[PULL 48/62] ppc440_uc.c: Move DDR2 SDRAM controller model to ppc4xx_sdram.c

[Daniel Henrique Barboza <danielhb413@gmail.com>]

From: BALATON Zoltan <balaton@eik.bme.hu>

In order to move PPC4xx SDRAM controller models together move out the
DDR2 controller model from ppc440_uc.c into a new ppc4xx_sdram.c file.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <2f2900f93e997480e54b7bf9c32bb482a0fb1022.1666194485.git.balaton@eik.bme.hu>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/ppc/meson.build    |   3 +-
 hw/ppc/ppc440_uc.c    | 332 ----------------------------------------
 hw/ppc/ppc4xx_sdram.c | 348 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 350 insertions(+), 333 deletions(-)
 create mode 100644 hw/ppc/ppc4xx_sdram.c

diff --git a/hw/ppc/meson.build b/hw/ppc/meson.build
index 32babc9b48..c927337da0 100644
--- a/hw/ppc/meson.build
+++ b/hw/ppc/meson.build
@@ -59,8 +59,9 @@ ppc_ss.add(when: 'CONFIG_PPC440', if_true: files(
   'ppc440_bamboo.c',
   'ppc440_pcix.c', 'ppc440_uc.c'))
 ppc_ss.add(when: 'CONFIG_PPC4XX', if_true: files(
+  'ppc4xx_devs.c',
   'ppc4xx_pci.c',
-  'ppc4xx_devs.c'))
+  'ppc4xx_sdram.c'))
 ppc_ss.add(when: 'CONFIG_SAM460EX', if_true: files('sam460ex.c'))
 # PReP
 ppc_ss.add(when: 'CONFIG_PREP', if_true: files('prep.c'))
diff --git a/hw/ppc/ppc440_uc.c b/hw/ppc/ppc440_uc.c
index 5fbf44009e..651263926e 100644
--- a/hw/ppc/ppc440_uc.c
+++ b/hw/ppc/ppc440_uc.c
@@ -10,21 +10,14 @@
 
 #include "qemu/osdep.h"
 #include "qemu/units.h"
-#include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "qemu/log.h"
-#include "qemu/module.h"
 #include "hw/irq.h"
-#include "exec/memory.h"
-#include "cpu.h"
 #include "hw/ppc/ppc4xx.h"
 #include "hw/qdev-properties.h"
 #include "hw/pci/pci.h"
-#include "sysemu/block-backend.h"
 #include "sysemu/reset.h"
 #include "ppc440.h"
-#include "qom/object.h"
-#include "trace.h"
 
 /*****************************************************************************/
 /* L2 Cache as SRAM */
@@ -478,331 +471,6 @@ void ppc4xx_sdr_init(CPUPPCState *env)
                      sdr, &dcr_read_sdr, &dcr_write_sdr);
 }
 
-/*****************************************************************************/
-/* SDRAM controller */
-enum {
-    SDRAM0_CFGADDR = 0x10,
-    SDRAM0_CFGDATA,
-    SDRAM_R0BAS = 0x40,
-    SDRAM_R1BAS,
-    SDRAM_R2BAS,
-    SDRAM_R3BAS,
-    SDRAM_CONF1HB = 0x45,
-    SDRAM_PLBADDULL = 0x4a,
-    SDRAM_CONF1LL = 0x4b,
-    SDRAM_CONFPATHB = 0x4f,
-    SDRAM_PLBADDUHB = 0x50,
-};
-
-static uint32_t sdram_ddr2_bcr(hwaddr ram_base, hwaddr ram_size)
-{
-    uint32_t bcr;
-
-    switch (ram_size) {
-    case 8 * MiB:
-        bcr = 0xffc0;
-        break;
-    case 16 * MiB:
-        bcr = 0xff80;
-        break;
-    case 32 * MiB:
-        bcr = 0xff00;
-        break;
-    case 64 * MiB:
-        bcr = 0xfe00;
-        break;
-    case 128 * MiB:
-        bcr = 0xfc00;
-        break;
-    case 256 * MiB:
-        bcr = 0xf800;
