serial: fsl_lpuart: add earlycon support

Add support for DT and command line based earlycon support for
lpuart and lpuart32 used on Freescale Vybrid and and QorIQ LS1021A
processors.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 22a4b687ea5b4b3cb9d576bfeffaed813256a795..8d9dd534c6a86e67ad2d79ab4d4c8d1819b5156b 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1023,6 +1023,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        serial port must already be setup and configured.
                        Options are not yet supported.
 
+               lpuart,<addr>
+               lpuart32,<addr>
+                       Use early console provided by Freescale LP UART driver
+                       found on Freescale Vybrid and QorIQ LS1021A processors.
+                       A valid base address must be provided, and the serial
+                       port must already be setup and configured.
+
        earlyprintk=    [X86,SH,BLACKFIN,ARM,M68k]
                        earlyprintk=vga
                        earlyprintk=efi

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 0667d1a512991932d5f00c3dc6af2f7023f32334..1aec4404062d8f1995e8da8da821a1b176cb0e7a 100644 (file)
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1539,6 +1539,7 @@ config SERIAL_FSL_LPUART
        tristate "Freescale lpuart serial port support"
        depends on HAS_DMA
        select SERIAL_CORE
+       select SERIAL_EARLYCON
        help
          Support for the on-chip lpuart on some Freescale SOCs.
 

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 08ce76f4f261043c20d843c88c8d4dfe8167ce64..3d790033744efd060bf42dad1f494a5ee4da0155 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1746,6 +1746,45 @@ static struct console lpuart32_console = {
        .data           = &lpuart_reg,
 };
 
+static void lpuart_early_write(struct console *con, const char *s, unsigned n)
+{
+       struct earlycon_device *dev = con->data;
+
+       uart_console_write(&dev->port, s, n, lpuart_console_putchar);
+}
+
+static void lpuart32_early_write(struct console *con, const char *s, unsigned n)
+{
+       struct earlycon_device *dev = con->data;
+
+       uart_console_write(&dev->port, s, n, lpuart32_console_putchar);
+}
+
+static int __init lpuart_early_console_setup(struct earlycon_device *device,
+                                         const char *opt)
+{
+       if (!device->port.membase)
+               return -ENODEV;
+
+       device->con->write = lpuart_early_write;
+       return 0;
+}
+
+static int __init lpuart32_early_console_setup(struct earlycon_device *device,
+                                         const char *opt)
+{
+       if (!device->port.membase)
+               return -ENODEV;
+
+       device->con->write = lpuart32_early_write;
+       return 0;
+}
+
+OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
+EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
+EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
+
 #define LPUART_CONSOLE (&lpuart_console)
 #define LPUART32_CONSOLE       (&lpuart32_console)
 #else