * should be set to 1 for the AST2500 SOC.
+ */
+#define ASPEED_SDMC_HW_VERSION(x)       ((x & 0xf) << 28) /* readonly */
+#define ASPEED_SDMC_SW_VERSION          ((x & 0xff) << 20)
+#define ASPEED_SDMC_CACHE_INITIAL_DONE  (1 << 19)  /* readonly */
+#define ASPEED_SDMC_AST2500_RESERVED    0x7C000 /* 18:14 reserved */
+#define ASPEED_SDMC_CACHE_DDR4_CONF     (1 << 13)
+#define ASPEED_SDMC_CACHE_INITIAL       (1 << 12)
+#define ASPEED_SDMC_CACHE_RANGE_CTRL    (1 << 11)
+#define ASPEED_SDMC_CACHE_ENABLE        (1 << 10) /* differs from AST2400 */
+#define ASPEED_SDMC_DRAM_TYPE           (1 << 4)  /* differs from AST2400 */
+
+/* DRAM size definitions differs */
+#define     ASPEED_SDMC_AST2500_128MB       0x0
+#define     ASPEED_SDMC_AST2500_256MB       0x1
+#define     ASPEED_SDMC_AST2500_512MB       0x2
+#define     ASPEED_SDMC_AST2500_1024MB      0x3
+
+#define ASPEED_SDMC_AST2500_READONLY_MASK                               \
+    (ASPEED_SDMC_HW_VERSION(0xf) | ASPEED_SDMC_CACHE_INITIAL_DONE |     \
+     ASPEED_SDMC_AST2500_RESERVED | ASPEED_SDMC_VGA_COMPAT |            \
+     ASPEED_SDMC_VGA_APERTURE(ASPEED_SDMC_VGA_64MB))
+
+static uint64_t aspeed_sdmc_read(void *opaque, hwaddr addr, unsigned size)
+{
+    AspeedSDMCState *s = ASPEED_SDMC(opaque);
+
+    addr >>= 2;
+
+    if (addr >= ARRAY_SIZE(s->regs)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out-of-bounds read at offset 0x%" HWADDR_PRIx "\n",
+                      __func__, addr);
+        return 0;
+    }
+
+    return s->regs[addr];
+}
+
+static void aspeed_sdmc_write(void *opaque, hwaddr addr, uint64_t data,
+                             unsigned int size)
+{
+    AspeedSDMCState *s = ASPEED_SDMC(opaque);
+
+    addr >>= 2;
+
+    if (addr >= ARRAY_SIZE(s->regs)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out-of-bounds write at offset 0x%" HWADDR_PRIx "\n",
+                      __func__, addr);
+        return;
+    }
+
+    if (addr != R_PROT && s->regs[R_PROT] != PROT_KEY_UNLOCK) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: SDMC is locked!\n", __func__);
+        return;
+    }
+
+    if (addr == R_CONF) {
+        /* Make sure readonly bits are kept */
+        switch (s->silicon_rev) {
+        case AST2400_A0_SILICON_REV:
+            data &= ~ASPEED_SDMC_READONLY_MASK;
+            break;
+        case AST2500_A0_SILICON_REV:
+            data &= ~ASPEED_SDMC_AST2500_READONLY_MASK;
+            break;
+        default:
+            g_assert_not_reached();
+        }
+    }
+
+    s->regs[addr] = data;
+}
+
+static const MemoryRegionOps aspeed_sdmc_ops = {
+    .read = aspeed_sdmc_read,
+    .write = aspeed_sdmc_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+};
+
+static int ast2400_rambits(void)
+{
+    switch (ram_size >> 20) {
+    case 64:
+        return ASPEED_SDMC_DRAM_64MB;
+    case 128:
+        return ASPEED_SDMC_DRAM_128MB;
+    case 256:
+        return ASPEED_SDMC_DRAM_256MB;
+    case 512:
+        return ASPEED_SDMC_DRAM_512MB;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid RAM size: 0x"
+                      RAM_ADDR_FMT "\n", __func__, ram_size);
+        break;
+    }
+
+    /* set a minimum default */
+    return ASPEED_SDMC_DRAM_64MB;
+}
+
+static int ast2500_rambits(void)
+{
+    switch (ram_size >> 20) {
+    case 128:
+        return ASPEED_SDMC_AST2500_128MB;
+    case 256:
+        return ASPEED_SDMC_AST2500_256MB;
+    case 512:
+        return ASPEED_SDMC_AST2500_512MB;
+    case 1024:
+        return ASPEED_SDMC_AST2500_1024MB;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid RAM size: 0x"
+                      RAM_ADDR_FMT "\n", __func__, ram_size);
+        break;
+    }
+
+    /* set a minimum default */
+    return ASPEED_SDMC_AST2500_128MB;
+}
+
+static void aspeed_sdmc_reset(DeviceState *dev)
+{
+    AspeedSDMCState *s = ASPEED_SDMC(dev);
+
+    memset(s->regs, 0, sizeof(s->regs));
+
+    /* Set ram size bit and defaults values */
+    switch (s->silicon_rev) {
+    case AST2400_A0_SILICON_REV:
+        s->regs[R_CONF] |=
+            ASPEED_SDMC_VGA_COMPAT |
+            ASPEED_SDMC_DRAM_SIZE(ast2400_rambits());
+        break;
+
+    case AST2500_A0_SILICON_REV:
+        s->regs[R_CONF] |=
+            ASPEED_SDMC_HW_VERSION(1) |
+            ASPEED_SDMC_VGA_APERTURE(ASPEED_SDMC_VGA_64MB) |
+            ASPEED_SDMC_DRAM_SIZE(ast2500_rambits());
+        break;
+
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static void aspeed_sdmc_realize(DeviceState *dev, Error **errp)
+{
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+    AspeedSDMCState *s = ASPEED_SDMC(dev);
+
+    if (!is_supported_silicon_rev(s->silicon_rev)) {
+        error_setg(errp, "Unknown silicon revision: 0x%" PRIx32,
+                s->silicon_rev);
+        return;
+    }
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_sdmc_ops, s,
+                          TYPE_ASPEED_SDMC, 0x1000);
+    sysbus_init_mmio(sbd, &s->iomem);
+}
+
+static const VMStateDescription vmstate_aspeed_sdmc = {
+    .name = "aspeed.sdmc",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, AspeedSDMCState, ASPEED_SDMC_NR_REGS),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static Property aspeed_sdmc_properties[] = {
+    DEFINE_PROP_UINT32("silicon-rev", AspeedSDMCState, silicon_rev, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void aspeed_sdmc_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    dc->realize = aspeed_sdmc_realize;
+    dc->reset = aspeed_sdmc_reset;
+    dc->desc = "ASPEED SDRAM Memory Controller";
+    dc->vmsd = &vmstate_aspeed_sdmc;
+    dc->props = aspeed_sdmc_properties;
+}
+
+static const TypeInfo aspeed_sdmc_info = {
+    .name = TYPE_ASPEED_SDMC,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(AspeedSDMCState),
+    .class_init = aspeed_sdmc_class_init,
+};
+
+static void aspeed_sdmc_register_types(void)
+{
+    type_register_static(&aspeed_sdmc_info);
+}
+
+type_init(aspeed_sdmc_register_types);