-        break;
-    case 512 * MiB:
-        bcr = 0xf000;
-        break;
-    case 1 * GiB:
-        bcr = 0xe000;
-        break;
-    case 2 * GiB:
-        bcr = 0xc000;
-        break;
-    case 4 * GiB:
-        bcr = 0x8000;
-        break;
-    default:
-        error_report("invalid RAM size " TARGET_FMT_plx, ram_size);
-        return 0;
-    }
-    bcr |= ram_base >> 2 & 0xffe00000;
-    bcr |= 1;
-
-    return bcr;
-}
-
-static inline hwaddr sdram_ddr2_base(uint32_t bcr)
-{
-    return (bcr & 0xffe00000) << 2;
-}
-
-static uint64_t sdram_ddr2_size(uint32_t bcr)
-{
-    uint64_t size;
-    int sh;
-
-    sh = 1024 - ((bcr >> 6) & 0x3ff);
-    size = 8 * MiB * sh;
-
-    return size;
-}
-
-static void sdram_bank_map(Ppc4xxSdramBank *bank)
-{
-    memory_region_init(&bank->container, NULL, "sdram-container", bank->size);
-    memory_region_add_subregion(&bank->container, 0, &bank->ram);
-    memory_region_add_subregion(get_system_memory(), bank->base,
-                                &bank->container);
-}
-
-static void sdram_bank_unmap(Ppc4xxSdramBank *bank)
-{
-    memory_region_del_subregion(get_system_memory(), &bank->container);
-    memory_region_del_subregion(&bank->container, &bank->ram);
-    object_unparent(OBJECT(&bank->container));
-}
-
-static void sdram_ddr2_set_bcr(Ppc4xxSdramDdr2State *sdram, int i,
-                               uint32_t bcr, int enabled)
-{
-    if (sdram->bank[i].bcr & 1) {
-        /* First unmap RAM if enabled */
-        trace_ppc4xx_sdram_unmap(sdram_ddr2_base(sdram->bank[i].bcr),
-                                 sdram_ddr2_size(sdram->bank[i].bcr));
-        sdram_bank_unmap(&sdram->bank[i]);
-    }
-    sdram->bank[i].bcr = bcr & 0xffe0ffc1;
-    if (enabled && (bcr & 1)) {
-        trace_ppc4xx_sdram_map(sdram_ddr2_base(bcr), sdram_ddr2_size(bcr));
-        sdram_bank_map(&sdram->bank[i]);
-    }
-}
-
-static void sdram_ddr2_map_bcr(Ppc4xxSdramDdr2State *sdram)
-{
-    int i;
-
-    for (i = 0; i < sdram->nbanks; i++) {
-        if (sdram->bank[i].size) {
-            sdram_ddr2_set_bcr(sdram, i,
-                               sdram_ddr2_bcr(sdram->bank[i].base,
-                                              sdram->bank[i].size), 1);
-        } else {
-            sdram_ddr2_set_bcr(sdram, i, 0, 0);
-        }
-    }
-}
-
-static void sdram_ddr2_unmap_bcr(Ppc4xxSdramDdr2State *sdram)
-{
-    int i;
-
-    for (i = 0; i < sdram->nbanks; i++) {
-        if (sdram->bank[i].size) {
-            sdram_ddr2_set_bcr(sdram, i, sdram->bank[i].bcr & ~1, 0);
-        }
-    }
-}
-
-static uint32_t sdram_ddr2_dcr_read(void *opaque, int dcrn)
-{
-    Ppc4xxSdramDdr2State *sdram = opaque;
-    uint32_t ret = 0;
-
-    switch (dcrn) {
-    case SDRAM_R0BAS:
-    case SDRAM_R1BAS:
-    case SDRAM_R2BAS:
-    case SDRAM_R3BAS:
-        if (sdram->bank[dcrn - SDRAM_R0BAS].size) {
-            ret = sdram_ddr2_bcr(sdram->bank[dcrn - SDRAM_R0BAS].base,
