Re: [PATCH v2 23/25] tty: serial: samsung_tty: Add earlycon support for Apple UARTs
From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2021-02-15 19:18:41
Also in:
linux-arm-kernel, lkml
On Mon, Feb 15, 2021 at 09:17:11PM +0900, Hector Martin wrote:
quoted hunk ↗ jump to hunk
Earlycon support is identical to S3C2410, but Apple SoCs also need MMIO mapped as nGnRnE. This is handled generically for normal drivers including the normal UART path here, but earlycon uses fixmap and runs before that scaffolding is ready. Since this is the only case where we need this fix, it makes more sense to do it here in the UART driver instead of introducing a whole fdt nonposted-mmio resolver just for earlycon/fixmap. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Hector Martin <redacted> --- drivers/tty/serial/samsung_tty.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index e7ab0b9d89a7..00262f0e704b 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c@@ -2988,6 +2988,23 @@ OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart", s5pv210_early_console_setup); OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart", s5pv210_early_console_setup); + +/* Apple S5L */ +static int __init apple_s5l_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + /* Close enough to S3C2410 for earlycon... */ + device->port.private_data = &s3c2410_early_console_data; + +#ifdef CONFIG_ARM64
if IS_ENABLED() (unless it cannot be used due to missing symbol?)
+ /* ... but we need to override the existing fixmap entry as nGnRnE */ + __set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase, + __pgprot(PROT_DEVICE_nGnRnE)); +#endif + return samsung_early_console_setup(device, opt);
Don't you need to handle the error code - set PROT_DEFAULT() or whatever was there before? Best regards, Krzysztof