tty: make use of tty_get_{char,frame}_size

In the previous patch, we introduced tty_get_char_size() and
tty_get_frame_size() for computing character and frame sizes,
respectively. Here, we make use of them in various tty drivers where
applicable.

The stats look nice: 12 insertions, 169 deletions.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Oliver Neukum <oneukum@suse.com>
Acked-by: Alex Elder <elder@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210610090247.2593-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 7 insertions, 111 deletions

diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
index 58aaa533203b..c719aa2b1832 100644
--- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
@@ -524,24 +524,7 @@ static void cpm_uart_set_termios(struct uart_port *port,
 	scval = 0;
 
 	/* byte size */
-	switch (termios->c_cflag & CSIZE) {
-	case CS5:
-		bits = 5;
-		break;
-	case CS6:
-		bits = 6;
-		break;
-	case CS7:
-		bits = 7;
-		break;
-	case CS8:
-		bits = 8;
-		break;
-		/* Never happens, but GCC is too dumb to figure it out */
-	default:
-		bits = 8;
-		break;
-	}
+	bits = tty_get_char_size(termios->c_cflag);
 	sbits = bits - 5;
 
 	if (termios->c_cflag & CSTOPB) {
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 7b4b6bb75424..ac45f3386e97 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -962,7 +962,7 @@ static void mxs_auart_settermios(struct uart_port *u,
 				 struct ktermios *old)
 {
 	struct mxs_auart_port *s = to_auart_port(u);
-	u32 bm, ctrl, ctrl2, div;
+	u32 ctrl, ctrl2, div;
 	unsigned int cflag, baud, baud_min, baud_max;
 
 	cflag = termios->c_cflag;
@@ -970,25 +970,7 @@ static void mxs_auart_settermios(struct uart_port *u,
 	ctrl = AUART_LINECTRL_FEN;
 	ctrl2 = mxs_read(s, REG_CTRL2);
 
-	/* byte size */
-	switch (cflag & CSIZE) {
-	case CS5:
-		bm = 5;
-		break;
-	case CS6:
-		bm = 6;
-		break;
-	case CS7:
-		bm = 7;
-		break;
-	case CS8:
-		bm = 8;
-		break;
-	default:
-		return;
-	}
-
-	ctrl |= AUART_LINECTRL_WLEN(bm);
+	ctrl |= AUART_LINECTRL_WLEN(tty_get_char_size(cflag));
 
 	/* parity */
 	if (cflag & PARENB) {
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 463f84a66f6e..379ab15daa85 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1050,21 +1050,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	}
 
 	/* bits per char */
-	switch (termios->c_cflag & CSIZE) {
-	case CS5:
-		bits_per_char = 5;
-		break;
-	case CS6:
-		bits_per_char = 6;
-		break;
-	case CS7:
-		bits_per_char = 7;
-		break;
-	case CS8:
-	default:
-		bits_per_char = 8;
-		break;
-	}
+	bits_per_char = tty_get_char_size(termios->c_cflag);
 
 	/* stop bits */
 	if (termios->c_cflag & CSTOPB)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index aabe66c99c1a..07eb56294371 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -2500,25 +2500,7 @@ done:
 	uart_update_timeout(port, termios->c_cflag, baud);
 
 	/* byte size and parity */
-	switch (termios->c_cflag & CSIZE) {
-	case CS5:
-		bits = 7;
-		break;
-	case CS6:
-		bits = 8;
-		break;
-	case CS7:
-		bits = 9;
-		break;
-	default:
-		bits = 10;
-		break;
-	}
-
-	if (termios->c_cflag & CSTOPB)
-		bits++;
-	if (termios->c_cflag & PARENB)
-		bits++;
+	bits = tty_get_frame_size(termios->c_cflag);
 
 	if (sci_getreg(port, SEMR)->size)
 		serial_port_out(port, SEMR, 0);
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index cd6adb979df9..ef793b3b4591 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -718,36 +718,6 @@ static void stm32_usart_shutdown(struct uart_port *port)
 	free_irq(port->irq, port);
 }
 
-static unsigned int stm32_usart_get_databits(struct ktermios *termios)
-{
-	unsigned int bits;
-
-	tcflag_t cflag = termios->c_cflag;
-
-	switch (cflag & CSIZE) {
-	/*
-	 * CSIZE settings are not necessarily supported in hardware.
-	 * CSIZE unsupported configurations are handled here to set word length
-	 * to 8 bits word as default configuration and to print debug message.
-	 */
-	case CS5:
-		bits = 5;
-		break;
-	case CS6:
-		bits = 6;
-		break;
-	case CS7:
-		bits = 7;
-		break;
-	/* default including CS8 */
-	default:
-		bits = 8;
-		break;
-	}
-
-	return bits;
-}
-
 static void stm32_usart_set_termios(struct uart_port *port,
 				    struct ktermios *termios,
 				    struct ktermios *old)
@@ -805,7 +775,7 @@ static void stm32_usart_set_termios(struct uart_port *port,
 	if (cflag & CSTOPB)
 		cr2 |= USART_CR2_STOP_2B;
 
-	bits = stm32_usart_get_databits(termios);
+	bits = tty_get_char_size(cflag);
 	stm32_port->rdr_mask = (BIT(bits) - 1);
 
 	if (cflag & PARENB) {
diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
index cf87dc66087b..5bb928b7873e 100644
--- a/drivers/tty/synclink_gt.c
+++ b/drivers/tty/synclink_gt.c
@@ -2465,14 +2465,7 @@ static void change_params(struct slgt_info *info)
 
 	/* byte size and parity */
 
-	switch (cflag & CSIZE) {
-	case CS5: info->params.data_bits = 5; break;
-	case CS6: info->params.data_bits = 6; break;
-	case CS7: info->params.data_bits = 7; break;
-	case CS8: info->params.data_bits = 8; break;
-	default:  info->params.data_bits = 7; break;
-	}
-
+	info->params.data_bits = tty_get_char_size(cflag);
 	info->params.stop_bits = (cflag & CSTOPB) ? 2 : 1;
 
 	if (cflag & PARENB)