tty: serial: samsung_tty: Separate S3C64XX ops structure

Instead of patching a single global ops structure depending on the port
type, use a separate s3c64xx_serial_ops for the S3C64XX type. This
allows us to mark the structures as const.

Also split out s3c64xx_serial_shutdown into a separate function now that
we have a separate ops structure; this avoids excessive branching
control flow and mirrors s3c64xx_serial_startup. tx_claimed and
rx_claimed are only used in the S3C24XX functions.
Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Tested-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210304213902.83903-19-marcan@marcan.stSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/samsung_tty.c

@@ -1099,27 +1099,36 @@ static void s3c24xx_serial_shutdown(struct uart_port *port)
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
 
 	if (ourport->tx_claimed) {
-		if (!s3c24xx_serial_has_interrupt_mask(port))
-			free_irq(ourport->tx_irq, ourport);
+		free_irq(ourport->tx_irq, ourport);
 		ourport->tx_enabled = 0;
 		ourport->tx_claimed = 0;
 		ourport->tx_mode = 0;
 	}
 
 	if (ourport->rx_claimed) {
-		if (!s3c24xx_serial_has_interrupt_mask(port))
-			free_irq(ourport->rx_irq, ourport);
+		free_irq(ourport->rx_irq, ourport);
 		ourport->rx_claimed = 0;
 		ourport->rx_enabled = 0;
 	}
 
-	/* Clear pending interrupts and mask all interrupts */
-	if (s3c24xx_serial_has_interrupt_mask(port)) {
-		free_irq(port->irq, ourport);
+	if (ourport->dma)
+		s3c24xx_serial_release_dma(ourport);
 
-		wr_regl(port, S3C64XX_UINTP, 0xf);
-		wr_regl(port, S3C64XX_UINTM, 0xf);
-	}
+	ourport->tx_in_progress = 0;
+}
+
+static void s3c64xx_serial_shutdown(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	ourport->tx_enabled = 0;
+	ourport->tx_mode = 0;
+	ourport->rx_enabled = 0;
+
+	free_irq(port->irq, ourport);
+
+	wr_regl(port, S3C64XX_UINTP, 0xf);
+	wr_regl(port, S3C64XX_UINTM, 0xf);
 
 	if (ourport->dma)
 		s3c24xx_serial_release_dma(ourport);
@@ -1194,9 +1203,7 @@ static int s3c64xx_serial_startup(struct uart_port *port)
 
 	/* For compatibility with s3c24xx Soc's */
 	ourport->rx_enabled = 1;
-	ourport->rx_claimed = 1;
 	ourport->tx_enabled = 0;
-	ourport->tx_claimed = 1;
 
 	spin_lock_irqsave(&port->lock, flags);
 
@@ -1609,7 +1616,7 @@ static void s3c24xx_serial_put_poll_char(struct uart_port *port,
 			 unsigned char c);
 #endif
 
-static struct uart_ops s3c24xx_serial_ops = {
+static const struct uart_ops s3c24xx_serial_ops = {
 	.pm		= s3c24xx_serial_pm,
 	.tx_empty	= s3c24xx_serial_tx_empty,
 	.get_mctrl	= s3c24xx_serial_get_mctrl,
@@ -1632,6 +1639,29 @@ static struct uart_ops s3c24xx_serial_ops = {
 #endif
 };
 
+static const struct uart_ops s3c64xx_serial_ops = {
+	.pm		= s3c24xx_serial_pm,
+	.tx_empty	= s3c24xx_serial_tx_empty,
+	.get_mctrl	= s3c24xx_serial_get_mctrl,
+	.set_mctrl	= s3c24xx_serial_set_mctrl,
+	.stop_tx	= s3c24xx_serial_stop_tx,
+	.start_tx	= s3c24xx_serial_start_tx,
+	.stop_rx	= s3c24xx_serial_stop_rx,
+	.break_ctl	= s3c24xx_serial_break_ctl,
+	.startup	= s3c64xx_serial_startup,
+	.shutdown	= s3c64xx_serial_shutdown,
+	.set_termios	= s3c24xx_serial_set_termios,
+	.type		= s3c24xx_serial_type,
+	.release_port	= s3c24xx_serial_release_port,
+	.request_port	= s3c24xx_serial_request_port,
+	.config_port	= s3c24xx_serial_config_port,
+	.verify_port	= s3c24xx_serial_verify_port,
+#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
+	.poll_get_char = s3c24xx_serial_get_poll_char,
+	.poll_put_char = s3c24xx_serial_put_poll_char,
+#endif
+};
+
 static struct uart_driver s3c24xx_uart_drv = {
 	.owner		= THIS_MODULE,
 	.driver_name	= "s3c2410_serial",
@@ -1864,10 +1894,6 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 	/* setup info for port */
 	port->dev	= &platdev->dev;
 
-	/* Startup sequence is different for s3c64xx and higher SoC's */
-	if (s3c24xx_serial_has_interrupt_mask(port))
-		s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
-
 	port->uartclk = 1;
 
 	if (cfg->uart_flags & UPF_CONS_FLOW) {
@@ -2015,6 +2041,17 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
 			dev_get_platdata(&pdev->dev) :
 			ourport->drv_data->def_cfg;
 
+	switch (ourport->info->type) {
+	case PORT_S3C2410:
+	case PORT_S3C2412:
+	case PORT_S3C2440:
+		ourport->port.ops = &s3c24xx_serial_ops;
+		break;
+	case PORT_S3C6400:
+		ourport->port.ops = &s3c64xx_serial_ops;
+		break;
+	}
+
 	if (np) {
 		of_property_read_u32(np,
 			"samsung,uart-fifosize", &ourport->port.fifosize);