diff mbox

[v2,6/9] i.MX: Add i.MX6 System Reset Controller device.

Message ID e597ae6f686b2defba87d7f24af1351ab267e6e1.1454967766.git.jcd@tribudubois.net (mailing list archive)
State New, archived
Headers show

Commit Message

Jean-Christophe DUBOIS Feb. 8, 2016, 10:08 p.m. UTC
This controller is also present in i.MX5X devices but they are not
yet emulated by QEMU.

Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
---

Changes since V1:
 * Change "reset" sematic to mean full power cyvle.

 hw/misc/Makefile.objs      |   1 +
 hw/misc/imx6_src.c         | 353 +++++++++++++++++++++++++++++++++++++++++++++
 include/hw/misc/imx6_src.h |  73 ++++++++++
 3 files changed, 427 insertions(+)
 create mode 100644 hw/misc/imx6_src.c
 create mode 100644 include/hw/misc/imx6_src.h

Comments

Peter Maydell Feb. 16, 2016, 3:35 p.m. UTC | #1
On 8 February 2016 at 22:08, Jean-Christophe Dubois <jcd@tribudubois.net> wrote:
> This controller is also present in i.MX5X devices but they are not
> yet emulated by QEMU.
>
> Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>

> @@ -0,0 +1,353 @@
> +/*
> + * 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 "hw/misc/imx6_src.h"
> +#include "sysemu/sysemu.h"
> +#include "qemu/bitops.h"

#include "qemu/osdep.h" as first #include line.

> +static void imx6_src_reset(DeviceState *dev)
> +{
> +    IMX6SRCState *s = IMX6_SRC(dev);
> +
> +    DPRINTF("\n");
> +
> +    /*
> +     * We only clear the first registers as all GPR registers are preserved
> +     * over resets
> +     */
> +    memset(s->regs, 0, SRC_MAX * sizeof(uint32_t));

Comment doesn't seem to match code?

> +    /* Set reset values */
> +    s->regs[SRC_SCR] = 0x521;
> +    s->regs[SRC_SRSR] = 0x1;
> +    s->regs[SRC_SIMR] = 0x1F;
> +}
> +
> +static CPUState *imx6_src_get_cpu_by_id(uint32_t id)
> +{
> +    CPUState *cpu;
> +
> +    DPRINTF("cpu %d\n", id);
> +
> +    CPU_FOREACH(cpu) {
> +        ARMCPU *armcpu = ARM_CPU(cpu);
> +
> +        if (armcpu->mp_affinity == id) {
> +            return cpu;
> +        }
> +    }
> +
> +    qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Resquesting unknown CPU %d\n",
> +                  TYPE_IMX6_SRC, __func__, id);
> +
> +    return NULL;
> +}
> +
> +static void imx6_src_cpu_on(uint32_t cpuid, uint32_t entry, uint32_t context_id)
> +{
> +    CPUState *target_cpu_state;
> +    ARMCPU *target_cpu;
> +    CPUClass *target_cpu_class;
> +
> +    DPRINTF("cpu %d @ 0x%08x with R0 = 0x%08x\n", cpuid, entry, context_id);
> +
> +    /* change to the cpu we are powering up */
> +    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
> +    if (!target_cpu_state) {
> +        return;
> +    }
> +    target_cpu = ARM_CPU(target_cpu_state);
> +    if (!target_cpu->powered_off) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already running\n",
> +                      TYPE_IMX6_SRC, __func__, cpuid);
> +        return;
> +    }
> +    target_cpu_class = CPU_GET_CLASS(target_cpu);
> +
> +    /* Initialize the cpu we are turning on */
> +    cpu_reset(target_cpu_state);
> +    target_cpu->powered_off = false;
> +    target_cpu_state->halted = 0;
> +
> +    target_cpu->env.regs[0] = context_id;
> +    target_cpu->env.thumb = entry & 1;
> +
> +    target_cpu_class->set_pc(target_cpu_state, entry);
> +}
> +
> +static void imx6_src_cpu_off(uint32_t cpuid)
> +{
> +    CPUState *target_cpu_state;
> +    ARMCPU *target_cpu;
> +
> +    DPRINTF("cpu %d\n", cpuid);
> +
> +    /* change to the cpu we are powering up */
> +    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
> +    if (!target_cpu_state) {
> +        return;
> +    }
> +    target_cpu = ARM_CPU(target_cpu_state);
> +    if (target_cpu->powered_off) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already off\n",
> +                      TYPE_IMX6_SRC, __func__, cpuid);
> +        return;
> +    }
> +
> +    target_cpu->powered_off = true;
> +    target_cpu_state->halted = 1;
> +    target_cpu_state->exception_index = EXCP_HLT;
> +    cpu_loop_exit(target_cpu_state);
> +}
>
> +static void imx6_src_cpu_reset(uint32_t cpuid)
> +{
> +    CPUState *target_cpu_state;
> +    ARMCPU *target_cpu;
> +
> +    DPRINTF("cpu %d\n", cpuid);
> +
> +    /* change to the cpu we are powering up */
> +    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
> +    if (!target_cpu_state) {
> +        return;
> +    }
> +    target_cpu = ARM_CPU(target_cpu_state);
> +    if (target_cpu->powered_off) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is off\n",
> +                      TYPE_IMX6_SRC, __func__, cpuid);
> +        return;
> +    }
> +
> +    /* Reset the cpu we are turning on */
> +    cpu_reset(target_cpu_state);
> +}