-                                 sdram->bank[dcrn - SDRAM_R0BAS].size);
-        }
-        break;
-    case SDRAM_CONF1HB:
-    case SDRAM_CONF1LL:
-    case SDRAM_CONFPATHB:
-    case SDRAM_PLBADDULL:
-    case SDRAM_PLBADDUHB:
-        break;
-    case SDRAM0_CFGADDR:
-        ret = sdram->addr;
-        break;
-    case SDRAM0_CFGDATA:
-        switch (sdram->addr) {
-        case 0x14: /* SDRAM_MCSTAT (405EX) */
-        case 0x1F:
-            ret = 0x80000000;
-            break;
-        case 0x21: /* SDRAM_MCOPT2 */
-            ret = sdram->mcopt2;
-            break;
-        case 0x40: /* SDRAM_MB0CF */
-            ret = 0x00008001;
-            break;
-        case 0x7A: /* SDRAM_DLCR */
-            ret = 0x02000000;
-            break;
-        case 0xE1: /* SDR0_DDR0 */
-            ret = SDR0_DDR0_DDRM_ENCODE(1) | SDR0_DDR0_DDRM_DDR1;
-            break;
-        default:
-            break;
-        }
-        break;
-    default:
-        break;
-    }
-
-    return ret;
-}
-
-#define SDRAM_DDR2_MCOPT2_DCEN BIT(27)
-
-static void sdram_ddr2_dcr_write(void *opaque, int dcrn, uint32_t val)
-{
-    Ppc4xxSdramDdr2State *sdram = opaque;
-
-    switch (dcrn) {
-    case SDRAM_R0BAS:
-    case SDRAM_R1BAS:
-    case SDRAM_R2BAS:
-    case SDRAM_R3BAS:
-    case SDRAM_CONF1HB:
-    case SDRAM_CONF1LL:
-    case SDRAM_CONFPATHB:
-    case SDRAM_PLBADDULL:
-    case SDRAM_PLBADDUHB:
-        break;
-    case SDRAM0_CFGADDR:
-        sdram->addr = val;
-        break;
-    case SDRAM0_CFGDATA:
-        switch (sdram->addr) {
-        case 0x00: /* B0CR */
-            break;
-        case 0x21: /* SDRAM_MCOPT2 */
-            if (!(sdram->mcopt2 & SDRAM_DDR2_MCOPT2_DCEN) &&
-                (val & SDRAM_DDR2_MCOPT2_DCEN)) {
-                trace_ppc4xx_sdram_enable("enable");
-                /* validate all RAM mappings */
-                sdram_ddr2_map_bcr(sdram);
-                sdram->mcopt2 |= SDRAM_DDR2_MCOPT2_DCEN;
-            } else if ((sdram->mcopt2 & SDRAM_DDR2_MCOPT2_DCEN) &&
-                       !(val & SDRAM_DDR2_MCOPT2_DCEN)) {
-                trace_ppc4xx_sdram_enable("disable");
-                /* invalidate all RAM mappings */
-                sdram_ddr2_unmap_bcr(sdram);
-                sdram->mcopt2 &= ~SDRAM_DDR2_MCOPT2_DCEN;
-            }
-            break;
-        default:
-            break;
-        }
-        break;
-    default:
-        break;
-    }
-}
-
-static void ppc4xx_sdram_ddr2_reset(DeviceState *dev)
-{
-    Ppc4xxSdramDdr2State *sdram = PPC4xx_SDRAM_DDR2(dev);
-
-    sdram->addr = 0;
-    sdram->mcopt2 = 0;
-}
-
-static void ppc4xx_sdram_ddr2_realize(DeviceState *dev, Error **errp)
-{
-    Ppc4xxSdramDdr2State *s = PPC4xx_SDRAM_DDR2(dev);
-    Ppc4xxDcrDeviceState *dcr = PPC4xx_DCR_DEVICE(dev);
-    /*
-     * SoC also has 4 GiB but that causes problem with 32 bit
-     * builds (4*GiB overflows the 32 bit ram_addr_t).
