[PATCH 0/7] STM32 uart cleanup and improvements

[PATCH 0/7] STM32 uart cleanup and improvements

[Erwan Le Ray]

This series brings various fixes, cleanups and improvements to stm32-usart
driver.

Erwan Le Ray (8):
  serial: stm32: fix -Wall W=1 compilation warnings
  serial: stm32: fix code cleaning warnings and checks
  serial: stm32: add "_usart" prefix in functions name
  serial: stm32: add author
  dt-bindings: serial: stm32: update rts-gpios and cts-gpios
  serial: stm32: update conflicting RTS/CTS config comment
  serial: stm32: clean probe and remove port deinit
  serial: stm32: update transmission complete error message in shutdown

 .../bindings/serial/st,stm32-uart.yaml        |  13 +-
 drivers/tty/serial/stm32-usart.c              | 417 +++++++++---------
 2 files changed, 227 insertions(+), 203 deletions(-)

-- 
2.17.1

[PATCH 1/8] serial: stm32: fix -Wall W=1 compilation warnings

[Erwan Le Ray]

Fix compilations warning detected by -Wall W=1 compilation option:
- warning: variable ‘cookie’ set but not used

Fixes: 3489187204eb ("serial: stm32: adding dma support")
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index ee6c7762d355..6248304a001f 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -350,7 +350,6 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 	struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
 	struct circ_buf *xmit = &port->state->xmit;
 	struct dma_async_tx_descriptor *desc = NULL;
-	dma_cookie_t cookie;
 	unsigned int count, i;
 
 	if (stm32port->tx_dma_busy)
@@ -384,17 +383,18 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 					   DMA_MEM_TO_DEV,
 					   DMA_PREP_INTERRUPT);
 
-	if (!desc) {
-		for (i = count; i > 0; i--)
-			stm32_transmit_chars_pio(port);
-		return;
-	}
+	if (!desc)
+		goto fallback_err;
 
 	desc->callback = stm32_tx_dma_complete;
 	desc->callback_param = port;
 
 	/* Push current DMA TX transaction in the pending queue */
-	cookie = dmaengine_submit(desc);
+	if (dma_submit_error(dmaengine_submit(desc))) {
+		/* dma no yet started, safe to free resources */
+		dmaengine_terminate_async(stm32port->tx_ch);
+		goto fallback_err;
+	}
 
 	/* Issue pending DMA TX requests */
 	dma_async_issue_pending(stm32port->tx_ch);
@@ -403,6 +403,11 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 
 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
 	port->icount.tx += count;
+	return;
+
+fallback_err:
+	for (i = count; i > 0; i--)
+		stm32_transmit_chars_pio(port);
 }
 
 static void stm32_transmit_chars(struct uart_port *port)
@@ -1087,7 +1092,6 @@ static int stm32_of_dma_rx_probe(struct stm32_port *stm32port,
 	struct device *dev = &pdev->dev;
 	struct dma_slave_config config;
 	struct dma_async_tx_descriptor *desc = NULL;
-	dma_cookie_t cookie;
 	int ret;
 
 	/* Request DMA RX channel */
@@ -1132,7 +1136,11 @@ static int stm32_of_dma_rx_probe(struct stm32_port *stm32port,
 	desc->callback_param = NULL;
 
 	/* Push current DMA transaction in the pending queue */
-	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(dmaengine_submit(desc));
+	if (ret) {
+		dmaengine_terminate_sync(stm32port->rx_ch);
+		goto config_err;
+	}
 
 	/* Issue pending DMA requests */
 	dma_async_issue_pending(stm32port->rx_ch);
-- 
2.17.1

[PATCH 2/8] serial: stm32: fix code cleaning warnings and checks

[Erwan Le Ray]

Fixes checkpatch --strict warnings and checks:
- checkpatch --strict "Unnecessary parentheses"
- checkpatch --strict "Blank lines aren't necessary before a close brace
- checkpatch --strict "Alignment should match open parenthesis"
- checkpatch --strict "Please don't use multiple blank lines"
- checkpatch --strict "Comparison to NULL could be written ..."
- visual check code ordering warning

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 6248304a001f..a0ef86d71317 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -176,8 +176,7 @@ static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res,
 		status = dmaengine_tx_status(stm32_port->rx_ch,
 					     stm32_port->rx_ch->cookie,
 					     &state);
-		if ((status == DMA_IN_PROGRESS) &&
-		    (*last_res != state.residue))
+		if (status == DMA_IN_PROGRESS && (*last_res != state.residue))
 			return 1;
 		else
 			return 0;
@@ -464,7 +463,7 @@ static irqreturn_t stm32_interrupt(int irq, void *ptr)
 		writel_relaxed(USART_ICR_RTOCF,
 			       port->membase + ofs->icr);
 
-	if ((sr & USART_SR_WUF) && (ofs->icr != UNDEF_REG))
+	if ((sr & USART_SR_WUF) && ofs->icr != UNDEF_REG)
 		writel_relaxed(USART_ICR_WUCF,
 			       port->membase + ofs->icr);
 
@@ -620,7 +619,6 @@ static void stm32_stop_rx(struct uart_port *port)
 	stm32_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
 	if (stm32_port->cr3_irq)
 		stm32_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
-
 }
 
 /* Handle breaks - ignored by us */
@@ -724,7 +722,7 @@ static unsigned int stm32_get_databits(struct ktermios *termios)
 }
 
 static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
-			    struct ktermios *old)
+			      struct ktermios *old)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -923,7 +921,7 @@ stm32_verify_port(struct uart_port *port, struct serial_struct *ser)
 }
 
 static void stm32_pm(struct uart_port *port, unsigned int state,
-		unsigned int oldstate)
+		     unsigned int oldstate)
 {
 	struct stm32_port *stm32port = container_of(port,
 			struct stm32_port, port);
@@ -973,18 +971,17 @@ static int stm32_init_port(struct stm32_port *stm32port,
 	struct resource *res;
 	int ret;
 
