diff options
Diffstat (limited to 'qemu/hw/misc/bcm2835_mbox.c')
| -rw-r--r-- | qemu/hw/misc/bcm2835_mbox.c | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/qemu/hw/misc/bcm2835_mbox.c b/qemu/hw/misc/bcm2835_mbox.c new file mode 100644 index 000000000..263280fd4 --- /dev/null +++ b/qemu/hw/misc/bcm2835_mbox.c @@ -0,0 +1,335 @@ +/* + * Raspberry Pi emulation (c) 2012 Gregory Estrade + * This code is licensed under the GNU GPLv2 and later. + * + * This file models the system mailboxes, which are used for + * communication with low-bandwidth GPU peripherals. Refs: + * https://github.com/raspberrypi/firmware/wiki/Mailboxes + * https://github.com/raspberrypi/firmware/wiki/Accessing-mailboxes + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "hw/misc/bcm2835_mbox.h" + +#define MAIL0_PEEK 0x90 +#define MAIL0_SENDER 0x94 +#define MAIL1_STATUS 0xb8 + +/* Mailbox status register */ +#define MAIL0_STATUS 0x98 +#define ARM_MS_FULL 0x80000000 +#define ARM_MS_EMPTY 0x40000000 +#define ARM_MS_LEVEL 0x400000FF /* Max. value depends on mailbox depth */ + +/* MAILBOX config/status register */ +#define MAIL0_CONFIG 0x9c +/* ANY write to this register clears the error bits! */ +#define ARM_MC_IHAVEDATAIRQEN 0x00000001 /* mbox irq enable: has data */ +#define ARM_MC_IHAVESPACEIRQEN 0x00000002 /* mbox irq enable: has space */ +#define ARM_MC_OPPISEMPTYIRQEN 0x00000004 /* mbox irq enable: Opp is empty */ +#define ARM_MC_MAIL_CLEAR 0x00000008 /* mbox clear write 1, then 0 */ +#define ARM_MC_IHAVEDATAIRQPEND 0x00000010 /* mbox irq pending: has space */ +#define ARM_MC_IHAVESPACEIRQPEND 0x00000020 /* mbox irq pending: Opp is empty */ +#define ARM_MC_OPPISEMPTYIRQPEND 0x00000040 /* mbox irq pending */ +/* Bit 7 is unused */ +#define ARM_MC_ERRNOOWN 0x00000100 /* error : none owner read from mailbox */ +#define ARM_MC_ERROVERFLW 0x00000200 /* error : write to fill mailbox */ +#define ARM_MC_ERRUNDRFLW 0x00000400 /* error : read from empty mailbox */ + +static void mbox_update_status(BCM2835Mbox *mb) +{ + mb->status &= ~(ARM_MS_EMPTY | ARM_MS_FULL); + if (mb->count == 0) { + mb->status |= ARM_MS_EMPTY; + } else if (mb->count == MBOX_SIZE) { + mb->status |= ARM_MS_FULL; + } +} + +static void mbox_reset(BCM2835Mbox *mb) +{ + int n; + + mb->count = 0; + mb->config = 0; + for (n = 0; n < MBOX_SIZE; n++) { + mb->reg[n] = MBOX_INVALID_DATA; + } + mbox_update_status(mb); +} + +static uint32_t mbox_pull(BCM2835Mbox *mb, int index) +{ + int n; + uint32_t val; + + assert(mb->count > 0); + assert(index < mb->count); + + val = mb->reg[index]; + for (n = index + 1; n < mb->count; n++) { + mb->reg[n - 1] = mb->reg[n]; + } + mb->count--; + mb->reg[mb->count] = MBOX_INVALID_DATA; + + mbox_update_status(mb); + + return val; +} + +static void mbox_push(BCM2835Mbox *mb, uint32_t val) +{ + assert(mb->count < MBOX_SIZE); + mb->reg[mb->count++] = val; + mbox_update_status(mb); +} + +static void bcm2835_mbox_update(BCM2835MboxState *s) +{ + uint32_t value; + bool set; + int n; + + s->mbox_irq_disabled = true; + + /* Get pending responses and put them in the vc->arm mbox, + * as long as it's not full + */ + for (n = 0; n < MBOX_CHAN_COUNT; n++) { + while (s->available[n] && !(s->mbox[0].status & ARM_MS_FULL)) { + value = ldl_le_phys(&s->mbox_as, n << MBOX_AS_CHAN_SHIFT); + assert(value != MBOX_INVALID_DATA); /* Pending interrupt but no data */ + mbox_push(&s->mbox[0], value); + } + } + + /* TODO (?): Try to push pending requests from the arm->vc mbox */ + + /* Re-enable calls from the IRQ routine */ + s->mbox_irq_disabled = false; + + /* Update ARM IRQ status */ + set = false; + s->mbox[0].config &= ~ARM_MC_IHAVEDATAIRQPEND; + if (!(s->mbox[0].status & ARM_MS_EMPTY)) { + s->mbox[0].config |= ARM_MC_IHAVEDATAIRQPEND; + if (s->mbox[0].config & ARM_MC_IHAVEDATAIRQEN) { + set = true; + } + } + qemu_set_irq(s->arm_irq, set); +} + +static void bcm2835_mbox_set_irq(void *opaque, int irq, int level) +{ + BCM2835MboxState *s = opaque; + + s->available[irq] = level; + + /* avoid recursively calling bcm2835_mbox_update when the interrupt + * status changes due to the ldl_phys call within that function + */ + if (!s->mbox_irq_disabled) { + bcm2835_mbox_update(s); + } +} + +static uint64_t bcm2835_mbox_read(void *opaque, hwaddr offset, unsigned size) +{ + BCM2835MboxState *s = opaque; + uint32_t res = 0; + + offset &= 0xff; + + switch (offset) { + case 0x80 ... 