[Qemu-devel] [RFC PATCH] hw: arm: Add basic support for cprman (clock subsystem)

* [Qemu-devel] [RFC PATCH] hw: arm: Add basic support for cprman (clock subsystem)
@ 2018-07-15 22:06 Guenter Roeck
  2018-07-16  9:08 ` Peter Maydell
                   ` (2 more replies)
  0 siblings, 3 replies; 11+ messages in thread
From: Guenter Roeck @ 2018-07-15 22:06 UTC (permalink / raw)
  To: Peter Maydell; +Cc: qemu-arm, qemu-devel, Pekka Enberg, Guenter Roeck

Add basic support for BCM283x CPRMAN. Provide support for reading and
writing CPRMAN registers and initialize registers with sensible default
values. During runtime retain any written values.

Basic CPRMAN support is necessary and sufficient to boot Linux on raspi2
and raspi3 systems.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
I don't seriously expect this patch to get accepted, but I thought
it might be valuable enough for others to use it when playing with
raspi2 and raspi3 emulations.

 hw/arm/bcm2835_peripherals.c         |  15 +++++
 hw/misc/Makefile.objs                |   1 +
 hw/misc/bcm2835_cprman.c             | 126 +++++++++++++++++++++++++++++++++++
 include/hw/arm/bcm2835_peripherals.h |   2 +
 include/hw/arm/raspi_platform.h      |   1 +
 include/hw/misc/bcm2835_cprman.h     |  28 ++++++++
 6 files changed, 173 insertions(+)
 create mode 100644 hw/misc/bcm2835_cprman.c
 create mode 100644 include/hw/misc/bcm2835_cprman.h

diff --git a/hw/arm/bcm2835_peripherals.c b/hw/arm/bcm2835_peripherals.c
index 6be7660..1a8993f 100644
--- a/hw/arm/bcm2835_peripherals.c
+++ b/hw/arm/bcm2835_peripherals.c
@@ -85,6 +85,11 @@ static void bcm2835_peripherals_init(Object *obj)
     object_property_add_const_link(OBJECT(&s->property), "dma-mr",
                                    OBJECT(&s->gpu_bus_mr), &error_abort);
 
+    /* Clock subsystem */
+    object_initialize(&s->cprman, sizeof(s->cprman), TYPE_BCM2835_CPRMAN);
+    object_property_add_child(obj, "cprman", OBJECT(&s->cprman), NULL);
+    qdev_set_parent_bus(DEVICE(&s->cprman), sysbus_get_default());
+
     /* Random Number Generator */
     object_initialize(&s->rng, sizeof(s->rng), TYPE_BCM2835_RNG);
     object_property_add_child(obj, "rng", OBJECT(&s->rng), NULL);
@@ -244,6 +249,13 @@ static void bcm2835_peripherals_realize(DeviceState *dev, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->property), 0,
                       qdev_get_gpio_in(DEVICE(&s->mboxes), MBOX_CHAN_PROPERTY));
 
+    /* Clock subsystem */
+    object_property_set_bool(OBJECT(&s->cprman), true, "realized", &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+
     /* Random Number Generator */
     object_property_set_bool(OBJECT(&s->rng), true, "realized", &err);
     if (err) {
@@ -251,6 +263,9 @@ static void bcm2835_peripherals_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    memory_region_add_subregion(&s->peri_mr, CPRMAN_OFFSET,
+                sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->cprman), 0));
+
     memory_region_add_subregion(&s->peri_mr, RNG_OFFSET,
                 sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->rng), 0));
 
diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 9350900..ae5fc8a 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -52,6 +52,7 @@ obj-$(CONFIG_OMAP) += omap_tap.o
 obj-$(CONFIG_RASPI) += bcm2835_mbox.o
 obj-$(CONFIG_RASPI) += bcm2835_property.o
 obj-$(CONFIG_RASPI) += bcm2835_rng.o
+obj-$(CONFIG_RASPI) += bcm2835_cprman.o
 obj-$(CONFIG_SLAVIO) += slavio_misc.o
 obj-$(CONFIG_ZYNQ) += zynq_slcr.o
 obj-$(CONFIG_ZYNQ) += zynq-xadc.o
diff --git a/hw/misc/bcm2835_cprman.c b/hw/misc/bcm2835_cprman.c
new file mode 100644
index 0000000..4051f2b
--- /dev/null
+++ b/hw/misc/bcm2835_cprman.c
@@ -0,0 +1,126 @@
+/*
+ * BCM2835 Clock subsystem (poor man's version)
+ *
+ * Copyright (C) 2018 Guenter Roeck <linux@roeck-us.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 "qemu/log.h"
+#include "qapi/error.h"
+#include "crypto/random.h"
+#include "hw/misc/bcm2835_cprman.h"
+
+static uint64_t bcm2835_cprman_read(void *opaque, hwaddr offset,
+                                 unsigned size)
+{
+    BCM2835CprmanState *s = (BCM2835CprmanState *)opaque;
+    uint32_t res = 0;
+
+    assert(size == 4);
+
+    if (offset / 4 < CPRMAN_NUM_REGS) {
+        res = s->regs[offset / 4];
+    }
+
+    return res;
+}
+
+#define CM_PASSWORD             0x5a000000
+#define CM_PASSWORD_MASK        0xff000000
+
+static void bcm2835_cprman_write(void *opaque, hwaddr offset,
+                              uint64_t value, unsigned size)
+{
+    BCM2835CprmanState *s = (BCM2835CprmanState *)opaque;
+
+    assert(size == 4);
+
+    if ((value & 0xff000000) == CM_PASSWORD &&
+        offset / 4 < CPRMAN_NUM_REGS)
+            s->regs[offset / 4] = value & ~CM_PASSWORD_MASK;
+}
+
+static const MemoryRegionOps bcm2835_cprman_ops = {
+    .read = bcm2835_cprman_read,
+    .write = bcm2835_cprman_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription vmstate_bcm2835_cprman = {
+    .name = TYPE_BCM2835_CPRMAN,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, BCM2835CprmanState, CPRMAN_NUM_REGS),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void bcm2835_cprman_init(Object *obj)
+{
+    BCM2835CprmanState *s = BCM2835_CPRMAN(obj);
+
+    memory_region_init_io(&s->iomem, obj, &bcm2835_cprman_ops, s,
+                          TYPE_BCM2835_CPRMAN, 0x2000);
+    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
+}
+
+#define CM_GNRICCTL        (0x000 / 4)
+#define CM_VECCTL        (0x0f8 / 4)
+#define CM_DFTCTL        (0x168 / 4)
+#define CM_EMMCCTL        (0x1c0 / 4)
+#define A2W_PLLA_CTRL        (0x1100 / 4)
+#define A2W_PLLB_CTRL        (0x11e0 / 4)
+
+static void bcm2835_cprman_reset(DeviceState *dev)
+{
+    BCM2835CprmanState *s = BCM2835_CPRMAN(dev);
+    int i;
+
+    /*
+     * Available information suggests that CPRMAN registers have default
+     * values which are not overwritten by ROMMON (u-boot). The hardware
+     * default values are unknown at this time.
+     * The default values selected here are necessary and sufficient
+     * to boot Linux directly (on raspi2 and raspi3). The selected
+     * values enable all clocks and set clock rates to match their
+     * parent rates.
+     */
+    for (i = CM_GNRICCTL; i <= CM_VECCTL; i += 2) {
+        s->regs[i] = 0x11;
+        s->regs[i + 1] = 0x1000;
+    }
+    for (i = CM_DFTCTL; i <= CM_EMMCCTL; i += 2) {
+        s->regs[i] = 0x11;
+        s->regs[i + 1] = 0x1000;
+    }
+    for (i = A2W_PLLA_CTRL; i <= A2W_PLLB_CTRL; i += 8) {
+        s->regs[i] = 0x10001;
+    }
+}
+
+static void bcm2835_cprman_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->reset = bcm2835_cprman_reset;
+    dc->vmsd = &vmstate_bcm2835_cprman;
+}
+
+static TypeInfo bcm2835_cprman_info = {
+    .name          = TYPE_BCM2835_CPRMAN,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(BCM2835CprmanState),
+    .class_init    = bcm2835_cprman_class_init,
+    .instance_init = bcm2835_cprman_init,
+};
+
+static void bcm2835_cprman_register_types(void)
+{
+    type_register_static(&bcm2835_cprman_info);
+}
+
+type_init(bcm2835_cprman_register_types)
diff --git a/include/hw/arm/bcm2835_peripherals.h b/include/hw/arm/bcm2835_peripherals.h
index f5b193f..f9f53e3 100644
--- a/include/hw/arm/bcm2835_peripherals.h
+++ b/include/hw/arm/bcm2835_peripherals.h
@@ -19,6 +19,7 @@
 #include "hw/intc/bcm2835_ic.h"
 #include "hw/misc/bcm2835_property.h"
 #include "hw/misc/bcm2835_rng.h"
+#include "hw/misc/bcm2835_cprman.h"
 #include "hw/misc/bcm2835_mbox.h"
 #include "hw/sd/sdhci.h"
 #include "hw/sd/bcm2835_sdhost.h"
@@ -44,6 +45,7 @@ typedef struct BCM2835PeripheralState {
     BCM2835ICState ic;
     BCM2835PropertyState property;
     BCM2835RngState rng;
+    BCM2835CprmanState cprman;
     BCM2835MboxState mboxes;
     SDHCIState sdhci;
     BCM2835SDHostState sdhost;
diff --git a/include/hw/arm/raspi_platform.h b/include/hw/arm/raspi_platform.h
index 6467e88..412d010 100644
--- a/include/hw/arm/raspi_platform.h
+++ b/include/hw/arm/raspi_platform.h
@@ -36,6 +36,7 @@
                                                       * Doorbells & Mailboxes */
 #define PM_OFFSET               0x100000 /* Power Management, Reset controller
                                           * and Watchdog registers */
+#define CPRMAN_OFFSET           0x101000
 #define PCM_CLOCK_OFFSET        0x101098
 #define RNG_OFFSET              0x104000
 #define GPIO_OFFSET             0x200000
diff --git a/include/hw/misc/bcm2835_cprman.h b/include/hw/misc/bcm2835_cprman.h
new file mode 100644
index 0000000..db250b3
--- /dev/null
+++ b/include/hw/misc/bcm2835_cprman.h
@@ -0,0 +1,28 @@
+/*
+ * BCM2835 Poor-man's version of CPRMAN
+ *
+ * Copyright (C) 2018 Guenter Roeck <linux@roeck-us.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 BCM2835_CPRMAN_H
+#define BCM2835_CPRMAN_H
+
+#include "hw/sysbus.h"
+
+#define TYPE_BCM2835_CPRMAN "bcm2835-cprman"
+#define BCM2835_CPRMAN(obj) \
+        OBJECT_CHECK(BCM2835CprmanState, (obj), TYPE_BCM2835_CPRMAN)
+
+#define CPRMAN_NUM_REGS         (0x1200 / 4)
+
+typedef struct {
+    SysBusDevice busdev;
+    MemoryRegion iomem;
+
+    uint32_t regs[CPRMAN_NUM_REGS];
+} BCM2835CprmanState;
+
+#endif
-- 
2.7.4

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