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(unknown [78.208.223.3]) by zproxy3.enst.fr (Postfix) with ESMTPSA id 3E4F0A0576; Sun, 24 Mar 2024 17:57:26 +0100 (CET) From: Arnaud Minier To: qemu-devel@nongnu.org Cc: Laurent Vivier , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= , qemu-arm@nongnu.org, Paolo Bonzini , Alistair Francis , Arnaud Minier , Thomas Huth , =?utf-8?q?In=C3=A8s_Varhol?= , Samuel Tardieu , Peter Maydell Subject: [PATCH v2 3/6] hw/char/stm32l4x5_usart: Enable serial read and write Date: Sun, 24 Mar 2024 17:55:43 +0100 Message-Id: <20240324165545.201908-4-arnaud.minier@telecom-paris.fr> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240324165545.201908-1-arnaud.minier@telecom-paris.fr> References: <20240324165545.201908-1-arnaud.minier@telecom-paris.fr> MIME-Version: 1.0 Received-SPF: pass client-ip=137.194.2.222; envelope-from=arnaud.minier@telecom-paris.fr; helo=zproxy3.enst.fr X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Implement the ability to read and write characters to the usart using the serial port. The character transmission is based on the cmsdk-apb-uart implementation. Signed-off-by: Arnaud Minier Signed-off-by: Inès Varhol Reviewed-by: Peter Maydell --- hw/char/stm32l4x5_usart.c | 139 ++++++++++++++++++++++++++++++ hw/char/trace-events | 7 ++ include/hw/char/stm32l4x5_usart.h | 1 + 3 files changed, 147 insertions(+) diff --git a/hw/char/stm32l4x5_usart.c b/hw/char/stm32l4x5_usart.c index 46e69bb096..ec8c2f6e63 100644 --- a/hw/char/stm32l4x5_usart.c +++ b/hw/char/stm32l4x5_usart.c @@ -154,6 +154,119 @@ REG32(RDR, 0x24) REG32(TDR, 0x28) FIELD(TDR, TDR, 0, 9) +static void stm32l4x5_update_irq(Stm32l4x5UsartBaseState *s) +{ + if (((s->isr & R_ISR_WUF_MASK) && (s->cr3 & R_CR3_WUFIE_MASK)) || + ((s->isr & R_ISR_CMF_MASK) && (s->cr1 & R_CR1_CMIE_MASK)) || + ((s->isr & R_ISR_ABRF_MASK) && (s->cr1 & R_CR1_RXNEIE_MASK)) || + ((s->isr & R_ISR_EOBF_MASK) && (s->cr1 & R_CR1_EOBIE_MASK)) || + ((s->isr & R_ISR_RTOF_MASK) && (s->cr1 & R_CR1_RTOIE_MASK)) || + ((s->isr & R_ISR_CTSIF_MASK) && (s->cr3 & R_CR3_CTSIE_MASK)) || + ((s->isr & R_ISR_LBDF_MASK) && (s->cr2 & R_CR2_LBDIE_MASK)) || + ((s->isr & R_ISR_TXE_MASK) && (s->cr1 & R_CR1_TXEIE_MASK)) || + ((s->isr & R_ISR_TC_MASK) && (s->cr1 & R_CR1_TCIE_MASK)) || + ((s->isr & R_ISR_RXNE_MASK) && (s->cr1 & R_CR1_RXNEIE_MASK)) || + ((s->isr & R_ISR_IDLE_MASK) && (s->cr1 & R_CR1_IDLEIE_MASK)) || + ((s->isr & R_ISR_ORE_MASK) && + ((s->cr1 & R_CR1_RXNEIE_MASK) || (s->cr3 & R_CR3_EIE_MASK))) || + /* TODO: Handle NF ? */ + ((s->isr & R_ISR_FE_MASK) && (s->cr3 & R_CR3_EIE_MASK)) || + ((s->isr & R_ISR_PE_MASK) && (s->cr1 & R_CR1_PEIE_MASK))) { + qemu_irq_raise(s->irq); + trace_stm32l4x5_usart_irq_raised(s->isr); + } else { + qemu_irq_lower(s->irq); + trace_stm32l4x5_usart_irq_lowered(); + } +} + +static int stm32l4x5_usart_base_can_receive(void *opaque) +{ + Stm32l4x5UsartBaseState *s = opaque; + + if (!