Hi Matyáš,
On 29/6/26 14:00, Peter Maydell wrote:
From: Matyáš Bobek <[email protected]>
Added the FlexCAN2 emulator implementation core, with
CAN_FLEXCAN Kconfig flag and MAINTAINERS entry.
FlexCAN2 version can be found in i.MX6 SoCs and others.
More information about the implementation can be found in [1].
Some macro and struct defintions were borrowed from the Linux kernel.
The original authors agreed with relicensing them to GPL-2.0-or-later on
the qemu-devel mailing list.
[1]
http://dspace.cvut.cz/bitstream/handle/10467/122654/F3-BP-2025-Bobek-Matyas-BP_Bobek_FlexCAN_final_4.pdf
Signed-off-by: Matyáš Bobek <[email protected]>
Signed-off-by: Pavel Pisa <[email protected]>
Tested-by: Pavel Pisa <[email protected]>
Reviewed-by: Bernhard Beschow <[email protected]>
Reviewed-by: Pavel Pisa <[email protected]>
Message-id:
03dc62ff8013bb946aab8f64e51638b810629529.1782140438.git.matyas.bo...@gmail.com
Signed-off-by: Peter Maydell <[email protected]>
---
MAINTAINERS | 8 +
hw/net/Kconfig | 5 +
hw/net/can/flexcan.c | 1396 +++++++++++++++++++++++++++++++++++++
hw/net/can/flexcan_regs.h | 197 ++++++
hw/net/can/meson.build | 1 +
hw/net/can/trace-events | 18 +
include/hw/net/flexcan.h | 145 ++++
7 files changed, 1770 insertions(+)
This commit is huge, not easy to follow / review.
create mode 100644 hw/net/can/flexcan.c
create mode 100644 hw/net/can/flexcan_regs.h
create mode 100644 include/hw/net/flexcan.h
diff --git a/hw/net/can/flexcan.c b/hw/net/can/flexcan.c
new file mode 100644
index 0000000000..1ea459d9f6
--- /dev/null
+++ b/hw/net/can/flexcan.c
@@ -0,0 +1,1396 @@
+/*
+ * QEMU model of the NXP FLEXCAN device.
+ *
+ * This implementation is based on the following reference manual:
+ * i.MX 6Dual/6Quad Applications Processor Reference Manual
+ * Document Number: IMX6DQRM, Rev. 6, 05/2020
+ *
+ * Copyright (c) 2025 Matyas Bobek <[email protected]>
+ *
+ * Based on CTU CAN FD emulation implemented by Jan Charvat.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "hw/core/sysbus.h"
+#include "qapi/error.h"
+#include "hw/core/irq.h"
+#include "migration/vmstate.h"
+#include "net/can_emu.h"
+#include "hw/core/qdev-properties.h"
+#include "trace.h"
+
+#include "hw/net/flexcan.h"
+#include "flexcan_regs.h"
+#include "qemu/timer.h"
+/**
+ * flexcan_get_bitrate() - Calculate CAN bitrate (in Hz)
+ * @s: FlexCAN device pointer
+ *
+ * The bitrate is determined by FlexCAN configuration in CTRL1 register,
+ * and CCM co
+ */
+static uint32_t flexcan_get_bitrate(FlexcanState *s)
+{
+ uint32_t conf_presdiv = (s->regs.ctrl & FLEXCAN_CTRL_PRESDIV_MASK) >> 24;
+ uint32_t conf_pseg1 = (s->regs.ctrl & FLEXCAN_CTRL_PSEG1_MASK) >> 19;
+ uint32_t conf_pseg2 = (s->regs.ctrl & FLEXCAN_CTRL_PSEG2_MASK) >> 16;
+ uint32_t conf_propseg = s->regs.ctrl & FLEXCAN_CTRL_PROPSEG_MASK;
+
+ /* N of time quanta for segments */
+ uint32_t tseg1 = 2 + conf_pseg1 + conf_propseg;
+ uint32_t tseg2 = 1 + conf_pseg2;
+ uint32_t total_qpb = 1 + tseg1 + tseg2;
+
+ uint32_t pe_freq, s_freq, bitrate;
+
+ assert(s->ccm);
Instead of that deep buried late unexplained assertion crashing
when the guest is running, ...
+
+ /* s_freq: CAN clock from CCM divided by the prescaler */
+ pe_freq = imx_ccm_get_clock_frequency(s->ccm, CLK_CAN);
+ s_freq = pe_freq / (1 + conf_presdiv);
+ bitrate = s_freq / total_qpb;
+
+ trace_flexcan_get_bitrate(DEVICE(s)->canonical_path, pe_freq,
+ 1 + conf_presdiv, s_freq, tseg1, tseg2,
total_qpb,
+ bitrate);
+ return bitrate;
+}
+static void flexcan_init(Object *obj)
+{
+ FlexcanState *s = CAN_FLEXCAN(obj);
+
+ memory_region_init_io(
+ &s->iomem, obj, &flexcan_ops, s, TYPE_CAN_FLEXCAN,
+ offsetof(FlexcanRegs, _reserved6)
+ );
+}
+
+static void flexcan_realize(DeviceState *dev, Error **errp)
+{
+ FlexcanState *s = CAN_FLEXCAN(dev);
+
+ if (s->canbus) {
+ if (flexcan_connect_to_bus(s, s->canbus) < 0) {
+ error_setg(errp, "%s: flexcan_connect_to_bus failed",
+ dev->canonical_path);
+ return;
+ }
+ }
... expose it as a link in [*] and check it is set here, returning
an error to the upper layer before starting emulation:
if (!s->dma_mr) {
error_setg(errp, TYPE_CAN_FLEXCAN " 'clock-control-module' "
"link not set");
return;
}
+
+ sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
+ sysbus_init_irq(SYS_BUS_DEVICE(SYS_BUS_DEVICE(dev)), &s->irq);
+}
+
+static const VMStateDescription vmstate_can = {
+ .name = TYPE_CAN_FLEXCAN,
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (const VMStateField[]) {
+ VMSTATE_INT64(timer_start, FlexcanState),
+ VMSTATE_UINT32_ARRAY(regs_raw, FlexcanState, sizeof(FlexcanRegs) / 4),
+ VMSTATE_INT32(locked_mbidx, FlexcanState),
+ VMSTATE_INT32(smb_target_mbidx, FlexcanState),
+ VMSTATE_END_OF_LIST(),
+ },
+};
+
+static const Property flexcan_properties[] = {
+ DEFINE_PROP_LINK("canbus", FlexcanState, canbus, TYPE_CAN_BUS,
+ CanBusState *),
[*] here:
DEFINE_PROP_LINK("clock-control-module", FlexcanState, ccm,
TYPE_IMX_CCM, IMXCCMState *),
+};
+
+static void flexcan_class_init(ObjectClass *klass, const void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ ResettableClass *rc = RESETTABLE_CLASS(klass);
+
+ rc->phases.enter = flexcan_reset_enter;
+ rc->phases.hold = flexcan_reset_hold;
+ dc->realize = flexcan_realize;
+ device_class_set_props(dc, flexcan_properties);
+ dc->vmsd = &vmstate_can;
+ dc->desc = "i.MX FLEXCAN Controller";
+}
+
+static const TypeInfo flexcan_info = {
+ .name = TYPE_CAN_FLEXCAN,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(FlexcanState),
+ .class_init = flexcan_class_init,
+ .instance_init = flexcan_init,
+};
