Add a function to change the settings of the serial connection. Signed-off-by: Arnaud Minier <arnaud.min...@telecom-paris.fr> Signed-off-by: Inès Varhol <ines.var...@telecom-paris.fr> --- hw/char/stm32l4x5_usart.c | 97 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+)
diff --git a/hw/char/stm32l4x5_usart.c b/hw/char/stm32l4x5_usart.c index 958d05a56d..95e792d09d 100644 --- a/hw/char/stm32l4x5_usart.c +++ b/hw/char/stm32l4x5_usart.c @@ -165,6 +165,91 @@ static int stm32l4x5_usart_base_can_receive(void *opaque) return 0; } +static void stm32l4x5_update_params(Stm32l4x5UsartBaseState *s) +{ + int speed, parity, data_bits, stop_bits; + uint32_t value, usart_div; + QEMUSerialSetParams ssp; + + /* Select the parity type */ + if (s->cr1 & R_CR1_PCE_MASK) { + if (s->cr1 & R_CR1_PS_MASK) { + parity = 'O'; + } else { + parity = 'E'; + } + } else { + parity = 'N'; + } + + /* Select the number of stop bits */ + value = FIELD_EX32(s->cr2, CR2, STOP); + if (value == 0b00) { + stop_bits = 1; + } else if (value == 0b10) { + stop_bits = 2; + } else { + /* TODO: raise an error here */ + stop_bits = 1; + error_report( + "UNIMPLEMENTED: fractionnal stop bits; CR2[13:12] = %x", + value); + return; + } + + /* Select the length of the word */ + value = (FIELD_EX32(s->cr1, CR1, M1) << 1) | FIELD_EX32(s->cr1, CR1, M0); + if (value == 0b00) { + data_bits = 8; + } else if (value == 0b01) { + data_bits = 9; + } else if (value == 0b01) { + data_bits = 7; + } else { + /* TODO: Raise an error here */ + data_bits = 8; + error_report("UNDEFINED: invalid word length, CR1.M = 0b11"); + return; + } + + /* Select the baud rate */ + value = FIELD_EX32(s->brr, BRR, BRR); + if (value < 16) { + /* TODO: Raise an error here */ + error_report("UNDEFINED: BRR lesser than 16: %u", value); + return; + } + + if (FIELD_EX32(s->cr1, CR1, OVER8) == 0) { + /* + * Oversampling by 16 + * BRR = USARTDIV + */ + usart_div = value; + } else { + /* + * Oversampling by 8 + * - BRR[2:0] = USARTDIV[3:0] shifted 1 bit to the right. + * - BRR[3] must be kept cleared. + * - BRR[15:4] = USARTDIV[15:4] + * - The frequency is multiplied by 2 + */ + usart_div = ((value & 0xFFF0) | ((value & 0x0007) << 1)) / 2; + } + + speed = clock_get_hz(s->clk) / usart_div; + + ssp.speed = speed; + ssp.parity = parity; + ssp.data_bits = data_bits; + ssp.stop_bits = stop_bits; + + qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); + + trace_stm32l4x5_usart_update_params( + speed, parity, data_bits, stop_bits, 0); +} + static void stm32l4x5_update_irq(Stm32l4x5UsartBaseState *s) { if (((s->isr & R_ISR_WUF_MASK) && (s->cr3 & R_CR3_WUFIE_MASK)) || @@ -318,16 +403,19 @@ static void stm32l4x5_usart_base_write(void *opaque, hwaddr addr, switch (addr) { case A_CR1: s->cr1 = value; + stm32l4x5_update_params(s); stm32l4x5_update_irq(s); return; case A_CR2: s->cr2 = value; + stm32l4x5_update_params(s); return; case A_CR3: s->cr3 = value; return; case A_BRR: s->brr = value; + stm32l4x5_update_params(s); return; case A_GTPR: s->gtpr = value; @@ -409,10 +497,19 @@ static void stm32l4x5_usart_base_init(Object *obj) s->clk = qdev_init_clock_in(DEVICE(s), "clk", NULL, s, 0); } +static int stm32l4x5_usart_base_post_load(void *opaque, int version_id) +{ + Stm32l4x5UsartBaseState *s = (Stm32l4x5UsartBaseState *)opaque; + + stm32l4x5_update_params(s); + return 0; +} + static const VMStateDescription vmstate_stm32l4x5_usart_base = { .name = TYPE_STM32L4X5_USART_BASE, .version_id = 1, .minimum_version_id = 1, + .post_load = stm32l4x5_usart_base_post_load, .fields = (VMStateField[]) { VMSTATE_UINT32(cr1, Stm32l4x5UsartBaseState), VMSTATE_UINT32(cr2, Stm32l4x5UsartBaseState), -- 2.34.1