+	ret = platform_get_irq(pdev, 0);
+	if (ret <= 0)
+		return ret ? : -ENODEV;
+
 	port->iotype	= UPIO_MEM;
 	port->flags	= UPF_BOOT_AUTOCONF;
 	port->ops	= &stm32_uart_ops;
 	port->dev	= &pdev->dev;
 	port->fifosize	= stm32port->info->cfg.fifosize;
 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_STM32_CONSOLE);
-
-	ret = platform_get_irq(pdev, 0);
-	if (ret <= 0)
-		return ret ? : -ENODEV;
 	port->irq = ret;
-
 	port->rs485_config = stm32_config_rs485;
 
 	ret = stm32_init_rs485(port, pdev);
@@ -1101,8 +1098,8 @@ static int stm32_of_dma_rx_probe(struct stm32_port *stm32port,
 		return -ENODEV;
 	}
 	stm32port->rx_buf = dma_alloc_coherent(&pdev->dev, RX_BUF_L,
-						 &stm32port->rx_dma_buf,
-						 GFP_KERNEL);
+					       &stm32port->rx_dma_buf,
+					       GFP_KERNEL);
 	if (!stm32port->rx_buf) {
 		ret = -ENOMEM;
 		goto alloc_err;
@@ -1177,8 +1174,8 @@ static int stm32_of_dma_tx_probe(struct stm32_port *stm32port,
 		return -ENODEV;
 	}
 	stm32port->tx_buf = dma_alloc_coherent(&pdev->dev, TX_BUF_L,
-						 &stm32port->tx_dma_buf,
-						 GFP_KERNEL);
+					       &stm32port->tx_dma_buf,
+					       GFP_KERNEL);
 	if (!stm32port->tx_buf) {
 		ret = -ENOMEM;
 		goto alloc_err;
@@ -1322,7 +1319,6 @@ static int stm32_serial_remove(struct platform_device *pdev)
 	return err;
 }
 
-
 #ifdef CONFIG_SERIAL_STM32_CONSOLE
 static void stm32_console_putchar(struct uart_port *port, int ch)
 {
@@ -1335,7 +1331,8 @@ static void stm32_console_putchar(struct uart_port *port, int ch)
 	writel_relaxed(ch, port->membase + ofs->tdr);
 }
 
-static void stm32_console_write(struct console *co, const char *s, unsigned cnt)
+static void stm32_console_write(struct console *co, const char *s,
+				unsigned int cnt)
 {
 	struct uart_port *port = &stm32_ports[co->index].port;
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -1388,7 +1385,7 @@ static int stm32_console_setup(struct console *co, char *options)
 	 * this to be called during the uart port registration when the
 	 * driver gets probed and the port should be mapped at that point.
 	 */
-	if (stm32port->port.mapbase == 0 || stm32port->port.membase == NULL)
+	if (stm32port->port.mapbase == 0 || !stm32port->port.membase)
 		return -ENXIO;
 
 	if (options)
-- 
2.17.1

[PATCH 3/8] serial: stm32: add "_usart" prefix in functions name

[Erwan Le Ray]

Adds the prefix "_usart" in the name of stm32 usart functions in order to
ease the usage of kernel trace and tools, such as f-trace.
Allows to trace "stm32_usart_*" functions with f-trace. Without this patch,
all the driver functions needs to be added manually in f-trace filter.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index a0ef86d71317..717a97759928 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -34,15 +34,15 @@
 #include "serial_mctrl_gpio.h"
 #include "stm32-usart.h"
 
-static void stm32_stop_tx(struct uart_port *port);
-static void stm32_transmit_chars(struct uart_port *port);
+static void stm32_usart_stop_tx(struct uart_port *port);
+static void stm32_usart_transmit_chars(struct uart_port *port);
 
 static inline struct stm32_port *to_stm32_port(struct uart_port *port)
 {
 	return container_of(port, struct stm32_port, port);
 }
 
-static void stm32_set_bits(struct uart_port *port, u32 reg, u32 bits)
+static void stm32_usart_set_bits(struct uart_port *port, u32 reg, u32 bits)
 {
 	u32 val;
 
@@ -51,7 +51,7 @@ static void stm32_set_bits(struct uart_port *port, u32 reg, u32 bits)
 	writel_relaxed(val, port->membase + reg);
 }
 
-static void stm32_clr_bits(struct uart_port *port, u32 reg, u32 bits)
+static void stm32_usart_clr_bits(struct uart_port *port, u32 reg, u32 bits)
 {
 	u32 val;
 
@@ -60,8 +60,8 @@ static void stm32_clr_bits(struct uart_port *port, u32 reg, u32 bits)
 	writel_relaxed(val, port->membase + reg);
 }
 
-static void stm32_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
-				   u32 delay_DDE, u32 baud)
+static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
+					 u32 delay_DDE, u32 baud)
 {
 	u32 rs485_deat_dedt;
 	u32 rs485_deat_dedt_max = (USART_CR1_DEAT_MASK >> USART_CR1_DEAT_SHIFT);
@@ -95,8 +95,8 @@ static void stm32_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
 	*cr1 |= rs485_deat_dedt;
 }
 
-static int stm32_config_rs485(struct uart_port *port,
-			      struct serial_rs485 *rs485conf)
+static int stm32_usart_config_rs485(struct uart_port *port,
+				    struct serial_rs485 *rs485conf)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -104,7 +104,7 @@ static int stm32_config_rs485(struct uart_port *port,
 	u32 usartdiv, baud, cr1, cr3;
 	bool over8;
 
-	stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+	stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 
 	port->rs485 = *rs485conf;
 
@@ -122,9 +122,10 @@ static int stm32_config_rs485(struct uart_port *port,
 				   << USART_BRR_04_R_SHIFT;
 
 		baud = DIV_ROUND_CLOSEST(port->uartclk, usartdiv);
-		stm32_config_reg_rs485(&cr1, &cr3,
-				       rs485conf->delay_rts_before_send,
-				       rs485conf->delay_rts_after_send, baud);
+		stm32_usart_config_reg_rs485(&cr1, &cr3,
+					     rs485conf->delay_rts_before_send,
+					     rs485conf->delay_rts_after_send,
+					     baud);
 
 		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
 			cr3 &= ~USART_CR3_DEP;
@@ -137,18 +138,19 @@ static int stm32_config_rs485(struct uart_port *port,
 		writel_relaxed(cr3, port->membase + ofs->cr3);
 		writel_relaxed(cr1, port->membase + ofs->cr1);
 	} else {
-		stm32_clr_bits(port, ofs->cr3, USART_CR3_DEM | USART_CR3_DEP);
-		stm32_clr_bits(port, ofs->cr1,
-			       USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK);
+		stm32_usart_clr_bits(port, ofs->cr3,
+				     USART_CR3_DEM | USART_CR3_DEP);
+		stm32_usart_clr_bits(port, ofs->cr1,
+				     USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK);
 	}
 
-	stm32_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+	stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 
 	return 0;
 }
 
-static int stm32_init_rs485(struct uart_port *port,
-			    struct platform_device *pdev)
+static int stm32_usart_init_rs485(struct uart_port *port,
+				  struct platform_device *pdev)
 {
 	struct serial_rs485 *rs485conf = &port->rs485;
 
