| Message ID | 20210227164157.30971-1-devik@eaxlabs.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] tty/serial: Add rx-tx-swap OF option to stm32-usart | expand |
On 2/27/21 5:41 PM, Martin Devera wrote: > STM32 F7/H7 usarts supports RX & TX pin swapping. > Add option to turn it on. > Tested on STM32MP157. > > Signed-off-by: Martin Devera <devik@eaxlabs.cz> > --- > drivers/tty/serial/stm32-usart.c | 3 ++- > drivers/tty/serial/stm32-usart.h | 1 + > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c > index b3675cf25a69..3650c8798061 100644 > --- a/drivers/tty/serial/stm32-usart.c > +++ b/drivers/tty/serial/stm32-usart.c > @@ -758,7 +758,7 @@ static void stm32_usart_set_termios(struct uart_port *port, > cr1 = USART_CR1_TE | USART_CR1_RE; > if (stm32_port->fifoen) > cr1 |= USART_CR1_FIFOEN; > - cr2 = 0; > + cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; Hi Martin, Same could be done in the startup routine, that enables the port for reception (as described in Documentation/driver-api/serial/driver.rst) > cr3 = readl_relaxed(port->membase + ofs->cr3); > cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE > | USART_CR3_TXFTCFG_MASK; > @@ -1078,6 +1078,7 @@ static struct stm32_port *stm32_usart_of_get_port(struct platform_device *pdev) > stm32_ports[id].hw_flow_control = > of_property_read_bool (np, "st,hw-flow-ctrl") /*deprecated*/ || > of_property_read_bool (np, "uart-has-rtscts"); > + stm32_ports[id].swap = of_property_read_bool(np, "rx-tx-swap"); The swap option/bit is available starting with stm32f7 (e.g. not on stm32f4). This could be added to compatible data, e.g. as done for other capabilities in stm32-usart.h. E.g you could add a "has_swap" in struct stm32_usart_config, then use it at probe time: if (cfg->has_swap) stm32_ports[id].swap = ...; Thanks for your patch, Best regards, Fabrice > stm32_ports[id].port.line = id; > stm32_ports[id].cr1_irq = USART_CR1_RXNEIE; > stm32_ports[id].cr3_irq = 0; > diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h > index cb4f327c46db..2f054e2dc0ab 100644 > --- a/drivers/tty/serial/stm32-usart.h > +++ b/drivers/tty/serial/stm32-usart.h > @@ -271,6 +271,7 @@ struct stm32_port { > int last_res; > bool tx_dma_busy; /* dma tx busy */ > bool hw_flow_control; > + bool swap; /* swap RX & TX pins */ > bool fifoen; > int wakeirq; > int rdr_mask; /* receive data register mask */ >
On 3/1/21 11:28 AM, Fabrice Gasnier wrote: > On 2/27/21 5:41 PM, Martin Devera wrote: >> STM32 F7/H7 usarts supports RX & TX pin swapping. >> Add option to turn it on. >> Tested on STM32MP157. >> >> Signed-off-by: Martin Devera <devik@eaxlabs.cz> >> --- >> drivers/tty/serial/stm32-usart.c | 3 ++- >> drivers/tty/serial/stm32-usart.h | 1 + >> 2 files changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c >> index b3675cf25a69..3650c8798061 100644 >> --- a/drivers/tty/serial/stm32-usart.c >> +++ b/drivers/tty/serial/stm32-usart.c >> @@ -758,7 +758,7 @@ static void stm32_usart_set_termios(struct uart_port *port, >> cr1 = USART_CR1_TE | USART_CR1_RE; >> if (stm32_port->fifoen) >> cr1 |= USART_CR1_FIFOEN; >> - cr2 = 0; >> + cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; > Hi Martin, > > Same could be done in the startup routine, that enables the port for > reception (as described in Documentation/driver-api/serial/driver.rst) Hello Fabrice, I already incorporated all your comments but I'm struggling with the one above. The code must be in stm32_usart_set_termios too, because CR2 is modified. What is the reason to have it in startup() ? Is it because USART can be started without calling set_termios at all ? Like to reuse bootloader's last settings ? Thanks, Martin