-     */
-    const ram_addr_t valid_bank_sizes[] = {
-        2 * GiB, 1 * GiB, 512 * MiB, 256 * MiB, 128 * MiB,
-        64 * MiB, 32 * MiB, 16 * MiB, 8 * MiB, 0
-    };
-
-    if (s->nbanks < 1 || s->nbanks > 4) {
-        error_setg(errp, "Invalid number of RAM banks");
-        return;
-    }
-    if (!s->dram_mr) {
-        error_setg(errp, "Missing dram memory region");
-        return;
-    }
-    ppc4xx_sdram_banks(s->dram_mr, s->nbanks, s->bank, valid_bank_sizes);
-
-    ppc4xx_dcr_register(dcr, SDRAM0_CFGADDR,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM0_CFGDATA,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-
-    ppc4xx_dcr_register(dcr, SDRAM_R0BAS,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_R1BAS,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_R2BAS,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_R3BAS,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_CONF1HB,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_PLBADDULL,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_CONF1LL,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_CONFPATHB,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-    ppc4xx_dcr_register(dcr, SDRAM_PLBADDUHB,
-                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
-}
-
-static Property ppc4xx_sdram_ddr2_props[] = {
-    DEFINE_PROP_LINK("dram", Ppc4xxSdramDdr2State, dram_mr, TYPE_MEMORY_REGION,
-                     MemoryRegion *),
-    DEFINE_PROP_UINT32("nbanks", Ppc4xxSdramDdr2State, nbanks, 4),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
-static void ppc4xx_sdram_ddr2_class_init(ObjectClass *oc, void *data)
-{
-    DeviceClass *dc = DEVICE_CLASS(oc);
-
-    dc->realize = ppc4xx_sdram_ddr2_realize;
-    dc->reset = ppc4xx_sdram_ddr2_reset;
-    /* Reason: only works as function of a ppc4xx SoC */
-    dc->user_creatable = false;
-    device_class_set_props(dc, ppc4xx_sdram_ddr2_props);
-}
-
-void ppc4xx_sdram_ddr2_enable(Ppc4xxSdramDdr2State *s)
-{
-    sdram_ddr2_dcr_write(s, SDRAM0_CFGADDR, 0x21);
-    sdram_ddr2_dcr_write(s, SDRAM0_CFGDATA, 0x08000000);
-}
-
-static const TypeInfo ppc4xx_types[] = {
-    {
-        .name           = TYPE_PPC4xx_SDRAM_DDR2,
-        .parent         = TYPE_PPC4xx_DCR_DEVICE,
-        .instance_size  = sizeof(Ppc4xxSdramDdr2State),
-        .class_init     = ppc4xx_sdram_ddr2_class_init,
-    }
-};
-DEFINE_TYPES(ppc4xx_types)
-
 /*****************************************************************************/
 /* PLB to AHB bridge */
 enum {
diff --git a/hw/ppc/ppc4xx_sdram.c b/hw/ppc/ppc4xx_sdram.c
new file mode 100644
index 0000000000..b49a7ed60a
--- /dev/null
+++ b/hw/ppc/ppc4xx_sdram.c
@@ -0,0 +1,348 @@
+/*
+ * DDR2 SDRAM controller:
+ * Copyright (c) 2012 François Revol
+ * Copyright (c) 2016-2019 BALATON Zoltan
+ *
+ * This work is licensed under the GNU GPL license version 2 or later.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "qapi/error.h"
+#include "exec/address-spaces.h" /* get_system_memory() */
+#include "hw/irq.h"
+#include "hw/qdev-properties.h"
+#include "hw/ppc/ppc4xx.h"