@@ -162,8 +164,8 @@ static int stm32_init_rs485(struct uart_port *port,
 	return uart_get_rs485_mode(port);
 }
 
-static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res,
-			    bool threaded)
+static int stm32_usart_pending_rx(struct uart_port *port, u32 *sr,
+				  int *last_res, bool threaded)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -186,8 +188,8 @@ static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res,
 	return 0;
 }
 
-static unsigned long stm32_get_char(struct uart_port *port, u32 *sr,
-				    int *last_res)
+static unsigned long stm32_usart_get_char(struct uart_port *port, u32 *sr,
+					  int *last_res)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -206,7 +208,7 @@ static unsigned long stm32_get_char(struct uart_port *port, u32 *sr,
 	return c;
 }
 
-static void stm32_receive_chars(struct uart_port *port, bool threaded)
+static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
 {
 	struct tty_port *tport = &port->state->port;
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -218,7 +220,8 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded)
 	if (irqd_is_wakeup_set(irq_get_irq_data(port->irq)))
 		pm_wakeup_event(tport->tty->dev, 0);
 
-	while (stm32_pending_rx(port, &sr, &stm32_port->last_res, threaded)) {
+	while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
+				      threaded)) {
 		sr |= USART_SR_DUMMY_RX;
 		flag = TTY_NORMAL;
 
@@ -237,7 +240,7 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded)
 			writel_relaxed(sr & USART_SR_ERR_MASK,
 				       port->membase + ofs->icr);
 
-		c = stm32_get_char(port, &sr, &stm32_port->last_res);
+		c = stm32_usart_get_char(port, &sr, &stm32_port->last_res);
 		port->icount.rx++;
 		if (sr & USART_SR_ERR_MASK) {
 			if (sr & USART_SR_ORE) {
@@ -277,20 +280,20 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded)
 	spin_lock(&port->lock);
 }
 
-static void stm32_tx_dma_complete(void *arg)
+static void stm32_usart_tx_dma_complete(void *arg)
 {
 	struct uart_port *port = arg;
 	struct stm32_port *stm32port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
 
-	stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+	stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 	stm32port->tx_dma_busy = false;
 
 	/* Let's see if we have pending data to send */
-	stm32_transmit_chars(port);
+	stm32_usart_transmit_chars(port);
 }
 
-static void stm32_tx_interrupt_enable(struct uart_port *port)
+static void stm32_usart_tx_interrupt_enable(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -300,30 +303,30 @@ static void stm32_tx_interrupt_enable(struct uart_port *port)
 	 * or TX empty irq when FIFO is disabled
 	 */
 	if (stm32_port->fifoen)
-		stm32_set_bits(port, ofs->cr3, USART_CR3_TXFTIE);
+		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_TXFTIE);
 	else
-		stm32_set_bits(port, ofs->cr1, USART_CR1_TXEIE);
+		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TXEIE);
 }
 
-static void stm32_tx_interrupt_disable(struct uart_port *port)
+static void stm32_usart_tx_interrupt_disable(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
 	if (stm32_port->fifoen)
-		stm32_clr_bits(port, ofs->cr3, USART_CR3_TXFTIE);
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_TXFTIE);
 	else
-		stm32_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
+		stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
 }
 
-static void stm32_transmit_chars_pio(struct uart_port *port)
+static void stm32_usart_transmit_chars_pio(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	struct circ_buf *xmit = &port->state->xmit;
 
 	if (stm32_port->tx_dma_busy) {
-		stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 		stm32_port->tx_dma_busy = false;
 	}
 
@@ -338,12 +341,12 @@ static void stm32_transmit_chars_pio(struct uart_port *port)
 
 	/* rely on TXE irq (mask or unmask) for sending remaining data */
 	if (uart_circ_empty(xmit))
-		stm32_tx_interrupt_disable(port);
+		stm32_usart_tx_interrupt_disable(port);
 	else
-		stm32_tx_interrupt_enable(port);
+		stm32_usart_tx_interrupt_enable(port);
 }
 
-static void stm32_transmit_chars_dma(struct uart_port *port)
+static void stm32_usart_transmit_chars_dma(struct uart_port *port)
 {
 	struct stm32_port *stm32port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
@@ -385,7 +388,7 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 	if (!desc)
 		goto fallback_err;
 
-	desc->callback = stm32_tx_dma_complete;
+	desc->callback = stm32_usart_tx_dma_complete;
 	desc->callback_param = port;
 
 	/* Push current DMA TX transaction in the pending queue */
@@ -398,7 +401,7 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 	/* Issue pending DMA TX requests */
 	dma_async_issue_pending(stm32port->tx_ch);
 
-	stm32_set_bits(port, ofs->cr3, USART_CR3_DMAT);
+	stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAT);
 
 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
 	port->icount.tx += count;
@@ -406,10 +409,10 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 
 fallback_err:
 	for (i = count; i > 0; i--)
-		stm32_transmit_chars_pio(port);
+		stm32_usart_transmit_chars_pio(port);
 }
 
-static void stm32_transmit_chars(struct uart_port *port)
+static void stm32_usart_transmit_chars(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -417,38 +420,38 @@ static void stm32_transmit_chars(struct uart_port *port)
 
 	if (port->x_char) {
 		if (stm32_port->tx_dma_busy)
-			stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+			stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 		writel_relaxed(port->x_char, port->membase + ofs->tdr);
 		port->x_char = 0;
 		port->icount.tx++;
 		if (stm32_port->tx_dma_busy)
-			stm32_set_bits(port, ofs->cr3, USART_CR3_DMAT);
+			stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAT);
 		return;
 	}
 
 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
-		stm32_tx_interrupt_disable(port);
+		stm32_usart_tx_interrupt_disable(port);
 		return;
 	}
 
 	if (ofs->icr == UNDEF_REG)
-		stm32_clr_bits(port, ofs->isr, USART_SR_TC);
+		stm32_usart_clr_bits(port, ofs->isr, USART_SR_TC);
 	else
 		writel_relaxed(USART_ICR_TCCF, port->membase + ofs->icr);
 
 	if (stm32_port->tx_ch)
-		stm32_transmit_chars_dma(port);
+		stm32_usart_transmit_chars_dma(port);
 	else
-		stm32_transmit_chars_pio(port);
+		stm32_usart_transmit_chars_pio(port);
 
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(port);
 
 	if (uart_circ_empty(xmit))
-		stm32_tx_interrupt_disable(port);
+		stm32_usart_tx_interrupt_disable(port);
 }
 
