diff options
Diffstat (limited to 'hw/char/cadence_uart.c')
| -rw-r--r-- | hw/char/cadence_uart.c | 153 |
1 files changed, 87 insertions, 66 deletions
diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c index f18db53bca..1012f1ad64 100644 --- a/hw/char/cadence_uart.c +++ b/hw/char/cadence_uart.c @@ -34,6 +34,9 @@ #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 @@ -43,6 +46,7 @@ #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 @@ -110,23 +114,37 @@ #define CADENCE_UART(obj) OBJECT_CHECK(UartState, (obj), TYPE_CADENCE_UART) typedef struct { + /*< private >*/ SysBusDevice parent_obj; + /*< public >*/ MemoryRegion iomem; uint32_t r[R_MAX]; - uint8_t r_fifo[RX_FIFO_SIZE]; + uint8_t rx_fifo[RX_FIFO_SIZE]; + uint8_t tx_fifo[TX_FIFO_SIZE]; uint32_t rx_wpos; uint32_t rx_count; + uint32_t tx_count; uint64_t char_tx_time; CharDriverState *chr; qemu_irq irq; QEMUTimer *fifo_trigger_handle; - QEMUTimer *tx_time_handle; } UartState; static void uart_update_status(UartState *s) { + s->r[R_SR] = 0; + + s->r[R_SR] |= s->rx_count == 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 == 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])); } @@ -139,24 +157,6 @@ static void fifo_trigger_update(void *opaque) uart_update_status(s); } -static void uart_tx_redo(UartState *s) -{ - uint64_t new_tx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - - timer_mod(s->tx_time_handle, new_tx_time + s->char_tx_time); - - s->r[R_SR] |= UART_SR_INTR_TEMPTY; - - uart_update_status(s); -} - -static void uart_tx_write(void *opaque) -{ - UartState *s = (UartState *)opaque; - - uart_tx_redo(s); -} - static void uart_rx_reset(UartState *s) { s->rx_wpos = 0; @@ -164,15 +164,11 @@ static void uart_rx_reset(UartState *s) if (s->chr) { qemu_chr_accept_input(s->chr); } - - s->r[R_SR] |= UART_SR_INTR_REMPTY; - s->r[R_SR] &= ~UART_SR_INTR_RFUL; } static void uart_tx_reset(UartState *s) { - s->r[R_SR] |= UART_SR_INTR_TEMPTY; - s->r[R_SR] &= ~UART_SR_INTR_TFUL; + s->tx_count = 0; } static void uart_send_breaks(UartState *s) @@ -237,8 +233,16 @@ static void uart_parameters_setup(UartState *s) static int uart_can_receive(void *opaque) { UartState *s = (UartState *)opaque; + int ret = MAX(RX_FIFO_SIZE, TX_FIFO_SIZE); + uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE; - return RX_FIFO_SIZE - s->rx_count; + if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { + ret = MIN(ret, RX_FIFO_SIZE - s->rx_count); + } + if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) { + ret = MIN(ret, TX_FIFO_SIZE - s->tx_count); + } + return ret; } static void uart_ctrl_update(UartState *s) @@ -253,10 +257,6 @@ static void uart_ctrl_update(UartState *s) s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST); - if ((s->r[R_CR] & UART_CR_TX_EN) && !(s->r[R_CR] & UART_CR_TX_DIS)) { - uart_tx_redo(s); - } - if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) { uart_send_breaks(s); } @@ -272,24 +272,13 @@ static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size) return; } - s->r[R_SR] &= ~UART_SR_INTR_REMPTY; - if (s->rx_count == RX_FIFO_SIZE) { s->r[R_CISR] |= UART_INTR_ROVR; } else { for (i = 0; i < size; i++) { - s->r_fifo[s->rx_wpos] = buf[i]; + s->rx_fifo[s->rx_wpos] = buf[i]; s->rx_wpos = (s->rx_wpos + 1) % RX_FIFO_SIZE; s->rx_count++; - - if (s->rx_count == RX_FIFO_SIZE) { - s->r[R_SR] |= UART_SR_INTR_RFUL; - break; - } - - if (s->rx_count >= s->r[R_RTRIG]) { - s->r[R_SR] |= UART_SR_INTR_RTRIG; - } } timer_mod(s->fifo_trigger_handle, new_rx_time + (s->char_tx_time * 4)); @@ -297,13 +286,55 @@ static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size) uart_update_status(s); } +static gboolean cadence_uart_xmit(GIOChannel *chan, GIOCondition cond, + void *opaque) +{ + UartState *s = opaque; + int ret; + + /* instant drain the fifo when there's no back-end */ + if (!s->chr) { + s->tx_count = 0; + } + + 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, cadence_uart_xmit, s); + assert(r); + } + + uart_update_status(s); + return FALSE; +} + static void uart_write_tx_fifo(UartState *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; } - qemu_chr_fe_write_all(s->chr, buf, size); + if (size > TX_FIFO_SIZE - s->tx_count) { + size = 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) @@ -337,26 +368,17 @@ static void uart_read_rx_fifo(UartState *s, uint32_t *c) return; } - s->r[R_SR] &= ~UART_SR_INTR_RFUL; - if (s->rx_count) { uint32_t rx_rpos = (RX_FIFO_SIZE + s->rx_wpos - s->rx_count) % RX_FIFO_SIZE; - *c = s->r_fifo[rx_rpos]; + *c = s->rx_fifo[rx_rpos]; s->rx_count--; - if (!s->rx_count) { - s->r[R_SR] |= UART_SR_INTR_REMPTY; - } qemu_chr_accept_input(s->chr); } else { *c = 0; - s->r[R_SR] |= UART_SR_INTR_REMPTY; } - if (s->rx_count < s->r[R_RTRIG]) { - s->r[R_SR] &= ~UART_SR_INTR_RTRIG; - } uart_update_status(s); } @@ -401,6 +423,7 @@ static void uart_write(void *opaque, hwaddr offset, uart_parameters_setup(s); break; } + uart_update_status(s); } static uint64_t uart_read(void *opaque, hwaddr offset, @@ -428,8 +451,10 @@ static const MemoryRegionOps uart_ops = { .endianness = DEVICE_NATIVE_ENDIAN, }; -static void cadence_uart_reset(UartState *s) +static void cadence_uart_reset(DeviceState *dev) { + UartState *s = CADENCE_UART(dev); + s->r[R_CR] = 0x00000128; s->r[R_IMR] = 0; s->r[R_CISR] = 0; @@ -440,8 +465,7 @@ static void cadence_uart_reset(UartState *s) uart_rx_reset(s); uart_tx_reset(s); - s->rx_count = 0; - s->rx_wpos = 0; + uart_update_status(s); } static int cadence_uart_init(SysBusDevice *dev) @@ -455,15 +479,10 @@ static int cadence_uart_init(SysBusDevice *dev) s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *)fifo_trigger_update, s); - s->tx_time_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL, - (QEMUTimerCB *)uart_tx_write, s); - s->char_tx_time = (get_ticks_per_sec() / 9600) * 10; s->chr = qemu_char_get_next_serial(); - cadence_uart_reset(s); - if (s->chr) { qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive, uart_event, s); @@ -483,17 +502,18 @@ static int cadence_uart_post_load(void *opaque, int version_id) static const VMStateDescription vmstate_cadence_uart = { .name = "cadence_uart", - .version_id = 1, - .minimum_version_id = 1, - .minimum_version_id_old = 1, + .version_id = 2, + .minimum_version_id = 2, + .minimum_version_id_old = 2, .post_load = cadence_uart_post_load, .fields = (VMStateField[]) { VMSTATE_UINT32_ARRAY(r, UartState, R_MAX), - VMSTATE_UINT8_ARRAY(r_fifo, UartState, RX_FIFO_SIZE), + VMSTATE_UINT8_ARRAY(rx_fifo, UartState, RX_FIFO_SIZE), + VMSTATE_UINT8_ARRAY(tx_fifo, UartState, RX_FIFO_SIZE), VMSTATE_UINT32(rx_count, UartState), + VMSTATE_UINT32(tx_count, UartState), VMSTATE_UINT32(rx_wpos, UartState), VMSTATE_TIMER(fifo_trigger_handle, UartState), - VMSTATE_TIMER(tx_time_handle, UartState), VMSTATE_END_OF_LIST() } }; @@ -505,6 +525,7 @@ static void cadence_uart_class_init(ObjectClass *klass, void *data) sdc->init = cadence_uart_init; dc->vmsd = &vmstate_cadence_uart; + dc->reset = cadence_uart_reset; } static const TypeInfo cadence_uart_info = { |