diff options
Diffstat (limited to 'src/hw/char/cadence_uart.c')
| -rw-r--r-- | src/hw/char/cadence_uart.c | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/src/hw/char/cadence_uart.c b/src/hw/char/cadence_uart.c new file mode 100644 index 0000000..9d379e5 --- /dev/null +++ b/src/hw/char/cadence_uart.c @@ -0,0 +1,536 @@ +/* + * Device model for Cadence UART + * + * Copyright (c) 2010 Xilinx Inc. + * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com) + * Copyright (c) 2012 PetaLogix Pty Ltd. + * Written by Haibing Ma + * M.Habib + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "hw/char/cadence_uart.h" + +#ifdef CADENCE_UART_ERR_DEBUG +#define DB_PRINT(...) do { \ + fprintf(stderr, ": %s: ", __func__); \ + fprintf(stderr, ## __VA_ARGS__); \ + } while (0); +#else + #define DB_PRINT(...) +#endif + +#define UART_SR_INTR_RTRIG 0x00000001 +#define UART_SR_INTR_REMPTY 0x00000002 +#define UART_SR_INTR_RFUL 0x00000004 +#define UART_SR_INTR_TEMPTY 0x00000008 +#define UART_SR_INTR_TFUL 0x00000010 +/* somewhat awkwardly, TTRIG is misaligned between SR and ISR */ +#define UART_SR_TTRIG 0x00002000 +#define UART_INTR_TTRIG 0x00000400 +/* bits fields in CSR that correlate to CISR. If any of these bits are set in + * SR, then the same bit in CISR is set high too */ +#define UART_SR_TO_CISR_MASK 0x0000001F + +#define UART_INTR_ROVR 0x00000020 +#define UART_INTR_FRAME 0x00000040 +#define UART_INTR_PARE 0x00000080 +#define UART_INTR_TIMEOUT 0x00000100 +#define UART_INTR_DMSI 0x00000200 +#define UART_INTR_TOVR 0x00001000 + +#define UART_SR_RACTIVE 0x00000400 +#define UART_SR_TACTIVE 0x00000800 +#define UART_SR_FDELT 0x00001000 + +#define UART_CR_RXRST 0x00000001 +#define UART_CR_TXRST 0x00000002 +#define UART_CR_RX_EN 0x00000004 +#define UART_CR_RX_DIS 0x00000008 +#define UART_CR_TX_EN 0x00000010 +#define UART_CR_TX_DIS 0x00000020 +#define UART_CR_RST_TO 0x00000040 +#define UART_CR_STARTBRK 0x00000080 +#define UART_CR_STOPBRK 0x00000100 + +#define UART_MR_CLKS 0x00000001 +#define UART_MR_CHRL 0x00000006 +#define UART_MR_CHRL_SH 1 +#define UART_MR_PAR 0x00000038 +#define UART_MR_PAR_SH 3 +#define UART_MR_NBSTOP 0x000000C0 +#define UART_MR_NBSTOP_SH 6 +#define UART_MR_CHMODE 0x00000300 +#define UART_MR_CHMODE_SH 8 +#define UART_MR_UCLKEN 0x00000400 +#define UART_MR_IRMODE 0x00000800 + +#define UART_DATA_BITS_6 (0x3 << UART_MR_CHRL_SH) +#define UART_DATA_BITS_7 (0x2 << UART_MR_CHRL_SH) +#define UART_PARITY_ODD (0x1 << UART_MR_PAR_SH) +#define UART_PARITY_EVEN (0x0 << UART_MR_PAR_SH) +#define UART_STOP_BITS_1 (0x3 << UART_MR_NBSTOP_SH) +#define UART_STOP_BITS_2 (0x2 << UART_MR_NBSTOP_SH) +#define NORMAL_MODE (0x0 << UART_MR_CHMODE_SH) +#define ECHO_MODE (0x1 << UART_MR_CHMODE_SH) +#define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH) +#define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH) + +#define UART_INPUT_CLK 50000000 + +#define R_CR (0x00/4) +#define R_MR (0x04/4) +#define R_IER (0x08/4) +#define R_IDR (0x0C/4) +#define R_IMR (0x10/4) +#define R_CISR (0x14/4) +#define R_BRGR (0x18/4) +#define R_RTOR (0x1C/4) +#define R_RTRIG (0x20/4) +#define R_MCR (0x24/4) +#define R_MSR (0x28/4) +#define R_SR (0x2C/4) +#define R_TX_RX (0x30/4) +#define R_BDIV (0x34/4) +#define R_FDEL (0x38/4) +#define R_PMIN (0x3C/4) +#define R_PWID (0x40/4) +#define R_TTRIG (0x44/4) + + +static void