[PATCH 19/44] Add RNG200 timer

[Sergey Kambalin]

Signed-off-by: Sergey Kambalin <sergey.kambalin@auriga.com>
---
 hw/arm/bcm2838_peripherals.c         |  14 ++++
 hw/arm/raspi4b.c                     |   1 -
 hw/misc/bcm2838_rng200.c             | 105 ++++++++++++++++++++++++---
 include/hw/arm/bcm2838_peripherals.h |   2 +
 4 files changed, 111 insertions(+), 11 deletions(-)

diff --git a/hw/arm/bcm2838_peripherals.c b/hw/arm/bcm2838_peripherals.c
index 41b321b254..df97953bbe 100644
--- a/hw/arm/bcm2838_peripherals.c
+++ b/hw/arm/bcm2838_peripherals.c
@@ -34,6 +34,9 @@ static void bcm2838_peripherals_init(Object *obj)
                        bc->peri_low_size);
     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->peri_low_mr);
 
+    /* Random Number Generator */
+    object_initialize_child(obj, "rng200", &s->rng200, TYPE_BCM2838_RNG200);
+
     /* PCIe Host Bridge */
     object_initialize_child(obj, "pcie-host", &s->pcie_host,
                             TYPE_BCM2838_PCIE_HOST);
@@ -84,6 +87,17 @@ static void bcm2838_peripherals_realize(DeviceState *dev, 
Error **errp)
                                         BCM2838_VC_PERI_LOW_BASE,
                                         &s->peri_low_mr_alias, 1);
 
+    /* Random Number Generator */
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->rng200), errp)) {
+        return;
+    }
+    memory_region_add_subregion(
+        &s_base->peri_mr, RNG_OFFSET,
+        sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->rng200), 0));
+    sysbus_connect_irq(SYS_BUS_DEVICE(&s->rng200), 0,
+        qdev_get_gpio_in_named(DEVICE(&s_base->ic), BCM2835_IC_GPU_IRQ,
+                               INTERRUPT_RNG));
+
     /* Extended Mass Media Controller 2 */
     object_property_set_uint(OBJECT(&s->emmc2), "sd-spec-version", 3,
                              &error_abort);
diff --git a/hw/arm/raspi4b.c b/hw/arm/raspi4b.c
index 115359e451..82b6b48d3c 100644
--- a/hw/arm/raspi4b.c
+++ b/hw/arm/raspi4b.c
@@ -66,7 +66,6 @@ static void raspi4_modify_dtb(const struct arm_boot_info 
*info, void *fdt)
 
     /* Temporary disable following devices until they are implemented*/
     const char *to_be_removed_from_dt_as_wa[] = {
-        "brcm,bcm2711-rng200",
         "brcm,bcm2711-thermal",
         "brcm,bcm2711-genet-v5",
     };
diff --git a/hw/misc/bcm2838_rng200.c b/hw/misc/bcm2838_rng200.c
index bfc40658e2..face1e9579 100644
--- a/hw/misc/bcm2838_rng200.c
+++ b/hw/misc/bcm2838_rng200.c
@@ -9,6 +9,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/log.h"
+#include "qom/object_interfaces.h"
 #include "qapi/error.h"
 #include "hw/qdev-properties.h"
 #include "hw/misc/bcm2838_rng200.h"
@@ -35,6 +36,15 @@ static void bcm2838_rng200_update_irq(BCM2838Rng200State 
*state)
                               & state->rng_int_status.value));
 }
 
+static void bcm2838_rng200_update_rbg_period(void *opaque, ClockEvent event)
+{
+    BCM2838Rng200State *s = (BCM2838Rng200State *)opaque;
+
+    ptimer_transaction_begin(s->ptimer);
+    ptimer_set_period_from_clock(s->ptimer, s->clock, s->rng_fifo_cap * 8);
+    ptimer_transaction_commit(s->ptimer);
+}
+
 static void bcm2838_rng200_update_fifo(void *opaque, const void *buf,
                                        size_t size)
 {
@@ -62,10 +72,11 @@ static void bcm2838_rng200_update_fifo(void *opaque, const 
void *buf,
     if ((num == 0) && (num_bits > 0)) {
         num = 1;
     }
-    if (num > 0) {
+    if (!state->use_timer || (num > 0)) {
         fifo8_push_all(fifo, buf, num);
 