-static irqreturn_t stm32_interrupt(int irq, void *ptr)
+static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 {
 	struct uart_port *port = ptr;
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -468,10 +471,10 @@ static irqreturn_t stm32_interrupt(int irq, void *ptr)
 			       port->membase + ofs->icr);
 
 	if ((sr & USART_SR_RXNE) && !(stm32_port->rx_ch))
-		stm32_receive_chars(port, false);
+		stm32_usart_receive_chars(port, false);
 
 	if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch))
-		stm32_transmit_chars(port);
+		stm32_usart_transmit_chars(port);
 
 	spin_unlock(&port->lock);
 
@@ -481,7 +484,7 @@ static irqreturn_t stm32_interrupt(int irq, void *ptr)
 		return IRQ_HANDLED;
 }
 
-static irqreturn_t stm32_threaded_interrupt(int irq, void *ptr)
+static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr)
 {
 	struct uart_port *port = ptr;
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -489,14 +492,14 @@ static irqreturn_t stm32_threaded_interrupt(int irq, void *ptr)
 	spin_lock(&port->lock);
 
 	if (stm32_port->rx_ch)
-		stm32_receive_chars(port, true);
+		stm32_usart_receive_chars(port, true);
 
 	spin_unlock(&port->lock);
 
 	return IRQ_HANDLED;
 }
 
-static unsigned int stm32_tx_empty(struct uart_port *port)
+static unsigned int stm32_usart_tx_empty(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -504,20 +507,20 @@ static unsigned int stm32_tx_empty(struct uart_port *port)
 	return readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE;
 }
 
-static void stm32_set_mctrl(struct uart_port *port, unsigned int mctrl)
+static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
 	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
-		stm32_set_bits(port, ofs->cr3, USART_CR3_RTSE);
+		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_RTSE);
 	else
-		stm32_clr_bits(port, ofs->cr3, USART_CR3_RTSE);
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_RTSE);
 
 	mctrl_gpio_set(stm32_port->gpios, mctrl);
 }
 
-static unsigned int stm32_get_mctrl(struct uart_port *port)
+static unsigned int stm32_usart_get_mctrl(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	unsigned int ret;
@@ -528,23 +531,23 @@ static unsigned int stm32_get_mctrl(struct uart_port *port)
 	return mctrl_gpio_get(stm32_port->gpios, &ret);
 }
 
-static void stm32_enable_ms(struct uart_port *port)
+static void stm32_usart_enable_ms(struct uart_port *port)
 {
 	mctrl_gpio_enable_ms(to_stm32_port(port)->gpios);
 }
 
-static void stm32_disable_ms(struct uart_port *port)
+static void stm32_usart_disable_ms(struct uart_port *port)
 {
 	mctrl_gpio_disable_ms(to_stm32_port(port)->gpios);
 }
 
 /* Transmit stop */
-static void stm32_stop_tx(struct uart_port *port)
+static void stm32_usart_stop_tx(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct serial_rs485 *rs485conf = &port->rs485;
 
-	stm32_tx_interrupt_disable(port);
+	stm32_usart_tx_interrupt_disable(port);
 
 	if (rs485conf->flags & SER_RS485_ENABLED) {
 		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
@@ -558,7 +561,7 @@ static void stm32_stop_tx(struct uart_port *port)
 }
 
 /* There are probably characters waiting to be transmitted. */
-static void stm32_start_tx(struct uart_port *port)
+static void stm32_usart_start_tx(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct serial_rs485 *rs485conf = &port->rs485;
@@ -577,56 +580,56 @@ static void stm32_start_tx(struct uart_port *port)
 		}
 	}
 
-	stm32_transmit_chars(port);
+	stm32_usart_transmit_chars(port);
 }
 
 /* Throttle the remote when input buffer is about to overflow. */
-static void stm32_throttle(struct uart_port *port)
+static void stm32_usart_throttle(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	unsigned long flags;
 
 	spin_lock_irqsave(&port->lock, flags);
-	stm32_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
 	if (stm32_port->cr3_irq)
-		stm32_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
+		stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
 
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
 /* Unthrottle the remote, the input buffer can now accept data. */
-static void stm32_unthrottle(struct uart_port *port)
+static void stm32_usart_unthrottle(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	unsigned long flags;
 
 	spin_lock_irqsave(&port->lock, flags);
-	stm32_set_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	stm32_usart_set_bits(port, ofs->cr1, stm32_port->cr1_irq);
 	if (stm32_port->cr3_irq)
-		stm32_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
+		stm32_usart_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
 
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
 /* Receive stop */
-static void stm32_stop_rx(struct uart_port *port)
+static void stm32_usart_stop_rx(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
-	stm32_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
 	if (stm32_port->cr3_irq)
-		stm32_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
+		stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
 }
 
 /* Handle breaks - ignored by us */
-static void stm32_break_ctl(struct uart_port *port, int break_state)
+static void stm32_usart_break_ctl(struct uart_port *port, int break_state)
 {
 }
 
-static int stm32_startup(struct uart_port *port)
+static int stm32_usart_startup(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -634,15 +637,15 @@ static int stm32_startup(struct uart_port *port)
 	u32 val;
 	int ret;
 
-	ret = request_threaded_irq(port->irq, stm32_interrupt,
-				   stm32_threaded_interrupt,
+	ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
+				   stm32_usart_threaded_interrupt,
 				   IRQF_NO_SUSPEND, name, port);
 	if (ret)
 		return ret;
 
 	/* RX FIFO Flush */
 	if (ofs->rqr != UNDEF_REG)
-		stm32_set_bits(port, ofs->rqr, USART_RQR_RXFRQ);
+		stm32_usart_set_bits(port, ofs->rqr, USART_RQR_RXFRQ);
 
 	/* Tx and RX FIFO configuration */
 	if (stm32_port->fifoen) {
@@ -657,12 +660,12 @@ static int stm32_startup(struct uart_port *port)
 	val = stm32_port->cr1_irq | USART_CR1_RE;
 	if (stm32_port->fifoen)
 		val |= USART_CR1_FIFOEN;
-	stm32_set_bits(port, ofs->cr1, val);
+	stm32_usart_set_bits(port, ofs->cr1, val);
 
 	return 0;
 }
 
-static void stm32_shutdown(struct uart_port *port)
+static void stm32_usart_shutdown(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -671,7 +674,7 @@ static void stm32_shutdown(struct uart_port *port)
 	int ret;
 
