diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2014-10-28 15:04:05 +0530 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2015-02-02 17:08:37 +0530 |
| commit | ffb7fcd66f14bc716b9fdf559e71909131fef39b (patch) | |
| tree | 35b7c289c75651d8244ac0e7d7ede0185da1f367 /arch/arc/kernel/devtree.c | |
| parent | 7bf6df575fd628fd7ec737789ae8bcb7081d77de (diff) | |
ARC: Dynamically determine BASE_BAUD from DeviceTree
8250 earlycon is broken on multi-platform ARC because the UART clk
value (BASE_BAUD) is fixed at build time.
Instead, determine the appropriate UART clk at runtime; parse the
devicetree early for platforms requiring alternate UART clk values
(currently only the TB10X platform).
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rob Herring <robh@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel/devtree.c')
| -rw-r--r-- | arch/arc/kernel/devtree.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c index fffdb5e41b20..5036d4c06996 100644 --- a/arch/arc/kernel/devtree.c +++ b/arch/arc/kernel/devtree.c @@ -17,6 +17,28 @@ #include <asm/clk.h> #include <asm/mach_desc.h> +#ifdef CONFIG_SERIAL_8250_CONSOLE + +static unsigned int __initdata arc_base_baud; + +unsigned int __init arc_early_base_baud(void) +{ + return arc_base_baud/16; +} + +static void __init arc_set_early_base_baud(unsigned long dt_root) +{ + unsigned int core_clk = arc_get_core_freq(); + + if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x")) + arc_base_baud = core_clk/3; + else + arc_base_baud = core_clk; +} +#else +#define arc_set_early_base_baud(dt_root) +#endif + static const void * __init arch_get_next_mach(const char *const **match) { static const struct machine_desc *mdesc = __arch_info_begin; @@ -56,5 +78,7 @@ const struct machine_desc * __init setup_machine_fdt(void *dt) if (clk) arc_set_core_freq(of_read_ulong(clk, len/4)); + arc_set_early_base_baud(dt_root); + return mdesc; } |