+#include "trace.h"
+
+/*****************************************************************************/
+/* Shared functions */
+
+static void sdram_bank_map(Ppc4xxSdramBank *bank)
+{
+    memory_region_init(&bank->container, NULL, "sdram-container", bank->size);
+    memory_region_add_subregion(&bank->container, 0, &bank->ram);
+    memory_region_add_subregion(get_system_memory(), bank->base,
+                                &bank->container);
+}
+
+static void sdram_bank_unmap(Ppc4xxSdramBank *bank)
+{
+    memory_region_del_subregion(get_system_memory(), &bank->container);
+    memory_region_del_subregion(&bank->container, &bank->ram);
+    object_unparent(OBJECT(&bank->container));
+}
+
+enum {
+    SDRAM0_CFGADDR = 0x010,
+    SDRAM0_CFGDATA = 0x011,
+};
+
+/*****************************************************************************/
+/* DDR2 SDRAM controller */
+enum {
+    SDRAM_R0BAS = 0x40,
+    SDRAM_R1BAS,
+    SDRAM_R2BAS,
+    SDRAM_R3BAS,
+    SDRAM_CONF1HB = 0x45,
+    SDRAM_PLBADDULL = 0x4a,
+    SDRAM_CONF1LL = 0x4b,
+    SDRAM_CONFPATHB = 0x4f,
+    SDRAM_PLBADDUHB = 0x50,
+};
+
+static uint32_t sdram_ddr2_bcr(hwaddr ram_base, hwaddr ram_size)
+{
+    uint32_t bcr;
+
+    switch (ram_size) {
+    case 8 * MiB:
+        bcr = 0xffc0;
+        break;
+    case 16 * MiB:
+        bcr = 0xff80;
+        break;
+    case 32 * MiB:
+        bcr = 0xff00;
+        break;
+    case 64 * MiB:
+        bcr = 0xfe00;
+        break;
+    case 128 * MiB:
+        bcr = 0xfc00;
+        break;
+    case 256 * MiB:
+        bcr = 0xf800;
+        break;
+    case 512 * MiB:
+        bcr = 0xf000;
+        break;
+    case 1 * GiB:
+        bcr = 0xe000;
+        break;
+    case 2 * GiB:
+        bcr = 0xc000;
+        break;
+    case 4 * GiB:
+        bcr = 0x8000;
+        break;
+    default:
+        error_report("invalid RAM size " TARGET_FMT_plx, ram_size);
+        return 0;
+    }
+    bcr |= ram_base >> 2 & 0xffe00000;
+    bcr |= 1;
+
+    return bcr;
+}
+
+static inline hwaddr sdram_ddr2_base(uint32_t bcr)
+{
+    return (bcr & 0xffe00000) << 2;
+}
+
+static uint64_t sdram_ddr2_size(uint32_t bcr)
+{
+    uint64_t size;
+    int sh;
+
+    sh = 1024 - ((bcr >> 6) & 0x3ff);
+    size = 8 * MiB * sh;
+
+    return size;
+}
+
+static void sdram_ddr2_set_bcr(Ppc4xxSdramDdr2State *sdram, int i,
+                               uint32_t bcr, int enabled)
+{
+    if (sdram->bank[i].bcr & 1) {
+        /* First unmap RAM if enabled */
+        trace_ppc4xx_sdram_unmap(sdram_ddr2_base(sdram->bank[i].bcr),
+                                 sdram_ddr2_size(sdram->bank[i].bcr));
+        sdram_bank_unmap(&sdram->bank[i]);
+    }
+    sdram->bank[i].bcr = bcr & 0xffe0ffc1;
+    if (enabled && (bcr & 1)) {
+        trace_ppc4xx_sdram_map(sdram_ddr2_base(bcr), sdram_ddr2_size(bcr));
+        sdram_bank_map(&sdram->bank[i]);
+    }
+}
+
+static void sdram_ddr2_map_bcr(Ppc4xxSdramDdr2State *sdram)
+{
+    int i;
+
+    for (i = 0; i < sdram->nbanks; i++) {
+        if (sdram->bank[i].size) {
+            sdram_ddr2_set_bcr(sdram, i,