 	/* Disable modem control interrupts */
-	stm32_disable_ms(port);
+	stm32_usart_disable_ms(port);
 
 	val = USART_CR1_TXEIE | USART_CR1_TE;
 	val |= stm32_port->cr1_irq | USART_CR1_RE;
@@ -686,12 +689,12 @@ static void stm32_shutdown(struct uart_port *port)
 	if (ret)
 		dev_err(port->dev, "transmission complete not set\n");
 
-	stm32_clr_bits(port, ofs->cr1, val);
+	stm32_usart_clr_bits(port, ofs->cr1, val);
 
 	free_irq(port->irq, port);
 }
 
-static unsigned int stm32_get_databits(struct ktermios *termios)
+static unsigned int stm32_usart_get_databits(struct ktermios *termios)
 {
 	unsigned int bits;
 
@@ -721,8 +724,9 @@ static unsigned int stm32_get_databits(struct ktermios *termios)
 	return bits;
 }
 
-static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
-			      struct ktermios *old)
+static void stm32_usart_set_termios(struct uart_port *port,
+				    struct ktermios *termios,
+				    struct ktermios *old)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -746,8 +750,8 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	/* flush RX & TX FIFO */
 	if (ofs->rqr != UNDEF_REG)
-		stm32_set_bits(port, ofs->rqr,
-			       USART_RQR_TXFRQ | USART_RQR_RXFRQ);
+		stm32_usart_set_bits(port, ofs->rqr,
+				     USART_RQR_TXFRQ | USART_RQR_RXFRQ);
 
 	cr1 = USART_CR1_TE | USART_CR1_RE;
 	if (stm32_port->fifoen)
@@ -760,7 +764,7 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (cflag & CSTOPB)
 		cr2 |= USART_CR2_STOP_2B;
 
-	bits = stm32_get_databits(termios);
+	bits = stm32_usart_get_databits(termios);
 	stm32_port->rdr_mask = (BIT(bits) - 1);
 
 	if (cflag & PARENB) {
@@ -813,9 +817,9 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	/* Handle modem control interrupts */
 	if (UART_ENABLE_MS(port, termios->c_cflag))
-		stm32_enable_ms(port);
+		stm32_usart_enable_ms(port);
 	else
-		stm32_disable_ms(port);
+		stm32_usart_disable_ms(port);
 
 	usartdiv = DIV_ROUND_CLOSEST(port->uartclk, baud);
 
@@ -828,11 +832,11 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (usartdiv < 16) {
 		oversampling = 8;
 		cr1 |= USART_CR1_OVER8;
-		stm32_set_bits(port, ofs->cr1, USART_CR1_OVER8);
+		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_OVER8);
 	} else {
 		oversampling = 16;
 		cr1 &= ~USART_CR1_OVER8;
-		stm32_clr_bits(port, ofs->cr1, USART_CR1_OVER8);
+		stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_OVER8);
 	}
 
 	mantissa = (usartdiv / oversampling) << USART_BRR_DIV_M_SHIFT;
@@ -869,9 +873,10 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 		cr3 |= USART_CR3_DMAR;
 
 	if (rs485conf->flags & SER_RS485_ENABLED) {
-		stm32_config_reg_rs485(&cr1, &cr3,
-				       rs485conf->delay_rts_before_send,
-				       rs485conf->delay_rts_after_send, baud);
+		stm32_usart_config_reg_rs485(&cr1, &cr3,
+					     rs485conf->delay_rts_before_send,
+					     rs485conf->delay_rts_after_send,
+					     baud);
 		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
 			cr3 &= ~USART_CR3_DEP;
 			rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
@@ -889,39 +894,39 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 	writel_relaxed(cr2, port->membase + ofs->cr2);
 	writel_relaxed(cr1, port->membase + ofs->cr1);
 
-	stm32_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+	stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
-static const char *stm32_type(struct uart_port *port)
+static const char *stm32_usart_type(struct uart_port *port)
 {
 	return (port->type == PORT_STM32) ? DRIVER_NAME : NULL;
 }
 
-static void stm32_release_port(struct uart_port *port)
+static void stm32_usart_release_port(struct uart_port *port)
 {
 }
 
-static int stm32_request_port(struct uart_port *port)
+static int stm32_usart_request_port(struct uart_port *port)
 {
 	return 0;
 }
 
-static void stm32_config_port(struct uart_port *port, int flags)
+static void stm32_usart_config_port(struct uart_port *port, int flags)
 {
 	if (flags & UART_CONFIG_TYPE)
 		port->type = PORT_STM32;
 }
 
 static int
-stm32_verify_port(struct uart_port *port, struct serial_struct *ser)
+stm32_usart_verify_port(struct uart_port *port, struct serial_struct *ser)
 {
 	/* No user changeable parameters */
 	return -EINVAL;
 }
 
-static void stm32_pm(struct uart_port *port, unsigned int state,
-		     unsigned int oldstate)
+static void stm32_usart_pm(struct uart_port *port, unsigned int state,
+			   unsigned int oldstate)
 {
 	struct stm32_port *stm32port = container_of(port,
 			struct stm32_port, port);
@@ -935,7 +940,7 @@ static void stm32_pm(struct uart_port *port, unsigned int state,
 		break;
 	case UART_PM_STATE_OFF:
 		spin_lock_irqsave(&port->lock, flags);
-		stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+		stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 		spin_unlock_irqrestore(&port->lock, flags);
 		pm_runtime_put_sync(port->dev);
 		break;
@@ -943,29 +948,29 @@ static void stm32_pm(struct uart_port *port, unsigned int state,
 }
 
 static const struct uart_ops stm32_uart_ops = {
-	.tx_empty	= stm32_tx_empty,
-	.set_mctrl	= stm32_set_mctrl,
-	.get_mctrl	= stm32_get_mctrl,
-	.stop_tx	= stm32_stop_tx,
-	.start_tx	= stm32_start_tx,
-	.throttle	= stm32_throttle,
-	.unthrottle	= stm32_unthrottle,
-	.stop_rx	= stm32_stop_rx,
-	.enable_ms	= stm32_enable_ms,
-	.break_ctl	= stm32_break_ctl,
-	.startup	= stm32_startup,
-	.shutdown	= stm32_shutdown,
-	.set_termios	= stm32_set_termios,
-	.pm		= stm32_pm,
-	.type		= stm32_type,
-	.release_port	= stm32_release_port,
-	.request_port	= stm32_request_port,
-	.config_port	= stm32_config_port,
-	.verify_port	= stm32_verify_port,
+	.tx_empty	= stm32_usart_tx_empty,
+	.set_mctrl	= stm32_usart_set_mctrl,
+	.get_mctrl	= stm32_usart_get_mctrl,
+	.stop_tx	= stm32_usart_stop_tx,
+	.start_tx	= stm32_usart_start_tx,
+	.throttle	= stm32_usart_throttle,
+	.unthrottle	= stm32_usart_unthrottle,
+	.stop_rx	= stm32_usart_stop_rx,
+	.enable_ms	= stm32_usart_enable_ms,
+	.break_ctl	= stm32_usart_break_ctl,
+	.startup	= stm32_usart_startup,
+	.shutdown	= stm32_usart_shutdown,
+	.set_termios	= stm32_usart_set_termios,
+	.pm		= stm32_usart_pm,
+	.type		= stm32_usart_type,
+	.release_port	= stm32_usart_release_port,
+	.request_port	= stm32_usart_request_port,
+	.config_port	= stm32_usart_config_port,
+	.verify_port	= stm32_usart_verify_port,
 };
 
