Merge tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of TTY and Serial driver updates for 6.1-rc1.

  Lots of cleanups in here, no real new functionality this time around,
  with the diffstat being that we removed more lines than we added!

  Included in here are:

   - termios unification cleanups from Al Viro, it's nice to finally get
     this work done

   - tty serial transmit cleanups in various drivers in preparation for
     more cleanup and unification in future releases (that work was not
     ready for this release)

   - n_gsm fixes and updates

   - ktermios cleanups and code reductions

   - dt bindings json conversions and updates for new devices

   - some serial driver updates for new devices

   - lots of other tiny cleanups and janitorial stuff. Full details in
     the shortlog.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (102 commits)
  serial: cpm_uart: Don't request IRQ too early for console port
  tty: serial: do unlock on a common path in altera_jtaguart_console_putc()
  tty: serial: unify TX space reads under altera_jtaguart_tx_space()
  tty: serial: use FIELD_GET() in lqasc_tx_ready()
  tty: serial: extend lqasc_tx_ready() to lqasc_console_putchar()
  tty: serial: allow pxa.c to be COMPILE_TESTed
  serial: stm32: Fix unused-variable warning
  tty: serial: atmel: Add COMMON_CLK dependency to SERIAL_ATMEL
  serial: 8250: Fix restoring termios speed after suspend
  serial: Deassert Transmit Enable on probe in driver-specific way
  serial: 8250_dma: Convert to use uart_xmit_advance()
  serial: 8250_omap: Convert to use uart_xmit_advance()
  MAINTAINERS: Solve warning regarding inexistent atmel-usart binding
  serial: stm32: Deassert Transmit Enable on ->rs485_config()
  serial: ar933x: Deassert Transmit Enable on ->rs485_config()
  tty: serial: atmel: Use FIELD_PREP/FIELD_GET
  tty: serial: atmel: Make the driver aware of the existence of GCLK
  tty: serial: atmel: Only divide Clock Divisor if the IP is USART
  tty: serial: atmel: Separate mode clearing between UART and USART
  dt-bindings: serial: atmel,at91-usart: Add gclk as a possible USART clock
  ...

1 files changed, 57 insertions, 51 deletions

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 2c85dbf165c4..dfdbcf092fac 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -37,7 +37,7 @@
 
 
 /* Register offsets */
-static struct stm32_usart_info stm32f4_info = {
+static struct stm32_usart_info __maybe_unused stm32f4_info = {
 	.ofs = {
 		.isr	= 0x00,
 		.rdr	= 0x04,
@@ -58,7 +58,7 @@ static struct stm32_usart_info stm32f4_info = {
 	}
 };
 
-static struct stm32_usart_info stm32f7_info = {
+static struct stm32_usart_info __maybe_unused stm32f7_info = {
 	.ofs = {
 		.cr1	= 0x00,
 		.cr2	= 0x04,
@@ -80,7 +80,7 @@ static struct stm32_usart_info stm32f7_info = {
 	}
 };
 
-static struct stm32_usart_info stm32h7_info = {
+static struct stm32_usart_info __maybe_unused stm32h7_info = {
 	.ofs = {
 		.cr1	= 0x00,
 		.cr2	= 0x04,
@@ -131,6 +131,53 @@ static void stm32_usart_clr_bits(struct uart_port *port, u32 reg, u32 bits)
 	writel_relaxed(val, port->membase + reg);
 }
 
+static unsigned int stm32_usart_tx_empty(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC)
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+static void stm32_usart_rs485_rts_enable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct serial_rs485 *rs485conf = &port->rs485;
+
+	if (stm32_port->hw_flow_control ||
+	    !(rs485conf->flags & SER_RS485_ENABLED))
+		return;
+
+	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl | TIOCM_RTS);
+	} else {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl & ~TIOCM_RTS);
+	}
+}
+
+static void stm32_usart_rs485_rts_disable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct serial_rs485 *rs485conf = &port->rs485;
+
+	if (stm32_port->hw_flow_control ||
+	    !(rs485conf->flags & SER_RS485_ENABLED))
+		return;
+
+	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl & ~TIOCM_RTS);
+	} else {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl | TIOCM_RTS);
+	}
+}
+
 static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
 					 u32 delay_DDE, u32 baud)
 {
@@ -214,6 +261,12 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
 
 	stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 
+	/* Adjust RTS polarity in case it's driven in software */
+	if (stm32_usart_tx_empty(port))
+		stm32_usart_rs485_rts_disable(port);
+	else
+		stm32_usart_rs485_rts_enable(port);
+
 	return 0;
 }
 
@@ -529,42 +582,6 @@ static void stm32_usart_tc_interrupt_disable(struct uart_port *port)
 	stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TCIE);
 }
 
-static void stm32_usart_rs485_rts_enable(struct uart_port *port)
-{
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	struct serial_rs485 *rs485conf = &port->rs485;
-
-	if (stm32_port->hw_flow_control ||
-	    !(rs485conf->flags & SER_RS485_ENABLED))
-		return;
-
-	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl | TIOCM_RTS);
-	} else {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl & ~TIOCM_RTS);
-	}
-}
-
-static void stm32_usart_rs485_rts_disable(struct uart_port *port)
-{
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	struct serial_rs485 *rs485conf = &port->rs485;
-
-	if (stm32_port->hw_flow_control ||
-	    !(rs485conf->flags & SER_RS485_ENABLED))
-		return;
-
-	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl & ~TIOCM_RTS);
-	} else {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl | TIOCM_RTS);
-	}
-}
-
 static void stm32_usart_transmit_chars_pio(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -807,17 +824,6 @@ static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr)
 	return IRQ_HANDLED;
 }
 
-static unsigned int stm32_usart_tx_empty(struct uart_port *port)
-{
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-
-	if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC)
-		return TIOCSER_TEMT;
-
-	return 0;
-}
-
 static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -1089,7 +1095,7 @@ static void stm32_usart_shutdown(struct uart_port *port)
 
 static void stm32_usart_set_termios(struct uart_port *port,
 				    struct ktermios *termios,
-				    struct ktermios *old)
+				    const struct ktermios *old)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;