-        if (fifo8_num_used(fifo) > state->rng_fifo_count.thld) {
+        if (!state->use_timer
+                || (fifo8_num_used(fifo) > state->rng_fifo_count.thld)) {
             state->rng_int_status.total_bits_count_irq = 1;
         }
     }
@@ -82,10 +93,14 @@ static void bcm2838_rng200_fill_fifo(BCM2838Rng200State 
*state)
                                 bcm2838_rng200_update_fifo, state);
 }
 
-/* state is temporary unused */
-static void bcm2838_rng200_disable_rbg(BCM2838Rng200State *state
-                                       __attribute__((unused)))
+static void bcm2838_rng200_disable_rbg(BCM2838Rng200State *state)
 {
+    if (state->use_timer) {
+        ptimer_transaction_begin(state->ptimer);
+        ptimer_stop(state->ptimer);
+        ptimer_transaction_commit(state->ptimer);
+    }
+
     trace_bcm2838_rng200_disable_rbg();
 }
 
@@ -93,11 +108,38 @@ static void bcm2838_rng200_enable_rbg(BCM2838Rng200State 
*state)
 {
     state->rng_total_bit_count = RNG_WARM_UP_PERIOD_ELAPSED;
 
-    bcm2838_rng200_fill_fifo(state);
+    if (state->use_timer) {
+        uint32_t div = state->rng_ctrl.div + 1;
+
+        ptimer_transaction_begin(state->ptimer);
+        ptimer_set_limit(state->ptimer, div, 1);
+        ptimer_set_count(state->ptimer, div);
+        ptimer_run(state->ptimer, 0);
+        ptimer_transaction_commit(state->ptimer);
+    } else {
+        bcm2838_rng200_fill_fifo(state);
+    }
 
     trace_bcm2838_rng200_enable_rbg();
 }
 
+static void bcm2838_rng200_ptimer_cb(void *arg)
+{
+    BCM2838Rng200State *state = (BCM2838Rng200State *)arg;
+    Fifo8 *fifo = &state->fifo;
+    size_t size = fifo8_num_free(fifo);
+
+    assert(state->rng_ctrl.rbg_enable);
+
+    if (size > 0) {
+        rng_backend_request_entropy(state->rng, size,
+                                    bcm2838_rng200_update_fifo, state);
+    } else {
+        ptimer_stop(state->ptimer);
+        trace_bcm2838_rng200_fifo_full();
+    }
+}
+
 static void bcm2838_rng200_rng_reset(BCM2838Rng200State *state)
 {
     state->rng_ctrl.value = 0;
@@ -129,6 +171,12 @@ static uint32_t 
bcm2838_rng200_read_fifo_data(BCM2838Rng200State *state)
         buf = fifo8_pop_buf(fifo, max, &num);
         if ((buf != NULL) && (num > 0)) {
             memcpy(&ret, buf, num);
+
+            if (state->rng_ctrl.rbg_enable && state->use_timer) {
+                ptimer_transaction_begin(state->ptimer);
+                ptimer_run(state->ptimer, 0);
+                ptimer_transaction_commit(state->ptimer);
+            }
         }
     } else {
         qemu_log_mask(
@@ -138,7 +186,10 @@ static uint32_t 
bcm2838_rng200_read_fifo_data(BCM2838Rng200State *state)
     }
 
     state->rng_fifo_count.count = fifo8_num_used(fifo) >> 2;
-    bcm2838_rng200_fill_fifo(state);
+
+    if (!state->use_timer) {
+        bcm2838_rng200_fill_fifo(state);
+    }
 