-static int stm32_init_port(struct stm32_port *stm32port,
-			  struct platform_device *pdev)
+static int stm32_usart_init_port(struct stm32_port *stm32port,
+				 struct platform_device *pdev)
 {
 	struct uart_port *port = &stm32port->port;
 	struct resource *res;
@@ -982,9 +987,9 @@ static int stm32_init_port(struct stm32_port *stm32port,
 	port->fifosize	= stm32port->info->cfg.fifosize;
 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_STM32_CONSOLE);
 	port->irq = ret;
-	port->rs485_config = stm32_config_rs485;
+	port->rs485_config = stm32_usart_config_rs485;
 
-	ret = stm32_init_rs485(port, pdev);
+	ret = stm32_usart_init_rs485(port, pdev);
 	if (ret)
 		return ret;
 
@@ -1043,7 +1048,7 @@ static int stm32_init_port(struct stm32_port *stm32port,
 	return ret;
 }
 
-static struct stm32_port *stm32_of_get_stm32_port(struct platform_device *pdev)
+static struct stm32_port *stm32_usart_of_get_port(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	int id;
@@ -1081,8 +1086,8 @@ static const struct of_device_id stm32_match[] = {
 MODULE_DEVICE_TABLE(of, stm32_match);
 #endif
 
-static int stm32_of_dma_rx_probe(struct stm32_port *stm32port,
-				 struct platform_device *pdev)
+static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
+				       struct platform_device *pdev)
 {
 	struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
 	struct uart_port *port = &stm32port->port;
@@ -1156,8 +1161,8 @@ static int stm32_of_dma_rx_probe(struct stm32_port *stm32port,
 	return ret;
 }
 
-static int stm32_of_dma_tx_probe(struct stm32_port *stm32port,
-				 struct platform_device *pdev)
+static int stm32_usart_of_dma_tx_probe(struct stm32_port *stm32port,
+				       struct platform_device *pdev)
 {
 	struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
 	struct uart_port *port = &stm32port->port;
@@ -1207,13 +1212,13 @@ static int stm32_of_dma_tx_probe(struct stm32_port *stm32port,
 	return ret;
 }
 
-static int stm32_serial_probe(struct platform_device *pdev)
+static int stm32_usart_serial_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
 	struct stm32_port *stm32port;
 	int ret;
 
-	stm32port = stm32_of_get_stm32_port(pdev);
+	stm32port = stm32_usart_of_get_port(pdev);
 	if (!stm32port)
 		return -ENODEV;
 
@@ -1223,7 +1228,7 @@ static int stm32_serial_probe(struct platform_device *pdev)
 	else
 		return -EINVAL;
 
-	ret = stm32_init_port(stm32port, pdev);
+	ret = stm32_usart_init_port(stm32port, pdev);
 	if (ret)
 		return ret;
 
@@ -1244,11 +1249,11 @@ static int stm32_serial_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_wirq;
 
-	ret = stm32_of_dma_rx_probe(stm32port, pdev);
+	ret = stm32_usart_of_dma_rx_probe(stm32port, pdev);
 	if (ret)
 		dev_info(&pdev->dev, "interrupt mode used for rx (no dma)\n");
 
-	ret = stm32_of_dma_tx_probe(stm32port, pdev);
+	ret = stm32_usart_of_dma_tx_probe(stm32port, pdev);
 	if (ret)
 		dev_info(&pdev->dev, "interrupt mode used for tx (no dma)\n");
 
@@ -1275,7 +1280,7 @@ static int stm32_serial_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int stm32_serial_remove(struct platform_device *pdev)
+static int stm32_usart_serial_remove(struct platform_device *pdev)
 {
 	struct uart_port *port = platform_get_drvdata(pdev);
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -1284,7 +1289,7 @@ static int stm32_serial_remove(struct platform_device *pdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
-	stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+	stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
 
 	if (stm32_port->rx_ch)
 		dma_release_channel(stm32_port->rx_ch);
@@ -1294,7 +1299,7 @@ static int stm32_serial_remove(struct platform_device *pdev)
 				  RX_BUF_L, stm32_port->rx_buf,
 				  stm32_port->rx_dma_buf);
 
-	stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+	stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 
 	if (stm32_port->tx_ch)
 		dma_release_channel(stm32_port->tx_ch);
@@ -1320,7 +1325,7 @@ static int stm32_serial_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_SERIAL_STM32_CONSOLE
-static void stm32_console_putchar(struct uart_port *port, int ch)
+static void stm32_usart_console_putchar(struct uart_port *port, int ch)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -1331,8 +1336,8 @@ static void stm32_console_putchar(struct uart_port *port, int ch)
 	writel_relaxed(ch, port->membase + ofs->tdr);
 }
 
-static void stm32_console_write(struct console *co, const char *s,
-				unsigned int cnt)
+static void stm32_usart_console_write(struct console *co, const char *s,
+				      unsigned int cnt)
 {
 	struct uart_port *port = &stm32_ports[co->index].port;
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -1356,7 +1361,7 @@ static void stm32_console_write(struct console *co, const char *s,
 	new_cr1 |=  USART_CR1_TE | BIT(cfg->uart_enable_bit);
 	writel_relaxed(new_cr1, port->membase + ofs->cr1);
 
-	uart_console_write(port, s, cnt, stm32_console_putchar);
+	uart_console_write(port, s, cnt, stm32_usart_console_putchar);
 
 	/* Restore interrupt state */
 	writel_relaxed(old_cr1, port->membase + ofs->cr1);
@@ -1366,7 +1371,7 @@ static void stm32_console_write(struct console *co, const char *s,
 	local_irq_restore(flags);
 }
 
