tty/serial: Migrate 8250_fsl to use has_sysrq

The SUPPORT_SYSRQ ifdeffery is not nice as:
- May create misunderstanding about sizeof(struct uart_port) between
  different objects
- Prevents moving functions from serial_core.h
- Reduces readability (well, it's ifdeffery - it's hard to follow)

In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added.
Initialise it in driver's probe and remove ifdeffery.

In contrast to 8250/8250_of, legacy_serial on powerpc does fill
(struct plat_serial8250_port). The reason is likely that it's done on
device_initcall(), not on probe. So, 8250_core is not yet probed.

Propagate value from platform_device on 8250 probe - in case powepc
legacy driver it's initialized on initcall, in case 8250_of it will be
initialized later on of_platform_serial_setup().

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-6-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
index 7cea5978f21f..f061e06e9f51 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -479,8 +479,10 @@ static void __init fixup_port_irq(int index,
 	port->irq = virq;
 
 #ifdef CONFIG_SERIAL_8250_FSL
-	if (of_device_is_compatible(np, "fsl,ns16550"))
+	if (of_device_is_compatible(np, "fsl,ns16550")) {
 		port->handle_irq = fsl8250_handle_irq;
+		port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+	}
 #endif
 }