The code that is messing about with target CPUs to power them up
and down needs to be abstracted out into a public API in target-arm/,
so it can be used both by your device and by target-arm/psci.c.
I don't want variations on this code to duplicate into various
devices, because chances are good it will need to change for
multithreaded TCG.

> +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";
> +}

> +/* SRC_SCR */
> +#define CORE3_ENABLE_SHIFT     (24)
> +#define CORE3_ENABLE_LENGTH    (1)
> +#define CORE2_ENABLE_SHIFT     (23)
> +#define CORE2_ENABLE_LENGTH    (1)
> +#define CORE1_ENABLE_SHIFT     (22)
> +#define CORE1_ENABLE_LENGTH    (1)
> +#define CORE3_RST_SHIFT        (16)
> +#define CORE3_RST_LENGTH       (1)
> +#define CORE2_RST_SHIFT        (15)
> +#define CORE2_RST_LENGTH       (1)
> +#define CORE1_RST_SHIFT        (14)
> +#define CORE1_RST_LENGTH       (1)
> +#define CORE0_RST_SHIFT        (13)
> +#define CORE0_RST_LENGTH       (1)
> +#define SW_IPU1_RST_SHIFT      (3)
> +#define SW_IPU1_RST_LENGTH     (1)
> +#define SW_IPU2_RST_SHIFT      (12)
> +#define SW_IPU2_RST_LENGTH     (1)
> +#define WARM_RST_ENABLE_SHIFT  (0)
> +#define WARM_RST_ENABLE_LENGTH (1)

The brackets here are unnecessary.

thanks
-- PMM
Jean-Christophe DUBOIS Feb. 27, 2016, 4:57 p.m. UTC | #2
Hi Peter and Peter,

I need to test that the changes I did for PSCI (factor out on/off code) 
do not introduce any regression.

On which QEMU target should I test my changes to PSCI to check I didn't 
mess up anything?