(s->isr & R_ISR_RXNE_MASK)) { + return 1; + } + + return 0; +} + +static void stm32l4x5_usart_base_receive(void *opaque, const uint8_t *buf, int size) +{ + Stm32l4x5UsartBaseState *s = opaque; + + if (!((s->cr1 & R_CR1_UE_MASK) && (s->cr1 & R_CR1_RE_MASK))) { + trace_stm32l4x5_usart_receiver_not_enabled( + FIELD_EX32(s->cr1, CR1, UE), FIELD_EX32(s->cr1, CR1, RE)); + return; + } + + /* Check if overrun detection is enabled and if there is an overrun */ + if (!(s->cr3 & R_CR3_OVRDIS_MASK) && (s->isr & R_ISR_RXNE_MASK)) { + /* + * A character has been received while + * the previous has not been read = Overrun. + */ + s->isr |= R_ISR_ORE_MASK; + trace_stm32l4x5_usart_overrun_detected(s->rdr, *buf); + } else { + /* No overrun */ + s->rdr = *buf; + s->isr |= R_ISR_RXNE_MASK; + trace_stm32l4x5_usart_rx(s->rdr); + } + + stm32l4x5_update_irq(s); +} + +/* Try to send tx data, and arrange to be called back later if + * we can't (ie the char backend is busy/blocking). + */ +static gboolean usart_transmit(void *do_not_use, GIOCondition cond, void *opaque) +{ + Stm32l4x5UsartBaseState *s = STM32L4X5_USART_BASE(opaque); + int ret; + /* TODO: Handle 9 bits transmission */ + uint8_t ch = s->tdr; + + s->watch_tag = 0; + + if (!(s->cr1 & R_CR1_TE_MASK) || (s->isr & R_ISR_TXE_MASK)) { + return G_SOURCE_REMOVE; + } + + ret = qemu_chr_fe_write(&s->chr, &ch, 1); + if (ret <= 0) { + s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, + usart_transmit, s); + if (!s->watch_tag) { + /* Most common reason to be here is "no chardev backend": + * just insta-drain the buffer, so the serial output + * goes into a void, rather than blocking the guest. + */ + goto buffer_drained; + } + /* Transmit pending */ + trace_stm32l4x5_usart_tx_pending(); + return G_SOURCE_REMOVE; + } + +buffer_drained: + /* Character successfully sent */ + trace_stm32l4x5_usart_tx(ch); + s->isr |= R_ISR_TC_MASK | R_ISR_TXE_MASK; + stm32l4x5_update_irq(s); + return G_SOURCE_REMOVE; +} + +static void usart_cancel_transmit(Stm32l4x5UsartBaseState *s) +{ + if (s->watch_tag) { + g_source_remove(s->watch_tag); + s->watch_tag = 0; + } +} + static void stm32l4x5_usart_base_reset_hold(Object *obj) { Stm32l4x5UsartBaseState *s = STM32L4X5_USART_BASE(obj); @@ -167,6 +280,22 @@ static void stm32l4x5_usart_base_reset_hold(Object *obj) s->isr = 0x020000C0; s->rdr = 0x00000000; s->tdr = 0x00000000; + + usart_cancel_transmit(s); + stm32l4x5_update_irq(s); +} + +static void usart_update_rqr(Stm32l4x5UsartBaseState *s, uint32_t value) +{ + /* TXFRQ */ + /* Reset RXNE flag */ + if (value & R_RQR_RXFRQ_MASK) { + s->isr &= ~R_ISR_RXNE_MASK; + } + /* MMRQ */ + /* SBKRQ */ + /* ABRRQ */ + stm32l4x5_update_irq(s); } static uint64_t stm32l4x5_usart_base_read(void *opaque, hwaddr addr, @@ -209,6 +338,7 @@ static uint64_t stm32l4x5_usart_base_read(void *opaque, hwaddr addr, retvalue = FIELD_EX32(s->rdr, RDR, RDR); /* Reset RXNE