From: Aleksey Makarov aleksey.makarov@linaro.org
Commit 10879ae5f12e9cab3c4e8e9504c1aaa8a033bde7 upstream.
This patch adds function pl011_console_match() that implements method match of struct console. It allows to match consoles against data specified in a string, for example taken from command line or compiled by ACPI SPCR table handler.
This patch was merged to tty-next but then reverted because of conflict with
commit 46e36683f433 ("serial: earlycon: Extend earlycon command line option to support 64-bit addresses")
Now it is fixed.
Signed-off-by: Aleksey Makarov aleksey.makarov@linaro.org Reviewed-by: Peter Hurley peter@hurleysoftware.com Acked-by: Russell King rmk+kernel@armlinux.org.uk Tested-by: Christopher Covington cov@codeaurora.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org ---
Please consider for v4.9-stable. It is the missing puzzle piece for SPCR support on arm64 ACPI systems, which got merged for v4.9 [0]. Now that more systems are becoming available to people working in the kernel community, it turns out that v4.9 distro installers (e.g., Debian Stretch) won't work unless you pass a 'console=' parameter explicitly, which is annoying. Given that it was clearly the intent to include this code at the time, I hope it will be considered for backporting.
[0] To quote the tty maintainer:
Also in here is the long-suffering ACPI SPCR patchset, which was passed around from maintainer to maintainer like a hot-potato. Seems I was the sucker^Wlucky one. All of those patches have been acked by the various subsystem maintainers as well.
drivers/tty/serial/amba-pl011.c | 55 ++++++++++++++++++++ 1 file changed, 55 insertions(+)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index b42d7f1c9089..6b1863293fe1 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2320,12 +2320,67 @@ static int __init pl011_console_setup(struct console *co, char *options) return uart_set_options(&uap->port, co, baud, parity, bits, flow); }
+/** + * pl011_console_match - non-standard console matching + * @co: registering console + * @name: name from console command line + * @idx: index from console command line + * @options: ptr to option string from console command line + * + * Only attempts to match console command lines of the form: + * console=pl011,mmio|mmio32,<addr>[,<options>] + * console=pl011,0x<addr>[,<options>] + * This form is used to register an initial earlycon boot console and + * replace it with the amba_console at pl011 driver init. + * + * Performs console setup for a match (as required by interface) + * If no <options> are specified, then assume the h/w is already setup. + * + * Returns 0 if console matches; otherwise non-zero to use default matching + */ +static int __init pl011_console_match(struct console *co, char *name, int idx, + char *options) +{ + unsigned char iotype; + resource_size_t addr; + int i; + + if (strcmp(name, "pl011") != 0) + return -ENODEV; + + if (uart_parse_earlycon(options, &iotype, &addr, &options)) + return -ENODEV; + + if (iotype != UPIO_MEM && iotype != UPIO_MEM32) + return -ENODEV; + + /* try to match the port specified on the command line */ + for (i = 0; i < ARRAY_SIZE(amba_ports); i++) { + struct uart_port *port; + + if (!amba_ports[i]) + continue; + + port = &amba_ports[i]->port; + + if (port->mapbase != addr) + continue; + + co->index = i; + port->cons = co; + return pl011_console_setup(co, options); + } + + return -ENODEV; +} + static struct uart_driver amba_reg; static struct console amba_console = { .name = "ttyAMA", .write = pl011_console_write, .device = uart_console_device, .setup = pl011_console_setup, + .match = pl011_console_match, .flags = CON_PRINTBUFFER, .index = -1, .data = &amba_reg,