Thanks

JC

Le 16/02/2016 16:35, Peter Maydell a écrit :
> On 8 February 2016 at 22:08, Jean-Christophe Dubois <jcd@tribudubois.net> wrote:
>> This controller is also present in i.MX5X devices but they are not
>> yet emulated by QEMU.
>>
>> Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
>> @@ -0,0 +1,353 @@
>> +/*
>> + * 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 "hw/misc/imx6_src.h"
>> +#include "sysemu/sysemu.h"
>> +#include "qemu/bitops.h"
> #include "qemu/osdep.h" as first #include line.
>
>> +static void imx6_src_reset(DeviceState *dev)
>> +{
>> +    IMX6SRCState *s = IMX6_SRC(dev);
>> +
>> +    DPRINTF("\n");
>> +
>> +    /*
>> +     * We only clear the first registers as all GPR registers are preserved
>> +     * over resets
>> +     */
>> +    memset(s->regs, 0, SRC_MAX * sizeof(uint32_t));
> Comment doesn't seem to match code?
>
>> +    /* Set reset values */
>> +    s->regs[SRC_SCR] = 0x521;
>> +    s->regs[SRC_SRSR] = 0x1;
>> +    s->regs[SRC_SIMR] = 0x1F;
>> +}
>> +
>> +static CPUState *imx6_src_get_cpu_by_id(uint32_t id)
>> +{
>> +    CPUState *cpu;
>> +
>> +    DPRINTF("cpu %d\n", id);
>> +
>> +    CPU_FOREACH(cpu) {
>> +        ARMCPU *armcpu = ARM_CPU(cpu);
>> +
>> +        if (armcpu->mp_affinity == id) {
>> +            return cpu;
>> +        }
>> +    }
>> +
>> +    qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Resquesting unknown CPU %d\n",
>> +                  TYPE_IMX6_SRC, __func__, id);
>> +
>> +    return NULL;
>> +}
>> +
>> +static void imx6_src_cpu_on(uint32_t cpuid, uint32_t entry, uint32_t context_id)
>> +{
>> +    CPUState *target_cpu_state;
>> +    ARMCPU *target_cpu;
>> +    CPUClass *target_cpu_class;
>> +
>> +    DPRINTF("cpu %d @ 0x%08x with R0 = 0x%08x\n", cpuid, entry, context_id);
>> +
>> +    /* change to the cpu we are powering up */
>> +    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
>> +    if (!target_cpu_state) {
>> +        return;
>> +    }
>> +    target_cpu = ARM_CPU(target_cpu_state);
>> +    if (!target_cpu->powered_off) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already running\n",
>> +                      TYPE_IMX6_SRC, __func__, cpuid);
>> +        return;
>> +    }
>> +    target_cpu_class = CPU_GET_CLASS(target_cpu);
>> +
>> +    /* Initialize the cpu we are turning on */
>> +    cpu_reset(target_cpu_state);
>> +    target_cpu->powered_off = false;
>> +    target_cpu_state->halted = 0;
>> +
>> +    target_cpu->env.regs[0] = context_id;
>> +    target_cpu->env.thumb = entry & 1;
>> +
>> +    target_cpu_class->set_pc(target_cpu_state, entry);
>> +}
>> +
>> +static void imx6_src_cpu_off(uint32_t cpuid)
>> +{
>> +    CPUState *target_cpu_state;
>> +    ARMCPU *target_cpu;
>> +
>> +    DPRINTF("cpu %d\n", cpuid);
>> +
>> +    /* change to the cpu we are powering up */
>> +    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
>> +    if (!target_cpu_state) {
>> +        return;
>> +    }
>> +    target_cpu = ARM_CPU(target_cpu_state);
>> +    if (target_cpu->powered_off) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already off\n",
>> +                      TYPE_IMX6_SRC, __func__, cpuid);
>> +        return;
>> +    }
>> +
>> +    target_cpu->powered_off = true;
>> +    target_cpu_state->halted = 1;
>> +    target_cpu_state->exception_index = EXCP_HLT;
>> +    cpu_loop_exit(target_cpu_state);
>> +}
>>
>> +static void imx6_src_cpu_reset(uint32_t cpuid)
>> +{
>> +    CPUState *target_cpu_state;
>> +    ARMCPU *target_cpu;
>> +
>> +    DPRINTF("cpu %d\n", cpuid);
>> +
>> +    /* change to the cpu we are powering up */
>> +    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
>> +    if (!target_cpu_state) {
>> +        return;
>> +    }
>> +    target_cpu = ARM_CPU(target_cpu_state);
>> +    if (target_cpu->powered_off) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is off\n",
>> +                      TYPE_IMX6_SRC, __func__, cpuid);
>> +        return;
>> +    }
>> +
>> +    /* Reset the cpu we are turning on */
>> +    cpu_reset(target_cpu_state);
>> +}
> The code that is messing about with target CPUs to power them up
> and down needs to be abstracted out into a public API in target-arm/,
> so it can be used both by your device and by target-arm/psci.c.
> I don't want variations on this code to duplicate into various
> devices, because chances are good it will need to change for
> multithreaded TCG.
>
>> +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";
>> +}
>> +/* SRC_SCR */
>> +#define CORE3_ENABLE_SHIFT     (24)
>> +#define CORE3_ENABLE_LENGTH    (1)
>> +#define CORE2_ENABLE_SHIFT     (23)
>> +#define CORE2_ENABLE_LENGTH    (1)
>> +#define CORE1_ENABLE_SHIFT     (22)
>> +#define CORE1_ENABLE_LENGTH    (1)
>> +#define CORE3_RST_SHIFT        (16)
>> +#define CORE3_RST_LENGTH       (1)
>> +#define CORE2_RST_SHIFT        (15)
>> +#define CORE2_RST_LENGTH       (1)
>> +#define CORE1_RST_SHIFT        (14)
>> +#define CORE1_RST_LENGTH       (1)
>> +#define CORE0_RST_SHIFT        (13)
>> +#define CORE0_RST_LENGTH       (1)
>> +#define SW_IPU1_RST_SHIFT      (3)
>> +#define SW_IPU1_RST_LENGTH     (1)
>> +#define SW_IPU2_RST_SHIFT      (12)
>> +#define SW_IPU2_RST_LENGTH     (1)
>> +#define WARM_RST_ENABLE_SHIFT  (0)
>> +#define WARM_RST_ENABLE_LENGTH (1)
> The brackets here are unnecessary.
>
> thanks
> -- PMM
>
Peter Maydell Feb. 27, 2016, 5:43 p.m. UTC | #3
On 27 February 2016 at 16:57, Jean-Christophe DUBOIS
<jcd@tribudubois.net> wrote:
> Hi Peter and Peter,
>
> I need to test that the changes I did for PSCI (factor out on/off code) do
> not introduce any regression.
>
> On which QEMU target should I test my changes to PSCI to check I didn't mess
> up anything?