-static int stm32_console_setup(struct console *co, char *options)
+static int stm32_usart_console_setup(struct console *co, char *options)
 {
 	struct stm32_port *stm32port;
 	int baud = 9600;
@@ -1397,8 +1402,8 @@ static int stm32_console_setup(struct console *co, char *options)
 static struct console stm32_console = {
 	.name		= STM32_SERIAL_NAME,
 	.device		= uart_console_device,
-	.write		= stm32_console_write,
-	.setup		= stm32_console_setup,
+	.write		= stm32_usart_console_write,
+	.setup		= stm32_usart_console_setup,
 	.flags		= CON_PRINTBUFFER,
 	.index		= -1,
 	.data		= &stm32_usart_driver,
@@ -1419,8 +1424,8 @@ static struct uart_driver stm32_usart_driver = {
 	.cons		= STM32_SERIAL_CONSOLE,
 };
 
-static void __maybe_unused stm32_serial_enable_wakeup(struct uart_port *port,
-						      bool enable)
+static void __maybe_unused stm32_usart_serial_en_wakeup(struct uart_port *port,
+							bool enable)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -1431,29 +1436,29 @@ static void __maybe_unused stm32_serial_enable_wakeup(struct uart_port *port,
 		return;
 
 	if (enable) {
-		stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
-		stm32_set_bits(port, ofs->cr1, USART_CR1_UESM);
+		stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_UESM);
 		val = readl_relaxed(port->membase + ofs->cr3);
 		val &= ~USART_CR3_WUS_MASK;
 		/* Enable Wake up interrupt from low power on start bit */
 		val |= USART_CR3_WUS_START_BIT | USART_CR3_WUFIE;
 		writel_relaxed(val, port->membase + ofs->cr3);
-		stm32_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+		stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 	} else {
-		stm32_clr_bits(port, ofs->cr1, USART_CR1_UESM);
+		stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_UESM);
 	}
 }
 
-static int __maybe_unused stm32_serial_suspend(struct device *dev)
+static int __maybe_unused stm32_usart_serial_suspend(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 
 	uart_suspend_port(&stm32_usart_driver, port);
 
 	if (device_may_wakeup(dev))
-		stm32_serial_enable_wakeup(port, true);
+		stm32_usart_serial_en_wakeup(port, true);
 	else
-		stm32_serial_enable_wakeup(port, false);
+		stm32_usart_serial_en_wakeup(port, false);
 
 	/*
 	 * When "no_console_suspend" is enabled, keep the pinctrl default state
@@ -1471,19 +1476,19 @@ static int __maybe_unused stm32_serial_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused stm32_serial_resume(struct device *dev)
+static int __maybe_unused stm32_usart_serial_resume(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 
 	pinctrl_pm_select_default_state(dev);
 
 	if (device_may_wakeup(dev))
-		stm32_serial_enable_wakeup(port, false);
+		stm32_usart_serial_en_wakeup(port, false);
 
 	return uart_resume_port(&stm32_usart_driver, port);
 }
 
-static int __maybe_unused stm32_serial_runtime_suspend(struct device *dev)
+static int __maybe_unused stm32_usart_runtime_suspend(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 	struct stm32_port *stm32port = container_of(port,
@@ -1494,7 +1499,7 @@ static int __maybe_unused stm32_serial_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused stm32_serial_runtime_resume(struct device *dev)
+static int __maybe_unused stm32_usart_runtime_resume(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 	struct stm32_port *stm32port = container_of(port,
@@ -1504,14 +1509,15 @@ static int __maybe_unused stm32_serial_runtime_resume(struct device *dev)
 }
 
 static const struct dev_pm_ops stm32_serial_pm_ops = {
-	SET_RUNTIME_PM_OPS(stm32_serial_runtime_suspend,
-			   stm32_serial_runtime_resume, NULL)
-	SET_SYSTEM_SLEEP_PM_OPS(stm32_serial_suspend, stm32_serial_resume)
+	SET_RUNTIME_PM_OPS(stm32_usart_runtime_suspend,
+			   stm32_usart_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(stm32_usart_serial_suspend,
+				stm32_usart_serial_resume)
 };
 
 static struct platform_driver stm32_serial_driver = {
-	.probe		= stm32_serial_probe,
-	.remove		= stm32_serial_remove,
+	.probe		= stm32_usart_serial_probe,
+	.remove		= stm32_usart_serial_remove,
 	.driver	= {
 		.name	= DRIVER_NAME,
 		.pm	= &stm32_serial_pm_ops,
@@ -1519,7 +1525,7 @@ static struct platform_driver stm32_serial_driver = {
 	},
 };
 
-static int __init usart_init(void)
+static int __init stm32_usart_init(void)
 {
 	static char banner[] __initdata = "STM32 USART driver initialized";
 	int ret;
@@ -1537,14 +1543,14 @@ static int __init usart_init(void)
 	return ret;
 }
 
-static void __exit usart_exit(void)
+static void __exit stm32_usart_exit(void)
 {
 	platform_driver_unregister(&stm32_serial_driver);
 	uart_unregister_driver(&stm32_usart_driver);
 }
 
-module_init(usart_init);
-module_exit(usart_exit);
+module_init(stm32_usart_init);
+module_exit(stm32_usart_exit);
 
 MODULE_ALIAS("platform:" DRIVER_NAME);
 MODULE_DESCRIPTION("STMicroelectronics STM32 serial port driver");
-- 
2.17.1

[PATCH 4/8] serial: stm32: add author

[Erwan Le Ray]

Update email address add new author in authors list.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 717a97759928..938d2c4aeaed 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -3,7 +3,8 @@
  * Copyright (C) Maxime Coquelin 2015
  * Copyright (C) STMicroelectronics SA 2017
  * Authors:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
- *	     Gerald Baeza <gerald.baeza@st.com>
+ *	     Gerald Baeza <gerald.baeza@foss.st.com>
+ *	     Erwan Le Ray <erwan.leray@foss.st.com>
  *
  * Inspired by st-asc.c from STMicroelectronics (c)
  */
-- 
2.17.1

[PATCH 5/8] dt-bindings: serial: stm32: update rts-gpios and cts-gpios

[Erwan Le Ray]

Update rts-gpios and cts-gpios:
- remove max-items as already defined in serial.yaml
- add a note describing rts-gpios and cts-gpios usage with stm32

Document the use of cts-gpios and rts-gpios for flow control in STM32 UART
controller. These properties can be used instead of 'uart-has-rtscts' or
'st,hw-flow-ctrl' (deprecated) for making use of any gpio pins for flow
control instead of dedicated pins.
It should be noted that both cts-gpios/rts-gpios and 'uart-has-rtscts' or
'st,hw-flow-ctrl' (deprecated) properties cannot co-exist in a design.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
index 06d5f251ec88..8631678283f9 100644
--- a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
+++ b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
@@ -50,11 +50,14 @@ properties:
     minItems: 1
     maxItems: 2
 