On 3/1/21 11:40 PM, Martin DEVERA wrote: > On 3/1/21 11:28 AM, Fabrice Gasnier wrote: >> On 2/27/21 5:41 PM, Martin Devera wrote: >>> STM32 F7/H7 usarts supports RX & TX pin swapping. >>> Add option to turn it on. >>> Tested on STM32MP157. >>> >>> Signed-off-by: Martin Devera <devik@eaxlabs.cz> >>> --- >>> drivers/tty/serial/stm32-usart.c | 3 ++- >>> drivers/tty/serial/stm32-usart.h | 1 + >>> 2 files changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/tty/serial/stm32-usart.c >>> b/drivers/tty/serial/stm32-usart.c >>> index b3675cf25a69..3650c8798061 100644 >>> --- a/drivers/tty/serial/stm32-usart.c >>> +++ b/drivers/tty/serial/stm32-usart.c >>> @@ -758,7 +758,7 @@ static void stm32_usart_set_termios(struct >>> uart_port *port, >>> cr1 = USART_CR1_TE | USART_CR1_RE; >>> if (stm32_port->fifoen) >>> cr1 |= USART_CR1_FIFOEN; >>> - cr2 = 0; >>> + cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; >> Hi Martin, >> >> Same could be done in the startup routine, that enables the port for >> reception (as described in Documentation/driver-api/serial/driver.rst) > Hello Fabrice, > > I already incorporated all your comments but I'm struggling with the one > above. > The code must be in stm32_usart_set_termios too, because CR2 is modified. Hi Martin, Yes, sure, > What is the reason to have it in startup() ? RX is enabled at both places. So the swap setting should be there too. > Is it because USART can be started without calling set_termios at all ? Yes, that's what the driver API expects: "startup(port)" ... "Enable the port for reception." Best Regards, Fabrice > Like > to reuse bootloader's last settings ? > > Thanks, Martin >
On 3/2/21 2:15 PM, Martin Devera wrote: > STM32 F7/H7 usarts supports RX & TX pin swapping. > Add option to turn it on. > Tested on STM32MP157. > > Signed-off-by: Martin Devera <devik@eaxlabs.cz> > --- > drivers/tty/serial/stm32-usart.c | 11 ++++++++++- > drivers/tty/serial/stm32-usart.h | 5 +++++ > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c > index b3675cf25a69..d390f7da1441 100644 > --- a/drivers/tty/serial/stm32-usart.c > +++ b/drivers/tty/serial/stm32-usart.c > @@ -644,6 +644,12 @@ static int stm32_usart_startup(struct uart_port *port) > if (ret) > return ret; > > + if (stm32_port->swap) { > + val = readl_relaxed(port->membase + ofs->cr2); > + val |= USART_CR2_SWAP; > + writel_relaxed(val, port->membase + ofs->cr2); > + } > + > /* RX FIFO Flush */ > if (ofs->rqr != UNDEF_REG) > stm32_usart_set_bits(port, ofs->rqr, USART_RQR_RXFRQ); > @@ -758,7 +764,7 @@ static void stm32_usart_set_termios(struct uart_port *port, > cr1 = USART_CR1_TE | USART_CR1_RE; > if (stm32_port->fifoen) > cr1 |= USART_CR1_FIFOEN; > - cr2 = 0; > + cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; > cr3 = readl_relaxed(port->membase + ofs->cr3); > cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE > | USART_CR3_TXFTCFG_MASK; > @@ -1006,6 +1012,9 @@ static int stm32_usart_init_port(struct stm32_port *stm32port, > return stm32port->wakeirq ? : -ENODEV; > } > > + stm32port->swap = stm32port->info->cfg.has_swap && > + of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"); > + > stm32port->fifoen = stm32port->info->cfg.has_fifo; > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h > index cb4f327c46db..bd18dd1c1bcd 100644 > --- a/drivers/tty/serial/stm32-usart.h > +++ b/drivers/tty/serial/stm32-usart.h > @@ -25,6 +25,7 @@ struct stm32_usart_offsets { > struct stm32_usart_config { > u8 uart_enable_bit; /* USART_CR1_UE */ > bool has_7bits_data; > + bool has_swap; > bool has_wakeup; > bool has_fifo; > int fifosize; > @@ -55,6 +56,7 @@ struct stm32_usart_info stm32f4_info = { > .cfg = { > .uart_enable_bit = 13, > .has_7bits_data = false, > + .has_swap = false, Hi Martin, Only one minor comment from me here. No need to add a false (zero) initialization in this struct. I'm not sure why this is the case for the has_7bits_data here... With that fixed, you can add my: Acked-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> Thanks for your patch, Best Regards, Fabrice > .fifosize = 1, > } > }; > @@ -76,6 +78,7 @@ struct stm32_usart_info stm32f7_info = { > .cfg = { > .uart_enable_bit = 0, > .has_7bits_data = true, > + .has_swap = true, > .fifosize = 1, > } > }; > @@ -97,6 +100,7 @@ struct stm32_usart_info stm32h7_info = { > .cfg = { > .uart_enable_bit = 0, > .has_7bits_data = true, > + .has_swap = true, > .has_wakeup = true, > .has_fifo = true, > .fifosize = 16, > @@ -271,6 +275,7 @@ struct stm32_port { > int last_res; > bool tx_dma_busy; /* dma tx busy */ > bool hw_flow_control; > + bool swap; /* swap RX & TX pins */ > bool fifoen; > int wakeirq; > int rdr_mask; /* receive data register mask */ >