     return ret;
 }
@@ -237,7 +288,11 @@ static void bcm2838_rng200_write(void *opaque, hwaddr 
offset,
         break;
     case RNG_TOTAL_BIT_COUNT_THRESHOLD_OFFSET:
         s->rng_bit_count_threshold = value;
-        s->rng_total_bit_count = value + 1;
+        if (s->use_timer) {
+            s->rng_total_bit_count = 0;
+        } else {
+            s->rng_total_bit_count = value + 1;
+        }
         break;
     default:
         qemu_log_mask(
@@ -253,15 +308,39 @@ static const MemoryRegionOps bcm2838_rng200_ops = {
     .read = bcm2838_rng200_read,
     .write = bcm2838_rng200_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
+    .impl = {
+        .max_access_size = 4,
+        .min_access_size = 4,
+    },
+    .valid = {
+        .max_access_size = 4,
+        .min_access_size = 4
+    },
 };
 
 static void bcm2838_rng200_realize(DeviceState *dev, Error **errp)
 {
     BCM2838Rng200State *s = BCM2838_RNG200(dev);
 
+    if (s->use_timer) {
+        s->ptimer = ptimer_init(bcm2838_rng200_ptimer_cb, s,
+                                BCM2838_RNG200_PTIMER_POLICY);
+        if (s->ptimer == NULL) {
+            error_setg(&error_fatal, "Failed to init RBG timer");
+            return;
+        }
+    }
+
     if (s->rng == NULL) {
         Object *default_backend = object_new(TYPE_RNG_BUILTIN);
 
+        if (!user_creatable_complete(USER_CREATABLE(default_backend),
+                                     errp)) {
+            object_unref(default_backend);
+            error_setg(errp, "Failed to create user creatable RNG backend");
+            return;
+        }
+
         object_property_add_child(OBJECT(dev), "default-backend",
                                   default_backend);
         object_unref(default_backend);
@@ -270,6 +349,12 @@ static void bcm2838_rng200_realize(DeviceState *dev, Error 
**errp)
                                  errp);
     }
 
+    if (s->use_timer && !clock_has_source(s->clock)) {
+        ptimer_transaction_begin(s->ptimer);
+        ptimer_set_period(s->ptimer, s->rbg_period * s->rng_fifo_cap * 8);
+        ptimer_transaction_commit(s->ptimer);
+    }
+
     fifo8_create(&s->fifo, s->rng_fifo_cap);
     sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
 }
@@ -280,7 +365,7 @@ static void bcm2838_rng200_init(Object *obj)
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 
     s->clock = qdev_init_clock_in(DEVICE(s), "rbg-clock",
-                                  NULL, s,
+                                  bcm2838_rng200_update_rbg_period, s,
                                   ClockPreUpdate);
     if (s->clock == NULL) {
         error_setg(&error_fatal, "Failed to init RBG clock");
@@ -305,7 +390,7 @@ static Property bcm2838_rng200_properties[] = {
     DEFINE_PROP_UINT32("rng-fifo-cap", BCM2838Rng200State, rng_fifo_cap, 128),
     DEFINE_PROP_LINK("rng", BCM2838Rng200State, rng,
                      TYPE_RNG_BACKEND, RngBackend *),
-    DEFINE_PROP_BOOL("use-timer", BCM2838Rng200State, use_timer, false),
+    DEFINE_PROP_BOOL("use-timer", BCM2838Rng200State, use_timer, true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/arm/bcm2838_peripherals.h 
b/include/hw/arm/bcm2838_peripherals.h
index d3e3449b2b..d52617f3bd 100644
--- a/include/hw/arm/bcm2838_peripherals.h
+++ b/include/hw/arm/bcm2838_peripherals.h
@@ -10,6 +10,7 @@
 #define BCM2838_PERIPHERALS_H
 
 #include "hw/arm/bcm2835_peripherals.h"
+#include "hw/misc/bcm2838_rng200.h"
 #include "hw/arm/bcm2838_pcie.h"
 #include "hw/sd/sdhci.h"
 #include "hw/gpio/bcm2838_gpio.h"
@@ -67,6 +68,7 @@ struct BCM2838PeripheralState {
     MemoryRegion mphi_mr_alias;
     MemoryRegion pcie_mmio_alias;
 
+    BCM2838Rng200State rng200;
     SDHCIState emmc2;
     BCM2838PcieHostState pcie_host;
     BCM2838GpioState gpio;
-- 
2.34.1