From: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
Acked-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Tested-by: Christopher Covington <cov@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
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,
--
2.17.0