On 3/2/21 6:44 PM, Fabrice Gasnier wrote: > On 3/2/21 2:15 PM, Martin Devera wrote: >> STM32 F7/H7 usarts supports RX & TX pin swapping. >> Add option to turn it on. >> Tested on STM32MP157. >> >> Signed-off-by: Martin Devera <devik@eaxlabs.cz> >> --- >> drivers/tty/serial/stm32-usart.c | 11 ++++++++++- >> drivers/tty/serial/stm32-usart.h | 5 +++++ >> 2 files changed, 15 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c >> index b3675cf25a69..d390f7da1441 100644 >> --- a/drivers/tty/serial/stm32-usart.c >> +++ b/drivers/tty/serial/stm32-usart.c >> @@ -644,6 +644,12 @@ static int stm32_usart_startup(struct uart_port *port) >> if (ret) >> return ret; >> >> + if (stm32_port->swap) { >> + val = readl_relaxed(port->membase + ofs->cr2); >> + val |= USART_CR2_SWAP; >> + writel_relaxed(val, port->membase + ofs->cr2); >> + } >> + >> /* RX FIFO Flush */ >> if (ofs->rqr != UNDEF_REG) >> stm32_usart_set_bits(port, ofs->rqr, USART_RQR_RXFRQ); >> @@ -758,7 +764,7 @@ static void stm32_usart_set_termios(struct uart_port *port, >> cr1 = USART_CR1_TE | USART_CR1_RE; >> if (stm32_port->fifoen) >> cr1 |= USART_CR1_FIFOEN; >> - cr2 = 0; >> + cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; >> cr3 = readl_relaxed(port->membase + ofs->cr3); >> cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE >> | USART_CR3_TXFTCFG_MASK; >> @@ -1006,6 +1012,9 @@ static int stm32_usart_init_port(struct stm32_port *stm32port, >> return stm32port->wakeirq ? : -ENODEV; >> } >> >> + stm32port->swap = stm32port->info->cfg.has_swap && >> + of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"); >> + >> stm32port->fifoen = stm32port->info->cfg.has_fifo; >> >> res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h >> index cb4f327c46db..bd18dd1c1bcd 100644 >> --- a/drivers/tty/serial/stm32-usart.h >> +++ b/drivers/tty/serial/stm32-usart.h >> @@ -25,6 +25,7 @@ struct stm32_usart_offsets { >> struct stm32_usart_config { >> u8 uart_enable_bit; /* USART_CR1_UE */ >> bool has_7bits_data; >> + bool has_swap; >> bool has_wakeup; >> bool has_fifo; >> int fifosize; >> @@ -55,6 +56,7 @@ struct stm32_usart_info stm32f4_info = { >> .cfg = { >> .uart_enable_bit = 13, >> .has_7bits_data = false, >> + .has_swap = false, > Hi Martin, > > Only one minor comment from me here. No need to add a false (zero) > initialization in this struct. I'm not sure why this is the case for the > has_7bits_data here... > > With that fixed, you can add my: > Acked-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> > The has_7bits_data was what made me a bit unsure. Ok fixed now. Thank you for your review. Martin
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index b3675cf25a69..3650c8798061 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -758,7 +758,7 @@ static void stm32_usart_set_termios(struct uart_port *port, cr1 = USART_CR1_TE | USART_CR1_RE; if (stm32_port->fifoen) cr1 |= USART_CR1_FIFOEN; - cr2 = 0; + cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; cr3 = readl_relaxed(port->membase + ofs->cr3); cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE | USART_CR3_TXFTCFG_MASK; @@ -1078,6 +1078,7 @@ static struct stm32_port *stm32_usart_of_get_port(struct platform_device *pdev) stm32_ports[id].hw_flow_control = of_property_read_bool (np, "st,hw-flow-ctrl") /*deprecated*/ || of_property_read_bool (np, "uart-has-rtscts"); + stm32_ports[id].swap = of_property_read_bool(np, "rx-tx-swap"); stm32_ports[id].port.line = id; stm32_ports[id].cr1_irq = USART_CR1_RXNEIE; stm32_ports[id].cr3_irq = 0; diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h index cb4f327c46db..2f054e2dc0ab 100644 --- a/drivers/tty/serial/stm32-usart.h +++ b/drivers/tty/serial/stm32-usart.h @@ -271,6 +271,7 @@ struct stm32_port { int last_res; bool tx_dma_busy; /* dma tx busy */ bool hw_flow_control; + bool swap; /* swap RX & TX pins */ bool fifoen; int wakeirq; int rdr_mask; /* receive data register mask */
STM32 F7/H7 usarts supports RX & TX pin swapping. Add option to turn it on. Tested on STM32MP157. Signed-off-by: Martin Devera <devik@eaxlabs.cz> --- drivers/tty/serial/stm32-usart.c | 3 ++- drivers/tty/serial/stm32-usart.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)