/* * IMX31 UARTS * * Copyright (c) 2008 OKL * Originally Written by Hans Jiang * Copyright (c) 2011 NICTA Pty Ltd. * Updated by Jean-Christophe Dubois * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * * This is a `bare-bones' implementation of the IMX series serial ports. * TODO: * -- implement FIFOs. The real hardware has 32 word transmit * and receive FIFOs; we currently use a 1-char buffer * -- implement DMA * -- implement BAUD-rate and modem lines, for when the backend * is a real serial device. */ #include "qemu/osdep.h" #include "hw/char/imx_serial.h" #include "hw/irq.h" #include "sysemu/sysemu.h" #include "qemu/log.h" #include "qemu/module.h" #ifndef DEBUG_IMX_UART #define DEBUG_IMX_UART 0 #endif #define DPRINTF(fmt, args...) \ do { \ if (DEBUG_IMX_UART) { \ fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_SERIAL, \ __func__, ##args); \ } \ } while (0) static const VMStateDescription vmstate_imx_serial = { .name = TYPE_IMX_SERIAL, .version_id = 2, .minimum_version_id = 2, .fields = (VMStateField[]) { VMSTATE_INT32(readbuff, IMXSerialState), VMSTATE_UINT32(usr1, IMXSerialState), VMSTATE_UINT32(usr2, IMXSerialState), VMSTATE_UINT32(ucr1, IMXSerialState), VMSTATE_UINT32(uts1, IMXSerialState), VMSTATE_UINT32(onems, IMXSerialState), VMSTATE_UINT32(ufcr, IMXSerialState), VMSTATE_UINT32(ubmr, IMXSerialState), VMSTATE_UINT32(ubrc, IMXSerialState), VMSTATE_UINT32(ucr3, IMXSerialState), VMSTATE_UINT32(ucr4, IMXSerialState), VMSTATE_END_OF_LIST() }, }; static void imx_update(IMXSerialState *s) { uint32_t usr1; uint32_t usr2; uint32_t mask; /* * Lucky for us TRDY and RRDY has the same offset in both USR1 and * UCR1, so we can get away with something as simple as the * following: */ usr1 = s->usr1 & s->ucr1 & (USR1_TRDY | USR1_RRDY); /* * Bits that we want in USR2 are not as conveniently laid out, * unfortunately. */ mask = (s->ucr1 & UCR1_TXMPTYEN) ? USR2_TXFE : 0; /* * TCEN and TXDC are both bit 3 * RDR and DREN are both bit 0 */ mask |= s->ucr4 & (UCR4_TCEN | UCR4_DREN); usr2 = s->usr2 & mask; qemu_set_irq(s->irq, usr1 || usr2); } static void imx_serial_reset(IMXSerialState *s) { s->usr1 = USR1_TRDY | USR1_RXDS; /* * Fake attachment of a terminal: assert RTS. */ s->usr1 |= USR1_RTSS; s->usr2 = USR2_TXFE | USR2_TXDC | USR2_DCDIN; s->uts1 = UTS1_RXEMPTY | UTS1_TXEMPTY; s->ucr1 = 0; s->ucr2 = UCR2_SRST; s->ucr3 = 0x700; s->ubmr = 0; s->ubrc = 4; s->readbuff = URXD_ERR; } static void imx_serial_reset_at_boot(DeviceState *dev) { IMXSerialState *s = IMX_SERIAL(dev); imx_serial_reset(s); /* * enable the uart on boot, so messages from the linux decompresser * are visible. On real hardware this is done by the boot rom * before anything else is loaded. */ s->ucr1 = UCR1_UARTEN; s->ucr2 = UCR2_TXEN; } static uint64_t imx_serial_read(void *opaque, hwaddr offset, unsigned size) { IMXSerialState *s = (IMXSerialState *)opaque; uint32_t c; DPRINTF("read(offset=0x%" HWADDR_PRIx ")\n", offset); switch (offset >> 2) { case 0x0: /* URXD */ c = s->readbuff; if (!(s->uts1 & UTS1_RXEMPTY)) { /* Character is valid */ c |= URXD_CHARRDY; s->usr1 &= ~USR1_RRDY; s->usr2 &= ~USR2_RDR; s->uts1 |= UTS1_RXEMPTY; imx_update(s); qemu_chr_fe_accept_input(&s->chr); } return c; case 0x20: /* UCR1 */ return s->ucr1; case 0x21: /* UCR2 */ return s->ucr2; case 0x25: /* USR1 */ return s->usr1; case 0x26: /* USR2 */ return s->usr2; case 0x2A: /* BRM Modulator */ return s->ubmr; case 0x2B: /* Baud Rate Count */ return s->ubrc; case 0x2d: /* Test register */ return s->uts1; case 0x24: /* UFCR */ return s->ufcr; case 0x2c: return s->onems; case 0x22: /* UCR3 */ return s->ucr3; case 0x23: /* UCR4 */ return s->ucr4; case 0x29: /* BRM Incremental */ return 0x0; /* TODO */ default: qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%" HWADDR_PRIx "\n", TYPE_IMX_SERIAL, __func__, offset); return 0; } } static void imx_serial_write(void *opaque, hwaddr offset, uint64_t value, unsigned size) { IMXSerialState *s = (IMXSerialState *)opaque; Chardev *chr = qemu_chr_fe_get_driver(&s->chr); unsigned char ch; DPRINTF("write(offset=0x%" HWADDR_PRIx ", value = 0x%x) to %s\n", offset, (unsigned int)value, chr ? chr->label : "NODEV"); switch (offset >> 2) { case 0x10: /* UTXD */ ch = value; if (s->ucr2 & UCR2_TXEN) { /* XXX this blocks entire thread. Rewrite to use * qemu_chr_fe_write and background I/O callbacks */ qemu_chr_fe_write_all(&s->chr, &ch, 1); s->usr1 &= ~USR1_TRDY; s->usr2 &= ~USR2_TXDC; imx_update(s); s->usr1 |= USR1_TRDY; s->usr2 |= USR2_TXDC; imx_update(s); } break; case 0x20: /* UCR1 */ s->ucr1 = value & 0xffff; DPRINTF("write(ucr1=%x)\n", (unsigned int)value); imx_update(s); break; case 0x21: /* UCR2 */ /* * Only a few bits in control register 2 are implemented as yet. * If it's intended to use a real serial device as a back-end, this * register will have to be implemented more fully. */ if (!(value & UCR2_SRST)) { imx_serial_reset(s); imx_update(s); value |= UCR2_SRST; } if (value & UCR2_RXEN) { if (!(s->ucr2 & UCR2_RXEN)) { qemu_chr_fe_accept_input(&s->chr); } } s->ucr2 = value & 0xffff; break; case 0x25: /* USR1 */ value &= USR1_AWAKE | USR1_AIRINT | USR1_DTRD | USR1_AGTIM | USR1_FRAMERR | USR1_ESCF | USR1_RTSD | USR1_PARTYER; s->usr1 &= ~value; break; case 0x26: /* USR2 */ /* * Writing 1 to some bits clears them; all other * values are ignored */ value &= USR2_ADET | USR2_DTRF | USR2_IDLE | USR2_ACST | USR2_RIDELT | USR2_IRINT | USR2_WAKE | USR2_DCDDELT | USR2_RTSF | USR2_BRCD | USR2_ORE; s->usr2 &= ~value; break; /* * Linux expects to see what it writes to these registers * We don't currently alter the baud rate */ case 0x29: /* UBIR */ s->ubrc = value & 0xffff; break; case 0x2a: /* UBMR */ s->ubmr = value & 0xffff; break; case 0x2c: /* One ms reg */ s->onems = value & 0xffff; break; case 0x24: /* FIFO control register */ s->ufcr = value & 0xffff; break; case 0x22: /* UCR3 */ s->ucr3 = value & 0xffff; break; case 0x23: /* UCR4 */ s->ucr4 = value & 0xffff; imx_update(s); break; case 0x2d: /* UTS1 */ qemu_log_mask(LOG_UNIMP, "[%s]%s: Unimplemented reg 0x%" HWADDR_PRIx "\n", TYPE_IMX_SERIAL, __func__, offset); /* TODO */ break; default: qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%" HWADDR_PRIx "\n", TYPE_IMX_SERIAL, __func__, offset); } } static int imx_can_receive(void *opaque) { IMXSerialState *s = (IMXSerialState *)opaque; return !(s->usr1 & USR1_RRDY); } static void imx_put_data(void *opaque, uint32_t value) { IMXSerialState *s = (IMXSerialState *)opaque; DPRINTF("received char\n"); s->usr1 |= USR1_RRDY; s->usr2 |= USR2_RDR; s->uts1 &= ~UTS1_RXEMPTY; s->readbuff = value; if (value & URXD_BRK) { s->usr2 |= USR2_BRCD; } imx_update(s); } static void imx_receive(void *opaque, const uint8_t *buf, int size) { imx_put_data(opaque, *buf); } static void imx_event(void *opaque, int event) { if (event == CHR_EVENT_BREAK) { imx_put_data(opaque, URXD_BRK | URXD_FRMERR | URXD_ERR); } } static const struct MemoryRegionOps imx_serial_ops = { .read = imx_serial_read, .write = imx_serial_write, .endianness = DEVICE_NATIVE_ENDIAN, }; static void imx_serial_realize(DeviceState *dev, Error **errp) { IMXSerialState *s = IMX_SERIAL(dev); DPRINTF("char dev for uart: %p\n", qemu_chr_fe_get_driver(&s->chr)); qemu_chr_fe_set_handlers(&s->chr, imx_can_receive, imx_receive, imx_event, NULL, s, NULL, true); } static void imx_serial_init(Object *obj) { SysBusDevice *sbd = SYS_BUS_DEVICE(obj); IMXSerialState *s = IMX_SERIAL(obj); memory_region_init_io(&s->iomem, obj, &imx_serial_ops, s, TYPE_IMX_SERIAL, 0x1000); sysbus_init_mmio(sbd, &s->iomem); sysbus_init_irq(sbd, &s->irq); } static Property imx_serial_properties[] = { DEFINE_PROP_CHR("chardev", IMXSerialState, chr), DEFINE_PROP_END_OF_LIST(), }; static void imx_serial_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); dc->realize = imx_serial_realize; dc->vmsd = &vmstate_imx_serial; dc->reset = imx_serial_reset_at_boot; set_bit(DEVICE_CATEGORY_INPUT, dc->categories); dc->desc = "i.MX series UART"; dc->props = imx_serial_properties; } static const TypeInfo imx_serial_info = { .name = TYPE_IMX_SERIAL, .parent = TYPE_SYS_BUS_DEVICE, .instance_size = sizeof(IMXSerialState), .instance_init = imx_serial_init, .class_init = imx_serial_class_init, }; static void imx_serial_register_types(void) { type_register_static(&imx_serial_info); } type_init(imx_serial_register_types)