uart_update_status(CadenceUARTState *s) +{ + s->r[R_SR] = 0; + + s->r[R_SR] |= s->rx_count == CADENCE_UART_RX_FIFO_SIZE ? UART_SR_INTR_RFUL + : 0; + s->r[R_SR] |= !s->rx_count ? UART_SR_INTR_REMPTY : 0; + s->r[R_SR] |= s->rx_count >= s->r[R_RTRIG] ? UART_SR_INTR_RTRIG : 0; + + s->r[R_SR] |= s->tx_count == CADENCE_UART_TX_FIFO_SIZE ? UART_SR_INTR_TFUL + : 0; + s->r[R_SR] |= !s->tx_count ? UART_SR_INTR_TEMPTY : 0; + s->r[R_SR] |= s->tx_count >= s->r[R_TTRIG] ? UART_SR_TTRIG : 0; + + s->r[R_CISR] |= s->r[R_SR] & UART_SR_TO_CISR_MASK; + s->r[R_CISR] |= s->r[R_SR] & UART_SR_TTRIG ? UART_INTR_TTRIG : 0; + qemu_set_irq(s->irq, !!(s->r[R_IMR] & s->r[R_CISR])); +} + +static void fifo_trigger_update(void *opaque) +{ + CadenceUARTState *s = opaque; + + s->r[R_CISR] |= UART_INTR_TIMEOUT; + + uart_update_status(s); +} + +static void uart_rx_reset(CadenceUARTState *s) +{ + s->rx_wpos = 0; + s->rx_count = 0; + if (s->chr) { + qemu_chr_accept_input(s->chr); + } +} + +static void uart_tx_reset(CadenceUARTState *s) +{ + s->tx_count = 0; +} + +static void uart_send_breaks(CadenceUARTState *s) +{ + int break_enabled = 1; + + if (s->chr) { + qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK, + &break_enabled); + } +} + +static void uart_parameters_setup(CadenceUARTState *s) +{ + QEMUSerialSetParams ssp; + unsigned int baud_rate, packet_size; + + baud_rate = (s->r[R_MR] & UART_MR_CLKS) ? + UART_INPUT_CLK / 8 : UART_INPUT_CLK; + + ssp.speed = baud_rate / (s->r[R_BRGR] * (s->r[R_BDIV] + 1)); + packet_size = 1; + + switch (s->r[R_MR] & UART_MR_PAR) { + case UART_PARITY_EVEN: + ssp.parity = 'E'; + packet_size++; + break; + case UART_PARITY_ODD: + ssp.parity = 'O'; + packet_size++; + break; + default: + ssp.parity = 'N'; + break; + } + + switch (s->r[R_MR] & UART_MR_CHRL) { + case UART_DATA_BITS_6: + ssp.data_bits = 6; + break; + case UART_DATA_BITS_7: + ssp.data_bits = 7; + break; + default: + ssp.data_bits = 8; + break; + } + + switch (s->r[R_MR] & UART_MR_NBSTOP) { + case UART_STOP_BITS_1: + ssp.stop_bits = 1; + break; + default: + ssp.stop_bits = 2; + break; + } + + packet_size += ssp.data_bits + ssp.stop_bits; + s->char_tx_time = (get_ticks_per_sec() / ssp.speed) * packet_size; + if (s->chr) { + qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); + } +} + +static int uart_can_receive(void *opaque) +{ + CadenceUARTState *s = opaque; + int ret = MAX(CADENCE_UART_RX_FIFO_SIZE, CADENCE_UART_TX_FIFO_SIZE); + uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE; + + if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { + ret = MIN(ret, CADENCE_UART_RX_FIFO_SIZE - s->rx_count); + } + if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) { + ret = MIN(ret, CADENCE_UART_TX_FIFO_SIZE - s->tx_count); + } + return ret; +} + +static void uart_ctrl_update(CadenceUARTState *s) +{ + if (s->r[R_CR] & UART_CR_TXRST) { + uart_tx_reset(s); + } + + if (s->r[R_CR] & UART_CR_RXRST) { + uart_rx_reset(s); + } + + s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST); + + if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) { + uart_send_breaks(s); + } +} + +static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size) +{ + CadenceUARTState *s = opaque; + uint64_t new_rx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + int i; + + if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) { + return; + } + + if (s->rx_count == CADENCE_UART_RX_FIFO_SIZE) { + s->r[R_CISR] |= UART_INTR_ROVR; + } else { + for (i = 0; i < size; i++) { + s->rx_fifo[s->rx_wpos] = buf[i]; + s->rx_wpos = (s->rx_wpos + 1) % CADENCE_UART_RX_FIFO_SIZE; + s->rx_count++; + } + timer_mod(s->fifo_trigger_handle, new_rx_time + + (s->char_tx_time * 4)); + } + uart_update_status(s); +} + +static gboolean cadence_uart_xmit(GIOChannel *chan, GIOCondition cond, + void *opaque) +{ + CadenceUARTState *s = opaque; + int ret; + + /* instant drain the fifo when there's no back-end */ + if (!s->chr) { + s->tx_count = 0; + return FALSE; + } + + if (!s->tx_count) { + return FALSE; + } + + ret = qemu_chr_fe_write(s->chr, s->tx_fifo, s->tx_count); + s->tx_count -= ret; + memmove(s->tx_fifo, s->tx_fifo + ret, s->tx_count); + + if (s->tx_count) { + int r = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, + cadence_uart_xmit, s); + assert(r); + } + + uart_update_status(s); + return FALSE; +} + +static void uart_write_tx_fifo(CadenceUARTState *s, const uint8_t *buf, + int size) +{ + if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) { + return; + } + + if (size > CADENCE_UART_TX_FIFO_SIZE - s->tx_count) { + size = CADENCE_UART_TX_FIFO_SIZE - s->tx_count; + /* + * This can only be a guest error via a bad tx fifo register push, + * as can_receive() should stop remote loop and echo modes ever getting + * us to here. + */ + qemu_log_mask(LOG_GUEST_ERROR, "cadence_uart: TxFIFO overflow"); + s->r[R_CISR] |= UART_INTR_ROVR; + } + + memcpy(s->tx_fifo + s->tx_count, buf, size); + s->tx_count += size; + + cadence_uart_xmit(NULL, G_IO_OUT, s); +} + +static void uart_receive(void *opaque, const uint8_t *buf, int size) +{ + CadenceUARTState *s = opaque; + uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE; + + if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { + uart_write_rx_fifo(opaque, buf, size); + } + if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) { + uart_write_tx_fifo(s, buf, size); + } +} + +static void uart_event(void *opaque, int event) +{ + CadenceUARTState *s = opaque; + uint8_t buf = '\0'; + + if (event == CHR_EVENT_BREAK) { + uart_write_rx_fifo(opaque, &buf, 1); + } + + uart_update_status(s); +} + +static void uart_read_rx_fifo(CadenceUARTState *s, uint32_t *c) +{ + if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) { + return; + } + + if (s->rx_count) { + uint32_t rx_rpos = (CADENCE_UART_RX_FIFO_SIZE + s->rx_wpos - + s->rx_count) % CADENCE_UART_RX_FIFO_SIZE; + *c = s->rx_fifo[rx_rpos]; + s->rx_count--; + + if (s->chr) { + qemu_chr_accept_input(s->chr); + } + } else { + *c = 0; + } + + uart_update_status(s); +} + +static void uart_write(void *opaque, hwaddr offset, + uint64_t value, unsigned size) +{ + CadenceUARTState *s = opaque; + + DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset, (unsigned)value); + offset >>= 2; + switch (offset) { + case R_IER: /* ier (wts imr) */ + s->r[R_IMR] |= value; + break; + case R_IDR: /* idr (wtc imr) */ + s->r[R_IMR] &= ~value; + break; + case R_IMR: /* imr (read only) */ + break; + case R_CISR: /* cisr (wtc) */ + s->r[R_CISR] &= ~value; + break; + case R_TX_RX: /* UARTDR */ + switch (s->r[R_MR] & UART_MR_CHMODE) { + case NORMAL_MODE: + uart_write_tx_fifo(s, (uint8_t *) &value, 1); + break; + case LOCAL_LOOPBACK: + uart_write_rx_fifo(opaque, (uint8_t *) &value, 1); + break; + } + break; + default: + s->r[offset] = value; + } + + switch (offset) { + case R_CR: + uart_ctrl_update(s); + break; + case R_MR: + uart_parameters_setup(s); + break; + } + uart_update_status(s); +} + +static uint64_t uart_read(void *opaque, hwaddr offset, + unsigned size) +{ + CadenceUARTState *s = opaque; + uint32_t c = 0; + + offset >>= 2; + if (offset >= CADENCE_UART_R_MAX) { + c = 0; + } else if (offset == R_TX_RX) { + uart_read_rx_fifo(s, &c); + } else { + c = s->r[offset]; + } + + DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset << 2), (unsigned)c); + return c; +} + +static const MemoryRegionOps uart_ops = { + .read = uart_read, + .write = uart_write, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + +static void cadence_uart_reset(DeviceState *dev) +{ + CadenceUARTState *s = CADENCE_UART(dev); + + s->r[R_CR] = 0x00000128; + s->r[R_IMR] = 0; + s->r[R_CISR] = 0; + s->r[R_RTRIG] = 0x00000020; + s->r[R_BRGR] = 0x0000000F; + s->r[R_TTRIG] = 0x00000020; + + uart_rx_reset(s); + uart_tx_reset(s); + + uart_update_status(s); +} + +static void cadence_uart_realize(DeviceState *dev, Error **errp) +{ + CadenceUARTState *s = CADENCE_UART(dev); + + s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL, + fifo_trigger_update, s); + + /* FIXME use a qdev chardev prop instead of qemu_char_get_next_serial() */ + s->chr = qemu_char_get_next_serial(); + + if (s->chr) { + qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive, + uart_event, s); + } +} + +static void cadence_uart_init(Object *obj) +{ + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + CadenceUARTState *s = CADENCE_UART(obj); + + memory_region_init_io(&s->iomem, obj, &uart_ops, s, "uart", 0x1000); + sysbus_init_mmio(sbd, &s->iomem); + sysbus_init_irq(sbd, &s->irq); + + s->char_tx_time = (get_ticks_per_sec() / 9600) * 10; +} + +static int cadence_uart_post_load(void *opaque, int version_id) +{ + CadenceUARTState *s = opaque; + + uart_parameters_setup(s); + uart_update_status(s); + return 0; +} + +static const VMStateDescription vmstate_cadence_uart = { + .name = "cadence_uart", + .version_id = 2, + .minimum_version_id = 2, + .post_load = cadence_uart_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT32_ARRAY(r, CadenceUARTState, CADENCE_UART_R_MAX), + VMSTATE_UINT8_ARRAY(rx_fifo, CadenceUARTState, + CADENCE_UART_RX_FIFO_SIZE), + VMSTATE_UINT8_ARRAY(tx_fifo, CadenceUARTState, + CADENCE_UART_TX_FIFO_SIZE), + VMSTATE_UINT32(rx_count, CadenceUARTState), + VMSTATE_UINT32(tx_count, CadenceUARTState), + VMSTATE_UINT32(rx_wpos, CadenceUARTState), + VMSTATE_TIMER_PTR(fifo_trigger_handle, CadenceUARTState), + VMSTATE_END_OF_LIST() + } +}; + +static void cadence_uart_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = cadence_uart_realize; + dc->vmsd = &vmstate_cadence_uart; + dc->reset = cadence_uart_reset; + /* Reason: realize() method uses qemu_char_get_next_serial() */ + dc->cannot_instantiate_with_device_add_yet = true; +} + +static const TypeInfo cadence_uart_info = { + .name = TYPE_CADENCE_UART, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(CadenceUARTState), + .instance_init = cadence_uart_init, + .class_init = cadence_uart_class_init, +}; + +static void cadence_uart_register_types(void) +{ + type_register_static(&cadence_uart_info); +} + +type_init(cadence_uart_register_types) |
