[PATCH v6 17/41] Implement BCM2838 thermal sensor

[Sergey Kambalin]

Signed-off-by: Sergey Kambalin <sergey.kambalin@auriga.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/bcm2838_peripherals.c         | 11 ++++
 hw/arm/raspi4b.c                     |  1 -
 hw/misc/bcm2838_thermal.c            | 98 ++++++++++++++++++++++++++++
 hw/misc/meson.build                  |  1 +
 include/hw/arm/bcm2838_peripherals.h |  2 +
 include/hw/misc/bcm2838_thermal.h    | 24 +++++++
 6 files changed, 136 insertions(+), 1 deletion(-)
 create mode 100644 hw/misc/bcm2838_thermal.c
 create mode 100644 include/hw/misc/bcm2838_thermal.h

diff --git a/hw/arm/bcm2838_peripherals.c b/hw/arm/bcm2838_peripherals.c
index 4a9cbe6cf6..6badda3045 100644
--- a/hw/arm/bcm2838_peripherals.c
+++ b/hw/arm/bcm2838_peripherals.c
@@ -37,6 +37,9 @@ static void bcm2838_peripherals_init(Object *obj)
     /* Random Number Generator */
     object_initialize_child(obj, "rng200", &s->rng200, TYPE_BCM2838_RNG200);
 
+    /* Thermal */
+    object_initialize_child(obj, "thermal", &s->thermal, TYPE_BCM2838_THERMAL);
+
     /* PCIe Host Bridge */
     object_initialize_child(obj, "pcie-host", &s->pcie_host,
                             TYPE_BCM2838_PCIE_HOST);
@@ -80,6 +83,7 @@ static void bcm2838_peripherals_realize(DeviceState *dev, 
Error **errp)
     MemoryRegion *mmio_mr;
     MemoryRegion *rng200_mr;
     qemu_irq rng_200_irq;
+    MemoryRegion *thermal_mr;
 
     int n;
 
@@ -105,6 +109,13 @@ static void bcm2838_peripherals_realize(DeviceState *dev, 
Error **errp)
                                          BCM2835_IC_GPU_IRQ, INTERRUPT_RNG);
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->rng200), 0, rng_200_irq);
 
+    /* THERMAL */
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->thermal), errp)) {
+        return;
+    }
+    thermal_mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->thermal), 0);
+    memory_region_add_subregion( &s->peri_low_mr, 0x15D2000, thermal_mr);
+
     /* 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 3c71fa9a9a..175fd2c4fa 100644
--- a/hw/arm/raspi4b.c
+++ b/hw/arm/raspi4b.c
@@ -67,7 +67,6 @@ static void raspi4_modify_dtb(const struct arm_boot_info 
*info, void *fdt)
 
     /* Temporarily disable following devices until they are implemented */
     const char *nodes_to_remove[] = {
-        "brcm,bcm2711-thermal",
         "brcm,bcm2711-genet-v5",
     };
 
