serial: samsung: alloc dma stucture in ourport

When we have "dmas" property in serial node in device-tree, we do
memory alocation for dma structure which will be used in DMA handling
code.

Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index 19273e3..7196a3e 100644 (file)
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1209,6 +1209,18 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
        ret = platform_get_irq(platdev, 1);
        if (ret > 0)
                ourport->tx_irq = ret;
+       /*
+        * DMA is currently supported only on DT platforms, if DMA properties
+        * are specified.
+        */
+       if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
+                                                    "dmas", NULL)) {
+               ourport->dma = devm_kzalloc(port->dev,
+                                           sizeof(*ourport->dma),
+                                           GFP_KERNEL);
+               if (!ourport->dma)
+                       return -ENOMEM;
+       }
 
        ourport->clk    = clk_get(&platdev->dev, "uart");
        if (IS_ERR(ourport->clk)) {