The 'virt' board uses PSCI.

thanks
-- PMM
Jean-Christophe DUBOIS Feb. 28, 2016, noon UTC | #4
Le 27/02/2016 18:43, Peter Maydell a écrit :
> On 27 February 2016 at 16:57, Jean-Christophe DUBOIS
> <jcd@tribudubois.net> wrote:
>> Hi Peter and Peter,
>>
>> I need to test that the changes I did for PSCI (factor out on/off code) do
>> not introduce any regression.
>>
>> On which QEMU target should I test my changes to PSCI to check I didn't mess
>> up anything?
> The 'virt' board uses PSCI.

Is there some quick howto somewhere on the 'virt' plateform (which linux 
defconfig to use, which DT tree to use, which command line t use, ...) ?

Thanks

JC

>
> thanks
> -- PMM
>
diff mbox

Patch

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index a2a8e91..6bac654 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 0000000..2cf97ef
--- /dev/null
+++ b/hw/misc/imx6_src.c
@@ -0,0 +1,353 @@ 
+/*
+ * 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 "hw/misc/imx6_src.h"
+#include "sysemu/sysemu.h"
+#include "qemu/bitops.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");
+
+    /*
+     * We only clear the first registers as all GPR registers are preserved
+     * over resets
+     */
+    memset(s->regs, 0, SRC_MAX * sizeof(uint32_t));
+
+    /* Set reset values */
+    s->regs[SRC_SCR] = 0x521;
+    s->regs[SRC_SRSR] = 0x1;
+    s->regs[SRC_SIMR] = 0x1F;
+}
+
+static CPUState *imx6_src_get_cpu_by_id(uint32_t id)
+{
+    CPUState *cpu;
+
+    DPRINTF("cpu %d\n", id);
+
+    CPU_FOREACH(cpu) {
+        ARMCPU *armcpu = ARM_CPU(cpu);
+
+        if (armcpu->mp_affinity == id) {
+            return cpu;
+        }
+    }
+
+    qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Resquesting unknown CPU %d\n",
+                  TYPE_IMX6_SRC, __func__, id);
+
+    return NULL;
+}
+
+static void imx6_src_cpu_on(uint32_t cpuid, uint32_t entry, uint32_t context_id)
+{
+    CPUState *target_cpu_state;
+    ARMCPU *target_cpu;
+    CPUClass *target_cpu_class;
+
+    DPRINTF("cpu %d @ 0x%08x with R0 = 0x%08x\n", cpuid, entry, context_id);
+
+    /* change to the cpu we are powering up */
+    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
+    if (!target_cpu_state) {
+        return;
+    }
+    target_cpu = ARM_CPU(target_cpu_state);
+    if (!target_cpu->powered_off) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already running\n",
+                      TYPE_IMX6_SRC, __func__, cpuid);
+        return;
+    }
+    target_cpu_class = CPU_GET_CLASS(target_cpu);
+
+    /* Initialize the cpu we are turning on */
+    cpu_reset(target_cpu_state);
+    target_cpu->powered_off = false;
+    target_cpu_state->halted = 0;
+
+    target_cpu->env.regs[0] = context_id;
+    target_cpu->env.thumb = entry & 1;
+
+    target_cpu_class->set_pc(target_cpu_state, entry);
+}
+
+static void imx6_src_cpu_off(uint32_t cpuid)
+{
+    CPUState *target_cpu_state;
+    ARMCPU *target_cpu;
+
+    DPRINTF("cpu %d\n", cpuid);
+
+    /* change to the cpu we are powering up */
+    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
