serial: imx: stop casting struct uart_port to struct imx_port

struct imx_port does have a struct uart_port as its first member, so
the current code works, but it is not how kernel code is usually
written.

Similar to many other serial drivers, introduce and use a
to_imx_port() helper based on container_of(). No functional change.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20240528094022.2161066-1-linux@rasmusvillemoes.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Villemoes

drivers/tty/serial/imx.c

@@ -264,6 +264,11 @@ static const struct of_device_id imx_uart_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
 
+static inline struct imx_port *to_imx_port(struct uart_port *port)
+{
+        return container_of(port, struct imx_port, port);
+}
+
 static inline void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
 {
 	writel(val, sport->port.membase + offset);
@@ -377,7 +382,7 @@ static void imx_uart_disable_loopback_rs485(struct imx_port *sport)
 /* called with port.lock taken and irqs off */
 static void imx_uart_start_rx(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned int ucr1, ucr2;
 
 	ucr1 = imx_uart_readl(sport, UCR1);
@@ -401,7 +406,7 @@ static void imx_uart_start_rx(struct uart_port *port)
 /* called with port.lock taken and irqs off */
 static void imx_uart_stop_tx(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	u32 ucr1, ucr4, usr2;
 
 	if (sport->tx_state == OFF)
@@ -466,7 +471,7 @@ static void imx_uart_stop_tx(struct uart_port *port)
 
 static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	u32 ucr1, ucr2, ucr4, uts;
 
 	ucr1 = imx_uart_readl(sport, UCR1);
@@ -511,7 +516,7 @@ static void imx_uart_stop_rx(struct uart_port *port)
 /* called with port.lock taken and irqs off */
 static void imx_uart_enable_ms(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 
 	mod_timer(&sport->timer, jiffies);
 
@@ -662,7 +667,7 @@ static void imx_uart_dma_tx(struct imx_port *sport)
 /* called with port.lock taken and irqs off */
 static void imx_uart_start_tx(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	struct tty_port *tport = &sport->port.state->port;
 	u32 ucr1;
 
@@ -1043,7 +1048,7 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id)
  */
 static unsigned int imx_uart_tx_empty(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned int ret;
 
 	ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
@@ -1058,7 +1063,7 @@ static unsigned int imx_uart_tx_empty(struct uart_port *port)
 /* called with port.lock taken and irqs off */
 static unsigned int imx_uart_get_mctrl(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned int ret = imx_uart_get_hwmctrl(sport);
 
 	mctrl_gpio_get(sport->gpios, &ret);
@@ -1069,7 +1074,7 @@ static unsigned int imx_uart_get_mctrl(struct uart_port *port)
 /* called with port.lock taken and irqs off */
 static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	u32 ucr3, uts;
 
 	if (!(port->rs485.flags & SER_RS485_ENABLED)) {
@@ -1112,7 +1117,7 @@ static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
  */
 static void imx_uart_break_ctl(struct uart_port *port, int break_state)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned long flags;
 	u32 ucr1;
 
@@ -1434,7 +1439,7 @@ static void imx_uart_disable_dma(struct imx_port *sport)
 
 static int imx_uart_startup(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	int retval;
 	unsigned long flags;
 	int dma_is_inited = 0;
@@ -1548,7 +1553,7 @@ static int imx_uart_startup(struct uart_port *port)
 
 static void imx_uart_shutdown(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned long flags;
 	u32 ucr1, ucr2, ucr4, uts;
 
@@ -1622,7 +1627,7 @@ static void imx_uart_shutdown(struct uart_port *port)
 /* called with port.lock taken and irqs off */
 static void imx_uart_flush_buffer(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	struct scatterlist *sgl = &sport->tx_sgl[0];
 
 	if (!sport->dma_chan_tx)
@@ -1649,7 +1654,7 @@ static void
 imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 		     const struct ktermios *old)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned long flags;
 	u32 ucr2, old_ucr2, ufcr;
 	unsigned int baud, quot;
@@ -1852,7 +1857,7 @@ imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
 
 static int imx_uart_poll_init(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned long flags;
 	u32 ucr1, ucr2;
 	int retval;
@@ -1901,7 +1906,7 @@ static int imx_uart_poll_init(struct uart_port *port)
 
 static int imx_uart_poll_get_char(struct uart_port *port)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
 		return NO_POLL_CHAR;
 
@@ -1910,7 +1915,7 @@ static int imx_uart_poll_get_char(struct uart_port *port)
 
 static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	unsigned int status;
 
 	/* drain */
@@ -1932,7 +1937,7 @@ static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
 static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termios,
 				 struct serial_rs485 *rs485conf)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 	u32 ucr2;
 
 	if (rs485conf->flags & SER_RS485_ENABLED) {
@@ -1986,7 +1991,7 @@ static struct imx_port *imx_uart_ports[UART_NR];
 #if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
 static void imx_uart_console_putchar(struct uart_port *port, unsigned char ch)
 {
-	struct imx_port *sport = (struct imx_port *)port;
+	struct imx_port *sport = to_imx_port(port);
 
 	while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
 		barrier();