diff options
Diffstat (limited to 'hw/char/cadence_uart.c')
| -rw-r--r-- | hw/char/cadence_uart.c | 73 |
1 files changed, 63 insertions, 10 deletions
diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c index 22e47972f1..e196906c92 100644 --- a/hw/char/cadence_uart.c +++ b/hw/char/cadence_uart.c @@ -31,6 +31,8 @@ #include "qemu/module.h" #include "hw/char/cadence_uart.h" #include "hw/irq.h" +#include "hw/qdev-clock.h" +#include "trace.h" #ifdef CADENCE_UART_ERR_DEBUG #define DB_PRINT(...) do { \ @@ -97,7 +99,7 @@ #define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH) #define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH) -#define UART_INPUT_CLK 50000000 +#define UART_DEFAULT_REF_CLK (50 * 1000 * 1000) #define R_CR (0x00/4) #define R_MR (0x04/4) @@ -171,12 +173,15 @@ static void uart_send_breaks(CadenceUARTState *s) static void uart_parameters_setup(CadenceUARTState *s) { QEMUSerialSetParams ssp; - unsigned int baud_rate, packet_size; + unsigned int baud_rate, packet_size, input_clk; + input_clk = clock_get_hz(s->refclk); - baud_rate = (s->r[R_MR] & UART_MR_CLKS) ? - UART_INPUT_CLK / 8 : UART_INPUT_CLK; + baud_rate = (s->r[R_MR] & UART_MR_CLKS) ? input_clk / 8 : input_clk; + baud_rate /= (s->r[R_BRGR] * (s->r[R_BDIV] + 1)); + trace_cadence_uart_baudrate(baud_rate); + + ssp.speed = baud_rate; - ssp.speed = baud_rate / (s->r[R_BRGR] * (s->r[R_BDIV] + 1)); packet_size = 1; switch (s->r[R_MR] & UART_MR_PAR) { @@ -215,6 +220,13 @@ static void uart_parameters_setup(CadenceUARTState *s) } packet_size += ssp.data_bits + ssp.stop_bits; + if (ssp.speed == 0) { + /* + * Avoid division-by-zero below. + * TODO: find something better + */ + ssp.speed = 1; + } s->char_tx_time = (NANOSECONDS_PER_SECOND / ssp.speed) * packet_size; qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); } @@ -340,6 +352,11 @@ 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; + /* ignore characters when unclocked or in reset */ + if (!clock_is_enabled(s->refclk) || device_is_in_reset(DEVICE(s))) { + return; + } + if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { uart_write_rx_fifo(opaque, buf, size); } @@ -353,6 +370,11 @@ static void uart_event(void *opaque, QEMUChrEvent event) CadenceUARTState *s = opaque; uint8_t buf = '\0'; + /* ignore characters when unclocked or in reset */ + if (!clock_is_enabled(s->refclk) || device_is_in_reset(DEVICE(s))) { + return; + } + if (event == CHR_EVENT_BREAK) { uart_write_rx_fifo(opaque, &buf, 1); } @@ -462,9 +484,9 @@ static const MemoryRegionOps uart_ops = { .endianness = DEVICE_NATIVE_ENDIAN, }; -static void cadence_uart_reset(DeviceState *dev) +static void cadence_uart_reset_init(Object *obj, ResetType type) { - CadenceUARTState *s = CADENCE_UART(dev); + CadenceUARTState *s = CADENCE_UART(obj); s->r[R_CR] = 0x00000128; s->r[R_IMR] = 0; @@ -473,6 +495,11 @@ static void cadence_uart_reset(DeviceState *dev) s->r[R_BRGR] = 0x0000028B; s->r[R_BDIV] = 0x0000000F; s->r[R_TTRIG] = 0x00000020; +} + +static void cadence_uart_reset_hold(Object *obj) +{ + CadenceUARTState *s = CADENCE_UART(obj); uart_rx_reset(s); uart_tx_reset(s); @@ -491,6 +518,14 @@ static void cadence_uart_realize(DeviceState *dev, Error **errp) uart_event, NULL, s, NULL, true); } +static void cadence_uart_refclk_update(void *opaque) +{ + CadenceUARTState *s = opaque; + + /* recompute uart's speed on clock change */ + uart_parameters_setup(s); +} + static void cadence_uart_init(Object *obj) { SysBusDevice *sbd = SYS_BUS_DEVICE(obj); @@ -500,9 +535,23 @@ static void cadence_uart_init(Object *obj) sysbus_init_mmio(sbd, &s->iomem); sysbus_init_irq(sbd, &s->irq); + s->refclk = qdev_init_clock_in(DEVICE(obj), "refclk", + cadence_uart_refclk_update, s); + /* initialize the frequency in case the clock remains unconnected */ + clock_set_hz(s->refclk, UART_DEFAULT_REF_CLK); + s->char_tx_time = (NANOSECONDS_PER_SECOND / 9600) * 10; } +static int cadence_uart_pre_load(void *opaque) +{ + CadenceUARTState *s = opaque; + + /* the frequency will be overriden if the refclk field is present */ + clock_set_hz(s->refclk, UART_DEFAULT_REF_CLK); + return 0; +} + static int cadence_uart_post_load(void *opaque, int version_id) { CadenceUARTState *s = opaque; @@ -521,8 +570,9 @@ static int cadence_uart_post_load(void *opaque, int version_id) static const VMStateDescription vmstate_cadence_uart = { .name = "cadence_uart", - .version_id = 2, + .version_id = 3, .minimum_version_id = 2, + .pre_load = cadence_uart_pre_load, .post_load = cadence_uart_post_load, .fields = (VMStateField[]) { VMSTATE_UINT32_ARRAY(r, CadenceUARTState, CADENCE_UART_R_MAX), @@ -534,8 +584,9 @@ static const VMStateDescription vmstate_cadence_uart = { VMSTATE_UINT32(tx_count, CadenceUARTState), VMSTATE_UINT32(rx_wpos, CadenceUARTState), VMSTATE_TIMER_PTR(fifo_trigger_handle, CadenceUARTState), + VMSTATE_CLOCK_V(refclk, CadenceUARTState, 3), VMSTATE_END_OF_LIST() - } + }, }; static Property cadence_uart_properties[] = { @@ -546,10 +597,12 @@ static Property cadence_uart_properties[] = { static void cadence_uart_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); + ResettableClass *rc = RESETTABLE_CLASS(klass); dc->realize = cadence_uart_realize; dc->vmsd = &vmstate_cadence_uart; - dc->reset = cadence_uart_reset; + rc->phases.enter = cadence_uart_reset_init; + rc->phases.hold = cadence_uart_reset_hold; device_class_set_props(dc, cadence_uart_properties); } |