serial: samsung: Keep a copy of the location of platform data in driver's private data

Add a pointer to the location of the platform data in the driver's private
data. When instantiated using device tree, pdev->dev->platform_data does not
necessarily point to a valid instance of platform data. The platform data
pointer in the driver's private data could be set to pdev->dev->platform_data
or platform data instance created from device tree.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

3 files changed, 25 insertions, 7 deletions

diff --git a/drivers/tty/serial/s5pv210.c b/drivers/tty/serial/s5pv210.c
index 8b0b888a1b7..03b249e35bf 100644
--- a/drivers/tty/serial/s5pv210.c
+++ b/drivers/tty/serial/s5pv210.c
@@ -28,9 +28,13 @@
 static int s5pv210_serial_setsource(struct uart_port *port,
                                         struct s3c24xx_uart_clksrc *clk)
 {
-        struct s3c2410_uartcfg *cfg = port->dev->platform_data;
+        struct s3c24xx_uart_port *ourport;
+        struct s3c2410_uartcfg *cfg;
         unsigned long ucon = rd_regl(port, S3C2410_UCON);
 
+        ourport = container_of(port, struct s3c24xx_uart_port, port);
+        cfg = ourport->cfg;
+
         if (cfg->flags & NO_NEED_CHECK_CLKSRC)
                 return 0;
 
@@ -51,9 +55,13 @@ static int s5pv210_serial_setsource(struct uart_port *port,
 static int s5pv210_serial_getsource(struct uart_port *port,
                                         struct s3c24xx_uart_clksrc *clk)
 {
-        struct s3c2410_uartcfg *cfg = port->dev->platform_data;
+        struct s3c24xx_uart_port *ourport;
+        struct s3c2410_uartcfg *cfg;
         u32 ucon = rd_regl(port, S3C2410_UCON);
 
+        ourport = container_of(port, struct s3c24xx_uart_port, port);
+        cfg = ourport->cfg;
+
         clk->divisor = 1;
 
         if (cfg->flags & NO_NEED_CHECK_CLKSRC)
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index b31f1c3a2c4..51cfb9f1166 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -190,10 +190,13 @@ static inline struct s3c24xx_uart_info *s3c24xx_port_to_info(struct uart_port *p
 
 static inline struct s3c2410_uartcfg *s3c24xx_port_to_cfg(struct uart_port *port)
 {
+        struct s3c24xx_uart_port *ourport;
+
         if (port->dev == NULL)
                 return NULL;
 
-        return (struct s3c2410_uartcfg *)port->dev->platform_data;
+        ourport = container_of(port, struct s3c24xx_uart_port, port);
+        return ourport->cfg;
 }
 
 static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
@@ -1125,7 +1128,7 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
                                     struct platform_device *platdev)
 {
         struct uart_port *port = &ourport->port;
-        struct s3c2410_uartcfg *cfg;
+        struct s3c2410_uartcfg *cfg = platdev->dev.platform_data;
         struct resource *res;
         int ret;
 
@@ -1134,11 +1137,16 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
         if (platdev == NULL)
                 return -ENODEV;
 
-        cfg = s3c24xx_dev_to_cfg(&platdev->dev);
-
         if (port->mapbase != 0)
                 return 0;
 
+        /*
+         * If platform data is supplied, keep a copy of the location of
+         * platform data in the driver's private data.
+         */
+        if (cfg)
+                ourport->cfg = cfg;
+
         if (cfg->hwport > CONFIG_SERIAL_SAMSUNG_UARTS) {
                 printk(KERN_ERR "%s: port %d bigger than %d\n", __func__,
                        cfg->hwport, CONFIG_SERIAL_SAMSUNG_UARTS);
diff --git a/drivers/tty/serial/samsung.h b/drivers/tty/serial/samsung.h
index 8e87b788e5c..6c9cb9d5ccd 100644
--- a/drivers/tty/serial/samsung.h
+++ b/drivers/tty/serial/samsung.h
@@ -48,6 +48,9 @@ struct s3c24xx_uart_port {
         struct clk                      *baudclk;
         struct uart_port                port;
 
+        /* reference to platform data */
+        struct s3c2410_uartcfg          *cfg;
+
 #ifdef CONFIG_CPU_FREQ
         struct notifier_block           freq_transition;
 #endif
@@ -56,7 +59,6 @@ struct s3c24xx_uart_port {
 /* conversion functions */
 
 #define s3c24xx_dev_to_port(__dev) (struct uart_port *)dev_get_drvdata(__dev)
-#define s3c24xx_dev_to_cfg(__dev) (struct s3c2410_uartcfg *)((__dev)->platform_data)
 
 /* register access controls */