diff --git a/hw/misc/bcm2838_thermal.c b/hw/misc/bcm2838_thermal.c
new file mode 100644
index 0000000000..3764d55b59
--- /dev/null
+++ b/hw/misc/bcm2838_thermal.c
@@ -0,0 +1,98 @@
+/*
+ * BCM2838 dummy thermal sensor
+ *
+ * Copyright (C) 2022 Maksim Kopusov <maksim.kopusov@auriga.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qapi/error.h"
+#include "hw/misc/bcm2838_thermal.h"
+#include "hw/registerfields.h"
+#include "migration/vmstate.h"
+#include "qemu/error-report.h"
+
+REG32(STAT, 0x200)
+FIELD(STAT, DATA, 0, 10)
+FIELD(STAT, VALID_1, 10, 1)
+FIELD(STAT, VALID_2, 16, 1)
+
+#define BCM2838_THERMAL_SIZE 0xf00
+
+#define THERMAL_OFFSET_C 410040
+#define THERMAL_COEFF  (-487.0f)
+#define MILLIDEGREE_COEFF 1000
+
+static uint16_t bcm2838_thermal_temp2adc(int temp_C)
+{
+    return (temp_C * MILLIDEGREE_COEFF - THERMAL_OFFSET_C) / THERMAL_COEFF;
+}
+
+static uint64_t bcm2838_thermal_read(void *opaque, hwaddr addr, unsigned size)
+{
+    uint32_t val = 0;
+
+    switch (addr) {
+    case A_STAT:
+        /* Temperature is always 25°C */
+        val = FIELD_DP32(val, STAT, DATA, bcm2838_thermal_temp2adc(25));
+        val = FIELD_DP32(val, STAT, VALID_1, 1);
+        val = FIELD_DP32(val, STAT, VALID_2, 1);
+
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s can't access addr: 0x%"HWADDR_PRIx,
+                     TYPE_BCM2838_THERMAL, addr);
+    }
+    return val;
+}
+
+static void bcm2838_thermal_write(void *opaque, hwaddr addr,
+                                      uint64_t value, unsigned size)
+{
+    qemu_log_mask(LOG_GUEST_ERROR, "%s: write 0x%" PRIx64
+                                " to 0x%" HWADDR_PRIx "\n",
+                __func__, value, addr);
+}
+
+static const MemoryRegionOps bcm2838_thermal_ops = {
+    .read = bcm2838_thermal_read,
+    .write = bcm2838_thermal_write,
+    .impl.max_access_size = 4,
+    .valid.min_access_size = 4,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void bcm2838_thermal_realize(DeviceState *dev, Error **errp)
+{
+    Bcm2838ThermalState *s = BCM2838_THERMAL(dev);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &bcm2838_thermal_ops,
+                          s, TYPE_BCM2838_THERMAL, BCM2838_THERMAL_SIZE);
+    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
+}
+
+static void bcm2838_thermal_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = bcm2838_thermal_realize;
+
+    /* This device has no state: no need for vmstate or reset */
+}
+
+static const TypeInfo bcm2838_thermal_info = {
+    .name = TYPE_BCM2838_THERMAL,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(Bcm2838ThermalState),
+    .class_init = bcm2838_thermal_class_init,
+};
+
+static void bcm2838_thermal_register_types(void)
+{
+    type_register_static(&bcm2838_thermal_info);
+}
+
+type_init(bcm2838_thermal_register_types)
diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index a3bee4375d..764e27ef67 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -93,6 +93,7 @@ system_ss.add(when: 'CONFIG_RASPI', if_true: files(
   'bcm2835_cprman.c',
   'bcm2835_powermgt.c',
   'bcm2838_rng200.c',
+  'bcm2838_thermal.c',
 ))
 system_ss.add(when: 'CONFIG_SLAVIO', if_true: files('slavio_misc.c'))
 system_ss.add(when: 'CONFIG_ZYNQ', if_true: files('zynq_slcr.c'))
diff --git a/include/hw/arm/bcm2838_peripherals.h 
b/include/hw/arm/bcm2838_peripherals.h
index 914a287af2..49bb4fab08 100644
--- a/include/hw/arm/bcm2838_peripherals.h
+++ b/include/hw/arm/bcm2838_peripherals.h
@@ -11,6 +11,7 @@
 
 #include "hw/arm/bcm2835_peripherals.h"
 #include "hw/misc/bcm2838_rng200.h"
+#include "hw/misc/bcm2838_thermal.h"
 #include "hw/arm/bcm2838_pcie.h"
 #include "hw/sd/sdhci.h"
 #include "hw/gpio/bcm2838_gpio.h"
@@ -66,6 +67,7 @@ struct BCM2838PeripheralState {
     MemoryRegion mphi_mr_alias;
 
     BCM2838Rng200State rng200;
+    Bcm2838ThermalState thermal;
     SDHCIState emmc2;
     BCM2838PcieHostState pcie_host;
     BCM2838GpioState gpio;
diff --git a/include/hw/misc/bcm2838_thermal.h 
b/include/hw/misc/bcm2838_thermal.h
new file mode 100644
index 0000000000..bb6302a037
--- /dev/null
+++ b/include/hw/misc/bcm2838_thermal.h
@@ -0,0 +1,24 @@
+/*
+ * BCM2838 dummy thermal sensor
+ *
+ * Copyright (C) 2022 Maksim Kopusov <maksim.kopusov@auriga.com>
+ *
+ * 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 BCM2838_THERMAL_H
+#define BCM2838_THERMAL_H
+
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define TYPE_BCM2838_THERMAL "bcm2838-thermal"
+OBJECT_DECLARE_SIMPLE_TYPE(Bcm2838ThermalState, BCM2838_THERMAL)
+
+struct Bcm2838ThermalState {
+    SysBusDevice busdev;
+    MemoryRegion iomem;
+};
+
+#endif /* BCM2838_THERMAL_H */
-- 
2.34.1