+                               sdram_ddr2_bcr(sdram->bank[i].base,
+                                              sdram->bank[i].size), 1);
+        } else {
+            sdram_ddr2_set_bcr(sdram, i, 0, 0);
+        }
+    }
+}
+
+static void sdram_ddr2_unmap_bcr(Ppc4xxSdramDdr2State *sdram)
+{
+    int i;
+
+    for (i = 0; i < sdram->nbanks; i++) {
+        if (sdram->bank[i].size) {
+            sdram_ddr2_set_bcr(sdram, i, sdram->bank[i].bcr & ~1, 0);
+        }
+    }
+}
+
+static uint32_t sdram_ddr2_dcr_read(void *opaque, int dcrn)
+{
+    Ppc4xxSdramDdr2State *sdram = opaque;
+    uint32_t ret = 0;
+
+    switch (dcrn) {
+    case SDRAM_R0BAS:
+    case SDRAM_R1BAS:
+    case SDRAM_R2BAS:
+    case SDRAM_R3BAS:
+        if (sdram->bank[dcrn - SDRAM_R0BAS].size) {
+            ret = sdram_ddr2_bcr(sdram->bank[dcrn - SDRAM_R0BAS].base,
+                                 sdram->bank[dcrn - SDRAM_R0BAS].size);
+        }
+        break;
+    case SDRAM_CONF1HB:
+    case SDRAM_CONF1LL:
+    case SDRAM_CONFPATHB:
+    case SDRAM_PLBADDULL:
+    case SDRAM_PLBADDUHB:
+        break;
+    case SDRAM0_CFGADDR:
+        ret = sdram->addr;
+        break;
+    case SDRAM0_CFGDATA:
+        switch (sdram->addr) {
+        case 0x14: /* SDRAM_MCSTAT (405EX) */
+        case 0x1F:
+            ret = 0x80000000;
+            break;
+        case 0x21: /* SDRAM_MCOPT2 */
+            ret = sdram->mcopt2;
+            break;
+        case 0x40: /* SDRAM_MB0CF */
+            ret = 0x00008001;
+            break;
+        case 0x7A: /* SDRAM_DLCR */
+            ret = 0x02000000;
+            break;
+        case 0xE1: /* SDR0_DDR0 */
+            ret = SDR0_DDR0_DDRM_ENCODE(1) | SDR0_DDR0_DDRM_DDR1;
+            break;
+        default:
+            break;
+        }
+        break;
+    default:
+        break;
+    }
+
+    return ret;
+}
+
+#define SDRAM_DDR2_MCOPT2_DCEN BIT(27)
+
+static void sdram_ddr2_dcr_write(void *opaque, int dcrn, uint32_t val)
+{
+    Ppc4xxSdramDdr2State *sdram = opaque;
+
+    switch (dcrn) {
+    case SDRAM_R0BAS:
+    case SDRAM_R1BAS:
+    case SDRAM_R2BAS:
+    case SDRAM_R3BAS:
+    case SDRAM_CONF1HB:
+    case SDRAM_CONF1LL:
+    case SDRAM_CONFPATHB:
+    case SDRAM_PLBADDULL:
+    case SDRAM_PLBADDUHB:
+        break;
+    case SDRAM0_CFGADDR:
+        sdram->addr = val;
+        break;
+    case SDRAM0_CFGDATA:
+        switch (sdram->addr) {
+        case 0x00: /* B0CR */
+            break;
+        case 0x21: /* SDRAM_MCOPT2 */
+            if (!(sdram->mcopt2 & SDRAM_DDR2_MCOPT2_DCEN) &&
+                (val & SDRAM_DDR2_MCOPT2_DCEN)) {
+                trace_ppc4xx_sdram_enable("enable");
+                /* validate all RAM mappings */
+                sdram_ddr2_map_bcr(sdram);
+                sdram->mcopt2 |= SDRAM_DDR2_MCOPT2_DCEN;
+            } else if ((sdram->mcopt2 & SDRAM_DDR2_MCOPT2_DCEN) &&
+                       !(val & SDRAM_DDR2_MCOPT2_DCEN)) {
+                trace_ppc4xx_sdram_enable("disable");
+                /* invalidate all RAM mappings */
+                sdram_ddr2_unmap_bcr(sdram);
