Commit 86d4ac2c authored by Nick Chan's avatar Nick Chan Committed by Greg Kroah-Hartman
Browse files

tty: serial: samsung: Fix A7-A11 serial earlycon SError 



Apple's earlier SoCs, like A7-A11, requires 32-bit writes for the serial
port. Otherwise, a SError happens when writing to UTXH (+0x20). This only
manifested in earlycon as reg-io-width in the device tree is consulted
for normal serial writes.

Change the iotype of the port to UPIO_MEM32, to allow the serial port to
function on A7-A11 SoCs. This change does not appear to affect Apple M1 and
above.

Reviewed-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: default avatarNeal Gompa <neal@gompa.dev>
Tested-by: default avatarJanne Grunau <j@jannau.net>
Signed-off-by: default avatarNick Chan <towinchenmi@gmail.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20240911050741.14477-3-towinchenmi@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4c59c59e

drivers/tty/serial/samsung_tty.c

+4 −1
Original line number Diff line number Diff line
@@ -2536,7 +2536,7 @@ static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = { 
		.name		= "Apple S5L UART",

		.type		= TYPE_APPLE_S5L,

		.port_type	= PORT_8250,

		.iotype		= UPIO_MEM,

		.iotype		= UPIO_MEM32,

		.fifosize	= 16,

		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,

		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
@@ -2822,6 +2822,9 @@ OF_EARLYCON_DECLARE(gs101, "google,gs101-uart", gs101_early_console_setup); 
static int __init apple_s5l_early_console_setup(struct earlycon_device *device,

						const char *opt)

{

	/* Apple A7-A11 requires MMIO32 register accesses. */

	device->port.iotype = UPIO_MEM32;



	/* Close enough to S3C2410 for earlycon... */

	device->port.private_data = &s3c2410_early_console_data;