ENGR00229470-2 MX6SL-Add support for debug UART to be sourced from 24MHz.

If "debug_uart" is specified in the command line, uart will
be sourced from 24MHz XTAL. This is required for getting the
correct power measurements on MX6SL.
Certain analog power optimizations are done only if ALL PLLs
are bypassed on MX6SL. To verify this path, we need to ensure
that UART is not sourced from PLL3.

Signed-off-by: Ranjani Vaidyanathan <ra5478@freescale.com>

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 8a66f3eeb99227aef72677aa573be6cd774deb71..5e9594d744d952936238495cf126dc1448ab5c8d 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1742,6 +1742,8 @@ static int serial_imx_resume(struct platform_device *dev)
        return 0;
 }
 
+extern int uart_at_24;
+
 static int serial_imx_probe(struct platform_device *pdev)
 {
        struct imx_port *sport;
@@ -1788,6 +1790,9 @@ static int serial_imx_probe(struct platform_device *pdev)
                ret = PTR_ERR(sport->clk);
                goto unmap;
        }
+       if (uart_at_24)
+               clk_set_parent(sport->clk, clk_get(NULL, "osc"));
+
        clk_enable(sport->clk);
 
        sport->port.uartclk = clk_get_rate(sport->clk);