BASE_BAUD is pain in neck for multi-platform support as it hard codes at
build time the clk value for early uart.

Mitigate this by allowing arches/platforms to provide their own version
which can do dynamic setup based on DT values etc (see next patch for
usage)

This was needed for ARC SDP platforms based on 2 different FPGA flows, each
with a different UART clk value.

Signed-off-by: Vineet Gupta <vgu...@synopsys.com>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Jiri Slaby <jsl...@suse.cz>
Cc: linux-ser...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rob Herring <r...@kernel.org>
Cc: Arnd Bergmann <a...@arndb.de>
---
 drivers/tty/serial/earlycon.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 64fe25a4285c..bfd3537739e0 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -54,6 +54,15 @@ static void __iomem * __init earlycon_map(unsigned long 
paddr, size_t size)
        return base;
 }
 
+unsigned int __weak __init earlycon_base_baud(char *options)
+{
+#ifdef BASE_BAUD
+       return BASE_BAUD;
+#else
+       return 1843200/16;      /* x86 early console */
+#endif
+}
+
 static int __init parse_options(struct earlycon_device *device,
                                char *options)
 {
@@ -87,7 +96,7 @@ static int __init parse_options(struct earlycon_device 
*device,
                return -EINVAL;
        }
 
-       port->uartclk = BASE_BAUD * 16;
+       port->uartclk = earlycon_base_baud(options) * 16;
 
        options = strchr(options, ',');
        if (options) {
@@ -156,7 +165,7 @@ int __init of_setup_earlycon(unsigned long addr,
 
        port->iotype = UPIO_MEM;
        port->mapbase = addr;
-       port->uartclk = BASE_BAUD * 16;
+       port->uartclk = earlycon_base_baud(NULL) * 16;
        port->membase = earlycon_map(addr, SZ_4K);
 
        early_console_dev.con->data = &early_console_dev;
-- 
1.8.3.2

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