flag */ s->isr &= ~R_ISR_RXNE_MASK; + stm32l4x5_update_irq(s); break; case A_TDR: retvalue = FIELD_EX32(s->tdr, TDR, TDR); @@ -235,6 +365,7 @@ static void stm32l4x5_usart_base_write(void *opaque, hwaddr addr, switch (addr) { case A_CR1: s->cr1 = value; + stm32l4x5_update_irq(s); return; case A_CR2: s->cr2 = value; @@ -252,6 +383,7 @@ static void stm32l4x5_usart_base_write(void *opaque, hwaddr addr, s->rtor = value; return; case A_RQR: + usart_update_rqr(s, value); return; case A_ISR: qemu_log_mask(LOG_GUEST_ERROR, @@ -260,6 +392,7 @@ static void stm32l4x5_usart_base_write(void *opaque, hwaddr addr, case A_ICR: /* Clear the status flags */ s->isr &= ~value; + stm32l4x5_update_irq(s); return; case A_RDR: qemu_log_mask(LOG_GUEST_ERROR, @@ -267,6 +400,8 @@ static void stm32l4x5_usart_base_write(void *opaque, hwaddr addr, return; case A_TDR: s->tdr = value; + s->isr &= ~R_ISR_TXE_MASK; + usart_transmit(NULL, G_IO_OUT, s); return; default: qemu_log_mask(LOG_GUEST_ERROR, @@ -336,6 +471,10 @@ static void stm32l4x5_usart_base_realize(DeviceState *dev, Error **errp) error_setg(errp, "USART clock must be wired up by SoC code"); return; } + + qemu_chr_fe_set_handlers(&s->chr, stm32l4x5_usart_base_can_receive, + stm32l4x5_usart_base_receive, NULL, NULL, + s, NULL, true); } static void stm32l4x5_usart_base_class_init(ObjectClass *klass, void *data) diff --git a/hw/char/trace-events b/hw/char/trace-events index 689bed9e02..f22f0ee2bc 100644 --- a/hw/char/trace-events +++ b/hw/char/trace-events @@ -109,6 +109,13 @@ sh_serial_write(char *id, unsigned size, uint64_t offs, uint64_t val) "%s size % # stm32l4x5_usart.c stm32l4x5_usart_read(uint64_t addr, uint32_t data) "USART: Read <0x%" PRIx64 "> -> 0x%" PRIx32 "" stm32l4x5_usart_write(uint64_t addr, uint32_t data) "USART: Write <0x%" PRIx64 "> <- 0x%" PRIx32 "" +stm32l4x5_usart_rx(uint8_t c) "USART: got character 0x%x from backend" +stm32l4x5_usart_tx(uint8_t c) "USART: character 0x%x sent to backend" +stm32l4x5_usart_tx_pending(void) "USART: character send to backend pending" +stm32l4x5_usart_irq_raised(uint32_t reg) "USART: IRQ raised: 0x%08"PRIx32 +stm32l4x5_usart_irq_lowered(void) "USART: IRQ lowered" +stm32l4x5_usart_overrun_detected(uint8_t current, uint8_t received) "USART: Overrun detected, RDR='0x%x', received 0x%x" +stm32l4x5_usart_receiver_not_enabled(uint8_t ue_bit, uint8_t re_bit) "USART: Receiver not enabled, UE=0x%x, RE=0x%x" # xen_console.c xen_console_connect(unsigned int idx, unsigned int ring_ref, unsigned int port, unsigned int limit) "idx %u ring_ref %u port %u limit %u" diff --git a/include/hw/char/stm32l4x5_usart.h b/include/hw/char/stm32l4x5_usart.h index 8d38a85a6e..dd3866682a 100644 --- a/include/hw/char/stm32l4x5_usart.h +++ b/include/hw/char/stm32l4x5_usart.h @@ -55,6 +55,7 @@ struct Stm32l4x5UsartBaseState { Clock *clk; CharBackend chr; qemu_irq irq; + guint watch_tag; }; struct Stm32l4x5UsartBaseClass {