i.MX: Add i.MX6 System Reset Controller device.

This controller is also present in i.MX5X devices but they are not
yet emulated by QEMU.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 265 insertions, 0 deletions

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 93f952880a..bc0dd2cc75 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -29,6 +29,7 @@ obj-$(CONFIG_IMX) += imx_ccm.o
 obj-$(CONFIG_IMX) += imx31_ccm.o
 obj-$(CONFIG_IMX) += imx25_ccm.o
 obj-$(CONFIG_IMX) += imx6_ccm.o
+obj-$(CONFIG_IMX) += imx6_src.o
 obj-$(CONFIG_MILKYMIST) += milkymist-hpdmc.o
 obj-$(CONFIG_MILKYMIST) += milkymist-pfpu.o
 obj-$(CONFIG_MAINSTONE) += mst_fpga.o
diff --git a/hw/misc/imx6_src.c b/hw/misc/imx6_src.c
new file mode 100644
index 0000000000..6b026b459f
--- /dev/null
+++ b/hw/misc/imx6_src.c
@@ -0,0 +1,264 @@
+/*
+ * IMX6 System Reset Controller
+ *
+ * Copyright (c) 2015 Jean-Christophe Dubois <jcd@tribudubois.net>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "hw/misc/imx6_src.h"
+#include "sysemu/sysemu.h"
+#include "qemu/bitops.h"
+#include "arm-powerctl.h"
+
+#ifndef DEBUG_IMX6_SRC
+#define DEBUG_IMX6_SRC 0
+#endif
+
+#define DPRINTF(fmt, args...) \
+    do { \
+        if (DEBUG_IMX6_SRC) { \
+            fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX6_SRC, \
+                                             __func__, ##args); \
+        } \
+    } while (0)
+
+static char const *imx6_src_reg_name(uint32_t reg)
+{
+    static char unknown[20];
+
+    switch (reg) {
+    case SRC_SCR:
+        return "SRC_SCR";
+    case SRC_SBMR1:
+        return "SRC_SBMR1";
+    case SRC_SRSR:
+        return "SRC_SRSR";
+    case SRC_SISR:
+        return "SRC_SISR";
+    case SRC_SIMR:
+        return "SRC_SIMR";
+    case SRC_SBMR2:
+        return "SRC_SBMR2";
+    case SRC_GPR1:
+        return "SRC_GPR1";
+    case SRC_GPR2:
+        return "SRC_GPR2";
+    case SRC_GPR3:
+        return "SRC_GPR3";
+    case SRC_GPR4:
+        return "SRC_GPR4";
+    case SRC_GPR5:
+        return "SRC_GPR5";
+    case SRC_GPR6:
+        return "SRC_GPR6";
+    case SRC_GPR7:
+        return "SRC_GPR7";
+    case SRC_GPR8:
+        return "SRC_GPR8";
+    case SRC_GPR9:
+        return "SRC_GPR9";
+    case SRC_GPR10:
+        return "SRC_GPR10";
+    default:
+        sprintf(unknown, "%d ?", reg);
+        return unknown;
+    }
+}
+
+static const VMStateDescription vmstate_imx6_src = {
+    .name = TYPE_IMX6_SRC,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, IMX6SRCState, SRC_MAX),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void imx6_src_reset(DeviceState *dev)
+{
+    IMX6SRCState *s = IMX6_SRC(dev);
+
+    DPRINTF("\n");
+
+    memset(s->regs, 0, sizeof(s->regs));
+
+    /* Set reset values */
+    s->regs[SRC_SCR] = 0x521;
+    s->regs[SRC_SRSR] = 0x1;
+    s->regs[SRC_SIMR] = 0x1F;
+}
+
+static uint64_t imx6_src_read(void *opaque, hwaddr offset, unsigned size)
+{
+    uint32_t value = 0;
+    IMX6SRCState *s = (IMX6SRCState *)opaque;
+    uint32_t index = offset >> 2;
+
+    if (index < SRC_MAX) {
+        value = s->regs[index];
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
+
+    }
+
+    DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx6_src_reg_name(index), value);
+
+    return value;
+}
+
+static void imx6_src_write(void *opaque, hwaddr offset, uint64_t value,
+                           unsigned size)
+{
+    IMX6SRCState *s = (IMX6SRCState *)opaque;
+    uint32_t index = offset >> 2;
+    unsigned long change_mask;
+    unsigned long current_value = value;
+
+    if (index >=  SRC_MAX) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
+        return;
+    }
+
+    DPRINTF("reg[%s] <= 0x%" PRIx32 "\n", imx6_src_reg_name(index),
+            (uint32_t)current_value);
+
+    change_mask = s->regs[index] ^ (uint32_t)current_value;
+
+    switch (index) {
+    case SRC_SCR:
+        /*
+         * On real hardware when the system reset controller starts a
+         * secondary CPU it runs through some boot ROM code which reads
+         * the SRC_GPRX registers controlling the start address and branches
+         * to it.