-  cts-gpios:
-    maxItems: 1
-
-  rts-gpios:
-    maxItems: 1
+# cts-gpios and rts-gpios properties can be used instead of 'uart-has-rtscts'
+# or 'st,hw-flow-ctrl' (deprecated) for making use of any gpio pins for flow
+# control instead of dedicated pins.
+#
+# It should be noted that both cts-gpios/rts-gpios and 'uart-has-rtscts' or
+# 'st,hw-flow-ctrl' (deprecated) properties cannot co-exist in a design.
+  cts-gpios: true
+  rts-gpios: true
 
   wakeup-source: true
 
-- 
2.17.1

Re: [PATCH 5/8] dt-bindings: serial: stm32: update rts-gpios and cts-gpios

[Rob Herring]

On Fri, 18 Dec 2020 20:00:16 +0100, Erwan Le Ray wrote:
> Update rts-gpios and cts-gpios:
> - remove max-items as already defined in serial.yaml
> - add a note describing rts-gpios and cts-gpios usage with stm32
> 
> Document the use of cts-gpios and rts-gpios for flow control in STM32 UART
> controller. These properties can be used instead of 'uart-has-rtscts' or
> 'st,hw-flow-ctrl' (deprecated) for making use of any gpio pins for flow
> control instead of dedicated pins.
> It should be noted that both cts-gpios/rts-gpios and 'uart-has-rtscts' or
> 'st,hw-flow-ctrl' (deprecated) properties cannot co-exist in a design.
> 
> Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
> 

Acked-by: Rob Herring <robh@kernel.org>

[PATCH 6/8] serial: stm32: update conflicting RTS/CTS config comment

[Erwan Le Ray]

The comment for conflicting RTS/CTS config refers to "st, hw-flow-ctrl",
but this property is deprecated since the generic RTS/CTS property has
been introduced by the patch 'serial: stm32: Use generic DT binding for
announcing RTS/CTS lines'.
Update the comment to refer to both generic and deprecated RTS/CTS
properties.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 938d2c4aeaed..0d6c7f3375f0 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -1031,7 +1031,10 @@ static int stm32_usart_init_port(struct stm32_port *stm32port,
 		goto err_clk;
 	}
 
-	/* Both CTS/RTS gpios and "st,hw-flow-ctrl" should not be specified */
+	/*
+	 * Both CTS/RTS gpios and "st,hw-flow-ctrl" (deprecated) or "uart-has-rtscts"
+	 * properties should not be specified.
+	 */
 	if (stm32port->hw_flow_control) {
 		if (mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_CTS) ||
 		    mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_RTS)) {
-- 
2.17.1

[PATCH 7/8] serial: stm32: clean probe and remove port deinit

[Erwan Le Ray]

Clean probe and remove port deinit by moving clk_disable_unprepare in a
new dedicated deinit_port function.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 0d6c7f3375f0..9d73f6976586 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -970,6 +970,11 @@ static const struct uart_ops stm32_uart_ops = {
 	.verify_port	= stm32_usart_verify_port,
 };
 
+static void stm32_usart_deinit_port(struct stm32_port *stm32port)
+{
+	clk_disable_unprepare(stm32port->clk);
+}
+
 static int stm32_usart_init_port(struct stm32_port *stm32port,
 				 struct platform_device *pdev)
 {
@@ -1279,7 +1284,7 @@ static int stm32_usart_serial_probe(struct platform_device *pdev)
 		device_init_wakeup(&pdev->dev, false);
 
 err_uninit:
-	clk_disable_unprepare(stm32port->clk);
+	stm32_usart_deinit_port(stm32port);
 
 	return ret;
 }
@@ -1318,7 +1323,7 @@ static int stm32_usart_serial_remove(struct platform_device *pdev)
 		device_init_wakeup(&pdev->dev, false);
 	}
 
-	clk_disable_unprepare(stm32_port->clk);
+	stm32_usart_deinit_port(stm32_port);
 
 	err = uart_remove_one_port(&stm32_usart_driver, port);
 
-- 
2.17.1

[PATCH 8/8] serial: stm32: update transmission complete error message in shutdown

[Erwan Le Ray]

The transmission complete error message provides the status of the
ISR_USART_TC bit. This bit, when set, indicates that the transmission
has not been completed.
The bit status indication is not a very understandable information.
The error message sent on console should indicate that the transmission is
not complete, instead of providing USART_TC bit status.
Update the error message and add a comment for better understanding.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 9d73f6976586..6a9a5ef5f5ba 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -687,8 +687,9 @@ static void stm32_usart_shutdown(struct uart_port *port)
 					 isr, (isr & USART_SR_TC),
 					 10, 100000);
 
+	/* Send the TC error message only when ISR_TC is not set */
 	if (ret)
-		dev_err(port->dev, "transmission complete not set\n");
+		dev_err(port->dev, "Transmission is not complete\n");
 
 	stm32_usart_clr_bits(port, ofs->cr1, val);
 
-- 
2.17.1

Re: [PATCH 0/7] STM32 uart cleanup and improvements

[Greg Kroah-Hartman]

On Fri, Dec 18, 2020 at 08:00:11PM +0100, Erwan Le Ray wrote:
> This series brings various fixes, cleanups and improvements to stm32-usart
> driver.

This patch series does not apply to 5.11-rc1.

Please fix up and resend.

thanks,

greg k-h

[PATCH 0/7] STM32 uart cleanup and improvements

[Erwan Le Ray]

This series brings various fixes, cleanups and improvements to stm32-usart
driver.

Changes in v2:
- delete DMA cookie variables removal from V1 patch as already done by a
previous patch
- update commit message as DMA cookie variables removal is no more
included in this patch

Erwan Le Ray (8):
  serial: stm32: fix DMA initialization error handling
  serial: stm32: fix code cleaning warnings and checks
  serial: stm32: add "_usart" prefix in functions name
  serial: stm32: add author
  dt-bindings: serial: stm32: update rts-gpios and cts-gpios
  serial: stm32: update conflicting RTS/CTS config comment
  serial: stm32: clean probe and remove port deinit
  serial: stm32: update transmission complete error message in shutdown

 .../bindings/serial/st,stm32-uart.yaml        |  13 +-
 drivers/tty/serial/stm32-usart.c              | 415 +++++++++---------
 2 files changed, 227 insertions(+), 201 deletions(-)

-- 
2.17.1