+                sdram->mcopt2 &= ~SDRAM_DDR2_MCOPT2_DCEN;
+            }
+            break;
+        default:
+            break;
+        }
+        break;
+    default:
+        break;
+    }
+}
+
+static void ppc4xx_sdram_ddr2_reset(DeviceState *dev)
+{
+    Ppc4xxSdramDdr2State *sdram = PPC4xx_SDRAM_DDR2(dev);
+
+    sdram->addr = 0;
+    sdram->mcopt2 = 0;
+}
+
+static void ppc4xx_sdram_ddr2_realize(DeviceState *dev, Error **errp)
+{
+    Ppc4xxSdramDdr2State *s = PPC4xx_SDRAM_DDR2(dev);
+    Ppc4xxDcrDeviceState *dcr = PPC4xx_DCR_DEVICE(dev);
+    /*
+     * SoC also has 4 GiB but that causes problem with 32 bit
+     * builds (4*GiB overflows the 32 bit ram_addr_t).
+     */
+    const ram_addr_t valid_bank_sizes[] = {
+        2 * GiB, 1 * GiB, 512 * MiB, 256 * MiB, 128 * MiB,
+        64 * MiB, 32 * MiB, 16 * MiB, 8 * MiB, 0
+    };
+
+    if (s->nbanks < 1 || s->nbanks > 4) {
+        error_setg(errp, "Invalid number of RAM banks");
+        return;
+    }
+    if (!s->dram_mr) {
+        error_setg(errp, "Missing dram memory region");
+        return;
+    }
+    ppc4xx_sdram_banks(s->dram_mr, s->nbanks, s->bank, valid_bank_sizes);
+
+    ppc4xx_dcr_register(dcr, SDRAM0_CFGADDR,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM0_CFGDATA,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+
+    ppc4xx_dcr_register(dcr, SDRAM_R0BAS,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_R1BAS,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_R2BAS,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_R3BAS,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_CONF1HB,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_PLBADDULL,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_CONF1LL,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_CONFPATHB,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+    ppc4xx_dcr_register(dcr, SDRAM_PLBADDUHB,
+                        s, &sdram_ddr2_dcr_read, &sdram_ddr2_dcr_write);
+}
+
+static Property ppc4xx_sdram_ddr2_props[] = {
+    DEFINE_PROP_LINK("dram", Ppc4xxSdramDdr2State, dram_mr, TYPE_MEMORY_REGION,
+                     MemoryRegion *),
+    DEFINE_PROP_UINT32("nbanks", Ppc4xxSdramDdr2State, nbanks, 4),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void ppc4xx_sdram_ddr2_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = ppc4xx_sdram_ddr2_realize;
+    dc->reset = ppc4xx_sdram_ddr2_reset;
+    /* Reason: only works as function of a ppc4xx SoC */
+    dc->user_creatable = false;
+    device_class_set_props(dc, ppc4xx_sdram_ddr2_props);
+}
+
+void ppc4xx_sdram_ddr2_enable(Ppc4xxSdramDdr2State *s)
+{
+    sdram_ddr2_dcr_write(s, SDRAM0_CFGADDR, 0x21);
+    sdram_ddr2_dcr_write(s, SDRAM0_CFGDATA, 0x08000000);
+}
+
+static const TypeInfo ppc4xx_sdram_types[] = {
+    {
+        .name           = TYPE_PPC4xx_SDRAM_DDR2,
+        .parent         = TYPE_PPC4xx_DCR_DEVICE,
+        .instance_size  = sizeof(Ppc4xxSdramDdr2State),
+        .class_init     = ppc4xx_sdram_ddr2_class_init,
+    }
+};
+
+DEFINE_TYPES(ppc4xx_sdram_types)
-- 
2.37.3