+    if (!target_cpu_state) {
+        return;
+    }
+    target_cpu = ARM_CPU(target_cpu_state);
+    if (target_cpu->powered_off) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already off\n",
+                      TYPE_IMX6_SRC, __func__, cpuid);
+        return;
+    }
+
+    target_cpu->powered_off = true;
+    target_cpu_state->halted = 1;
+    target_cpu_state->exception_index = EXCP_HLT;
+    cpu_loop_exit(target_cpu_state);
+}
+
+static void imx6_src_cpu_reset(uint32_t cpuid)
+{
+    CPUState *target_cpu_state;
+    ARMCPU *target_cpu;
+
+    DPRINTF("cpu %d\n", cpuid);
+
+    /* change to the cpu we are powering up */
+    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
+    if (!target_cpu_state) {
+        return;
+    }
+    target_cpu = ARM_CPU(target_cpu_state);
+    if (target_cpu->powered_off) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is off\n",
+                      TYPE_IMX6_SRC, __func__, cpuid);
+        return;
+    }
+
+    /* Reset the cpu we are turning on */
+    cpu_reset(target_cpu_state);
+}
+
+static uint64_t imx6_src_read(void *opaque, hwaddr offset, unsigned size)
+{
+    uint32 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 (uint64_t)value;
+}
+
+static void imx6_src_write(void *opaque, hwaddr offset, uint64_t value,
+                           unsigned size)
+{
+    IMX6SRCState *s = (IMX6SRCState *)opaque;
+    uint32_t index = offset >> 2;
+    uint64_t change_mask;
+
+    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)value);
+
+    change_mask = s->regs[index] ^ (uint32_t)value;
+
+    switch (index) {
+    case SRC_SCR:
+        if (EXTRACT(change_mask, CORE3_ENABLE)) {
+            if (EXTRACT(value, CORE3_ENABLE)) {
+                /* CORE 3 is brought up */
+                imx6_src_cpu_on(3, s->regs[SRC_GPR7], s->regs[SRC_GPR8]);
+            } else {
+                /* CORE 3 is shut down */
+                imx6_src_cpu_off(3);
+            }
+            /* We clear the reset bits as the processor changed state */
+            clear_bit(CORE3_RST_SHIFT, &value);
+            clear_bit(CORE3_RST_SHIFT, &change_mask);
+        }
+        if (EXTRACT(change_mask, CORE2_ENABLE)) {
+            if (EXTRACT(value, CORE2_ENABLE)) {
+                /* CORE 2 is brought up */
+                imx6_src_cpu_on(2, s->regs[SRC_GPR5], s->regs[SRC_GPR6]);
+            } else {
+                /* CORE 3 is shut down */
+                imx6_src_cpu_off(2);
+            }
+            /* We clear the reset bits as the processor changed state */
+            clear_bit(CORE2_RST_SHIFT, &value);
+            clear_bit(CORE2_RST_SHIFT, &change_mask);
+        }
+        if (EXTRACT(change_mask, CORE1_ENABLE)) {
+            if (EXTRACT(value, CORE1_ENABLE)) {
+                /* CORE 1 is brought up */
+                imx6_src_cpu_on(1, s->regs[SRC_GPR3], s->regs[SRC_GPR4]);
+            } else {
+                /* CORE 3 is shut down */
+                imx6_src_cpu_off(1);
+            }
+            /* We clear the reset bits as the processor changed state */