0x8c: /* MAIL0_READ */ + if (s->mbox[0].status & ARM_MS_EMPTY) { + res = MBOX_INVALID_DATA; + } else { + res = mbox_pull(&s->mbox[0], 0); + } + break; + + case MAIL0_PEEK: + res = s->mbox[0].reg[0]; + break; + + case MAIL0_SENDER: + break; + + case MAIL0_STATUS: + res = s->mbox[0].status; + break; + + case MAIL0_CONFIG: + res = s->mbox[0].config; + break; + + case MAIL1_STATUS: + res = s->mbox[1].status; + break; + + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n", + __func__, offset); + return 0; + } + + bcm2835_mbox_update(s); + + return res; +} + +static void bcm2835_mbox_write(void *opaque, hwaddr offset, + uint64_t value, unsigned size) +{ + BCM2835MboxState *s = opaque; + hwaddr childaddr; + uint8_t ch; + + offset &= 0xff; + + switch (offset) { + case MAIL0_SENDER: + break; + + case MAIL0_CONFIG: + s->mbox[0].config &= ~ARM_MC_IHAVEDATAIRQEN; + s->mbox[0].config |= value & ARM_MC_IHAVEDATAIRQEN; + break; + + case 0xa0 ... 0xac: /* MAIL1_WRITE */ + if (s->mbox[1].status & ARM_MS_FULL) { + /* Mailbox full */ + qemu_log_mask(LOG_GUEST_ERROR, "%s: mailbox full\n", __func__); + } else { + ch = value & 0xf; + if (ch < MBOX_CHAN_COUNT) { + childaddr = ch << MBOX_AS_CHAN_SHIFT; + if (ldl_le_phys(&s->mbox_as, childaddr + MBOX_AS_PENDING)) { + /* Child busy, push delayed. Push it in the arm->vc mbox */ + mbox_push(&s->mbox[1], value); + } else { + /* Push it directly to the child device */ + stl_le_phys(&s->mbox_as, childaddr, value); + } + } else { + /* Invalid channel number */ + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid channel %u\n", + __func__, ch); + } + } + break; + + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n", + __func__, offset); + return; + } + + bcm2835_mbox_update(s); +} + +static const MemoryRegionOps bcm2835_mbox_ops = { + .read = bcm2835_mbox_read, + .write = bcm2835_mbox_write, + .endianness = DEVICE_NATIVE_ENDIAN, + .valid.min_access_size = 4, + .valid.max_access_size = 4, +}; + +/* vmstate of a single mailbox */ +static const VMStateDescription vmstate_bcm2835_mbox_box = { + .name = TYPE_BCM2835_MBOX "_box", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32_ARRAY(reg, BCM2835Mbox, MBOX_SIZE), + VMSTATE_UINT32(count, BCM2835Mbox), + VMSTATE_UINT32(status, BCM2835Mbox), + VMSTATE_UINT32(config, BCM2835Mbox), + VMSTATE_END_OF_LIST() + } +}; + +/* vmstate of the entire device */ +static const VMStateDescription vmstate_bcm2835_mbox = { + .name = TYPE_BCM2835_MBOX, + .version_id = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .fields = (VMStateField[]) { + VMSTATE_BOOL_ARRAY(available, BCM2835MboxState, MBOX_CHAN_COUNT), + VMSTATE_STRUCT_ARRAY(mbox, BCM2835MboxState, 2, 1, + vmstate_bcm2835_mbox_box, BCM2835Mbox), + VMSTATE_END_OF_LIST() + } +}; + +static void bcm2835_mbox_init(Object *obj) +{ + BCM2835MboxState *s = BCM2835_MBOX(obj); + + memory_region_init_io(&s->iomem, obj, &bcm2835_mbox_ops, s, + TYPE_BCM2835_MBOX, 0x400); + sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem); + sysbus_init_irq(SYS_BUS_DEVICE(s), &s->arm_irq); + qdev_init_gpio_in(DEVICE(s), bcm2835_mbox_set_irq, MBOX_CHAN_COUNT); +} + +static void bcm2835_mbox_reset(DeviceState *dev) +{ + BCM2835MboxState *s = BCM2835_MBOX(dev); + int n; + + mbox_reset(&s->mbox[0]); + mbox_reset(&s->mbox[1]); + s->mbox_irq_disabled = false; + for (n = 0; n < MBOX_CHAN_COUNT; n++) { + s->available[n] = false; + } +} + +static void bcm2835_mbox_realize(DeviceState *dev, Error **errp) +{ + BCM2835MboxState *s = BCM2835_MBOX(dev); + Object *obj; + Error *err = NULL; + + obj = object_property_get_link(OBJECT(dev), "mbox-mr", &err); + if (obj == NULL) { + error_setg(errp, "%s: required mbox-mr link not found: %s", + __func__, error_get_pretty(err)); + return; + } + + s->mbox_mr = MEMORY_REGION(obj); + address_space_init(&s->mbox_as, s->mbox_mr, NULL); + bcm2835_mbox_reset(dev); +} + +static void bcm2835_mbox_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = bcm2835_mbox_realize; + dc->reset = bcm2835_mbox_reset; + dc->vmsd = &vmstate_bcm2835_mbox; +} + +static TypeInfo bcm2835_mbox_info = { + .name = TYPE_BCM2835_MBOX, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(BCM2835MboxState), + .class_init = bcm2835_mbox_class_init, + .instance_init = bcm2835_mbox_init, +}; + +static void bcm2835_mbox_register_types(void) +{ + type_register_static(&bcm2835_mbox_info); +} + +type_init(bcm2835_mbox_register_types) |