+         * Here we are taking a short cut and branching directly to the
+         * requested address (we don't want to run the boot ROM code inside
+         * QEMU)
+         */
+        if (EXTRACT(change_mask, CORE3_ENABLE)) {
+            if (EXTRACT(current_value, CORE3_ENABLE)) {
+                /* CORE 3 is brought up */
+                arm_set_cpu_on(3, s->regs[SRC_GPR7], s->regs[SRC_GPR8],
+                               3, false);
+            } else {
+                /* CORE 3 is shut down */
+                arm_set_cpu_off(3);
+            }
+            /* We clear the reset bits as the processor changed state */
+            clear_bit(CORE3_RST_SHIFT, &current_value);
+            clear_bit(CORE3_RST_SHIFT, &change_mask);
+        }
+        if (EXTRACT(change_mask, CORE2_ENABLE)) {
+            if (EXTRACT(current_value, CORE2_ENABLE)) {
+                /* CORE 2 is brought up */
+                arm_set_cpu_on(2, s->regs[SRC_GPR5], s->regs[SRC_GPR6],
+                               3, false);
+            } else {
+                /* CORE 3 is shut down */
+                arm_set_cpu_off(2);
+            }
+            /* We clear the reset bits as the processor changed state */
+            clear_bit(CORE2_RST_SHIFT, &current_value);
+            clear_bit(CORE2_RST_SHIFT, &change_mask);
+        }
+        if (EXTRACT(change_mask, CORE1_ENABLE)) {
+            if (EXTRACT(current_value, CORE1_ENABLE)) {
+                /* CORE 1 is brought up */
+                arm_set_cpu_on(1, s->regs[SRC_GPR3], s->regs[SRC_GPR4],
+                               3, false);
+            } else {
+                /* CORE 3 is shut down */
+                arm_set_cpu_off(1);
+            }
+            /* We clear the reset bits as the processor changed state */
+            clear_bit(CORE1_RST_SHIFT, &current_value);
+            clear_bit(CORE1_RST_SHIFT, &change_mask);
+        }
+        if (EXTRACT(change_mask, CORE0_RST)) {
+            arm_reset_cpu(0);
+            clear_bit(CORE0_RST_SHIFT, &current_value);
+        }
+        if (EXTRACT(change_mask, CORE1_RST)) {
+            arm_reset_cpu(1);
+            clear_bit(CORE1_RST_SHIFT, &current_value);
+        }
+        if (EXTRACT(change_mask, CORE2_RST)) {
+            arm_reset_cpu(2);
+            clear_bit(CORE2_RST_SHIFT, &current_value);
+        }
+        if (EXTRACT(change_mask, CORE3_RST)) {
+            arm_reset_cpu(3);
+            clear_bit(CORE3_RST_SHIFT, &current_value);
+        }
+        if (EXTRACT(change_mask, SW_IPU2_RST)) {
+            /* We pretend the IPU2 is reset */
+            clear_bit(SW_IPU2_RST_SHIFT, &current_value);
+        }
+        if (EXTRACT(change_mask, SW_IPU1_RST)) {
+            /* We pretend the IPU1 is reset */
+            clear_bit(SW_IPU1_RST_SHIFT, &current_value);
+        }
+        s->regs[index] = current_value;
+        break;
+    default:
+        s->regs[index] = current_value;
+        break;
+    }
+}
+
+static const struct MemoryRegionOps imx6_src_ops = {
+    .read = imx6_src_read,
+    .write = imx6_src_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        /*
+         * Our device would not work correctly if the guest was doing
+         * unaligned access. This might not be a limitation on the real
+         * device but in practice there is no reason for a guest to access
+         * this device unaligned.
+         */
+        .min_access_size = 4,
+        .max_access_size = 4,
+        .unaligned = false,
+    },
+};
+
+static void imx6_src_realize(DeviceState *dev, Error **errp)
+{
+    IMX6SRCState *s = IMX6_SRC(dev);
+
+    memory_region_init_io(&s->iomem, OBJECT(dev), &imx6_src_ops, s,
+                          TYPE_IMX6_SRC, 0x1000);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
+}
+
+static void imx6_src_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = imx6_src_realize;
+    dc->reset = imx6_src_reset;
+    dc->vmsd = &vmstate_imx6_src;
+    dc->desc = "i.MX6 System Reset Controller";
+}
+
+static const TypeInfo imx6_src_info = {
+    .name          = TYPE_IMX6_SRC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(IMX6SRCState),
+    .class_init    = imx6_src_class_init,
+};
+
+static void imx6_src_register_types(void)
+{
+    type_register_static(&imx6_src_info);
+}
+
+type_init(imx6_src_register_types)