+            clear_bit(CORE1_RST_SHIFT, &value);
+            clear_bit(CORE1_RST_SHIFT, &change_mask);
+        }
+        if (EXTRACT(change_mask, CORE0_RST)) {
+            imx6_src_cpu_reset(0);
+            clear_bit(CORE0_RST_SHIFT, &value);
+        }
+        if (EXTRACT(change_mask, CORE1_RST)) {
+            imx6_src_cpu_reset(1);
+            clear_bit(CORE1_RST_SHIFT, &value);
+        }
+        if (EXTRACT(change_mask, CORE2_RST)) {
+            imx6_src_cpu_reset(2);
+            clear_bit(CORE2_RST_SHIFT, &value);
+        }
+        if (EXTRACT(change_mask, CORE3_RST)) {
+            imx6_src_cpu_reset(3);
+            clear_bit(CORE3_RST_SHIFT, &value);
+        }
+        if (EXTRACT(change_mask, SW_IPU2_RST)) {
+            /* We pretend the IPU2 is reseted */
+            clear_bit(SW_IPU2_RST_SHIFT, &value);
+        }
+        if (EXTRACT(change_mask, SW_IPU1_RST)) {
+            /* We pretend the IPU1 is reseted */
+            clear_bit(SW_IPU1_RST_SHIFT, &value);
+        }
+        s->regs[index] = value;
+        break;
+    default:
+        s->regs[index] = 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)
diff --git a/include/hw/misc/imx6_src.h b/include/hw/misc/imx6_src.h
new file mode 100644
index 0000000..c669488
--- /dev/null
+++ b/include/hw/misc/imx6_src.h
@@ -0,0 +1,73 @@ 
+/*
+ * IMX6 System Reset Controller
+ *
+ * Copyright (C) 2012 NICTA
+ * Updated by 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.
+ */
+
+#ifndef IMX6_SRC_H
+#define IMX6_SRC_H
+
+#include "hw/sysbus.h"
+#include "qemu/bitops.h"
+
+#define SRC_SCR 0
+#define SRC_SBMR1 1
+#define SRC_SRSR 2
+#define SRC_SISR 5
+#define SRC_SIMR 6
+#define SRC_SBMR2 7
+#define SRC_GPR1 8
+#define SRC_GPR2 9
+#define SRC_GPR3 10
+#define SRC_GPR4 11
+#define SRC_GPR5 12
+#define SRC_GPR6 13
+#define SRC_GPR7 14
+#define SRC_GPR8 15
+#define SRC_GPR9 16
+#define SRC_GPR10 17
+#define SRC_MAX 18
+
+/* SRC_SCR */
+#define CORE3_ENABLE_SHIFT     (24)
+#define CORE3_ENABLE_LENGTH    (1)
+#define CORE2_ENABLE_SHIFT     (23)
+#define CORE2_ENABLE_LENGTH    (1)
+#define CORE1_ENABLE_SHIFT     (22)
+#define CORE1_ENABLE_LENGTH    (1)
+#define CORE3_RST_SHIFT        (16)
+#define CORE3_RST_LENGTH       (1)
+#define CORE2_RST_SHIFT        (15)
+#define CORE2_RST_LENGTH       (1)
+#define CORE1_RST_SHIFT        (14)
+#define CORE1_RST_LENGTH       (1)
+#define CORE0_RST_SHIFT        (13)
+#define CORE0_RST_LENGTH       (1)
+#define SW_IPU1_RST_SHIFT      (3)
+#define SW_IPU1_RST_LENGTH     (1)
+#define SW_IPU2_RST_SHIFT      (12)
+#define SW_IPU2_RST_LENGTH     (1)
+#define WARM_RST_ENABLE_SHIFT  (0)
+#define WARM_RST_ENABLE_LENGTH (1)
+
+#define EXTRACT(value, name) extract32(value, name##_SHIFT, name##_LENGTH)
+
+#define TYPE_IMX6_SRC "imx6.src"
+#define IMX6_SRC(obj) OBJECT_CHECK(IMX6SRCState, (obj), TYPE_IMX6_SRC)
+
+typedef struct IMX6SRCState {
+    /* <private> */
+    SysBusDevice parent_obj;
+
+    /* <public> */
+    MemoryRegion iomem;
+
+    uint32_t regs[SRC_MAX];
+
+} IMX6SRCState;
+
+#endif /* IMX6_SRC_H */