diff options
| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2015-10-30 05:46:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-12-14 06:59:48 +0300 |
| commit | b8d20e06eaad4c2bd64746cacd95be9a5d3e747f (patch) | |
| tree | 3aa1041bf764569535c02fe39a6055febe4311f0 /drivers/tty/serial/8250/8250_uniphier.c | |
| parent | d72d391c126e0ffd3047c06c4bef4d795853d5d5 (diff) | |
| download | linux-b8d20e06eaad4c2bd64746cacd95be9a5d3e747f.tar.xz | |
serial: 8250_uniphier: add earlycon support
This reuses the code of drivers/tty/serial/8250/8250_early.c except
- Overwrite device->port.iotype and device->port.regshift for
UPIO_MEM32 because of_setup_earlycon() has set them for UPIO_MEM.
- Set device->baud to zero to prevent early8250_setup() from
initializing the divisor register because port->uartclk does not
match the frequency expected by this hardware.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/8250/8250_uniphier.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_uniphier.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_uniphier.c b/drivers/tty/serial/8250/8250_uniphier.c index d11621e2cf1d..1e2237a9c489 100644 --- a/drivers/tty/serial/8250/8250_uniphier.c +++ b/drivers/tty/serial/8250/8250_uniphier.c @@ -13,6 +13,7 @@ */ #include <linux/clk.h> +#include <linux/console.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> @@ -34,6 +35,29 @@ struct uniphier8250_priv { spinlock_t atomic_write_lock; }; +#ifdef CONFIG_SERIAL_8250_CONSOLE +static int __init uniphier_early_console_setup(struct earlycon_device *device, + const char *options) +{ + if (!device->port.membase) + return -ENODEV; + + /* This hardware always expects MMIO32 register interface. */ + device->port.iotype = UPIO_MEM32; + device->port.regshift = 2; + + /* + * Do not touch the divisor register in early_serial8250_setup(); + * we assume it has been initialized by a boot loader. + */ + device->baud = 0; + + return early_serial8250_setup(device, options); +} +OF_EARLYCON_DECLARE(uniphier, "socionext,uniphier-uart", + uniphier_early_console_setup); +#endif + /* * The register map is slightly different from that of 8250. * IO callbacks must be overridden for correct access to FCR, LCR, and MCR. |